Publications by authors named "Léanie Kleynhans"

30 Publications

  • Page 1 of 1

Mycobacterium tuberculosis-stimulated whole blood culture to detect host biosignatures for tuberculosis treatment response.

Tuberculosis (Edinb) 2021 Apr 10;128:102082. Epub 2021 Apr 10.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Host markers to monitor the response to tuberculosis (TB) therapy hold some promise. We evaluated the changes in concentration of Mycobacterium tuberculosis (M.tb)-induced soluble biomarkers during early treatment for predicting short- and long-term treatment outcomes. Whole blood samples from 30 cured and 12 relapsed TB patients from diagnosis, week 1, 2, and 4 of treatment were cultured in the presence of live M.tb for seven days and patients followed up for 24 weeks after the end of treatment. 57 markers were measured in unstimulated and antigen-stimulated culture supernatants using Luminex assays. Top performing multi-variable models at diagnosis using unstimulated values predicted outcome at 24 months after treatment completion with a sensitivity of 75.0% (95% CI, 42.8-94.5%) and specificity of 72.4% (95% CI, 52.8-87.3%) in leave-one-out cross validation. Month two treatment responder classification was correctly predicted with a sensitivity of 79.2% (95% CI, 57.8-92.9%) and specificity of 92.3% (95% CI, 64.0-99.8%). This study provides evidence of the early M.tb-specific treatment response in TB patients but shows that the observed unstimulated marker models are not outperformed by stimulated marker models. Performance of unstimulated predictive host marker signatures is promising and requires validation in larger studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2021.102082DOI Listing
April 2021

Novel molecular transport medium used in combination with Xpert MTB/RIF ultra provides rapid detection of Mycobacterium bovis in African buffaloes.

Sci Rep 2021 Mar 29;11(1):7061. Epub 2021 Mar 29.

DSI‑NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.

Mycobacterium bovis is the causative agent of bovine tuberculosis (bTB) in wildlife. Confirmation of M. bovis infection relies on mycobacterial culture, which is time-consuming. Collection and transportation of infectious material also pose a human health risk. PrimeStore Molecular Transport Medium (MTM) has been shown to effectively inactivate infectious organisms, making it a safe method for handling infectious samples. This study investigated an in-field sampling technique for rapid, safe detection of M. bovis in buffalo tissues. Potentially infected tissues from bTB test-positive buffaloes were swabbed at post-mortem examination and stored in PrimeStore MTM at ambient temperature until Xpert MTB/RIF Ultra testing was performed. Additionally, tissue samples were frozen and transported before homogenisation for culture and Ultra testing. Oral swabs were collected from M. bovis-unexposed buffaloes as a negative control cohort. Mycobacterium tuberculosis complex (MTBC) DNA was detected by Ultra in 13/16 tissue swabs and 9/16 matched tissue homogenates from culture-confirmed M. bovis-positive buffalo tissues. MTBC DNA was not detected in swabs from M. bovis-unexposed animals, showing the potentially high specificity of Ultra with PrimeStore swabs. PrimeStore MTM sample processing, in combination with the Ultra assay, has the potential to provide a safe, rapid post-mortem screening test for M. bovis in buffaloes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-86682-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8007588PMC
March 2021

Cell-Mediated Immunological Biomarkers and Their Diagnostic Application in Livestock and Wildlife Infected With .

Front Immunol 2021 4;12:639605. Epub 2021 Mar 4.

Division of Molecular Biology and Human Genetics, Department of Science and Innovation-National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Faculty of Medicine and Health Sciences, South African Medical Research Council Centre for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa.

has the largest host range of the complex and infects domestic animal species, wildlife, and humans. The presence of global wildlife maintenance hosts complicates bovine tuberculosis (bTB) control efforts and further threatens livestock and wildlife-related industries. Thus, it is imperative that early and accurate detection of in all affected animal species is achieved. Further, an improved understanding of the complex species-specific host immune responses to could enable the development of diagnostic tests that not only identify infected animals but distinguish between infection and active disease. The primary bTB screening standard worldwide remains the tuberculin skin test (TST) that presents several test performance and logistical limitations. Hence additional tests are used, most commonly an interferon-gamma (IFN-γ) release assay (IGRA) that, similar to the TST, measures a cell-mediated immune (CMI) response to . There are various cytokines and chemokines, in addition to IFN-γ, involved in the CMI component of host adaptive immunity. Due to the dominance of CMI-based responses to mycobacterial infection, cytokine and chemokine biomarkers have become a focus for diagnostic tests in livestock and wildlife. Therefore, this review describes the current understanding of host immune responses to as it pertains to the development of diagnostic tools using CMI-based biomarkers in both gene expression and protein release assays, and their limitations. Although the study of CMI biomarkers has advanced fundamental understanding of the complex host- interplay and bTB progression, resulting in development of several promising diagnostic assays, most of this research remains limited to cattle. Considering differences in host susceptibility, transmission and immune responses, and the wide variety of affected animal species, knowledge gaps continue to pose some of the biggest challenges to the improvement of and bTB diagnosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2021.639605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7969648PMC
March 2021

The Peripheral Blood Transcriptome Is Correlated With PET Measures of Lung Inflammation During Successful Tuberculosis Treatment.

Front Immunol 2020 10;11:596173. Epub 2021 Feb 10.

Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa.

