Immunologically reactive M. leprae antigens with relevance to diagnosis and vaccine development

<p>Abstract</p> <p>Background</p> <p>Leprosy is a chronic infectious disease caused by <it>Mycobacterium leprae </it>that can manifest a wide variety of immunological and clinical outcomes ranging from potent humoral responses among borderline lepromatous (BL) and lepromatous (LL) patients to strong cellular responses among tuberculoid (TT) and borderline tuberculoid (BT) patients. Until recently, relatively little has been known about the immune responses to individual proteins of <it>M. leprae </it>recognized during leprosy.</p> <p>Methods</p> <p>The immune reactivity to a panel of 33 <it>M. leprae </it>recombinant proteins was evaluated among leprosy patients and controls from a high endemic area for leprosy (Goiania/GO, Central Brazil). Serum IgG responses were measured by ELISA (45 participants/group) and T cell responses (20 participants/group) were evaluated by IFN-gamma production in 24 hours whole blood cultures with antigen (whole blood assay-WBA). Study groups were newly diagnosed, untreated TT/BT and BL/LL leprosy patients classified by Ridley Jopling criteria and household contacts of BL/LL patients (HHC). Control groups were HIV-1 negative pulmonary tuberculosis patients (TB) and healthy individuals from the same endemic area (EC). In silico predictions indicated the level of identity of <it>M. leprae </it>proteins with homologues in other mycobacteria and the presence of T cell and B cell epitopes.</p> <p>Results</p> <p>Despite the prediction that all proteins would be reactive, 16 of 33 (48%) of the single proteins tested were immunogenic (recognized in WBA or ELISA) and seventeen were non-immunogenic (not recognized in either assay). Among the 16 immunogenic proteins, 9 were considered leprosy specific in WBA inducing cell-mediated IFN-gamma secretion from TT/BT patients and HHC. Three of these proteins were also leprosy specific in serology being recognized by serum IgG from LL/BL patients. Seven of the immunogenic proteins were not leprosy specific.</p> <p>Conclusions</p> <p>New <it>M. leprae </it>antigens recognized by antibody responses of BL/LL patients and cellular responses of TT/BT leprosy patients were identified. An improved serological diagnostic test for leprosy could be developed by incorporating these IgG-reactive antigens to the current PGL-I based tests. Moreover our data indicate that the WBA is a robust, relatively simple and user friendly format for a T cell based diagnostic test. The field use of these test formats in leprosy endemic countries could contribute to early leprosy diagnosis before the development of deformities and disabilities.</p

Prevalence and risk factors for Hepatitis C and HIV-1 infections among pregnant women in Central Brazil

<p>Abstract</p> <p>Background</p> <p>Hepatitis C (HCV) and human immunodeficiency virus (HIV) infections are a major burden to public health worldwide. Routine antenatal HIV-1 screening to prevent maternal-infant transmission is universally recommended. Our objectives were to evaluate the prevalence of and potential risk factors for HCV and HIV infection among pregnant women who attended prenatal care under the coverage of public health in Central Brazil.</p> <p>Methods</p> <p>Screening and counselling for HIV and HCV infections was offered free of charge to all pregnant women attending antenatal clinic (ANC) in the public health system, in Goiania city (~1.1 million inhabitants) during 2004–2005. Initial screening was performed on a dried blood spot collected onto standard filter paper; positive or indeterminate results were confirmed by a second blood sample. HCV infection was defined as a positive or indeterminate sample (EIA test) and confirmed HCV-RNA technique. HIV infection was defined according to standard criteria. Factors associated with HIV and HCV infections were identified with logistic regression. The number needed to screen (NNS) to prevent one case of infant HIV infection was calculated using the Monte Carlo simulation method.</p> <p>Results</p> <p>A total of 28,561 pregnant women were screened for HCV and HIV-1 in ANC. Mean maternal age was 23.9 years (SD = 5.6), with 45% of the women experiencing their first pregnancy. Prevalence of HCV infection was 0.15% (95% CI 0.11%–0.20%), and the risk increased with age (p < 0.01). The prevalence of anti-HIV infection was 0.09% (95% CI 0.06%–0.14%). Black women had a 4.9-fold (95% CI 1.42–16.95) greater risk of HIV-1 infection compared to non-black women. NNS to prevent one case of infant HIV infection ranged from 4,141 to 13,928.</p> <p>Conclusion</p> <p>The prevalence of HIV and HCV infections were low among pregnant women, with high acceptability rates in the opt-in strategy in primary care. Older maternal age was a risk factor for HCV and antenatal HCV testing does not fulfill the requirements for screening recommendation. The finding of higher risk of HIV-1 infection among black women despite being in consonance with the HIV-1 ethnic pattern in some American regions cannot be ruled out to be a surrogate marker of socio-economic condition.</p

