Publications by authors named "Elaine Raniero Fernandes"

21 Publications

  • Page 1 of 1

Rabies Virus Exposure in Wild Lowland Tapirs (Tapirus terrestris) from Three Brazilian Biomes.

J Wildl Dis 2021 Apr;57(2):443-446

Lowland Tapir Conservation Initiative, Institute for Ecological Research, Campo Grande, Mato Grosso do Sul 79046-150, Brazil.

We evaluated the presence of antibodies for rabies virus in 177 serum samples from 125 wild lowland tapirs (Tapirus terrestris) from three different Brazilian biomes. The rapid fluorescent focus inhibition test was performed. No antibody titers suggesting the circulation of the rabies virus in tapir habitat were detected.
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http://dx.doi.org/10.7589/JWD-D-20-00089DOI Listing
April 2021

Glycosylation is required for the neutralizing activity of human IgG1 antibodies against human rabies induced by pre-exposure prophylaxis.

Immunobiology 2021 Mar 23;226(2):152058. Epub 2021 Jan 23.

Instituto Pasteur, São Paulo, Brazil. Electronic address:

Rabies lyssavirus (RABV) neutralizing IgG antibodies confer protection after rabies vaccination, although how the RABV-specific antibodies neutralize the virus is still unknown. As changes in the antibody's carbohydrate chain can interfere with its effector functions, we compared the glycosylation patterns of both neutralizing and non-neutralizing IgG1 induced by pre-exposure prophylaxis to human rabies and analyzed their influence on in vitro antibody neutralizing activities. Specific IgG1 were purified from human serum using affinity chromatography. Purity and avidity were analyzed by SDS-PAGE and indirect ELISA using NHSCN respectively. The N-linked oligosaccharide chain of the purified IgG antibody was evaluated using a lectin-based ELISA assay with a panel of seven lectins. The activity of purified IgG1 and neutralizing IgG1 deglycosylated by PNGase F enzyme were analyzed using the rapid fluorescent focus inhibition test. The purified IgG1 showed an electrophoretic pattern compatible with human IgG. All of the antibodies recognized RABV, although neutralizing IgG1 had a higher avidity (RAI = 80%) than non-neutralizing IgG1 (RAI = 30%). The neutralizing IgG1 also showed higher binding to WFA, ECA, WGA, and ConA lectins, indicating possible different N-acetylgalactosamine, galactose, N-acetylglucosamine, and mannose contents. Non-neutralizing IgG1, on the other hand, showed strong binding at UEA-1 and SNA, which bind to fucose and sialic acid residues respectively. Different glycosylation profiles were also observed in Fab and Fc fragments from neutralizing and non-neutralizing IgG1, although the deglycosylated IgG1 lost its neutralizing activity. Our results suggest that antibody glycosylation is important for neutralizing RABV in vitro, since neutralizing IgG1 has a different glycosylation profile than non-neutralizing IgG1. Further research will be needed to better evaluate the differential glycosylation patterns between IgG1 antibodies following vaccination.
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http://dx.doi.org/10.1016/j.imbio.2021.152058DOI Listing
March 2021

Development of biotinylated polyclonal anti-ribonucleoprotein IgG for detection of rabies virus antigen by direct rapid immunohistochemical test.

Biologicals 2020 Nov 26;68:74-78. Epub 2020 Aug 26.

Instituto Pasteur, São Paulo, Brazil. Electronic address:

The direct rapid immunohistochemical test (dRIT) has been recommended for laboratorial diagnosis of rabies, especially in developing countries. The absence of commercial primary antibodies, however, still represents a major limitation to its wider use in testing. We describe here the development of a biotinylated polyclonal antibody against Rabies lyssavirus (RABV) ribonucleoprotein (RNP) and its use as a primary reagent in dRIT. Anti-RNP polyclonal horse IgG was purified by ionic exchange chromatography followed by immunoaffinity column chromatography, and its affinity, diagnostic sensitivity, and specificity were evaluated. CNS samples (120) of suspected rabies cases in different animal species were tested by dRIT, with the positive (n = 14) and negative (n = 106) results confirmed by direct fluorescence antibody testing (dFAT). Comparing the results of dRIT and dFAT, we found that the biotinylated anti-RNP IgG delivered 100% diagnostic specificity and sensibility for rabies diagnosis. Our findings show that the biotinylated anti-RNP polyclonal IgG can be produced with the quality required for application in dRIT. This work represents an important step in efforts to diagnose rabies in developing countries.
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http://dx.doi.org/10.1016/j.biologicals.2020.08.004DOI Listing
November 2020

