Produção de anticorpos e citocinas em resposta ao SARS-CoV-2: comparação entre imunidade vacinal e híbrida / Antibody and cytokine production in response to SARS-CoV-2: vaccine versus hybrid immunity comparison

A resposta imunológica pelo SARS-CoV-2 após protocolos vacinais e infecção natural é pouco compreendida. Comparando indivíduos vacinados com esquema heterólogo que receberam um reforço vacinal (imunidade vacinal) com aqueles que apresentaram episódio leve de COVID-19 (imunidade híbrida) no mesmo período, verificamos níveis semelhantes de anticorpos contra SARS-CoV-2. Em culturas de células mononucleares, o estímulo com o antígeno viral induziu produção de citocinas pró-inflamatórias nos dois grupos, entretanto, os níveis de IL-17 foram menores em indivíduos com imunidade vacinal. Nossos resultados sugerem que o reforço vacinal teve efeitos semelhantes à infecção natural pelo SARS-CoV-2 na resposta imunológica de indivíduos previamente vacinados. (AU)

The immune response generated by SARS-CoV-2 vaccination protocols and natural infection remains incompletely understood. We compared individuals who received a heterologous vaccination scheme with a booster shot (vaccine immunity) to those who experienced a mild COVID-19 episode (hybrid immunity) during the same timeframe. Our findings revealed similar levels of SARS-CoV-2 antibodies in both groups. Stimulation by viral antigen in mononuclear cell cultures induced pro-inflammatory cytokines in both groups, while individuals with vaccine immunity exhibited lower IL-17. These results suggest that a vaccine booster can induce an immune response in previously vaccinated individuals comparable to that elicited by natural SARS-CoV-2 infection. (AU)

Time between symptom and testing in relation to familial transmission of severe acute respiratory syndrome coronavirus 2 / Tempo entre o início dos sintomas e a testagem está relacionado à maior transmissão de SARS-CoV-2 entre contatos familiares

Abstract Brazil has a huge number of cases and deaths due to coronavirus disease 2019 (COVID-19); however, few studies have dealt with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among familial contacts in Brazil. Here, we report our findings on transmission in a family-based study in Bauru, São Paulo, Brazil. The study, conducted from July to November 2020, comprised 974 individuals with 233 index patients and 741 familial contacts. Familial contacts were evaluated using the rapid COVID-19 Ag ECO and reverse transcription-polymerase chain reaction (RT-PCR) tests immediately after the index patient diagnosis. The antigen-based rapid test was validated in 121 individuals using RT-PCR as the gold standard. Additionally, 30 days later, familial contacts were evaluated for IgM and IgG antibodies against SARS-CoV-2. We found 333 cases of COVID-19 among familial contacts (44.9%). A positive correlation was observed between the time elapsed from the onset of symptoms until the index patient's COVID-19 testing and the number of family contacts infected by SARS-CoV-2. Early SARS-CoV-2 testing and familial contact evaluation are relevant strategies to contain transmission.

Resumo O Brasil apresenta um alto número de casos e óbitos por coronavírus (COVID-19), apesar disso, poucos estudos tratavam da infecção pelo coronavirus-2 causador de síndrome respiratória aguda grave (SARS-CoV-2) entre contatos familiares no Brasil. Relatamos aqui nossos achados sobre a transmissão de SARS-CoV-2 em um estudo de base familiar de Bauru, no estado de São Paulo, Brasil. O estudo foi realizado de julho a novembro de 2020 e compreendeu 974 indivíduos, sendo 233 pacientes índice e 741 contatos familiares. Os contatos familiares foram avaliados por meio do teste rápido COVID-19 Ag ECO Test e RT-PCR imediatamente após o diagnóstico do paciente índice. O uso do teste rápido baseado em antígeno foi validado em 121 indivíduos utilizando RT-PCR como padrão ouro. Adicionalmente, 30 dias após a avaliação inicial, os contatos familiares foram avaliados quanto à presença de anticorpos IgM e IgG contra SARS-CoV-2. Encontramos 333 casos de COVID-19 entre contatos familiares (44,9%). Observamos uma correlação positiva entre o tempo decorrido entre o início dos sintomas e o teste para COVID-19 do paciente índice e o número de contatos familiares infectados por SARS-CoV-2. A testagem precoce da infecção por SARS-CoV-2 e a avaliação de contatos familiares são estratégias relevantes para conter a transmissão.