Comparative genomic and phylogeographic analysis of Mycobacterium leprae

Reductive evolution and massive pseudogene formation have shaped the 3.31-Mb genome of Mycobacterium leprae, an unculturable obligate pathogen that causes leprosy in humans. The complete genome sequence of M. leprae strain Br4923 from Brazil was obtained by conventional methods (6 x coverage), and Illumina resequencing technology was used to obtain the sequences of strains Thai53 (38 x coverage) and NHDP63 (46 x coverage) from Thailand and the United States, respectively. Whole-genome comparisons with the previously sequenced TN strain from India revealed that the four strains share 99.995% sequence identity and differ only in 215 polymorphic sites, mainly SNPs, and by 5 pseudogenes. Sixteen interrelated SNP subtypes were defined by genotyping both extant and extinct strains of M. leprae from around the world. The 16 SNP subtypes showed a strong geographical association that reflects the migration patterns of early humans and trade routes, with the Silk Road linking Europe to China having contributed to the spread of leprosy

Thalidomide in the treatment of erythema nodosum leprosum (ENL): systematic review of clinical trials and prospects of new investigations

FUNDAMENTOS: A hanseníase persiste como problema de saúde pública, e episódios de ENH são eventos agudos que ocorrem antes, durante e após PQT. Na última década, o uso da talidomida como agente imunomodulador foi expandido a outras doenças. OBJETIVOS: realizar revisão sistemática dos ensaios clínicos publicados sobre a eficácia e efeitos colaterais da talidomida no ENH. Descrever metodologia e resultados da triagem para recrutamento de ensaio clínico visando avaliar dose-resposta da talidomida seguida de desmame no ENH moderado e grave, realizado no Brasil. MÉTODOS: Analisaram-se ensaios publicados sobre talidomida no ENH. Foi delineado um ensaio clínico duplo-cego randomizado para avaliar dose de 100 thalid 300mg/dia de talidomida durante fase aguda de ENH, seguida de desmame da talidomida, thalid placebo. Para este ensaio clínico descreve-se metodologia e dados de recrutamento de pacientes, com ênfase na gravidade dos episódios de ENH. RESULTADOS: Os seis ensaios clínicos publicados nas décadas de 1960 e 1970 apontam para o benefício da talidomida no ENH, embora diferenças metodológicas dificultem a comparação. Na fase de recrutamento do ensaio brasileiro, dos 143 pacientes de ENH triados, 65% eram potencialmente elegíveis. A associação com neurite em 56,4% dos ENH moderados e graves exigiu co-intervenção com corticosteróide. CONCLUSÃO: O padrão de recrutamento dos pacientes evidenciou alta freqüência de neurite nos episódios de ENH. O esquema de talidomida isolada no ENH foi avaliado como infreqüente na prática clínica brasileira. O desafio atual é acumular evidências sobre a eficácia e efeitos colaterais da talidomida em associação com corticosteróides.BACKGROUND: Leprosy remains a public health problem. Episodes of erythema nodosum leprosum (ENL) are acute events that occur before, during and after polychemotherapy. In the last decade, the use of thalidomide as an immunomodulating agent was expanded to other diseases. OBJECTIVES: To perform a systematic review of published clinical trials on efficacy and side effects of thalidomide in ENL. To describe the methodology and screening results of recruiting for a clinical trial performed in Brazil, which aimed to assess the dose-response of thalidomide followed by tapering regimen in severe and moderate cases of ENL. METHODS: Published clinical trials on the use of thalidomide in ENL were analyzed. A randomized, double-blind clinical trial was designed to evaluate the doses of 100mg versus 300mg/day thalidomide during the acute stage of ENL, followed by thalidomide tapering regimen versus placebo. For this clinical trial, the methodology and data for enrollment of patients were described, with an emphasis on severity of ENL episodes. RESULTS: Six clinical trials published in the 1960's and 1970's indicated the benefits of thalidomide in ENL, although methodological differences made comparison difficult. In the enrollment stage of the Brazilian trial, 65% of patients were potentially eligible out of 143 ENL patients screened. The association with neuritis in 56.4% of moderate and severe cases of ENL required the co-intervention with steroids. CONCLUSION: The patients' enrollment pattern demonstrated high frequency of neuritis in ENL episodes. The treatment regimen with thalidomide in monotherapy for ENL was considered infrequent in the clinical practice in Brazil. The current challenge is to accumulate evidence about efficacy and side effects of thalidomide in combination with steroids