Pulmonary tuberculosis (PTB) is characterized by lung granulomas, inflammation and tissue destruction. Here we used within-subject peripheral blood gene expression over time to correlate with the within-subject lung metabolic activity, as measured by positron emission tomography (PET) to identify biological processes and pathways underlying overall resolution of lung inflammation. We used next-generation RNA sequencing and [F]FDG PET-CT data, collected at diagnosis, week 4, and week 24, from 75 successfully cured PTB patients, with the [F]FDG activity as a surrogate for lung inflammation. Our linear mixed-effects models required that for each individual the slope of the line of [F]FDG data in the outcome and the slope of the peripheral blood transcript expression data correlate, i.e., the slopes of the outcome and explanatory variables had to be similar. Of 10,295 genes that changed as a function of time, we identified 639 genes whose expression profiles correlated with decreasing [F]FDG uptake levels in the lungs. Gene enrichment over-representation analysis revealed that numerous biological processes were significantly enriched in the 639 genes, including several well known in TB transcriptomics such as platelet degranulation and response to interferon gamma, thus validating our novel approach. Others not previously associated with TB pathobiology included smooth muscle contraction, a set of pathways related to mitochondrial function and cell death, as well as a set of pathways connecting transcription, translation and vesicle formation. We observed up-regulation in genes associated with B cells, and down-regulation in genes associated with platelet activation. We found 254 transcription factor binding sites to be enriched among the 639 gene promoters. In conclusion, we demonstrated that of the 10,295 gene expression changes in peripheral blood, only a subset of 639 genes correlated with inflammation in the lungs, and the enriched pathways provide a description of the biology of resolution of lung inflammation as detectable in peripheral blood. Surprisingly, resolution of PTB inflammation is positively correlated with smooth muscle contraction and, extending our previous observation on mitochondrial genes, shows the presence of mitochondrial stress. We focused on pathway analysis which can enable therapeutic target discovery and potential modulation of the host response to TB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.596173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902901PMC
February 2021

Higher SARS-CoV-2 seroprevalence in workers with lower socioeconomic status in Cape Town, South Africa.

PLoS One 2021 25;16(2):e0247852. Epub 2021 Feb 25.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Department of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Background: Inequality is rife throughout South Africa. The first wave of COVID-19 may have affected people in lower socioeconomic groups worse than the affluent. The SARS-CoV-2 seroprevalence and the specificity of anti-SARS-CoV-2 antibody tests in South Africa is not known.

Methods: We tested 405 volunteers representing all socioeconomic strata from the workforce of a popular shopping and tourist complex in central Cape Town with the Abbott SARS-CoV-2 IgG assay. We assessed the association between antibody positivity and COVID-19 symptom status, medical history, and sociodemographic variables. We tested 137 serum samples from healthy controls collected in Cape Town prior to the COVID-19 pandemic, to confirm the specificity of the assay in the local population.

Results: Of the 405 volunteers tested one month after the first peak of the epidemic in Cape Town, 96(23.7%) were SARS-CoV-2 IgG positive. Of those who tested positive, 46(47.9%) reported no symptoms of COVID-19 in the previous 6 months. Seropositivity was significantly associated with living in informal housing, residing in a subdistrict with low income-per household, and having a low-earning occupation. The specificity of the assay was 98.54%(95%CI 94.82%-99.82%) in the pre-COVID controls.

Conclusions: There is a high background seroprevalence in Cape Town, particularly in people of lower socioeconomic status. Almost half of cases are asymptomatic, and therefore undiagnosed by local testing strategies. These results cannot be explained by low assay specificity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247852PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7906413PMC
March 2021

Mycobacterium bovis Infection in Free-Ranging African Elephants.

Emerg Infect Dis 2021 Mar;27(3):990-992

Mycobacterium bovis infection in wildlife species occurs worldwide. However, few cases of M. bovis infection in captive elephants have been reported. We describe 2 incidental cases of bovine tuberculosis in free-ranging African elephants (Loxodonta africana) from a tuberculosis-endemic national park in South Africa and the epidemiologic implications of these infections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2703.204729DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7920657PMC
March 2021

Review of Diagnostic Tests for Detection of Infection in South African Wildlife.

Front Vet Sci 2021 28;8:588697. Epub 2021 Jan 28.

Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa.

Wildlife tuberculosis is a major economic and conservation concern globally. Bovine tuberculosis (bTB), caused by (), is the most common form of wildlife tuberculosis. In South Africa, to date, infection has been detected in 24 mammalian wildlife species. The identification of infection in wildlife species is essential to limit the spread and to control the disease in these populations, sympatric wildlife species and neighboring livestock. The detection of -infected individuals is challenging as only severely diseased animals show clinical disease manifestations and diagnostic tools to identify infection are limited. The emergence of novel reagents and technologies to identify infection in wildlife species are instrumental in improving the diagnosis and control of bTB. This review provides an update on the diagnostic tools to detect infection in South African wildlife but may be a useful guide for other wildlife species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2021.588697DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7876456PMC
January 2021

Development of a cytokine gene expression assay for the relative quantification of the African elephant (Loxodonta africana) cell-mediated immune responses.

Cytokine 2021 May 4;141:155453. Epub 2021 Feb 4.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

Immunological assays are the basis for many diagnostic tests for infectious diseases in animals and humans. Application in wildlife species, including the African elephant (Loxodonta africana), is limited however due to lack of information on immune responses. Since many immunoassays require both identified biomarkers of immune activation as well as species-specific reagents, it is crucial to have knowledge of basic immunological responses in the species of interest. Cytokine gene expression assays (GEAs) used to measure specific immune responses in wildlife have frequently shown that targeted biomarkers are often species-specific. Therefore, the aim of this study was to identify elephant-specific cytokine biomarkers to detect immune activation and to develop a GEA, using pokeweed mitogen stimulated whole blood from African elephants. This assay will provide the foundation for the development of future cytokine GEAs that can be used to detect antigen specific immune responses and potentially lead to various diagnostic tests for this species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cyto.2021.155453DOI Listing
May 2021

Optimisation of the tuberculin skin test for detection of Mycobacterium bovis in African buffaloes (Syncerus caffer).