Time between symptom and testing in relation to familial transmission of severe acute respiratory syndrome coronavirus 2.

Brazil has a huge number of cases and deaths due to coronavirus disease 2019 (COVID-19); however, few studies have dealt with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among familial contacts in Brazil. Here, we report our findings on transmission in a family-based study in Bauru, São Paulo, Brazil. The study, conducted from July to November 2020, comprised 974 individuals with 233 index patients and 741 familial contacts. Familial contacts were evaluated using the rapid COVID-19 Ag ECO and reverse transcription-polymerase chain reaction (RT-PCR) tests immediately after the index patient diagnosis. The antigen-based rapid test was validated in 121 individuals using RT-PCR as the gold standard. Additionally, 30 days later, familial contacts were evaluated for IgM and IgG antibodies against SARS-CoV-2. We found 333 cases of COVID-19 among familial contacts (44.9%). A positive correlation was observed between the time elapsed from the onset of symptoms until the index patient's COVID-19 testing and the number of family contacts infected by SARS-CoV-2. Early SARS-CoV-2 testing and familial contact evaluation are relevant strategies to contain transmission.

HLA-DPB1 and HLA-C alleles are associated with leprosy in a Brazilian population

Despite intense efforts, the number of new cases of leprosy has remained significantly high over the past 20 years. Host genetic background is strongly linked to the pathogenesis of this disease, which is caused by Mycobacterium leprae (M. leprae), and there is a consensus that the most significant genetic association with leprosy is attributed to the major histocompatibility complex (MHC). Here, we investigated the association of human leukocyte antigen (HLA) class I and II genes with leprosy in a Brazilian population encompassing 826 individuals from a hyperendemic area of Brazil; HLA typing of class I (-A, -B, -C) and class II (-DRB1, -DQA1, -DQB1, -DPA1, and -DPB1) loci was conducted. Initially, the associations were tested using the chi-square test, with p-values adjusted using the false discovery rate (FDR) method. Next, statistically significant signals of the associations were submitted to logistic regression analyses to adjust for sex and molecular ancestry data. The results showed that HLA-C*08, -DPB1*04, and -DPB1*18 were associated with protective effects, while HLA-C*12 and -DPB1*105 were associated with susceptibility to leprosy. Thus, our findings reveal new associations between leprosy and the HLA-DPB1 locus and confirm previous associations between the HLA-C locus and leprosy(AU).

Perfil sociodemográfico, clínico e geoespacial de casos novos de hanseníase diagnosticados no Instituto Lauro de Souza Lima, Bauru, São Paulo, entre 2015 e 2019 / Sociodemographic, clinical and geospatial profile of new leprosy cases diagnosed at Institute Lauro de Souza Lima, Bauru, São Paulo, between 2015 and 2019