Geographic and temporal trends in the molecular epidemiology and genetic mechanisms of transmitted HIV-1 drug resistance:an individual-patient- and sequence-level meta-analysis

Regional and subtype-specific mutational patterns of HIV-1 transmitted drug resistance (TDR) are essential for informing first-line antiretroviral (ARV) therapy guidelines and designing diagnostic assays for use in regions where standard genotypic resistance testing is not affordable. We sought to understand the molecular epidemiology of TDR and to identify the HIV-1 drug-resistance mutations responsible for TDR in different regions and virus subtypes.status: publishe

Identification of New HIV-1 Circulating Recombinant Forms CRF81_cpx and CRF99_BF1 in Central Western Brazil and of Unique BF1 Recombinant Forms

Submitted by Sandra Infurna ([email protected]) on 2019-05-02T10:31:20Z No. of bitstreams: 1 MonicaNGReis_MarianeStefanni_etal_IOC_2019.pdf: 5869909 bytes, checksum: 8d97a2f4f3df1e30398a8a7ff69fe57c (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-05-02T10:37:21Z (GMT) No. of bitstreams: 1 MonicaNGReis_MarianeStefanni_etal_IOC_2019.pdf: 5869909 bytes, checksum: 8d97a2f4f3df1e30398a8a7ff69fe57c (MD5)Made available in DSpace on 2019-05-02T10:37:21Z (GMT). No. of bitstreams: 1 MonicaNGReis_MarianeStefanni_etal_IOC_2019.pdf: 5869909 bytes, checksum: 8d97a2f4f3df1e30398a8a7ff69fe57c (MD5) Previous issue date: 2019Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Laboratório de Imunologia da Aids e da Hanseníase. Goiânia, GO, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de AIDS e Imunologia Molecular. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de AIDS e Imunologia Molecular. Rio de Janeiro, RJ. Brasil.Universidade Federal de Goiás. Instituto de Patologia Tropical e Saúde Pública. Laboratório de Imunologia da Aids e da Hanseníase. Goiânia, GO, Brasil.Intersubtype recombinants classified as circulating recombinant forms (CRFs) or unique recombinant forms (URFs) have been shown to play an important role in the complex and dynamic Brazilian HIV/AIDS epidemic. Previous pol region studies (2003-2013) in 828 patients from six states from Central Western, Northern and Northeastern Brazil reported variable rates of BF1, F1CB, BC, and CF1 mosaics. In this study HIV-1 subtype diversity BF1, F1CB, BC, and CF1 recombinants in pol were analyzed. Full/near-full/partial genome sequences were generated from F1CB and BF1 recombinants. Genomic DNA extracted from whole blood was used in nested-PCR to amplify four overlapping fragments encompassing the full HIV-1 genome. Phylogenetic trees were generated using the neighbor-joining/NJ method (MEGA 6.0). The time of the most recent common ancestor (TMRCA) of F1CB and BF1 clades was estimated using a Bayesian Markov Chain Monte Carlo approach (BEAST v1.8; BEAGLE). Bootscanning was used for recombination analyses (Simplot v3.5.1); separate NJ phylogenetic analysis of fragments confirmed subtypes. The phylogenetic analyses of protease/reverse-transcriptase sequences in 828 patients revealed 76% subtype B (n = 629), 6.4% subtype C (n = 53), 4.2% subtype F1 (n = 35), 13.4% intersubtype recombinants: 10.5% BF1 (n = 87), 2.3% BC (n = 19), 0.4% F1CB (n = 3), and 0.2% CF1 (n = 2). Two full and one partial BF1C genomes allowed the characterization of the CRF81_cpx that has 9 breakpoints dividing the genome into 10 subregions. Basic Local Alignment Search Tool searches (Los Alamos HIV Sequence Database) identified six other sequences with the same recombination profile in pol, five from Brazil, and one from Italy. The estimated median TMRCA of CRF81_cpx was 1999 (1992-2003). CRF60_BC-like sequences, originally described in Italy, were also found. Two full and one near full-length BF1 genomes led to the characterization of the new CRF99_BF1 that has six recombination breakpoints dividing the genome into seven subregions. Two new URFs BF1, with six recombination breakpoints and seven subregions were also characterized. The description of the first Brazilian BF1C CRF81_cpx and of the new CRF99_BF1 corroborate the important role of CRFs in the HIV/AIDS epidemic throughout Brazil. Our data also highlight the value of HIV-1 full-genome sequence studies in order to fully reveal the complexity of the epidemic in a huge country as Brazil

In situ T regulatory cells and Th17 cytokines in paired samples of leprosy type 1 and type 2 reactions.