Prev Vet Med 2021 Mar 5;188:105254. Epub 2021 Jan 5.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

Effective screening methods are critical for preventing the spread of bovine tuberculosis (bTB) among livestock and wildlife species. The tuberculin skin test (TST) remains the primary test for bTB globally, although performance is suboptimal. African buffaloes (Syncerus caffer) are a maintenance host of Mycobacterium bovis in South Africa, tested using the single intradermal tuberculin test (SITT) or comparative test (SICTT). The interpretation of these tests has been based on cattle thresholds due to the lack of species-specific cut-off values for African buffaloes. Therefore, the aims of this study were to calculate buffalo-specific thresholds for different TST criteria (SITT, SICTT, and SICTT that calculates the differential change at 72 h only) and compare performance using these cut-off values. The results confirm that 3 mm best discriminates M. bovis-infected from unexposed control buffaloes with sensitivities of 69 % (95 % CI 60-78; SITT and SICTT) and 76 % (95 % CI 65-83; SICTT), and specificities of 86 % (95 % CI 80-90; SITT), 96 % (95 % CI 92-98; SICTT) and 97 % (95 % CI 93-99; SICTT), respectively. A comparison between TST criteria using buffalo-specific thresholds demonstrates that the comparative TST performs better than the SITT, although sensitivity remains suboptimal. Therefore, further research and the addition of ancillary tests, such as cytokine release assays, are necessary to improve M. bovis detection in African buffaloes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2020.105254DOI Listing
March 2021

Diagnosis of Mycobacterium bovis infection in free-ranging common hippopotamus (Hippopotamus amphibius).

Transbound Emerg Dis 2021 Jan 10. Epub 2021 Jan 10.

Department of Science and Innovation-National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Bovine tuberculosis (bTB), caused by Mycobacterium bovis (M. bovis) infection, is a multi-host disease which negatively affects the wildlife industry, with adverse consequences for conservation, ecotourism, and game/wildlife sales. Although interspecies transmission has been reported between some wildlife hosts, the risk of spread in complex ecosystems is largely unknown. As a controlled disease, tools for accurate detection of M. bovis infection are crucial for effective surveillance and management, especially in wildlife populations. There are, however, limited species-specific diagnostic tests available for wildlife. Hippopotamuses are rarely tested for M. bovis infection, and infection has not previously been confirmed in these species. In this study, blood and tissue samples collected from common hippopotamus (Hippopotamus amphibius) residing in a bTB-endemic area, the Greater Kruger Protected area (GKPA), were retrospectively screened to determine whether there was evidence for interspecies transmission of M. bovis, and identify tools for M. bovis detection in this species. Using the multi-species DPP VetTB serological assay, a bTB seroprevalence of 8% was found in hippopotamus from GKPA. In addition, the first confirmed case of M. bovis infection in a free-ranging common hippopotamus is reported, based on the isolation in mycobacterial culture, genetic speciation and detection of DNA in tissue samples. Importantly, the M. bovis spoligotype (SB0121) isolated from this common hippopotamus is shared with other M. bovis-infected hosts in GKPA, suggesting interspecies transmission. These results support the hypothesis that M. bovis infection may be under recognized in hippopotamus. Further investigation is needed to determine the risk of interspecies transmission of M. bovis to common hippopotamus in bTB-endemic ecosystems and evaluate serological and other diagnostic tools in this species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/tbed.13989DOI Listing
January 2021

GPR183 Regulates Interferons, Autophagy, and Bacterial Growth During Infection and Is Associated With TB Disease Severity.

Front Immunol 2020 6;11:601534. Epub 2020 Nov 6.

Translational Research Institute-Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia.

Oxidized cholesterols have emerged as important signaling molecules of immune function, but little is known about the role of these oxysterols during mycobacterial infections. We found that expression of the oxysterol-receptor GPR183 was reduced in blood from patients with tuberculosis (TB) and type 2 diabetes (T2D) compared to TB patients without T2D and was associated with TB disease severity on chest x-ray. GPR183 activation by 7,25-dihydroxycholesterol (7,25-OHC) reduced growth of (Mtb) and BCG in primary human monocytes, an effect abrogated by the GPR183 antagonist GSK682753. Growth inhibition was associated with reduced IFN-β and IL-10 expression and enhanced autophagy. Mice lacking GPR183 had significantly increased lung Mtb burden and dysregulated IFNs during early infection. Together, our data demonstrate that GPR183 is an important regulator of intracellular mycobacterial growth and interferons during mycobacterial infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.601534DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7677584PMC
November 2020

Use of the MILLIPLEX bovine cytokine/chemokine multiplex assay to identify Mycobacterium bovis-infection biomarkers in African buffaloes (Syncerus caffer).

Vet Immunol Immunopathol 2021 Jan 11;231:110152. Epub 2020 Nov 11.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

As a recognized Mycobacterium bovis maintenance host, the African buffalo (Syncerus caffer) poses transmission risks to livestock, humans and other wildlife. Early detection of M. bovis infection is critical for limiting its spread. Currently, tests detecting cell-mediated immune responses are used for diagnosis in buffaloes. However, these may have suboptimal sensitivity or specificity, depending on the blood stimulation method. Recent evidence suggests that assays using combinations of host cytokine biomarkers may increase diagnostic performance. Therefore, this study aimed to investigate the application of a MILLIPLEX bovine cytokine/chemokine multiplex assay to identify candidate biomarkers of M. bovis infection in buffaloes. Whole blood from twelve culture-confirmed M. bovis-infected buffaloes, stimulated with the QuantiFERON TB Gold Plus in-tube system, was tested using the MILLIPLEX platform. Results indicated binding of bovine antibodies to fifteen buffalo cytokine/chemokine targets. Moreover, there was a significant difference in concentrations between unstimulated and TB antigen-stimulated buffalo samples for seven cytokines/chemokines included in the kit. Although these preliminary results require further investigation in larger sample sets and a comparison between M. bovis-infected and uninfected cohorts, the utility of the MILLIPLEX platform in a novel species was demonstrated, in addition to identifying potential African buffalo cytokines for future research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetimm.2020.110152DOI Listing
January 2021

Screening diabetes mellitus patients for pulmonary tuberculosis: a multisite study in Indonesia, Peru, Romania and South Africa.