Embora o Brasil venha apresentando uma redução considerável no número de casos novos de hanseníase, alguns estudos têm demonstrado transmissão ativa mesmo em áreas não endêmicas, como o estado de São Paulo. Diante disso, investigamos o perfil sociodemográfico, clínico e geoespacial dos casos novos de hanseníase diagnosticados entre 2015 e 2019 no Instituto Lauro de Souza Lima (ILSL), um centro de referência localizado no município de Bauru, interior do estado de São Paulo. Foram diagnosticados 177 novos casos de hanseníase nesse período, sendo 61,6% dos pacientes naturais do estado. A maioria dos indivíduos era do sexo masculino (59,9%) e a faixa etária mais prevalente foi de 60 a 69 anos; 79,1% se autodeclaravam brancos e 65,6% possuíam pouca ou nenhuma escolaridade. A forma clínica dimorfa foi a mais frequente (42,4%), a baciloscopia foi positiva em 38,4% dos pacientes (49,0% entre o sexo masculino e 22,5% entre o sexo feminino) e 49,0% dos pacientes possuíam incapacidades no diagnóstico. O georreferenciamento, realizado para os casos oriundos do município de Bauru (n = 31), revelou que a maioria dos pacientes residia em regiões com elevado nível de vulnerabilidade social. O perfil dos pacientes atendidos no ILSL apontou para predominância de homens adultos ou idosos com baixa escolaridade, multibacilares, apresentando incapacidades físicas e longo tempo de sintomas. Em conjunto, nossos dados sugerem atraso no diagnóstico que pode contribuir para a manutenção da transmissão da hanseníase mesmo numa região não endêmica.(AU)

Although Brazil has shown a considerable reduction in the number of new cases of leprosy, some studies have shown active transmission even in non-endemic areas, such as São Paulo state. Considering this, we investigated the sociodemographic, clinical and geospatial profile of new cases of leprosy diagnosed between 2015 and 2019 at the Lauro de Souza Lima Institute (ILSL) a reference center localized in Bauru, a municipality in the interior of São Paulo state. A total of 177 new cases of leprosy were diagnosed in this period, with 61.6% of the patients born in the state. The majority of the individuals was male (59.9%), the most prevalent age group was 60 to 69 years old, 79.1% declared themselves white color/race and 65.6% had little or no schooling. The borderline form of leprosy was the most frequent (42.4%), slit skin smear was positive in 38.4% of patients (49.0% among men and 22.5% among women) and 49.0% had disabilities at diagnosis. Georeferencing, performed for cases from the municipality of Bauru (n = 31), revealed that most patients lived in regions with a high level of social vulnerability. The profile of leprosy new cases found at ILSL pointed to a predominance of adult or elderly men with low education, multibacillary, presenting physical disabilities and a long time of symptoms. Altogether, our data suggests a delay in diagnosis that may contribute to the maintenance of leprosy transmission even in a non-endemic region.(AU)

Large-scale gene expression signatures reveal a microbicidal pattern of activation in Mycobacterium leprae-infected monocyte-derived macrophages with low multiplicity of infection

Leprosy is a disease with a clinical spectrum of presentations that is also manifested in diverse histological features. At one pole, lepromatous lesions (L-pole) have phagocytic foamy macrophages heavily parasitized with freely multiplying intracellular Mycobacterium leprae. At the other pole, the presence of epithelioid giant cells and granulomatous formation in tuberculoid lesions (T-pole) lead to the control of M. leprae replication and the containment of its spread. The mechanism that triggers this polarization is unknown, but macrophages are central in this process. Over the past few years, leprosy has been studied using large scale techniques to shed light on the basic pathways that, upon infection, rewire the host cellular metabolism and gene expression. M. leprae is particularly peculiar as it invades Schwann cells in the nerves, reprogramming their gene expression leading to a stem-like cell phenotype. This modulatory behavior exerted by M. leprae is also observed in skin macrophages. Here, we used live M. leprae to infect (10:1 multiplicity of infection) monocyte-derived macrophages (MDMs) for 48 h and analyzed the whole gene expression profile using microarrays. In this model, we observe an intense upregulation of genes consistent with a cellular immune response, with enriched pathways including peptide and protein secretion, leukocyte activation, inflammation, and cellular divalent inorganic cation homeostasis. Among the most differentially expressed genes (DEGs) are CCL5/RANTES and CYP27B1, and several members of the metallothionein and metalloproteinase families. This is consistent with a proinflammatory state that would resemble macrophage rewiring toward granulomatous formation observed at the T-pole. Furthermore, a comparison with a dataset retrieved from the Gene Expression Omnibus of M. leprae-infected Schwann cells (MOI 100:1) showed that the patterns among the DEGs are highly distinct, as the Schwann cells under these conditions had a scavenging and phagocytic gene profile similar to M2-like macrophages, with enriched pathways rearrangements in the cytoskeleton, lipid and cholesterol metabolism and upregulated genes including MVK, MSMO1, and LACC1/FAMIN. In summary, macrophages may have a central role in defining the paradigmatic cellular (T-pole) vs. humoral (L-pole) responses and it is likely that the multiplicity of infection and genetic polymorphisms in key genes are gearing this polarization.

