Publications by authors named "Denise L Doolan"

124 Publications

CD8 T cells specific for an immunodominant SARS-CoV-2 nucleocapsid epitope display high naive precursor frequency and TCR promiscuity.

Immunity 2021 05 15;54(5):1066-1082.e5. Epub 2021 Apr 15.

Department of Infectious Diseases, Austin Hospital, Heidelberg, VIC 3084, Australia; Department of Medicine and Radiology, The University of Melbourne, Parkville, VIC 3000, Australia; Data Analytics Research and Evaluation (DARE) Centre, Austin Health and The University of Melbourne, Heidelberg, VIC 3084, Australia.

To better understand primary and recall T cell responses during coronavirus disease 2019 (COVID-19), it is important to examine unmanipulated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells. By using peptide-human leukocyte antigen (HLA) tetramers for direct ex vivo analysis, we characterized CD8 T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8 T cells directed toward subdominant epitopes (B7/N, A2/S, and A24/S) CD8 T cells specific for the immunodominant B7/N epitope were detected at high frequencies in pre-pandemic samples and at increased frequencies during acute COVID-19 and convalescence. SARS-CoV-2-specific CD8 T cells in pre-pandemic samples from children, adults, and elderly individuals predominantly displayed a naive phenotype, indicating a lack of previous cross-reactive exposures. T cell receptor (TCR) analyses revealed diverse TCRαβ repertoires and promiscuous αβ-TCR pairing within B7/NCD8 T cells. Our study demonstrates high naive precursor frequency and TCRαβ diversity within immunodominant B7/N-specific CD8 T cells and provides insight into SARS-CoV-2-specific T cell origins and subsequent responses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2021.04.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8049468PMC
May 2021

Systems serology detects functionally distinct coronavirus antibody features in children and elderly.

Nat Commun 2021 04 1;12(1):2037. Epub 2021 Apr 1.

Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.

The hallmarks of COVID-19 are higher pathogenicity and mortality in the elderly compared to children. Examining baseline SARS-CoV-2 cross-reactive immunological responses, induced by circulating human coronaviruses (hCoVs), is needed to understand such divergent clinical outcomes. Here we show analysis of coronavirus antibody responses of pre-pandemic healthy children (n = 89), adults (n = 98), elderly (n = 57), and COVID-19 patients (n = 50) by systems serology. Moderate levels of cross-reactive, but non-neutralizing, SARS-CoV-2 antibodies are detected in pre-pandemic healthy individuals. SARS-CoV-2 antigen-specific Fcγ receptor binding accurately distinguishes COVID-19 patients from healthy individuals, suggesting that SARS-CoV-2 infection induces qualitative changes to antibody Fc, enhancing Fcγ receptor engagement. Higher cross-reactive SARS-CoV-2 IgA and IgG are observed in healthy elderly, while healthy children display elevated SARS-CoV-2 IgM, suggesting that children have fewer hCoV exposures, resulting in less-experienced but more polyreactive humoral immunity. Age-dependent analysis of COVID-19 patients, confirms elevated class-switched antibodies in elderly, while children have stronger Fc responses which we demonstrate are functionally different. These insights will inform COVID-19 vaccination strategies, improved serological diagnostics and therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-22236-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8016934PMC
April 2021

Memory CD8 T cell compartment associated with delayed onset of infection and better parasite control in sickle-cell trait children.

Clin Transl Immunology 2021 19;10(3):e1265. Epub 2021 Mar 19.

Centre for Molecular Therapeutics Australian Institute of Tropical Health and Medicine James Cook University Cairns QLD Australia.

Objectives: Study of individuals with protection from () infection and clinical malaria, including individuals affected by the sickle-cell trait (HbAS), offers the potential to identify cellular targets that could be translated for therapeutic development. We previously reported the first involvement of cellular immunity in HbAS-associated relative protection and identified a novel subset of memory-activated NK cells that was enriched in HbAS children and associated with parasite control. We hypothesised that other memory cell subsets might distinguish the baseline profile of HbAS children and children with normal haemoglobin (HbAA).

Methods: Subsets of memory T cells and NK cells were analysed by flow cytometry in paired samples collected from HbAS and HbAA children, at baseline and during the first malaria episode of the ensuing transmission season. Correlations between cell frequencies and features of HbAS-mediated protection from malaria were determined.

Results: HbAS children displayed significantly higher frequency of memory CD8 T cells at baseline than HbAA children. Baseline frequency of memory CD8 T cells correlated with features of HbAS-mediated protection from malaria. Exploration of memory CD8 T cell subsets revealed that central memory CD8 T cell frequency was higher in HbAS children than in HbAA children.

Conclusion: This study shows that HbAS children develop a larger memory CD8 T cell compartment than HbAA children, and associates this compartment with better control of subsequent onset of infection and parasite density. Our data suggest that central memory CD8 T cells may play an important role in the relative protection against malaria experienced by HbAS individuals, and further work to investigate this is warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cti2.1265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7979311PMC
March 2021

Robust correlations across six SARS-CoV-2 serology assays detecting distinct antibody features.

Clin Transl Immunology 2021 28;10(3):e1258. Epub 2021 Feb 28.