Trans R Soc Trop Med Hyg 2020 Oct 28. Epub 2020 Oct 28.

Centre for International Health, University of Otago Medical School, University of Otago, Dunedin, New Zealand.

Background: Diabetes mellitus (DM) patients are three times more likely to develop tuberculosis (TB) than the general population. Active TB screening in people with DM is part of a bidirectional approach. The aim of this study was to conduct pragmatic active TB screening among DM patients in four countries to inform policy.

Methods: DM patients were recruited in Indonesia (n=809), Peru (n=600), Romania (n=603) and South Africa (n=51). TB cases were diagnosed using an algorithm including clinical symptoms and chest X-ray. Presumptive TB patients were examined with sputum smear and culture.

Results: A total of 171 (8.3%) individuals reported ever having had TB (South Africa, 26%; Indonesia, 12%; Peru, 7%; Romania, 4%), 15 of whom were already on TB treatment. Overall, 14 (0.73% [95% confidence interval 0.40 to 1.23]) TB cases were identified from screening. Poor glucose control, smoking, lower body mass index, education and socio-economic status were associated with newly diagnosed/current TB. Thirteen of the 14 TB cases diagnosed from this screening would have been found using a symptom-based approach.

Conclusions: These data support the World Health Organization recommendation for routine symptom-based screening for TB in known DM patients in high TB-burden countries. DM patients with any symptoms consistent with TB should be investigated and diagnostic tools should be easily accessible.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/trstmh/traa100DOI Listing
October 2020

The Xpert MTB/RIF Ultra assay detects Mycobacterium tuberculosis complex DNA in white rhinoceros (Ceratotherium simum) and African elephants (Loxodonta africana).

Sci Rep 2020 09 2;10(1):14482. Epub 2020 Sep 2.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.

The study describes the novel use of the Xpert MTB/RIF Ultra assay for detection of Mycobacterium tuberculosis complex (MTBC) DNA in samples from white rhinoceros (Ceratotherium simum) and African elephants (Loxodonta africana). Culture negative respiratory sample matrices were spiked to determine if the Ultra could detect MTBC DNA in rhinoceros and elephant samples. Rhinoceros bronchial alveolar lavage fluid (BALF) was found to have an inhibitory effect on the Ultra. In this study, the limit of detection (LOD) of M. tuberculosis H37Rv in all spiked animal samples were 2 CFU/ml compared to 15.6 CFU/ml for humans, while the LOD for M. bovis SB0121 was 30 CFU/ml compared to 143.4 CFU/ml for M. bovis BCG in humans. Screening was performed on stored tissue and respiratory samples from known MTBC-infected animals and MTBC DNA was detected in 92% of samples collected from six rhinoceros and two elephants. Conversely, 83% of culture-negative tissue and respiratory samples from uninfected animals tested negative on the Ultra. In conclusion, the Ultra assay appears to be a sensitive and rapid diagnostic test for the detection of MTBC DNA from tissue and respiratory samples collected from African elephants and rhinoceros. Furthermore, the Ultra assay could provide a new tool for the detection of MTBC in various sample types from other wildlife species.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-71568-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468236PMC
September 2020

The VetMAX™ M. tuberculosis complex PCR kit detects MTBC DNA in antemortem and postmortem samples from white rhinoceros (Ceratotherium simum), African elephants (Loxodonta africana) and African buffaloes (Syncerus caffer).

BMC Vet Res 2020 Jun 29;16(1):220. Epub 2020 Jun 29.

DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.

Background: Bovine tuberculosis and tuberculosis are chronic infectious diseases caused by the Mycobacterium tuberculosis complex members, Mycobacterium bovis and Mycobacterium tuberculosis, respectively. Infection with M. bovis and M. tuberculosis have significant implications for wildlife species management, public health, veterinary disease control, and conservation endeavours.

Results: Here we describe the first use of the VetMAX™ Mycobacterium tuberculosis complex (MTBC) DNA quantitative real-time polymerase chain reaction (qPCR) detection kit for African wildlife samples. DNA was extracted from tissues harvested from 48 African buffaloes and MTBC DNA was detected (test-positive) in all 26 M. bovis culture-confirmed animals with an additional 12 PCR-positive results in culture-negative buffaloes (originating from an exposed population). Of six MTBC-infected African rhinoceros tested, MTBC DNA was detected in antemortem and postmortem samples from five animals. The PCR was also able to detect MTBC DNA in samples from two African elephants confirmed to have M. bovis and M. tuberculosis infections (one each). Culture-confirmed uninfected rhinoceros and elephants' samples tested negative in the PCR assay.

Conclusions: These results suggest this new detection kit is a sensitive screening test for the detection of MTBC-infected African buffaloes, African elephants and white rhinoceros.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-020-02438-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325085PMC
June 2020

Impact of Intermediate Hyperglycemia and Diabetes on Immune Dysfunction in Tuberculosis.

Clin Infect Dis 2021 01;72(1):69-78

Tuberculosis Centre and Department of Infection and Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom.

Background: People with diabetes have an increased risk of developing active tuberculosis (TB) and are more likely to have poor TB-treatment outcomes, which may impact on control of TB as the prevalence of diabetes is increasing worldwide. Blood transcriptomes are altered in patients with active TB relative to healthy individuals. The effects of diabetes and intermediate hyperglycemia (IH) on this transcriptomic signature were investigated to enhance understanding of immunological susceptibility in diabetes-TB comorbidity.