High rate of sensitization to Kathon CG, detected by patch tests in patients with suspected allergic contact dermatitis.

BACKGROUND: Kathon CG, a combination of methylchloroisothiazolinone and methylisothiazolinone, is widely used as preservative in cosmetics, as well in household cleaning products, industrial products such as paints and glues. It has emerged as an important sensitizing agent in allergic contact dermatitis. OBJECTIVES: This study evaluated the reactivity to this substance in patients subjected to patch tests at the Dermatology Institute in Bauru, São Paulo from 2015 to 2017 and its correlation with other preservatives, the professional activity and location of the lesions. METHODS: The patients were submitted to standard series of epicutaneous tests, standardized by the Brazilian Group Studies on Contact Dermatitis. RESULTS: Out the 267 patients tested, 192 presented positivity to at least one substance and 29 of the patients (15.10%) presented reaction to Kathon CG, with predominance of the female gender (n=27); main professional activity associated with Kathon CG sensibilization was cleaning (17.24%), followed by aesthetic areas (13.79%) and health care (10.34%). The most prevalent sensitizations among the substances tested were nickel sulphate (56.3%), followed by cobalt chloride (23.4%), neomycin (18.2%), potassium dichromate (17.7%), thimerosal (14.5%), formaldehyde (13.2%), paraphenylenediamine (9.3%), and fragrance mix (8.3%). STUDY LIMITATIONS: We do not have data from patients that were submitted to patch test a decade ago in order to confront to current data and establish whether or no sensitization to Kathon CG has increased. CONCLUSION: High positivity to Kathon CG corroborates the recent findings in the literature, suggesting more attention to concentration of this substance, used in cosmetics and products for domestic use.

High rate of sensitization to Kathon CG, detected by patch tests in patients with suspected allergic contact dermatitis

Abstract Background: Kathon CG, a combination of methylchloroisothiazolinone and methylisothiazolinone, is widely used as preservative in cosmetics, as well in household cleaning products, industrial products such as paints and glues. It has emerged as an important sensitizing agent in allergic contact dermatitis. Objectives: This study evaluated the reactivity to this substance in patients subjected to patch tests at the Dermatology Institute in Bauru, São Paulo from 2015 to 2017 and its correlation with other preservatives, the professional activity and location of the lesions. Methods: The patients were submitted to standard series of epicutaneous tests, standardized by the Brazilian Group Studies on Contact Dermatitis. Results: Out the 267 patients tested, 192 presented positivity to at least one substance and 29 of the patients (15.10%) presented reaction to Kathon CG, with predominance of the female gender (n = 27); main professional activity associated with Kathon CG sensibilization was cleaning (17.24%), followed by aesthetic areas (13.79%) and health care (10.34%). The most prevalent sensitizations among the substances tested were nickel sulphate (56.3%), followed by cobalt chloride (23.4%), neomycin (18.2%), potassium dichromate (17.7%), thimerosal (14.5%), formaldehyde (13.2%), paraphenylenediamine (9.3%), and fragrance mix (8.3%). Study limitations: We do not have data from patients that were submitted to patch test a decade ago in order to confront to current data and establish whether or no sensitization to Kathon CG has increased. Conclusion: High positivity to Kathon CG corroborates the recent findings in the literature, suggesting more attention to concentration of this substance, used in cosmetics and products for domestic use.