Department of Microbiology and Immunology University of Melbourne, at the Peter Doherty Institute for Infection and Immunity Melbourne VIC Australia.

Objectives: As the world transitions into a new era of the COVID-19 pandemic in which vaccines become available, there is an increasing demand for rapid reliable serological testing to identify individuals with levels of immunity considered protective by infection or vaccination.

Methods: We used 34 SARS-CoV-2 samples to perform a rapid surrogate virus neutralisation test (sVNT), applicable to many laboratories as it circumvents the need for biosafety level-3 containment. We correlated results from the sVNT with five additional commonly used SARS-CoV-2 serology techniques: the microneutralisation test (MNT), in-house ELISAs, commercial Euroimmun- and Wantai-based ELISAs (RBD, spike and nucleoprotein; IgG, IgA and IgM), antigen-binding avidity, and high-throughput multiplex analyses to profile isotype, subclass and Fc effector binding potential. We correlated antibody levels with antibody-secreting cell (ASC) and circulatory T follicular helper (cTfh) cell numbers.

Results: Antibody data obtained with commercial ELISAs closely reflected results using in-house ELISAs against RBD and spike. A correlation matrix across ten measured ELISA parameters revealed positive correlations for all factors. The frequency of inhibition by rapid sVNT strongly correlated with spike-specific IgG and IgA titres detected by both commercial and in-house ELISAs, and MNT titres. Multiplex analyses revealed strongest correlations between IgG, IgG1, FcR and C1q specific to spike and RBD. Acute cTfh-type 1 cell numbers correlated with spike and RBD-specific IgG antibodies measured by ELISAs and sVNT.

Conclusion: Our comprehensive analyses provide important insights into SARS-CoV-2 humoral immunity across distinct serology assays and their applicability for specific research and/or diagnostic questions to assess SARS-CoV-2-specific humoral responses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cti2.1258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916820PMC
February 2021

Integrated immune dynamics define correlates of COVID-19 severity and antibody responses.

Cell Rep Med 2021 Mar 5;2(3):100208. Epub 2021 Feb 5.

Department of Medicine, Central Clinical School, Monash University, Melbourne, VIC, Australia.

SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells. Importantly, activated CXCR3cT1 cells in acute COVID-19 significantly correlate with and predict antibody levels and their avidity at convalescence as well as acute neutralization activity. Strikingly, intensive care unit (ICU) patients with severe COVID-19 display higher levels of soluble IL-6, IL-6R, and IL-18, and hyperactivation of innate, adaptive, and myeloid compartments than patients with moderate disease. Our analyses provide a comprehensive map of longitudinal immunological responses in COVID-19 patients and integrate key cellular pathways of complex immune networks underpinning severe COVID-19, providing important insights into potential biomarkers and immunotherapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.xcrm.2021.100208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862905PMC
March 2021

A population of CD4CD38 T cells correlates with disease severity in patients with acute malaria.

Clin Transl Immunology 2020 24;9(11):e1209. Epub 2020 Nov 24.

Infectious Diseases Program QIMR Berghofer Medical Research Institute Brisbane QLD Australia.

Objective: CD4 T cells are critical mediators of immunity to spp. infection, but their characteristics during malarial episodes and immunopathology in naturally infected adults are poorly defined. Flow cytometric analysis of PBMCs from patients with either or malaria revealed a pronounced population of CD4 T cells co-expressing very high levels of CD4 and CD38 we have termed CD4CD38 T cells. We set out to gain insight into the function of these novel cells.

Methods: CD4 T cells from 18 patients with or malaria were assessed by flow cytometry and sorted into populations of CD4CD38 or CD4 T cells. Gene expression in the sorted populations was assessed by qPCR and NanoString.

Results: CD4CD38 T cells expressed high levels of mRNA and canonical type 1 regulatory T-cell (TR1) genes including , , and (TIM3), and other genes with relevance to cell migration and immunomodulation. These cells increased in proportion to malaria disease severity and were absent after parasite clearance with antimalarials.

Conclusion: In naturally infected adults with acute malaria, a prominent population of type 1 regulatory T cells arises that can be defined by high co-expression of CD4 and CD38 (CD4CD38) and that correlates with disease severity in patients with falciparum malaria. This study provides fundamental insights into T-cell biology, including the first evidence that CD4 expression is modulated at the mRNA level. These findings have important implications for understanding the balance between immunity and immunopathology during malaria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cti2.1209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684974PMC
November 2020

Chimeric Virus-Like Particles and Capsomeres Induce Similar CD8 T Cell Responses but Differ in Capacity to Induce CD4 T Cell Responses and Antibody Responses.

Front Immunol 2020 29;11:564627. Epub 2020 Sep 29.

Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.