Leprosy is a complex chronic, infectious dermato-neurological disease that affects the skin and peripheral nerves especially during immuno-inflammatory episodes known as type 1/T1R and type 2/T2R reactions. This study investigated the in situ expression of CD25+Foxp3+ Treg cells and TGF-β1, IFN-γ, IL-17 in leprosy T1R and T2R. Tregs were evaluated in 114 skin biopsies from 74 leprosy patients: 56 T1R (28-paired reaction-free/reactional biopsies, 28 unpaired T1R), 18 T2R (12 paired reaction-free/reactional biopsies, 6 unpaired T2R). Double CD25+Foxp3+immunostained Treg cells obtained by automated platform (Ventana BenchMark XT, Roche, Mannheim, Germany) were counted (Nikon Eclipse E400 2mm2). Cytokine expression was evaluated by immunostaining in 96 biopsies (48 paired reaction-free/reactional lesions, 24 T1R, 24 T2R) using rabbit polyclonal anti human TGF-β1, IFN-γ, IL-17 antibodies (Santa Cruz Biotechnology CA, USA). Treg cell counts in leprosy reactional lesions were higher compared to reaction-free (p = 0.002). Treg numbers were higher in T1R compared to paired unreactional T1R lesions (p = 0.001). Similar frequency of Treg was seen in paired reactional versus unreactional T2R lesions. Higher expression of TGF-β, IFN-γ and IL-17 was seen in T2R lesions compared to T1R and reaction-free lesions. The increase in Treg cells during T1R suggests a suppressive role to control the exacerbated cellular immune response during T1R that can cause tissue and nerve damage. Evidences of upregulated Treg cells in TR1, which usually occurs in patients with Th1-Th17 immunity and the indications of the expression of Th17/IL-17 in T2R, which develops in patients with Th2-Treg profile, suggest plasticity of Treg-Th17 cells populations and a potential role for these cell populations in the immunopathogenesis of leprosy reactions

High Prevalence and Onward Transmission of Non-Pandemic HIV-1 Subtype B Clades in Northern and Northeastern Brazilian Regions

<div><p>The Human immunodeficiency virus type-1 (HIV-1) epidemic in Brazil is mainly driven by the subtype B pandemic lineage (B_PANDEMIC), while Caribbean non-pandemic subtype B clades (B_CAR) seem to account for a very low fraction of HIV-infections in this country. The molecular characteristics of the HIV-1 subtype B strains disseminated in the Northern and Northeastern Brazilian regions, however, have not been explored so far. In this study, we estimate the prevalence of the HIV-1 B_PANDEMIC and B_CAR clades across different Brazilian regions and we reconstruct the spatiotemporal dynamics of dissemination of the major Brazilian B_CAR clades. A total of 2,682 HIV-1 subtype B <i>pol</i> sequences collected from 21 different Brazilian states from the five country regions between 1998 and 2013 were analyzed. Maximum Likelihood phylogenetic analyses revealed that the B_CAR strains reached 16 out 21 Brazilian states here analyzed. The B_CAR clades comprise a low fraction (<10%) of subtype B infections in most Brazilian states analyzed, with exception of Roraima (41%), Amazonas (14%) and Maranhão (14%). Bayesian phylogeographic analyses indicate that B_CAR strains originally from the Hispaniola and Trinidad and Tobago were introduced at multiple times into different states from all Brazilian regions and a few of those strains, probably introduced into Roraima, Maranhão and São Paulo between the late 1970s and the early 1980s, established secondary outbreaks in the Brazilian population. These results support that the HIV-1 subtype B epidemics in some Brazilian states from the Northern and Northeastern regions display a unique molecular pattern characterized by the high prevalence of B_CAR lineages, which probably reflects a strong epidemiological link with the HIV-1 epidemics in the Caribbean region.</p></div