Myelination key factor krox­20 is downregulated in Schwann cells and murine sciatic nerves infected by Mycobacterium leprae

Schwann cells (SCs) critically maintain the plasticity of the peripheral nervous system. Peripheral nerve injuries and infections stimulate SCs in order to retrieve homeostasis in neural tissues. Previous studies indicate that Mycobacterium leprae (ML) regulates the expression of key factors related to SC identity, suggesting that alterations in cell phenotype may be involved in the pathogenesis of neural damage in leprosy. To better understand whether ML restricts the plasticity of peripheral nerves, the present study sought to determine the expression of Krox­20, Sox­10, c­Jun and p75NTR in SC culture and mice sciatic nerves, both infected by ML Thai­53 strain. Primary SC cultures were stimulated with two different multiplicities of infection (MOI 100:1; MOI 50:1) and assessed after 7 and 14 days. Sciatic nerves of nude mice (NU­Foxn1nu) infected with ML were evaluated after 6 and 9 months. In vitro results demonstrate downregulation of Krox­20 and Sox­10 along with the increase in p75NTR­immunolabelled cells. Concurrently, sciatic nerves of infected mice showed a significant decrease in Krox­20 and increase in p75NTR. Our results corroborate previous findings on the interference of ML in the expression of factors involved in cell maturation, favouring the maintenance of a non­myelinating phenotype in SCs, with possible implications for the repair of adult peripheral nerves(AU).

Desempenho dos antígenos PGL-I, LID-1e NDO-LID para diagnóstico sorológico de hanseníase em pacientes e contatos domiciliares: revisão de literatura / Performance of PGL-I, LID-1 and NDO-LID antigens for leprosy serological diagnosis in patients and household contacts: a review of the literature

A hanseníase afeta os nervos periféri-cos e a pele levando a ocorrência de incapacidades na ausência de tratamento específico oportuno. Portanto, parâmetros sorológicos são necessários para intervenções terapêuticas precoces. A detecção de anticorpos contra o glicolipídio fenólico I (PGL-I) é amplamente empregada no diagnóstico e classificação clínica, enquanto a proteína Leprosy IDRI Diagnostic (LID)-1 foi desenhada com a intenção de melhorar o diagnóstico de pacien-tes paucibacilares. Posteriormente, este antígeno foi conjugado com o na-tural dissacarídeo ligado ao radical oc-til (ND-O) do PGL-I, originando o NDO--LID, para aumentar sua sensibilidade. Nesta revisão, avaliamos 16 estudos, comparando a performance desses três antígenos (PGL-I, LID-1 e NDO--LID) para diagnóstico da hanseníase e avaliação de contatos domiciliares. Verificamos grande variação quanto às populações envolvidas, tamanho das amostras, classificação clínica dos pacientes e metodologia utilizada, dificultando a comparação. Entre os pacientes multibacilares, a positividade anti-PGL-I variou de 54,0 a 96,0%, en-quanto para LID-1 foi de 47,4 a 94,8% e para NDO-LID apresentou níveis de 60,0 a 98,9%. Nos pacientes paucibacilares, a positividade variou de 6,4 a 52,9% quando PGL-I foi utilizado, 4,0 a 60% contra LID-1 e 16,0 a 63,6% frente ao NDO-LID. Para os contatos domiciliares, as respostas anti-PGL-I, LID-1 e NDO-LID foram 13,2%, 21,7% e 22,9%, respectivamente. O antígeno NDO-LID apresentou maior sensibilidade na maioria dos estudos refletindo seu potencial como ferramenta para o diagnóstico da hanseníase, principalmente em pacientes MB, entretanto, o reconhecimento desse antígeno por contatos domiciliares saudáveis reforça o valor da avaliação clínica para o diagnóstico da hanseníase.(au)