Despite extensive research, the development of an effective malaria vaccine remains elusive. The induction of robust and sustained T cell and antibody response by vaccination is an urgent unmet need. Chimeric virus-like particles (VLPs) are a promising vaccine platform. VLPs are composed of multiple subunit capsomeres which can be rapidly produced in a cost-effective manner, but the ability of capsomeres to induce antigen-specific cellular immune responses has not been thoroughly investigated. Accordingly, we have compared chimeric VLPs and their sub-unit capsomeres for capacity to induce CD8 and CD4 T cell and antibody responses. We produced chimeric murine polyomavirus VLPs and capsomeres each incorporating defined CD8 T cell, CD4 T cell or B cell repeat epitopes derived from CSP. VLPs and capsomeres were evaluated using both homologous or heterologous DNA prime/boost immunization regimens for T cell and antibody immunogenicity. Chimeric VLP and capsomere vaccine platforms induced robust CD8 T cell responses at similar levels which was enhanced by a heterologous DNA prime. The capsomere platform was, however, more efficient at inducing CD4 T cell responses and less efficient at inducing antigen-specific antibody responses. Our data suggest that capsomeres, which have significant manufacturing advantages over VLPs, should be considered for diseases where a T cell response is the desired outcome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.564627DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7550421PMC
May 2021

A Dual-Antigen Enzyme-Linked Immunosorbent Assay Allows the Assessment of Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Seroprevalence in a Low-Transmission Setting.

J Infect Dis 2021 01;223(1):10-14

Department of Immunology and Infectious Disease, John Curtin School of Medical Research, The Australian National University, Canberra, Australia.

Estimates of seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies have been hampered by inadequate assay sensitivity and specificity. Using an enzyme-linked immunosorbent assay-based approach that combines data about immunoglobulin G responses to both the nucleocapsid and spike receptor binding domain antigens, we show that excellent sensitivity and specificity can be achieved. We used this assay to assess the frequency of virus-specific antibodies in a cohort of elective surgery patients in Australia and estimated seroprevalence in Australia to be 0.28% (95% Confidence Interval, 0-1.15%). These data confirm the low level of transmission of SARS-CoV-2 in Australia before July 2020 and validate the specificity of our assay.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiaa623DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7665523PMC
January 2021

Suboptimal SARS-CoV-2-specific CD8 T cell response associated with the prominent HLA-A*02:01 phenotype.

Proc Natl Acad Sci U S A 2020 09 10;117(39):24384-24391. Epub 2020 Sep 10.

Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3000, Australia;

An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8 T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2-specific CD8 and CD4 T cells in vitro, with CD4 T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8 T cell epitopes, A2/S and A2/Orf1ab Using peptide-HLA tetramer enrichment, direct ex vivo assessment of A2/SCD8 and A2/Orf1abCD8 populations indicated that A2/SCD8 T cells were detected at comparable frequencies (∼1.3 × 10) in acute and convalescent HLA-A*02:01 patients. These frequencies were higher than those found in uninfected HLA-A*02:01 donors (∼2.5 × 10), but low when compared to frequencies for influenza-specific (A2/M1) and Epstein-Barr virus (EBV)-specific (A2/BMLF) (∼1.38 × 10) populations. Phenotyping A2/SCD8 T cells from COVID-19 convalescents ex vivo showed that A2/SCD8 T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8 T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/SCD8 T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8 T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8 T cell immunity in COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.2015486117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7533701PMC
September 2020

Uptake of Schistosoma mansoni extracellular vesicles by human endothelial and monocytic cell lines and impact on vascular endothelial cell gene expression.

Int J Parasitol 2020 08 27;50(9):685-696. Epub 2020 Jun 27.

Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia. Electronic address:

The ability of the parasitic blood fluke Schistosoma mansoni and other parasitic helminths to manipulate host biology is well recognised, but the mechanisms that underpin these phenomena are not well understood. An emerging paradigm is that helminths transfer their biological cargo to host cells by secretion of extracellular vesicles (EVs). Herein, we show that two populations of S. mansoni secreted EVs - exosome-like vesicles (ELVs) and microvesicles (MVs) - are actively internalised in two distinct human cell lines that reflect the resident cell types encountered by the parasite in vivo: human umbilical vein endothelial cells (HUVECs) and THP-1 monocytes. RNA-sequencing of HUVECs co-cultured with S. mansoni ELVs compared with untreated HUVECs revealed differential expression of genes associated with intravascular parasitism, including vascular endothelial contraction, coagulation, arachidonic acid metabolism and immune cell trafficking and signalling. Finally, we show that antibodies raised against recombinant tetraspanin (TSP) proteins from the surface of S. mansoni EVs significantly blocked EV uptake by both HUVECs and THP-1 monocytes whereas pre-immunisation antibodies did not. To our knowledge, this is the first evidence demonstrating the internalisation of secreted EVs from any helminth into vascular endothelial cells, providing novel insight into the potential mechanisms underlying host-schistosome interactions. The ability of anti-TSP antibodies to block vesicle uptake by host target cells further supports the potential of TSPs as promising antigens for an anti-fluke vaccine. It also suggests a potential mechanism whereby the current candidate human schistosomiasis vaccine, Sm-TSP-2, exerts its protective effect in animal models.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijpara.2020.05.005DOI Listing
August 2020

Development and validation of serological markers for detecting recent Plasmodium vivax infection.

Nat Med 2020 05 11;26(5):741-749. Epub 2020 May 11.

Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.