Methods: Whole blood samples were collected from active TB patients with diabetes (glycated hemoglobin [HbA1c] ≥6.5%) or IH (HbA1c = 5.7% to <6.5%), TB-only patients, and healthy controls in 4 countries: South Africa, Romania, Indonesia, and Peru. Differential blood gene expression was determined by RNA-seq (n = 249).

Results: Diabetes increased the magnitude of gene expression change in the host transcriptome in TB, notably showing an increase in genes associated with innate inflammatory and decrease in adaptive immune responses. Strikingly, patients with IH and TB exhibited blood transcriptomes much more similar to patients with diabetes-TB than to patients with only TB. Both diabetes-TB and IH-TB patients had a decreased type I interferon response relative to TB-only patients.

Conclusions: Comorbidity in individuals with both TB and diabetes is associated with altered transcriptomes, with an expected enhanced inflammation in the presence of both conditions, but also reduced type I interferon responses in comorbid patients, suggesting an unexpected uncoupling of the TB transcriptome phenotype. These immunological dysfunctions are also present in individuals with IH, showing that altered immunity to TB may also be present in this group. The TB disease outcomes in individuals with IH diagnosed with TB should be investigated further.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciaa751DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7823074PMC
January 2021

Comprehensive Characterization of the Attenuated Double Auxotroph ΔΔ as an Alternative to H37Rv.

Front Microbiol 2019 20;10:1922. Epub 2019 Aug 20.

Department of Science and Technology/National Research Foundation (DST/NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Although currently available model organisms such as and Bacillus Calmette-Guérin (BCG) have significantly contributed to our understanding of tuberculosis (TB) biology, these models have limitations such as differences in genome size, growth rates and virulence. However, attenuated strains may provide more representative, safer models to study biology. For example, the ΔΔ double auxotroph, has undergone rigorous and safety testing. Like other auxotrophic strains, this has subsequently been approved for use in biosafety level (BSL) 2 facilities. Auxotrophic strains have been assessed as models for drug-resistant and for studying latent TB. These offer the potential as safe and useful models, but it is important to understand how well these recapitulate salient features of non-attenuated We therefore performed a comprehensive comparison of H37Rv and ΔΔ. These strains demonstrated similar and intra-macrophage replication rates, similar responses to anti-TB agents and whole genome sequence conservation. Shotgun proteomics analysis suggested that ΔΔ has a heightened stress response that leads to reduced bacterial replication during exposure to acid stress, which has been verified using a dual-fluorescent replication reporter assay. Importantly, infection of human peripheral blood mononuclear cells with the 2 strains elicited comparable cytokine production, demonstrating the suitability of ΔΔ for immunological assays. We provide comprehensive evidence to support the judicious use of ΔΔ as a safe and suitable model organism for research, without the need for a BSL3 facility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2019.01922DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6710366PMC
August 2019

Distinct serum biosignatures are associated with different tuberculosis treatment outcomes.

Tuberculosis (Edinb) 2019 09 12;118:101859. Epub 2019 Aug 12.

DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

Biomarkers for TB treatment response and outcome are needed. This study characterize changes in immune profiles during TB treatment, define biosignatures associated with treatment outcomes, and explore the feasibility of predictive models for relapse. Seventy-two markers were measured by multiplex cytokine array in serum samples from 78 cured, 12 relapsed and 15 failed treatment patients from South Africa before and during therapy for pulmonary TB. Promising biosignatures were evaluated in a second cohort from Uganda/Brazil consisting of 17 relapse and 23 cured patients. Thirty markers changed significantly with different response patterns during TB treatment in cured patients. The serum biosignature distinguished cured from relapse patients and a combination of two clinical (time to positivity in liquid culture and BMI) and four immunological parameters (TNF-β, sIL-6R, IL-12p40 and IP-10) at diagnosis predicted relapse with a 75% sensitivity (95%CI 0.38-1) and 85% specificity (95%CI 0.75-0.93). This biosignature was validated in an independent Uganda/Brazil cohort correctly classifying relapse patients with 83% (95%CI 0.58-1) sensitivity and 61% (95%CI 0.39-0.83) specificity. A characteristic biosignature with value as predictor of TB relapse was identified. The repeatability and robustness of these biomarkers require further validation in well-characterized cohorts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2019.101859DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839616PMC
September 2019

Diabetes Mellitus Among Pulmonary Tuberculosis Patients From 4 Tuberculosis-endemic Countries: The TANDEM Study.

Clin Infect Dis 2020 02;70(5):780-788

Department of Internal Medicine and Radboud Center of Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.

Background: Diabetes mellitus (DM) increases active tuberculosis (TB) risk and worsens TB outcomes, jeopardizing TB control especially in TB-endemic countries with rising DM prevalence rates. We assessed DM status and clinical correlates in TB patients across settings in Indonesia, Peru, Romania, and South Africa.

Methods: Age-adjusted DM prevalence was estimated using laboratory glycated hemoglobin (HbA1c) or fasting plasma glucose in TB patients. Detailed and standardized sociodemographic, anthropometric, and clinical measurements were made. Characteristics of TB patients with or without DM were compared using multilevel mixed-effect regression models with robust standard errors.

Results: Of 2185 TB patients (median age 36.6 years, 61.2% male, 3.8% human immunodeficiency virus-infected), 12.5% (267/2128) had DM, one third of whom were newly diagnosed. Age-standardized DM prevalence ranged from 10.9% (South Africa) to 19.7% (Indonesia). Median HbA1c in TB-DM patients ranged from 7.4% (Romania) to 11.3% (Indonesia). Compared to those without DM, TB-DM patients were older and had a higher body mass index (BMI) (P value < .05). Compared to those with newly diagnosed DM, TB patients with diagnosed DM had higher BMI and HbA1c, less severe TB, and more frequent comorbidities, DM complications, and hypertension (P value < .05).