Leprosy affects skin and peripheral nerves bringing several disabilities in absence of specific treatment. So that, effective diagnostic tools are required for early therapeutic interventions. Detection of antibodies against phenolic glycolipid I (PGL-I) is widely employed in the diagnosis and clinical classification while the leprosy IDRI diagnostic (LID-1) protein was designed to improve the diagnosis of paucibacillary patients. More recently, this synthetic antigen was conjugated with the natural octyl disaccharide (ND-O) of PGL-I, originating the NDO-LID in order to increase its sensitivity. Here, we evaluate 16 studies, comparing the performance of these three antigens (PGL-I, LID-1 and NDO-LID) for leprosy diagnosis and evaluation of the household contacts. We verified among the different studies high variation regarding to population involved, sample size, clinical classification of patients and methodology used, making difficult the comparison. Among multibacillary patients, anti-PGL-I positivity ranged from 54.0 to 96.0%, while for LID-1 it was between 47.4 to 94.8% and for NDO-LID presented levels from 60 to 98.9%. In paucibacillary patients, responsiveness ranged from 6.4 to 52.9% when PGL-I was used, 4.0 to 60% against LID-1 and 16.0 to 63.6% if NDO-LID was employed. For household contacts, the responseanti-PGL-I, LID-1 and NDO-LID was13.2%, 21.7% and 22.9%, respectively.NDO-LID antigen showed higher sensitivity in most studies reflecting its potential as tool for leprosy diagnosis, mainly of MB patients, however, the recognition of this antigen by healthy household contact reinforces the value of the clinical evaluation to leprosy diagnosis.(au)

Desempenho de antígenos do Mycobacterium lepra para diagnóstico sorológico da Hanseníase e avaliação de contatos intradomiciliares: revisão de literatura / Performance of mycobacterium leprae antigens for sorological diagnosis of leprosy and evaluation ofintradomicilary contacts: a review of literature

Até o momento não existe um teste padrão ouro para diagnóstico dahanseníase, o qual é feito através de anamnese, exames clínicos e exameslaboratoriais auxiliares. A detecção de anticorpos contra o glicolipídeo fenólico-I(PGL-I) é largamente empregada auxiliando no diagnóstico e classificaçãoclínica enquanto o antígeno leprosy IDRI diagnostic (LID-1) surgiu com apromessa de melhorar o diagnóstico de pacientes paucibacilares.Recentemente esse antígeno foi conjugado com o natural octildissacarídeo doPGL-I, originando NDO-LID com intuito de aumentar a sensibilidade do teste.Nesse estudo foi feita uma revisão bibliográfica compilando os dados de 14estudos, comparando o desempenho desses antígenos no diagnóstico dahanseníase e avaliação dos contatos intradomiciliares. Os dados revelaram altavariação quanto à população, número amostral, classificação clínica emetodologia, dificultando a comparação. Entre pacientes multibacilares apositividade ao PGL-I variou entre 56 e 96%, enquanto para LID-1 esteve entre47.4 e 94.8% e para NDO-LID mostrou-se entre 60 a 98.9%. Nos pacientespaucibacilares a responsividade oscilou de 6.4 a 45.5% quando usado o PGL-I,3.7 a 60% frente ao LID-1 e 14.8 a 63.6% se empregado o NDO-LID. Para oscontatos intradomiciliares, a positividade geral do PGL-I, LID-1 e NDO-LIDforam 9.8%, 28.1% e 22.7% respectivamente. O NDO-LID apresentou maiorsensibilidade na maioria dos estudos, embora uma análise geral demonstreníveis semelhantes entre os três antígenos, refletindo a dificuldade em se teruma ferramenta sorológica para a identificação da hanseníase, principalmentenos paucibacilares e para predição do risco de adoecimento em contatos