A major gap in the Plasmodium vivax elimination toolkit is the identification of individuals carrying clinically silent and undetectable liver-stage parasites, called hypnozoites. This study developed a panel of serological exposure markers capable of classifying individuals with recent P. vivax infections who have a high likelihood of harboring hypnozoites. We measured IgG antibody responses to 342 P. vivax proteins in longitudinal clinical cohorts conducted in Thailand and Brazil and identified candidate serological markers of exposure. Candidate markers were validated using samples from year-long observational cohorts conducted in Thailand, Brazil and the Solomon Islands and antibody responses to eight P. vivax proteins classified P. vivax infections in the previous 9 months with 80% sensitivity and specificity. Mathematical models demonstrate that a serological testing and treatment strategy could reduce P. vivax prevalence by 59-69%. These eight antibody responses can serve as a biomarker, identifying individuals who should be targeted with anti-hypnozoite therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41591-020-0841-4DOI Listing
May 2020

An Analytically and Diagnostically Sensitive RNA Extraction and RT-qPCR Protocol for Peripheral Blood Mononuclear Cells.

Front Immunol 2020 20;11:402. Epub 2020 Mar 20.

Centre for Molecular Therapeutics, Australian Institute of Tropical Health & Medicine, James Cook University, Cairns, QLD, Australia.

Reliable extraction and sensitive detection of RNA from human peripheral blood mononuclear cells (PBMCs) is critical for a broad spectrum of immunology research and clinical diagnostics. RNA analysis platforms are dependent upon high-quality and high-quantity RNA; however, sensitive detection of specific responses associated with high-quality RNA extractions from human samples with limited PBMCs can be challenging. Furthermore, the comparative sensitivity between RNA quantification and best-practice protein quantification is poorly defined. Therefore, we provide herein a critical evaluation of the wide variety of current generation of RNA-based kits for PBMCs, representative of several strategies designed to maximize sensitivity. We assess these kits with a reverse transcription quantitative PCR (RT-qPCR) assay optimized for both analytically and diagnostically sensitive cell-based RNA-based applications. Specifically, three RNA extraction kits, one post-extraction RNA purification/concentration kit, four SYBR master-mix kits, and four reverse transcription kits were tested. RNA extraction and RT-qPCR reaction efficiency were evaluated with commonly used reference and cytokine genes. Significant variation in RNA expression of reference genes was apparent, and absolute quantification based on cell number was established as an effective RT-qPCR normalization strategy. We defined an optimized RNA extraction and RT-qPCR protocol with an analytical sensitivity capable of single cell RNA detection. The diagnostic sensitivity of this assay was sufficient to show a CD8 T cell peptide epitope hierarchy with as few as 1 × 10 cells. Finally, we compared our optimized RNA extraction and RT-qPCR protocol with current best-practice immune assays and demonstrated that our assay is a sensitive alternative to protein-based assays for peptide-specific responses, especially with limited PBMCs number. This protocol with high analytical and diagnostic sensitivity has broad applicability for both primary research and clinical practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.00402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7098950PMC
March 2021

A novel population of memory-activated natural killer cells associated with low parasitaemia in -exposed sickle-cell trait children.

Clin Transl Immunology 2020 Apr 2;9(4):e1125. Epub 2020 Apr 2.

Centre for Molecular Therapeutics Australian Institute of Tropical Health & Medicine James Cook University Cairns QLD Australia.

Objectives: The sickle-cell trait phenotype is associated with protection from malaria. Multiple molecular mechanisms have been proposed to explain this protection, but the role of the host immune system has been poorly investigated. We hypothesised that cellular immunity to malaria may develop differently in sickle-cell trait children (HbAS) and children with normal haemoglobin (HbAA) repeatedly exposed to ().

Methods: Paired samples collected prior to the transmission season and during the first malaria episode of the ensuing transmission season from HbAS and HbAA children were analysed by multiplex bead-based assay and comprehensive multi-dimensional flow cytometry profiling.

Results: Cellular immune profiles were enriched in HbAS relative to HbAA children before the start of the transmission season, with a distinct NK subset. These cells were identified as a novel subset of memory-activated NK cells characterised by reduced expression of the ecto-enzyme CD38 as well as co-expression of high levels of HLA-DR and CD45RO. The frequency of this NK subset before the transmission season was negatively correlated with parasite density quantified during the first malaria episode of the ensuing transmission season. Functional assessment revealed that these CD38 CD45RO HLA-DR NK cells represent a important source of IFN-γ.

Conclusion: Our data suggest that this novel memory-activated NK cell subset may contribute to an accelerated and enhanced IFN-γ-mediated immune response and to control of parasite density in individuals with the sickle-cell trait. This distinct cellular immune profile may contribute to predispose HbAS children to a relative protection from malaria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cti2.1125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7114700PMC
April 2020

The Rise of Non-Tuberculosis Mycobacterial Lung Disease.

Front Immunol 2020 3;11:303. Epub 2020 Mar 3.

The Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia.