Conclusions: We show that DM prevalence and clinical characteristics of TB-DM vary across settings. Diabetes is primarily known but untreated, hyperglycemia is often severe, and many patients with TB-DM have significant cardiovascular disease risk and severe TB. This underlines the need to improve strategies for better clinical management of combined TB and DM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciz284DOI Listing
February 2020

Diabetes screen during tuberculosis contact investigations highlights opportunity for new diabetes diagnosis and reveals metabolic differences between ethnic groups.

Tuberculosis (Edinb) 2018 12 18;113:10-18. Epub 2018 Aug 18.

DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa; Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD, Australia. Electronic address:

Type 2 diabetes (T2D) is a prevalent risk factor for tuberculosis (TB), but most studies on TB-T2D have focused on TB patients, been limited to one community, and shown a variable impact of T2D on TB risk or treatment outcomes. We conducted a cross-sectional assessment of sociodemographic and metabolic factors in adult TB contacts with T2D (versus no T2D), from the Texas-Mexico border to study Hispanics, and in Cape Town to study South African Coloured ethnicities. The prevalence of T2D was 30.2% in Texas-Mexico and 17.4% in South Africa, with new diagnosis in 34.4% and 43.9%, respectively. Contacts with T2D differed between ethnicities, with higher smoking, hormonal contraceptive use and cholesterol levels in South Africa, and higher obesity in Texas-Mexico (p < 0.05). PCA analysis revealed striking differences between ethnicities in the relationships between factors defining T2D and dyslipidemias. Our findings suggest that screening for new T2D in adult TB contacts is effective to identify new T2D patients at risk for TB. Furthermore, studies aimed at predicting individual TB risk in T2D patients, should take into account the heterogeneity in dyslipidemias that are likely to modify the estimates of TB risk or adverse treatment outcomes that are generally attributed to T2D alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2018.08.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6284235PMC
December 2018

Disease characteristics and treatment of patients with diabetes mellitus attending government health services in Indonesia, Peru, Romania and South Africa.

Trop Med Int Health 2018 10 10;23(10):1118-1128. Epub 2018 Sep 10.

Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.

Objective: To describe the characteristics and management of Diabetes mellitus (DM) patients from low- and middle-income countries (LMIC).

Methods: We systematically characterised consecutive DM patients attending public health services in urban settings in Indonesia, Peru, Romania and South Africa, collecting data on DM treatment history, complications, drug treatment, obesity, HbA1c and cardiovascular risk profile; and assessing treatment gaps against relevant national guidelines.

Results: Patients (median 59 years, 62.9% female) mostly had type 2 diabetes (96%), half for >5 years (48.6%). Obesity (45.5%) and central obesity (females 84.8%; males 62.7%) were common. The median HbA1c was 8.7% (72 mmol/mol), ranging from 7.7% (61 mmol/mol; Peru) to 10.4% (90 mmol/mol; South Africa). Antidiabetes treatment included metformin (62.6%), insulin (37.8%), and other oral glucose-lowering drugs (34.8%). Disease complications included eyesight problems (50.4%), EGFR <60 ml/min (18.9%), heart disease (16.5%) and proteinuria (14.7%). Many had an elevated cardiovascular risk with elevated blood pressure (36%), LDL (71.0%) and smoking (13%), but few were taking antihypertensive drugs (47.1%), statins (28.5%) and aspirin (30.0%) when indicated. Few patients on insulin (8.0%), statins (8.4%) and antihypertensives (39.5%) reached treatment targets according to national guidelines. There were large differences between countries in terms of disease profile and medication use.

Conclusion: DM patients in government clinics in four LMIC with considerable growth of DM have insufficient glycaemic control, frequent macrovascular and other complications, and insufficient preventive measures for cardiovascular disease. These findings underline the need to identify treatment barriers and secure optimal DM care in such settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/tmi.13137DOI Listing
October 2018

The potential of imaging tools as correlates of infection and disease for new TB vaccine development.

Semin Immunol 2018 10 18;39:73-80. Epub 2018 Jun 18.

DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa. Electronic address:

The development of an improved vaccine to stimulate an effective response against Mycobacterium tuberculosis (MTB) infection and disease will be a major breakthrough in the fight against TB. A lack of tools to adequately track the progression or resolution of events in TB pathogenesis that occur at bacterial loads below the threshold for culture in human samples seriously hampers vaccine development and evaluation. In this review we discuss recent studies that use new imaging applications, modalities and analysis techniques to provide insight into the dynamic processes of MTB infection and disease that are challenging to monitor. These include early infection, the spectrum of latency and subclinical disease, the paucibacillary state induced by treatment, and events leading to recurrence, including relapse.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.smim.2018.06.001DOI Listing
October 2018

Patients with Concurrent Tuberculosis and Diabetes Have a Pro-Atherogenic Plasma Lipid Profile.

EBioMedicine 2018 Jun 17;32:192-200. Epub 2018 May 17.

Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands. Electronic address:

Background: Type 2 diabetes mellitus (DM) is a major risk factor for development of tuberculosis (TB), however the underlying molecular foundations are unclear. Since lipids play a central role in the development of both DM and TB, lipid metabolism may be important for TB-DM pathophysiology.

Methods: A H NMR spectroscopy-based platform was used to determine 225 lipid and other metabolic intermediates in plasma samples of healthy controls (n = 50) and patients with TB (n = 50), DM (n = 50) or TB-DM (n = 27).

Results: TB patients presented with wasting disease, represented by decreased amino acid levels including histidine and alanine. Conversely, DM patients were dyslipidemic as evidenced by high levels of very low-density lipoprotein triglycerides and low high-density lipoprotein cholesterol. TB-DM patients displayed metabolic characteristics of both wasting and dyslipidemia combined with disease interaction-specific increases in phospholipid metabolites (e.g. sphingomyelins) and atherogenic remnant-like lipoprotein particles. Biomarker analysis identified the ratios of phenylalanine/histidine and esterified cholesterol/sphingomyelin as markers for TB classification regardless of DM-status.