Performance evaluation of the polyclonal anti-rabies virus ribonucleoprotein IgG antibodies produced in-house for use in direct fluorescent antibody test.

J Virol Methods 2020 06 1;280:113879. Epub 2020 May 1.

Instituto Pasteur, São Paulo, Brazil. Electronic address:

Fluorescein isothiocyanate (FITC) labelled anti-rabies virus ribonucleoprotein (RNP) antibodies can be used as immunoreagents in direct fluorescent antibody testing (dFAT) for rabies diagnoses. While in-house products are occasionally used by laboratories, most conjugates are commercial reagents. Commercial anti-RNP antibodies are only available for research purposes in Brazil, however, which contributes to the increasing use of in-house produced antibodies. Considering that conjugate quality may influence the results obtained during rabies diagnosis, we sought to analyze the performance requirements of in-house produced polyclonal anti-RNP IgG-FITC for application in dFAT. To that end, their reproducibility, diagnostic sensitivity, and specificity were evaluated. The titer of polyclonal anti-RNP IgG-FITC was initially determined and evaluated by dFAT, using central nervous system (CNS) samples of different animal species (dogs, cats, bovines, equines, bats, and non-human primates). As our main result, the polyclonal anti-RNP IgG-FITC reached a titer of 1:30/1:40 in dFAT, with 100% of diagnostic sensitivity and specificity. In terms of reproducibility, the antibodies, regardless the production batch, presented the same performances. In conclusion, the in-house produced polyclonal anti-RNP IgG-FITC proved suitable for rabies virus antigen detection by dFAT.
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http://dx.doi.org/10.1016/j.jviromet.2020.113879DOI Listing
June 2020

Evaluation of polyclonal anti-RNP IgG antibody for rabies diagnosis by indirect rapid immunohistochemistry test.

Acta Trop 2020 Jun 21;206:105340. Epub 2020 Feb 21.

Instituto Pasteur, 393, Paulista Avenue, 01311-000, São Paulo, Brazil. Electronic address:

Rabies still represents a major public health threat and estimated to cause 60,000 human deaths annually, particularly in developing countries. Thus, adequate surveillance based on rapid and reliable rabies diagnosis for both humans and animals is essential. The WHO and OIE recommended gold standard diagnostic technique for rabies is the direct immunofluorescence assay (dFAT). However, dFAT is expensive and requires a high level of expertise. As an alternative, the rapid immunohistochemistry technique is a promise to be a simple and cost effective diagnostic tool for rabies, and can be performed on field conditions prevalent in developing countries. However, no validated commercial conjugate antibody for rabies is available to meet the laboratory demand. Here, we evaluated the polyclonal anti-rabies virus ribonucleoprotein (RNP) IgG antibody for Rabies lyssavirus (RABV) detection by indirect rapid immunohistochemistry test (iRIT). We tested polyclonal anti-RNP IgG antibody against a batch of 100 brain specimens representing a wide phylogenetic origin in the State of São Paulo, Brazil. The purified IgG obtained 100% of diagnostic specificity and sensibility for RABV antigen detection in iRIT compared with the gold standard dFAT. In conclusion, our results demonstrate that the polyclonal anti-RNP IgG antibody may be used as a diagnostic reagent for rabies using iRIT, with the expectation of increase in availability and cost reduction of the epidemiological surveillance for developing countries.
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http://dx.doi.org/10.1016/j.actatropica.2020.105340DOI Listing
June 2020

Nyctinomops laticaudatus bat-associated Rabies virus causes disease with a shorter clinical period and has lower pathogenic potential than strains isolated from wild canids.