There is no gold standard test for leprosy diagnosis, that is done by anamnesis,clinical evaluation and complementary laboratory tests. Detection of antibodiesagainst phenolic glycolipid I (PGL-I) is widely employed in the diagnosis andclinical classification while the leprosy antigen diagnostic IDRI (LID-1) arosewith the promise of improving the diagnosis of paucibacillary patients. Recentlyit was conjugated with the natural octyl disaccharide synthetic of PGL-I,originating the NDO-LID in order to increase the sensitivity of the test. Here, weevaluate 14 studies, comparing the performance of these three antigens forleprosy diagnosis and evaluation of the intradomiciliary contacts. The datarevealed high variation regarding population, sample number, clinicalclassification and methodology, making difficult the comparison. Amongmultibacillary patients, PGL-I positivity ranged from 56 to 96%, while for LID-1 itwas between 47.4 to 94.8% and for NDO-LID between 60 and 98.9%. Inpaucibacillary patients, responsiveness ranged from 6.4 to 45.5% when PGL-Iwas used, 3.7 to 60% against LID-1 and 14.8 to 63.6% if NDO-LID was used.For intradomiciliary contacts, the overall positivity of PGL-I, LID-1 and NDO-LIDwere 9.8%, 28.1% and 22.7%, respectively. The NDO-LID showed highersensitivity in most studies, although a general analysis showed similar levels ofresponse among the three antigens, reflecting the difficulty to develop aserological tool for leprosy diagnosis, mainly in paucibacillary patients, and forpredicting the risk of illness in leprosy contacts

The GATA3 gene is involved in leprosy susceptibitity in Brazilian patients

Leprosy outcome is a complex trait and the host-pathogen-environment interaction defines the emergence of the disease. Host genetic risk factors have been successfully associated to leprosy. The 10p13 chromosomal region was linked to leprosy in familial studies and GATA3 gene is a strong candidate to be part of this association. Here, we tested tag single nucleotide polymorphisms at GATA3 in two case-control samples from Brazil comprising a total of 1633 individuals using stepwise strategy. The A allele of rs10905284 marker was associated with leprosy resistance. Then, a functional analysis was conducted and showed that individuals carrying AA genotype express higher levels of GATA-3 protein in lymphocytes. So, we confirmed that the rs10905284 is a locus associated to leprosy and influences the levels of this transcription factor in the Brazilian population.

Advances in leprosy immunology and the field application: a gap to bridge

Advances concerning the hosts' immune response to Mycobacterium leprae infection have focused on elucidating the immune pathomechanisms involved, with the hope that predictive diagnostic and prognostic parameters (biomarkers) for field use would emerge; however, improvements in our understanding of the immunologic responses to this complex disease have, to date, somewhat failed to provide the effective and robust methods for improving its predictive diagnosis in the field situation, particularly in those patients suffering from paucibacillary disease. In this contribution we have attempted to review some of the advances both in the immunology and immunopathology of leprosy, and also highlight the limited clusters of immune parameters that are now available. Most importantly, we point out the limitations that still prevail in the provision of effective biomarkers in the field situation for either: (1) the diagnosis of indeterminate disease, (2) predictive diagnosis of individuals developing reactional states, (3) monitoring efficacy of treatment, or (4) monitoring treatment of reactional states.

Activation and cytokine profile of monocyte derived dendritic cells in leprosy: in vitro stimulation by sonicated Mycobacterium leprae induces decreased level of IL-12p70 in lepromatous leprosy

Dendritic cells (DCs) play a pivotal role in the connection of innate and adaptive immunity of hosts to mycobacterial infection. Studies on the interaction of monocyte-derived DCs (MO-DCs) using Mycobacterium leprae in leprosy patients are rare. The present study demonstrated that the differentiation of MOs to DCs was similar in all forms of leprosy compared to normal healthy individuals. In vitro stimulation of immature MO-DCs with sonicated M. leprae induced variable degrees of DC maturation as determined by the increased expression of HLA-DR, CD40, CD80 and CD86, but not CD83, in all studied groups. The production of different cytokines by the MO-DCs appeared similar in all of the studied groups under similar conditions. However, the production of interleukin (IL)-12p70 by MO-DCs from lepromatous (LL) leprosy patients after in vitro stimulation with M. lepraewas lower than tuberculoid leprosy patients and healthy individuals, even after CD40 ligation with CD40 ligand-transfected cells. The present cumulative findings suggest that the MO-DCs of LL patients are generally a weak producer of IL-12p70 despite the moderate activating properties ofM. leprae. These results may explain the poor M. leprae-specific cell-mediated immunity in the LL type of leprosy.