Conclusions: TB-DM patients possess a distinctive plasma lipid profile with pro-atherogenic properties. These findings support further research on the benefits of improved blood lipid control in the treatment of TB-DM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ebiom.2018.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020709PMC
June 2018

Changes in Host Immune-Endocrine Relationships during Tuberculosis Treatment in Patients with Cured and Failed Treatment Outcomes.

Front Immunol 2017 15;8:690. Epub 2017 Jun 15.

SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa.

A bidirectional communication between the immune and endocrine systems exists and facilitates optimum responses in the host during infections. This is in part achieved through changes in secretion patterns of hypothalamic hormones induced by inflammatory cytokines. The aim of this study was to elucidate the immune-endocrine alterations during tuberculosis (TB) treatment in patients with cured and failed TB treatment outcomes. Blood samples were collected from 27 cured and 10 failed patients and hormone as well as cytokine concentrations quantified at baseline, week 4, and month 6 of TB treatment. Hormone profiles of the two treatment outcome groups were different from each other prior to as well as during TB treatment. Treatment response effects were observed for cortisol, estradiol, T3, T4 ghrelin, leptin, amylin, adiponectin, and dehydroepiandrosterone (DHEA). Trends suggest that T4, amylin, and DHEA concentrations were different between treatment outcomes, although these did not reach statistical significance. Relationships between endocrine and inflammatory markers and the biological pathways involved differed between cured and failed treatment patients. These results highlight the complex interaction between the endocrine and immune system during active TB disease and throughout treatment and suggest that endocrine markers in conjunction with inflammatory markers may be useful in predicting unfavorable treatment outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2017.00690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5475380PMC
June 2017

B-cells with a FasL expressing regulatory phenotype are induced following successful anti-tuberculosis treatment.

Immun Inflamm Dis 2017 03 27;5(1):57-67. Epub 2016 Dec 27.

Division of Molecular Biology and Human Genetics Faculty of Medicine and Health Sciences SA MRC Centre for TB Research DST/NRF Centre of Excellence for Biomedical Tuberculosis Research Stellenbosch University Cape Town South Africa.

Introduction: Studies show that B-cells, in addition to producing antibodies and antigen-presentation, are able to produce cytokines as well. These include regulatory cytokines such as IL-10 by regulatory B-cells. Furthermore, a rare regulatory subset of B-cells have the potential to express FasL, which is a death-inducing ligand. This subset of B-cells have a positive role during autoimmune disease, but has not yet been studied during tuberculosis. These FasL-expressing B-cells are induced by bacterial LPS and CpG, thus we hypothesized that this phenotype might be induced during tuberculosis as well.

Methods: B-cells from participants with TB (at diagnosis and during treatment) and controls were collected, and analyzed by means of real-time PCR and flow cytometry. In addition to this, BAL was collected from TB participants as well and analyzed by means of MAGPix (multi-cytokine) technology.

Results: Gene expression analysis show that FASL transcript levels increase by the end of treatment. Similarly, phenotypic analysis show that there is a higher frequency of FasL-expressing B-cells by the end of treatment.

Conclusion: Collectively, these results indicate that these FasL-expressing B-cells are being induced during anti-TB treatment, and thus may play a positive role. Further studies are required to elucidate this.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/iid3.140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5322165PMC
March 2017

The Functional Response of B Cells to Antigenic Stimulation: A Preliminary Report of Latent Tuberculosis.

PLoS One 2016 6;11(4):e0152710. Epub 2016 Apr 6.

SA MRC Centre for TB Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

Mycobacterium tuberculosis (M.tb) remains a successful pathogen, causing tuberculosis disease numbers to constantly increase. Although great progress has been made in delineating the disease, the host-pathogen interaction is incompletely described. B cells have shown to function as both effectors and regulators of immunity via non-humoral methods in both innate and adaptive immune settings. Here we assessed specific B cell functional interaction following stimulation with a broad range of antigens within the LTBI milieu. Our results indicate that B cells readily produce pro- and anti-inflammatory cytokines (including IL-1β, IL-10, IL-17, IL-21 and TNF-α) in response to stimulation. TLR4 and TLR9 based stimulations achieved the greatest secreted cytokine-production response and BCG stimulation displayed a clear preference for inducing IL-1β production. We also show that the cytokines produced by B cells are implicated strongly in cell-mediated communication and that plasma (memory) B cells (CD19+CD27+CD138+) is the subset with the greatest contribution to cytokine production. Collectively our data provides insight into B cell responses, where they are implicated in and quantifies responses from specific B cell phenotypes. These findings warrant further functional B cell research with a focus on specific B cell phenotypes under conditions of active TB disease to further our knowledge about the contribution of various cell subsets which could have implications for future vaccine development or refined B cell orientated treatment in the health setting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152710PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822853PMC
August 2016

Clinical immunology and multiplex biomarkers of human tuberculosis.

Cold Spring Harb Perspect Med 2014 Dec 4;5(4). Epub 2014 Dec 4.

Department of Infectious Diseases, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.

The discovery of tuberculosis (TB) biomarkers is an important goal in current TB research, because the availability of such markers would have significant impact on TB prevention and treatment. Correlates of protection would greatly facilitate vaccine development and evaluation, whereas correlates of TB disease risk would facilitate early diagnosis and help installing early or preventive treatment. Currently, no such markers are available. This review describes several strategies that are currently being pursued to identify TB biomarkers and places these in a clinical context. The approaches discussed include both targeted and untargeted hypothesis-free strategies. Among the first are the measurements of specific biomarkers in antigen-stimulated peripheral blood, in serum or plasma, and detailed immune cell phenotyping. Among the latter are proteomic, genomic, and transcriptomic (mRNA, miRNA) approaches. Recent and promising developments are described.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1101/cshperspect.a018515DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4382732PMC
December 2014

Mycobacterium bovis BCG infection severely delays Trichuris muris expulsion and co-infection suppresses immune responsiveness to both pathogens.