Arch Virol 2019 Oct 10;164(10):2469-2477. Epub 2019 Jul 10.

Pasteur Institute, Av. Paulista 393, São Paulo, SP, CEP 01311-000, Brazil.

Rabies is a lethal viral disease that can affect a wide range of mammals. Currently, Rabies virus (RABV) in some European and American countries is maintained primarily in wild species. The regulation of viral replication is one of the critical mechanisms involved in RABV pathogenesis. However, the relationship between replication and the pathogenesis of RABV isolated from wild animals remains poorly understood. In the present study, we evaluated the pathogenicity of the street viruses Nyctinomops laticaudatus bat-associated RABV (NYBRV) and Cerdocyon thous canid-associated RABV (CECRV). Infection of mice with NYBRV led to 33% mortality with rapid disease evolution and marked histopathological changes in the CNS. In contrast, infection with CECRV led to 67% mortality and caused mild neuropathological lesions. The proportion of RABV antigen was significantly higher in the cytoplasm of neuronal cells of the cerebral cortex and in the meninges of mice infected with CECRV and NYBRV, respectively. Moreover, the replication rate of NYBRV was significantly higher (p < 0.001) than that of CECRV in neuroblastoma cells. However, CECRV replicated to a significantly higher titer in epithelial cells. Our results indicate that NYBRV infection results in rapid disease progression accompanied by frequent and intense histopathological alterations in the CNS in mice, and in a high replication rate in neuroblastoma cells. Although, CECRV is more pathogenic in mice, it caused milder histopathological changes in the CNS and replicated more efficiently in epithelial cells. Our data point to a correlation between clinical aspects of disease and the replication of RABV in different cell lines.
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http://dx.doi.org/10.1007/s00705-019-04335-5DOI Listing
October 2019

Purification of IgG against ribonucleoprotein by a homemade immunoaffinity chromatography column for rabies diagnosis.

J Immunol Methods 2019 08 20;471:1-10. Epub 2019 Mar 20.

Instituto Pasteur, São Paulo, Brazil. Electronic address:

Polyclonal or monoclonal antibodies against rabies virus ribonucleoprotein (RNP) conjugated to fluorescein isothiocyanate (FITC) have been employed for Rabies virus (RABV) antigen detection by the direct fluorescent antibody test (DFA). To date, these biomolecules have been purified by traditional methods such as precipitation by ammonium sulfate or ion exchange chromatography followed by ammonium sulfate precipitation, which allows only for partial detection of the protein of interest. In this study, we aimed to purify anti-RNP polyclonal horse IgG antibodies by cation-exchange chromatography in combination with a homemade immunoaffinity chromatography on RNP immobilized (RNP-IAC). Furthermore, to evaluate the accuracy of the prepared anti-RNP IgG fluorescent antibody in diagnostic purposes, DFA was applied for RABV antigen detection in suspected brain samples of different animal species. The combination of these two techniques made it possible to obtain antibodies with high selectivity and purity. Compared with the performance of the traditional method, anti-RNP IgG antibodies purified by RNP-IAC can be obtained from a smaller volume of hyperimmune serum and with greater avidity. Furthermore, the results obtained by DFA analyses revealed that the prepared anti-RNP IgG fluorescent antibody achieved 100% diagnostic specificity and sensitivity for RABV antigen detection. Thus, two-technique chromatographic, including RNP-IAC technology could be appropriate methods for the purification of polyclonal anti-RNP IgG for the use as a diagnostic reagent for rabies.
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http://dx.doi.org/10.1016/j.jim.2019.03.007DOI Listing
August 2019

Street rabies virus strains associated with insectivorous bats are less pathogenic than strains isolated from other reservoirs.

Antiviral Res 2018 12 26;160:94-100. Epub 2018 Oct 26.