The incidence and number of deaths from non-tuberculous mycobacterial (NTM) disease have been steadily increasing globally. These lesser known "cousins" of (TB) were once thought to be harmless environmental saprophytics and only dangerous to individuals with defective lung structure or the immunosuppressed. However, NTM are now commonly infecting seemingly immune competent children and adults at increasing rates through pulmonary infection. This is of concern as the pathology of NTM is difficult to treat. Indeed, NTM have become extremely antibiotic resistant, and now have been found to be internationally dispersed through person-to-person contact. The reasons behind this NTM increase are only beginning to be elucidated. Solutions to the problem are needed given NTM disease is more common in the tropics. Importantly, 40% of the world's population live in the tropics and due to climate change, the Tropics are expanding which will increase NTM infection regions. This review catalogs the global and economic disease burden, at risk populations, treatment options, host-bacterial interaction, immune dynamics, recent developments and research priorities for NTM disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.00303DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7062685PMC
March 2021

Validation of an Epstein-Barr Virus Antibody Risk Stratification Signature for Nasopharyngeal Carcinoma by Use of Multiplex Serology.

J Clin Microbiol 2020 04 23;58(5). Epub 2020 Apr 23.

Infections and Cancer Epidemiology, Infection, Inflammation and Cancer Program, German Cancer Research Center (DKFZ), Heidelberg, Germany.

Serological testing for nasopharyngeal carcinoma (NPC) has recently been reinvigorated by the implementation of novel Epstein-Barr virus (EBV)-specific IgA and IgG antibodies from a proteome array. Although proteome arrays are well suited for comprehensive antigen selection, they are not applicable for large-scale studies. We adapted a 13-marker EBV antigen signature for NPC risk identified by proteome arrays to multiplex serology to establish an assay for large-scale studies. Taiwanese NPC cases ( = 175) and matched controls ( = 175) were used for assay validation. Spearman's correlation was calculated, and the diagnostic value of all multiplex markers was assessed independently using the area under the receiver operating characteristic curve (AUC). Two refined signatures were identified using stepwise logistic regression and internally validated with 10-fold cross validation. Array and multiplex serology showed strong correlation for each individual EBV marker, as well as for a 13-marker combined model on continuous data. Two refined signatures with either four (LF2 and BGLF2 IgG, LF2 and BMRF1 IgA) or two (LF2 and BGLF2 IgG) antibodies on dichotomous data were identified as the most parsimonious set of serological markers able to distinguish NPC cases from controls with AUCs of 0.992 (95% confidence interval [CI], 0.983 to 1.000) and 0.984 (95% CI, 0.971 to 0.997), respectively. Neither differed significantly from the 13-marker model (AUC, 0.992; 95% CI, 0.982 to 1.000). All models were internally validated. Multiplex serology successfully validated the original EBV proteome microarray data. Two refined signatures of four and two antibodies were capable of detecting NPC with 99.2% and 98.4% accuracy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.00077-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7180240PMC
April 2020

Protective Immunity against Severe Malaria in Children Is Associated with a Limited Repertoire of Antibodies to Conserved PfEMP1 Variants.

Cell Host Microbe 2019 11;26(5):579-590.e5

Division of Population Health and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, VIC, Australia; Department of Medical Biology, University of Melbourne, Melbourne 3000, VIC, Australia. Electronic address:

Extreme diversity of the major Plasmodium falciparum antigen, PfEMP1, poses a barrier to identifying targets of immunity to malaria. Here, we used protein microarrays containing hundreds of variants of the DBLα domain of PfEMP1 to cover the diversity of Papua New Guinean (PNG) parasites. Probing the plasma of a longitudinal cohort of malaria-exposed PNG children showed that group 2 DBLα antibodies were moderately associated with a lower risk of uncomplicated malaria, whereas individual variants were only weakly associated with clinical immunity. In contrast, antibodies to 85 individual group 1 and 2 DBLα variants were associated with a 70%-100% reduction in severe malaria. Of these, 17 variants were strong predictors of severe malaria. Analysis of full-length PfEMP1 sequences from PNG samples shows that these 17 variants are linked to pathogenic CIDR domains. This suggests that whereas immunity to uncomplicated malaria requires a broad repertoire of antibodies, immunity to severe malaria targets a subset of conserved variants. These findings provide insights into antimalarial immunity and potential antibody biomarkers for disease risk.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chom.2019.10.012DOI Listing
November 2019

Immune Signature Against Antigens Predicts Clinical Immunity in Distinct Malaria Endemic Communities.

Mol Cell Proteomics 2020 01 28;19(1):101-113. Epub 2019 Oct 28.

Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD, Australia; QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia. Electronic address:

A large body of evidence supports the role of antibodies directed against the parasite in the development of naturally acquired immunity to malaria, however an antigen signature capable of predicting protective immunity against remains to be identified. Key challenges for the identification of a predictive immune signature include the high dimensionality of data produced by high-throughput technologies and the limitation of standard statistical tests in accounting for synergetic interactions between immune responses to multiple targets. In this study, using samples collected from young children in Ghana at multiple time points during a longitudinal study, we adapted a predictive modeling framework which combines feature selection and machine learning techniques to identify an antigen signature of clinical immunity to malaria. Our results show that an individual's immune status can be accurately predicted by measuring antibody responses to a small defined set of 15 target antigens. We further demonstrate that the identified immune signature is highly versatile and capable of providing precise and accurate estimates of clinical protection from malaria in an independent geographic community. Our findings pave the way for the development of a robust point-of-care test to identify individuals at high risk of disease and which could be applied to monitor the impact of vaccinations and other interventions. This approach could be also translated to biomarker discovery for other infectious diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/mcp.RA118.001256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6944240PMC
January 2020

The Association between the Comprehensive Epstein-Barr Virus Serologic Profile and Endemic Burkitt Lymphoma.