BMC Microbiol 2014 Jan 17;14. Epub 2014 Jan 17.

Division of Molecular Biology and Human Genetics, MRC Centre for Molecular and Cellular Biology, NRF/DST Centre of Excellence in Biomedical TB Research, Faculty Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.

Background: The global epidemiology of parasitic helminths and mycobacterial infections display extensive geographical overlap, especially in the rural and urban communities of developing countries. We investigated whether co-infection with the gastrointestinal tract-restricted helminth, Trichuris muris, and the intracellular bacterium, Mycobacterium bovis (M. bovis) BCG, would alter host immune responses to, or the pathological effect of, either infection.

Results: We demonstrate that both pathogens are capable of negatively affecting local and systemic immune responses towards each other by modifying cytokine phenotypes and by inducing general immune suppression. T. muris infection influenced non-specific and pathogen-specific immunity to M. bovis BCG by down-regulating pulmonary TH1 and Treg responses and inducing systemic TH2 responses. However, co-infection did not alter mycobacterial multiplication or dissemination and host pulmonary histopathology remained unaffected compared to BCG-only infected mice. Interestingly, prior M. bovis BCG infection significantly delayed helminth clearance and increased intestinal crypt cell proliferation in BALB/c mice. This was accompanied by a significant reduction in systemic helminth-specific TH1 and TH2 cytokine responses and significantly reduced local TH1 and TH2 responses in comparison to T. muris-only infected mice.

Conclusion: Our data demonstrate that co-infection with pathogens inducing opposing immune phenotypes, can have differential effects on compartmentalized host immune protection to either pathogen. In spite of local and systemic decreases in TH1 and increases in TH2 responses co-infected mice clear M. bovis BCG at the same rate as BCG only infected animals, whereas prior mycobacterial infection initiates prolonged worm infestation in parallel to decreased pathogen-specific TH2 cytokine production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1471-2180-14-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898725PMC
January 2014

The contraceptive depot medroxyprogesterone acetate impairs mycobacterial control and inhibits cytokine secretion in mice infected with Mycobacterium tuberculosis.

Infect Immun 2013 Apr 4;81(4):1234-44. Epub 2013 Feb 4.

DST/NRF Centre of Excellence for Biomedical TB Research/MRC Centre for Molecular and Cellular Biology, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.

The contraceptive depot medroxyprogesterone acetate (DMPA), with progestin as the single active compound, possesses selective glucocorticoid activity and can alter the expression of glucocorticoid receptor-regulated genes. We therefore propose that pharmacological doses of DMPA used for endocrine therapy could have significant immune modulatory effects and impact on susceptibility to, as well as clinical manifestation and outcome of, infectious diseases. We investigated the effect of contraceptive doses of DMPA in two different murine Mycobacterium tuberculosis models. Multiplex bead array analysis revealed that DMPA altered serum cytokine levels of tumor necrosis factor alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), and interleukin 10 (IL-10) in C57BL/6 mice and gamma interferon (IFN-γ) in BALB/c mice. DMPA also suppressed antigen-specific production of TNF-α, G-CSF, IL-10, and IL-6 and induced the production of IP-10 in C57BL/6 mice. In BALB/c mice, DMPA altered the antigen-specific secretion of IFN-γ, IL-17, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6, and monocyte chemotactic protein 1 (MCP-1). Furthermore, we show that C57BL/6 mice treated with doses of DMPA, which result in serum concentrations similar to those observed in contraceptive users, have a significantly higher bacterial load in their lungs. Our data show for the first time that DMPA impacts tuberculosis (TB) disease severity in a mouse model and that the effects of this contraceptive are not confined to infections of the genital tract. This could have major implications for the contraceptive policies not only in developing countries like South Africa but also worldwide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/IAI.01189-12DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639598PMC
April 2013

Medroxyprogesterone acetate alters Mycobacterium bovis BCG-induced cytokine production in peripheral blood mononuclear cells of contraceptive users.

PLoS One 2011 8;6(9):e24639. Epub 2011 Sep 8.

Division of Molecular Biology and Human Genetics, MRC Centre for Molecular and Cellular Biology, DST/NRF Centre of Excellence for Biomedical TB Research, Faculty of Health Sciences, Stellenbosch University, Tygerberg, South Africa.

Most individuals latently infected with Mycobacterium tuberculosis (M.tb) contain the infection by a balance of effector and regulatory immune responses. This balance can be influenced by steroid hormones such as glucocorticoids. The widely used contraceptive medroxyprogesterone acetate (MPA) possesses glucocorticoid activity. We investigated the effect of this hormone on immune responses to BCG in household contacts of active TB patients. Multiplex bead array analysis revealed that MPA demonstrated both glucocorticoid and progestogenic properties at saturating and pharmacological concentrations in peripheral blood mononuclear cells (PBMCs) and suppressed antigen specific cytokine production. Furthermore we showed that PBMCs from women using MPA produced significantly lower levels of IL-1α, IL-12p40, IL-10, IL-13 and G-CSF in response to BCG which corresponded with lower numbers of circulating monocytes observed in these women. Our research study is the first to show that MPA impacts on infections outside the genital tract due to a systemic effect on immune function. Therefore MPA use could alter susceptibility to TB, TB disease severity as well as change the efficacy of new BCG-based vaccines, especially prime-boost vaccine strategies which may be administered to adult or adolescent women in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0024639PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169620PMC
February 2012