Laboratory of Diagnostic, Pasteur Institute, São Paulo, Brazil. Electronic address:

Rabies is a fatal and viral zoonosis that causes acute, progressive encephalitis and remains an important concern in public health. In the last few years, there has been a change in the epidemiological profile of rabies after implementing canine rabies control in the Americas, which has led to a significant increase in both human and pet cases of rabies associated with insectivorous bats. Thus, it is important to understand the pathogenesis caused by Rabies virus (RABV) isolates from insectivorous bats. Viral growth kinetics, cell-to-cell spread and virus uptake in vitro were analyzed for RABV isolates from Eptesicus furiralis and Myotis nigricans. For pathogenesis evaluation, mice were inoculated with RABV isolates from Eptesicus furiralis and Myotis nigricans, and clinical signs were observed for 40 days. We observed that the insectivorous bat strains showed a higher replication rate, faster cell-to-cell spread and delayed virus uptake in N2a cells. Furthermore, after the first sign of a clinical infection, mice infected with Myotis nigricans and Eptesicus furiralis isolates succumbed rapidly (6 ± 9 days) compared with RABV strains associated with other reservoirs. Our results show that the insectivorous bat RABV strains are less pathogenic for mice than strains associated with other reservoirs. In addition, this study also indicates that the differences in the biological characteristics of the RABV strains are important to their pathogenicity. An enhanced understanding of rabies pathogenesis may be important for the development of novel therapies for humans and in the implementation of rabies control strategies.
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http://dx.doi.org/10.1016/j.antiviral.2018.10.023DOI Listing
December 2018

Infection of neuroblastoma cells by rabies virus is modulated by the virus titer.

Antiviral Res 2018 01 6;149:89-94. Epub 2017 Nov 6.

Laboratory of Diagnostic, Pasteur Institute, São Paulo, Brazil. Electronic address:

Rabies is a lethal viral infection that can affect almost all mammals, including humans. To better understand the replication of Rabies lyssavirus, we investigated if the viral load in brains naturally infected with rabies influences viral internalization and viral growth kinetics in neuroblastoma cells, and if the viral load affects mortality in mice after intradermal infection. We noted that high initial viral loads in brains (group II) were unfavourable for increasing viral titers during serial passages in neuroblastoma cells when compared to low initial viral loads in brains (group I). In addition, group I strains showed higher viral growth and enhanced internalization efficiency in neuroblastoma cells than group II strains. However, we observed that the dominant virus subpopulation in group II promoted efficient viral infection in the central nervous system in the new host, providing a selective advantage to the virus. Our data indicate that rabies infection in animal models depends on not only the virus strain but also the amount of virus. This study may serve as a basis for understanding the biologic proprieties of Rabies lyssavirus strains with respect to the effects on viral replication and the impact on pathogenesis, improving virus yields for use in vaccine development.
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http://dx.doi.org/10.1016/j.antiviral.2017.11.003DOI Listing
January 2018

Immunological aspects of rabies: a literature review.

Arch Virol 2017 Nov 19;162(11):3251-3268. Epub 2017 Jul 19.

Instituto Pasteur, 393, Paulista Avenue, São Paulo, SP, 01311-000, Brazil.

Rabies is a lethal disease caused by the neurotropic virus rabies virus (RABV), and it remains an important public health problem globally. It is known that the host immune response is important for control of viral infection and promoting viral clearance. In this context, it is well documented that, in addition to RABV neutralizing antibody, interferons and cell-mediated immunity also have an important role in preventing the establishment of disease. On the other hand, RABV suppresses host immunity through different mechanisms, for example, direct inhibition of host gene expression, sequestration of pathogen-associated molecular patterns, or modification of cytokine signalling pathways, which hinder the protective host immune responses to RABV infection. Here, we review the immunological aspects of rabies, highlighting innate and adaptive immunity, as well as the host evasion immune mechanisms used by the virus. Finally, we briefly discuss how this knowledge can direct new research and be harnessed for future therapeutic strategies.
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http://dx.doi.org/10.1007/s00705-017-3484-0DOI Listing
November 2017

Constitutive expression of genes encoding notch receptors and ligands in developing lymphocytes, nTreg cells and dendritic cells in the human thymus.