Cancer Epidemiol Biomarkers Prev 2020 01 16;29(1):57-62. Epub 2019 Oct 16.

Infections and Immunoepidemiology Branch, Division of Cancer Epidemiology and Genetics, NCI, Bethesda, Maryland.

Background: The discovery of Epstein-Barr virus (EBV) in Burkitt lymphoma tumors represented the first link between a virus and cancer in humans, but the underlying role of this virus in endemic Burkitt lymphoma remains unclear. Nearly all children in Burkitt lymphoma-endemic areas are seropositive for EBV, but only a small percentage develop disease. Variation in EBV-directed immunity could be an explanatory cofactor.

Methods: We examined serum from 150 Burkitt lymphoma cases and 150 controls using a protein microarray that measured IgG and IgA antibodies against 202 sequences across the entire EBV proteome. Variation in the EBV-directed antibody repertoire between Burkitt lymphoma cases and controls was assessed using unpaired tests. ORs quantifying the association between anti-EBV IgG response tertiles and Burkitt lymphoma status were adjusted for age, sex, and study year.

Results: Thirty-three anti-EBV IgG responses were elevated in Burkitt lymphoma cases compared with controls ( ≤ 0.0003). Burkitt lymphoma-associated IgG elevations were strongest for EBV proteins involved in viral replication and antiapoptotic signaling. Specifically, we observed ORs ≥4 for BMRF1 (early antigen), BBLF1 (tegument protein), BHRF1 (Bcl-2 homolog), BZLF1 (Zebra), BILF2 (glycoprotein), BLRF2 [viral capsid antigen (VCA)p23], BDLF4, and BFRF3 (VCAp18). Adjustment for malaria exposure and inheritance of the sickle cell variant did not alter associations.

Conclusions: Our data suggest that the anti-EBV serologic profile in patients with Burkitt lymphoma is altered, with strong elevations in 33 of the measured anti-EBV IgG antibodies relative to disease-free children.

Impact: The Burkitt lymphoma-specific signature included EBV-based markers relevant for viral replication and antiapoptotic activity, providing clues for future Burkitt lymphoma pathogenesis research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1055-9965.EPI-19-0551DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6954331PMC
January 2020

Casting a Wide Net around Immunity to Malaria Catches p53.

Immunity 2019 10;51(4):603-605

Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4870, Australia. Electronic address:

The mechanisms underlying acquisition of naturally acquired immunity to malaria are poorly understood. In this issue of Immunity, Tran and colleagues (2019) demonstrate that systems immunology is a powerful tool to decipher molecular and cellular components contributing to this immunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2019.09.011DOI Listing
October 2019

Evaluation of the antibody response to the EBV proteome in EBV-associated classical Hodgkin lymphoma.

Int J Cancer 2020 08 14;147(3):608-618. Epub 2019 Nov 14.

Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD.

The humoral immune response to Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (cHL) stratified by EBV tumor status is unclear. We examined IgG and IgA antibody responses against 202 protein sequences representing 86 EBV proteins using a microarray and sera from 139 EBV-positive cHL cases, 70 EBV-negative cHL cases and 141 population-based controls frequency matched to EBV-positive cHL cases on sex and age by area (UK, Denmark and Sweden). We leveraged existing data on the proportion of circulating B-cells infected by EBV and levels of serum CCL17, a chemokine secreted by cHL tumor cells, from a subset of the cHL cases in the UK. Total IgG but not IgA response level was significantly different between EBV-positive cHL cases and controls. The distinct serological response included significant elevations in 16 IgG antibodies and 2 IgA antibodies, with odds ratios observed for the following EBV proteins: LMP1 (oncogene), BcLF1 (VCAp160, two variants) and BBLF1 (two variants). Our cHL IgG signature correlated with the proportion of circulating EBV-infected B-cells, but not serum CCL17 levels. We observed no differences in the anti-EBV antibody profile between EBV-negative cHL cases and controls. BdRF1(VCAp40)-IgG and BZLF1(Zta)-IgG were identified as the serological markers best able to distinguish EBV-positive from EBV-negative cHL tumors. Our results support the hypothesis that differences in the EBV antibody profile are specific to patients with EBV-positive cHL and are not universally observed as part of a systematically dysregulated immune response present in all cHL cases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ijc.32741DOI Listing
August 2020

Deciphering host immunity to malaria using systems immunology.

Immunol Rev 2020 01 14;293(1):115-143. Epub 2019 Oct 14.

Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Qld, Australia.