Activation and cytokine profile of monocyte derived dendritic cells in leprosy: in vitro stimulation by sonicated Mycobacterium leprae induces decreased level of IL-12p70 in lepromatous leprosy.

Dendritic cells (DCs) play a pivotal role in the connection of innate and adaptive immunity of hosts to mycobacterial infection. Studies on the interaction of monocyte-derived DCs (MO-DCs) using Mycobacterium leprae in leprosy patients are rare. The present study demonstrated that the differentiation of MOs to DCs was similar in all forms of leprosy compared to normal healthy individuals. In vitro stimulation of immature MO-DCs with sonicated M. leprae induced variable degrees of DC maturation as determined by the increased expression of HLA-DR, CD40, CD80 and CD86, but not CD83, in all studied groups. The production of different cytokines by the MO-DCs appeared similar in all of the studied groups under similar conditions. However, the production of interleukin (IL)-12p70 by MO-DCs from lepromatous (LL) leprosy patients after in vitro stimulation with M. leprae was lower than tuberculoid leprosy patients and healthy individuals, even after CD40 ligation with CD40 ligand-transfected cells. The present cumulative findings suggest that the MO-DCs of LL patients are generally a weak producer of IL-12p70 despite the moderate activating properties ofM. leprae. These results may explain the poor M. leprae-specific cell-mediated immunity in the LL type of leprosy.

Activation and cytokine profile of monocyte derived dendritic cells in leprosy: in vitro stimulation by sonicated Mycobacterium leprae induces decreased level of IL-12p70 in lepromatous leprosy

Dendritic cells (DCs) play a pivotal role in the connection of innate and adaptive immunity of hosts to mycobacterial infection. Studies on the interaction of monocyte-derived DCs (MO-DCs) using Mycobacterium leprae in leprosy patients are rare. The present study demonstrated that the differentiation of MOs to DCs was similar in all forms of leprosy compared to normal healthy individuals. In vitro stimulation of immature MO-DCs with sonicated M. leprae induced variable degrees of DC maturation as determined by the increased expression of HLA-DR, CD40, CD80 and CD86, but not CD83, in all studied groups. The production of different cytokines by the MO-DCs appeared similar in all of the studied groups under similar conditions. However, the production of interleukin (IL)-12p70 by MO-DCs from lepromatous (LL) leprosy patients after in vitro stimulation with M. leprae was lower than tuberculoid leprosy patients and healthy individuals, even after CD40 ligation with CD40 ligand-transfected cells. The present cumulative findings suggest that the MO-DCs of LL patients are generally a weak producer of IL-12p70 despite the moderate activating properties of M. leprae. These results may explain the poor M. leprae-specific cell-mediated immunity in the LL type of leprosy

Toll-like receptor 1 N248S single-nucleotide polymorphism is associated with leprosy risk and regulates immune activation during mycobacterial infection

Conflicting findings about the association between leprosy and TLR1 variants N248S and I602S have been reported. Here, we performed case-control and family based studies, followed by replication in 2 case-control populations from Brazil, involving 3162 individuals. Results indicated an association between TLR1 248S and leprosy in the case-control study (SS genotype odds ratio [OR], 1.81; P = .004) and the family based study (z = 2.02; P = .05). This association was consistently replicated in other populations (combined OR, 1.51; P < .001), corroborating the finding that 248S is a susceptibility factor for leprosy. Additionally, we demonstrated that peripheral blood mononuclear cells (PBMCs) carrying 248S produce a lower tumor necrosis factor/interleukin-10 ratio when stimulated with Mycobacterium leprae but not with lipopolysaccharide or PAM3cysK4. The same effect was observed after infection of PBMCs with the Moreau strain of bacillus Calmette-Guerin but not after infection with other strains. Finally, molecular dynamics simulations indicated that the Toll-like receptor 1 structure containing 248S amino acid is different from the structure containing 248N. Our results suggest that TLR1 248S is associated with an increased risk for leprosy, consistent with its hypoimmune regulatory function.