Results Immunol 2016 5;6:15-20. Epub 2016 Apr 5.

Laboratory of Medical Investigation in Dermatology and Immunodeficiencies (LIM56), School of Medicine - USP, São Paulo, Brazil; Heart Hospital - Hcor, São Paulo, Brazil.

The thymus is the site of T cell maturation. Notch receptors (Notch1-4) and ligands (DLL1-3 and Jagged1-2) constitute one of several pathways involved in this process. Our data revealed differential constitutive expression of Notch genes and ligands in T lymphocytes and thymic dendritic cells (tDCs), suggesting their participation in human thymocyte maturation. nTreg analyses indicated that the Notch components function in parallel to promote maturation in the thymus.
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http://dx.doi.org/10.1016/j.rinim.2016.04.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4969261PMC
August 2016

Immunopathogenesis of dengue hemorrhagic fever: contribution to the study of human liver lesions.

J Med Virol 2014 Jul 23;86(7):1193-7. Epub 2013 Sep 23.

Faculdade de Medicina da Universidade de São Paulo, Laboratório da Disciplina de Patologia de Moléstias Transmissíveis, Departamento de Patologia, São Paulo, Brazil.

Dengue infection is an important tropical disease worldwide. The host immune response has been studied in order to better understand lesion mechanisms. It was performed an immunohistochemical study in 14 specimens of liver from patients with dengue hemorrhagic fever (DHF) to characterize cytokines and some factors present in liver lesions and their possible role in the pathogenesis of hepatic injury. Portal tract and hepatic acinus presented high expression of TLR2, TLR3, IL6, and granzyme B. Hepatic acinus also presented iNOS, IL18, and TGF-beta. Cells expressing IL12, IL13, JAk1, STAT1, and NF-κB were rarely visualized. Treg cells foxp3+ were absent. TLR2 and TLR3 seem to participate in cellular activation and cytokine production. Cytotoxic response seems to play a role. Although TGF-beta promotes the activation of Foxp3+ regulatory T cells, IL6 can significantly suppresses their generation. The expression of Treg cells is diminished probably as a result of the high frequency of these cytokines. Both cytokines play a role in the increased vascular permeability and edema observed in dengue liver specimens, with consequent plasma leakage and severity of the disease. It was observed a regular expression of IL-18 in hepatocytes and lymphocytes of the inflammatory infiltrate in portal tract, which reflects the acute inflammatory response that occurs in the liver and contributes to hepatic injury. At least in part, the increased number of cells expressing IL-18 could play a role of "up" regulation of FasL and correlate to the phenomenon of apoptosis, a mechanism of destruction of hepatocytes in DHF.
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http://dx.doi.org/10.1002/jmv.23758DOI Listing
July 2014

Revisiting Langerhans cells in paracoccidioidomycosis: expression of CD207/langerin in human cutaneous and mucosal lesions.

Microbes Infect 2011 Nov 1;13(12-13):1012-7. Epub 2011 Jul 1.

Departamento de Patologia, Faculdade de Medicina, Universidade de São Paulo, Brazil.

Langerhans cells are identified by the expression of langerin. We detected this molecule in cutaneous and mucosal lesions in paracoccidioidomycosis, an important infection in Latin America. Langerin+ cells were scarcely distributed, with short dendrites in epidermis and epithelium and were frequent in the dermis and corium, in the inflammatory infiltrate and granulomas. Mucosal lesions presented a higher expression of langerin in lesions with loose granulomas. For the first time we presented the expression of langerin in paracoccidioidomycosis. Positive cells in dermis and corium could represent migrating Langerhans cells or a new subset of langerin+ cells with a role in paracoccidioidomycosis.
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http://dx.doi.org/10.1016/j.micinf.2011.06.006DOI Listing
November 2011

Paracoccidioidomycosis: cells expressing IL17 and Foxp3 in cutaneous and mucosal lesions.