A century of conceptual and technological advances in infectious disease research has changed the face of medicine. However, there remains a lack of effective interventions and a poor understanding of host immunity to the most significant and complex pathogens, including malaria. The development of successful interventions against such intractable diseases requires a comprehensive understanding of host-pathogen immune responses. A major advance of the past decade has been a paradigm switch in thinking from the contemporary reductionist (gene-by-gene or protein-by-protein) view to a more holistic (whole organism) view. Also, a recognition that host-pathogen immunity is composed of complex, dynamic interactions of cellular and molecular components and networks that cannot be represented by any individual component in isolation. Systems immunology integrates the field of immunology with omics technologies and computational sciences to comprehensively interrogate the immune response at a systems level. Herein, we describe the system immunology toolkit and report recent studies deploying systems-level approaches in the context of natural exposure to malaria or controlled human malaria infection. We contribute our perspective on the potential of systems immunity for the rational design and development of effective interventions to improve global public health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/imr.12814DOI Listing
January 2020

2018 ISV Congress: advances in the 100 years since the world's deadliest pandemic.

Hum Vaccin Immunother 2019 ;15(9):2006-2008

Center for Vaccines and Immunology, University of Georgia , Athens , GA , USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/21645515.2019.1660544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6773408PMC
March 2020

Multilaboratory Assessment of Epstein-Barr Virus Serologic Assays: the Case for Standardization.

J Clin Microbiol 2019 11 23;57(11). Epub 2019 Oct 23.

Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA.

IgA antibodies targeting Epstein-Barr virus (EBV) have been proposed for screening for nasopharyngeal carcinoma (NPC). However, methods differ, and the antigens used in these assays differ considerably between laboratories. To enable formal comparisons across a range of established EBV serology assays, we created a panel of 66 pooled serum samples and 66 pooled plasma samples generated from individuals with a broad range of IgA antibody levels. Aliquots from these panels were distributed to six laboratories and were tested by 26 assays measuring antibodies against VCA, EBNA1, EA-EBNA1, Zta, or EAd antigens. We estimated the correlation between assay pairs using Spearman coefficients (continuous measures) and percentages of agreement (positive versus negative, using predefined positivity cutoffs by each assay developer/manufacturer). While strong correlations were observed between some assays, considerable differences were also noted, even for assays that targeted the same protein. For VCA-IgA assays in serum, two distinct clusters were identified, with a median Spearman coefficient of 0.41 (range, 0.20 to 0.66) across these two clusters. EBNA1-IgA assays in serum grouped into a single cluster with a median Spearman coefficient of 0.79 (range, 0.71 to 0.89). Percentages of agreement differed broadly for both VCA-IgA (12% to 98%) and EBNA1-IgA (29% to 95%) assays in serum. Moderate-to-strong correlations were observed across assays in serum that targeted other proteins (correlations ranged from 0.44 to 0.76). Similar results were noted for plasma. We conclude that standardization of EBV serology assays is needed to allow for comparability of results obtained in different translational research studies across laboratories and populations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.01107-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6813000PMC
November 2019

Chimeric Murine Polyomavirus Virus-Like Particles Induce Antigen-Specific CD8 T Cell and Antibody Responses.

Front Cell Infect Microbiol 2019 19;9:215. Epub 2019 Jun 19.

Infectious Diseases Programme, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.

An effective vaccine against the parasite is likely to require the induction of robust antibody and T cell responses. Chimeric virus-like particles are an effective vaccine platform for induction of antibody responses, but their capacity to induce robust cellular responses and cell-mediated protection against pathogen challenge has not been established. To evaluate this, we produced chimeric constructs using the murine polyomavirus structural protein with surface-exposed CD8 or CD4 T cell or B cell repeat epitopes derived from the circumsporozoite protein, and assessed immunogenicity and protective capacity in a murine model. Robust CD8 T cell responses were induced by immunization with the chimeric CD8 T cell epitope virus-like particles, however CD4 T cell responses were very low. The B cell chimeric construct induced robust antibody responses but there was no apparent synergy when T cell and B cell constructs were administered as a pool. A heterologous prime/boost regimen using plasmid DNA priming followed by a VLP boost was more effective than homologous VLP immunization for cellular immunity and protection. These data show that chimeric murine polyomavirus virus-like particles are a good platform for induction of CD8 T cell responses as well as antibody responses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcimb.2019.00215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6593135PMC
February 2020

Human challenge models: tools to accelerate the development of malaria vaccines.

Expert Rev Vaccines 2019 03 27;18(3):241-251. Epub 2019 Feb 27.

a Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine , James Cook University , Cairns , Australia.

Introduction: Malaria challenge models, where healthy human volunteers are intentionally infected with Plasmodium species parasites under controlled conditions, can be undertaken in several well-defined ways. These challenge models enable evaluation of the kinetics of parasite growth and clearance, host-pathogen interactions and the host immune response. They can facilitate discovery of candidate diagnostic biomarkers and novel vaccine targets. As translational tools they can facilitate testing of candidate vaccines and drugs and evaluation of diagnostic tests.

Areas Covered: Until recently, malaria human challenge models have been limited to only a few Plasmodium falciparum strains and used exclusively in malaria-naïve volunteers in non-endemic regions. Several recent advances include the use of alternate P. falciparum strains and other species of Plasmodia, as well as strains attenuated by chemical, radiation or genetic modification, and the conduct of studies in pre-exposed individuals. Herein, we discuss how this diversification is enabling more thorough vaccine efficacy testing and informing rational vaccine development.

Expert Opinion: The ability to comprehensively evaluate vaccine efficacy in controlled settings will continue to accelerate the translation of candidate malaria vaccines to the clinic, and inform the development and optimisation of potential vaccines that would be effective against multiple strains in geographically and demographically diverse settings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/14760584.2019.1580577DOI Listing
March 2019

Identification of antigens via protein microarray and assessment of expression library immunization against cytauxzoonosis.

Clin Proteomics 2018 29;15:44. Epub 2018 Dec 29.

1College of Veterinary Medicine, North Carolina State University, Research Building Room 464, 1060 William Moore Drive, Raleigh, NC 27607 USA.

Background: Cytauxzoonosis is a disease of felids in North America caused by the tick-transmitted apicomplexan parasite . Cytauxzoonosis is particularly virulent for domestic cats, but no vaccine currently exists. The parasite cannot be cultivated in vitro, presenting a significant limitation for vaccine development.

Methods: Recent sequencing of the genome has identified over 4300 putative protein-encoding genes. From this pool we constructed a protein microarray containing 673 putative proteins. This microarray was probed with sera from -infected and naïve cats to identify differentially reactive antigens which were incorporated into two expression library vaccines, one polyvalent and one monovalent. We assessed the efficacy of these vaccines to prevent of infection and/or disease in a tick-challenge model.

Results: Probing of the protein microarray resulted in identification of 30 differentially reactive antigens that were incorporated into the two expression library vaccines. However, expression library immunization failed to prevent infection or disease in cats challenged with .

Conclusions: Protein microarray facilitated high-throughput identification of novel antigens, substantially increasing the pool of characterized antigens. These antigens should be considered for development of vaccines, diagnostics, and therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12014-018-9218-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6310948PMC
December 2018

Defined Small Molecules Produced by Himalayan Medicinal Plants Display Immunomodulatory Properties.

Int J Mol Sci 2018 Nov 6;19(11). Epub 2018 Nov 6.

Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia.

Plant-derived compounds that modulate the immune responses are emerging as frontline treatment agents for cancer, infectious diseases and autoimmunity. Herein we have isolated 40 phytochemicals from five Bhutanese medicinal plants-, , , and -and tested 14 purified compounds for their immunomodulatory properties using a murine dendritic cell (DC) line, and cytotoxicity against a human cholangiocyte cell line using xCELLigence real time cell monitoring. These compounds were: pseudaconitine, 14-veratryolpseudaconitine, 14--acetylneoline, linalool oxide acetate, ()-spiroether, luteolin, luteolin-7--β-d-glucopyranoside, protopine, ochrobirine, scoulerine, capnoidine, isomyristicin, bergapten, and isoimperatorin. Of the 14 compounds tested here, scoulerine had adjuvant-like properties and strongly upregulated gene and protein expression whereas bergapten displayed immunosuppressive properties and strongly down-regulated gene and protein expression of MHC-I and other co-stimulatory molecules. Both scoulerine and bergapten showed low cytotoxicity against normal healthy cells that were consistent with their immunoregulatory properties. These findings highlight the breadth of immunomodulatory properties of defined compounds from Bhutanese medicinal plants and show that some of these compounds exert their mechanisms of action by modulating DC activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms19113490DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274922PMC
November 2018

A Balanced Proinflammatory and Regulatory Cytokine Signature in Young African Children Is Associated With Lower Risk of Clinical Malaria.

Clin Infect Dis 2019 08;69(5):820-828

ISGlobal, Hospital Clínic, Universitat de Barcelona, Catalonia, Spain.

Background: The effect of timing of exposure to first Plasmodium falciparum infections during early childhood on the induction of innate and adaptive cytokine responses and their contribution to the development of clinical malaria immunity is not well established.

Methods: As part of a double-blind, randomized, placebo-controlled trial in Mozambique using monthly chemoprophylaxis with sulfadoxine-pyrimethamine plus artesunate to selectively control timing of malaria exposure during infancy, peripheral blood mononuclear cells collected from participants at age 2.5, 5.5, 10.5, 15, and 24 months were stimulated ex vivo with parasite schizont and erythrocyte lysates. Cytokine messenger RNA expressed in cell pellets and proteins secreted in supernatants were quantified by reverse-transcription quantitative polymerase chain reaction and multiplex flow cytometry, respectively. Children were followed up for clinical malaria from birth until 4 years of age.

Results: Higher proinflammatory (interleukin [IL] 1, IL-6, tumor necrosis factor) and regulatory (IL-10) cytokine concentrations during the second year of life were associated with reduced incidence of clinical malaria up to 4 years of age, adjusting by chemoprophylaxis and prior malaria exposure. Significantly lower concentrations of antigen-specific T-helper 1 (IL-2, IL-12, interferon-γ) and T-helper 2 (IL-4, IL-5) cytokines by 2 years of age were measured in children undergoing chemoprophylaxis compared to children receiving placebo (P < .03).

Conclusions: Selective chemoprophylaxis altering early natural exposure to malaria blood stage antigens during infancy had a significant effect on T-helper lymphocyte cytokine production >1 year later. Importantly, a balanced proinflammatory and anti-inflammatory cytokine signature, probably by innate cells, around age 2 years was associated with protective clinical immunity during childhood.

Clinical Trials Registration: NCT00231452.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciy934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7675332PMC
August 2019

ISV Congress back to Europe.

Hum Vaccin Immunother 2018 ;14(9):2101-2104

b University of Massachusetts Medical School , Worcester , MA , USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/21645515.2018.1518065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6183265PMC
May 2019