Microb Pathog 2011 May 3;50(5):263-7. Epub 2011 Feb 3.

Laboratório da Disciplina de Patologia de Moléstias Transmissíveis, Departamento de Patologia, Faculdade de Medicina da Universidade de São Paulo, Brazil.

We demonstrated and quantified by immunohistochemistry the population of cells expressing IL17 and Foxp3 in cutaneous and mucosal paracoccidioidomycosis lesions, associating these populations of cells with different presentations of granulomatous response. For this purpose, 61 skin biopsies and 55 oral mucosal biopsies were evaluated. Cells expressing IL17 were distributed in the inflammatory infiltrate in both groups of lesions and were found in the vessels' wall too. Foxp3+ expression was limited to the nuclei of lymphocytes in the inflammatory infiltrate. The distribution of IL17 was similar among the groups; however, Foxp3+ cells were increased in mucosal lesions that displayed compact granulomas. The results suggest that IL17 seems to play a role in paracoccidioidomycosis cutaneous and mucosal lesions, probably as secondary cells in the clearance of the fungal antigens. The presence of Foxp3+ cells both in skin and mucosa corroborates some previous researches that suggest the role of this group of cells in the modulation of local immune response.
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http://dx.doi.org/10.1016/j.micpath.2010.12.008DOI Listing
May 2011

In situ apoptosis of adaptive immune cells and the cellular escape of rabies virus in CNS from patients with human rabies transmitted by Desmodus rotundus.

Virus Res 2011 Mar 19;156(1-2):121-6. Epub 2011 Jan 19.

Faculdade de Medicina da Universidade de São Paulo, Laboratório da Disciplina de Patologia de Moléstias Transmissíveis, Departamento de Patologia, São Paulo, Brazil.

The aim of the current study was to investigate the apoptosis of neurons, astrocytes and immune cells from human patients that were infected with rabies virus by vampire bats bite. Apoptotic neurons were identified by their morphology and immune cells were identified using double immunostaining. There were very few apoptotic neurons present in infected tissue samples, but there was an increase of apoptotic infiltrating CD4+ and TCD8+ adaptive immune cells in the rabies infected tissue. No apoptosis was present in NK, macrophage and astrocytes. The dissemination of the human rabies virus within an infected host may be mediated by viral escape of the virus from an infected cell and may involve an anti-apoptotic mechanism, which does not kill the neuron or pro-apoptosis of TCD4+ and TCD8+ lymphocytes and which allows for increased proliferation of the virus within the CNS by attenuation of the adaptive immune response.
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http://dx.doi.org/10.1016/j.virusres.2011.01.006DOI Listing
March 2011

Immunohistochemistry and polymerase chain reaction on paraffin-embedded material improve the diagnosis of cutaneous leishmaniasis in the Amazon region.

Int J Dermatol 2009 Oct;48(10):1091-5

Infectious and Parasitic Diseases Clinic, Parasitology (LIM 46), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, Avenida Dr. Enéas de Carvalho, São Paulo, Brazil.

Background: Recently, there has been an increase in the incidence of cutaneous leishmaniasis (CL), which represents an important health problem. This increase may be related to the epidemiologic expansion of the infective agent and the increase in tourism in tropical areas. The difficulty in clinical diagnosis, mainly in areas in which CL is not the first consideration of local physicians, has intensified efforts to describe diagnostic tests, which should be specific, sensitive, and practical. Amongst the new tests described are those including nucleic acid amplification (polymerase chain reaction, PCR) and immunohistochemistry (IHC).

Methods: In this study, we evaluated the sensitivity of a PCR based on small subunit (SSU) ribosomal DNA, in comparison with IHC using Leishmania spp. antibodies, in biopsies embedded in paraffin.

Result: The results indicated a total sensitivity of 96% (90.9% with PCR and 68.8% with IHC), showing the possibility of using paraffin-embedded biopsies to diagnose CL.

Conclusion: We propose the use of the two tests together as a routine protocol for diagnosis. This would require the provision of local medical services to perform molecular biology techniques and adequate Leishmania antibodies.
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http://dx.doi.org/10.1111/j.1365-4632.2009.04099.xDOI Listing
October 2009

Wave expansion of CD34+ progenitor cells in the spleen in rodent malaria.

Exp Parasitol 2009 Mar 3;121(3):230-7. Epub 2008 Dec 3.

Instituto de Ciências Biomédicas da Universidade de São Paulo Professor Lineu Prestes Avenue, Cidade Universitária, São Paulo, SP 05508-900, Brazil.

Defense against malaria depends upon amplification of the spleen structure and function for the clearance of parasitized red blood cells (pRBC). We studied the distribution and amount of CD34(+) cells in the spleens of mice infected with rodent malaria. We sought to identify these cells in the spleen and determine their relationship to infection. C57BL/6J mice were infected with self-resolving, Plasmodium chabaudi CR, or one of the lethal rodent malaria strains, P. chabaudi AJ and P. berghei ANKA. We then recorded parasitemia, mortality, and the presence of CD34(+) cells in spleen, as determined by immunohistochemistry and flow cytometry. In the non-lethal strain, the spleen structure was maintained during amplification, but disrupted in lethal models. The abundance of CD34(+) cells increased in the red pulp on the 4th and 6th days p.i. in all models, and subsided on the 8th day p.i. Faint CD34(+) staining on the 8th day p.i., was probably due to differentiation of committed cell lineages. In this work, increase of spleen CD34(+) cells did not correlate with infection control.
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http://dx.doi.org/10.1016/j.exppara.2008.11.008DOI Listing
March 2009

Chronic colitis associated with HIV infection can be related to intraepithelial infiltration of the colon by CD8+ T lymphocytes.

Int J STD AIDS 2008 Aug;19(8):524-8

Laboratório da Disciplina de Patologia de Moléstias Transmissíveis, Departamento de Patologia, Faculdade de Medicina da Universidade de São Paulo, Av. Dr Arnaldo, 455 Cerqueira César, São Paulo.

Gastrointestinal complications in AIDS patients with diarrhoea are common clinical manifestations, frequently diagnosed by colonoscopy as non-specific colitis. We retrospectively study colon biopsies diagnosed as chronic colitis associated with HIV (CCH). Biopsies were sorted as patients with AIDS (serum CD4 <200 cell/mm3) but without any clear infectious process (n = 12) and patients without HIV infection (n = 24). There are low numbers of CD4+ T lymphocytes in lamina propria of AIDS patients, but CD8+ T populations in this area appear to be similar in all studied groups, regardless of HIV infection or laboratory evidence of a specific agent. We found the clear evidence of CD8+ T cells infiltration in colonic mucosa in HIV patients with microscopic colitis. An imbalance of lymphocyte subpopulations in the colon, both in the lamina propria and epithelium, could result in an intraepithelial CD8 infiltration, involved in the pathogenesis of CCH in AIDS patients.
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http://dx.doi.org/10.1258/ijsa.2007.007282DOI Listing
August 2008

Portal CD4+ and CD8+ T lymphocyte correlate to intensity of interface hepatitis in chronic hepatitis C.

Rev Inst Med Trop Sao Paulo 2007 Nov-Dec;49(6):371-8

Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP.

Background: The pathogenesis of chronic hepatitis C is still a matter of debate. CD4+ and CD8+ T lymphocytes (TL) are typically observed within the portal and periportal spaces of affected livers, but their functional role in hepatitis C progression has not been fully elucidated.

Methods: CD4+ and CD8+ TL were quantified by immunohistochemistry in portal and periportal spaces of 39 liver biopsies from patients with chronic hepatitis C. They were associated to demographic data, histological parameters, laboratory findings of patients and hepatitis C genotypes.

Results: There was high numbers of CD4+ and CD8+ TL from which the density of CD4+ T was higher than CD8+ TL in portal and periportal spaces. CD4+ and CD8+ TL were directly correlated to intensity of interface hepatitis. CD8+ TL correlated to serum enzyme levels.

Conclusion: The high numbers of CD4+ and CD8+ TL in portal and periportal spaces and their correlation to interface hepatitis suggest that hepatitis C evolution depends on the action of intrahepatic T lymphocytes, lending support to the notion of an immune-mediated mechanism in the pathogenesis of chronic hepatitis C.
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http://dx.doi.org/10.1590/s0036-46652007000600007DOI Listing
June 2008

Lung involvement in childhood measles: severe immune dysfunction revealed by quantitative immunohistochemistry.

Hum Pathol 2007 Aug 11;38(8):1239-47. Epub 2007 May 11.

Laboratory of Pathology of Transmissible Diseases, Depto Pathology, Faculdade de Medicina da Universidade de São Paulo, CEP 01246-903 Brazil.

Measles, accounting for nearly 1 million deaths each year, presents intense involvement of lymphoid organs and the lungs. The immune response in situ in the lungs was determined in blocks recovered from 42 necropsies of children who died from measles determined by immune cell phenotype (CD4, CD8, CD20, CD45RO, CD68, natural killer [NK], and antigen S-100 B [S100]) and cytokine production (interferon, tumor necrosis factor, interleukin [IL]-1, IL-2, IL-4, IL-10, and IL-12). Compared with the lungs of age-paired controls, patients with measles presented severe depletion of CD4+, CD20+, CD68+, NK+, and S100+ cells in alveolus- and bronchus-associated lymphoid tissue without depletion of CD8+ cells. Most of these features were similar in both forms of measles lung involvement, Hecht giant cell, or interstitial pneumonia, but S100+ cells were depleted in bronchus-associated lymphoid tissue from patients with Hecht pneumonia, which also occurs more frequently in malnourished children. IL-10- and IL-12-producing cells were depleted in patients with measles, whereas IL-1-, interferon-, and IL-4-producing cells were more frequently seen in the alveolus of patients with measles compared with controls. Quantitative in situ immune cell phenotype and function in the lung in measles demonstrated severe immune dysfunction, with loss of key cells, such as dendritic, CD4+, and NK+ cells, and deficient cytokine production, which allows for a better comprehension of local reactions in this process.
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http://dx.doi.org/10.1016/j.humpath.2007.01.015DOI Listing
August 2007

Immunohistochemical examination of the role of Fas ligand and lymphocytes in the pathogenesis of human liver yellow fever.

Virus Res 2006 Mar 10;116(1-2):91-7. Epub 2005 Oct 10.

Núcleo de Medicina Tropical, Universidade Federal do Pará, Av. Generalissimo Deodoro 92, 66055-240, Belém, Pará, Brazil.

Yellow fever is an infectious, non-contagious disease caused by an RNA virus of the family Flaviviridae, which is transmitted to man by the bite of hematophagous mosquitoes. Infection with the yellow fever virus can progress with lesions in the heart, kidneys, central nervous system, and liver. In the liver, the histopathological picture is characterized by necrosis, steatosis and hepatocyte apoptosis, with a preferential midzone distribution. In the present study, liver samples from fatal patients with yellow fever were analyzed. The histopathological pattern was characterized by steatosis, lytic necrosis and hepatocyte apoptosis associated with a moderate mononuclear inflammatory infiltrate. The inflammatory component mainly consisted of CD4+ T lymphocytes, followed by CD8+ T lymphocytes, which showed a preferential portal and midzone distribution. Immunoreactivity to Fas ligand was mainly observed in hepatocytes of the midzone region. Based on these findings, we conclude that lymphocytes play an important role in the genesis of hepatic lesions in severe yellow fever, inducing hepatocyte apoptosis through the binding to Fas receptors. However, further studies are necessary to investigate the participation of other immune factors and to quantify the role of the cytotoxic cellular response in the lesion evolution during the course of disease in the liver.
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http://dx.doi.org/10.1016/j.virusres.2005.08.019DOI Listing
March 2006