Search

Background: Erythema nodosum leprosum (ENL) is a frequent complication of multibacillary leprosy that can result in significant morbidity, including peripheral nerve damage and physical disability. The identification of possible serum markers could be a valuable tool for the early detection of ENL. Aims: The purpose of this study was to evaluate selected serum mediators involved in the innate and adaptive immune responses to identify possible immunomarkers for ENL. Methods: The levels of interleukin-2, interleukin-4, interleukin-6, interleukin-10, interleukin-17, interferon-γ, tumor necrosis factor, nitric oxide and anti-phenolic glycolipid-I antibodies were measured in the sera of leprosy patients with ENL [at the beginning of reaction (M0) and 1 month later (M1)], and then compared with the levels of the same markers in patients with untreated multibacillary leprosy without ENL (controls with leprosy: CTRL) and healthy individuals (healthy controls: CTRH). Results: Significantly higher levels of serum interleukin-6 were observed in M0 than in CTRL. In addition, pairwise comparisons showed higher levels of interleukin-6 in M0 compared to M1. Levels of tumor necrosis factor were higher in M0 than in CTRL, with no significant difference between M0 and M1. There were no differences in the levels of interleukin-2, interleukin-4, interleukin-10, interleukin-17 or interferon-γ between groups. The CTRL group had higher levels of nitric oxide compared to M0 and M1. High levels of anti-phenolic glycolipid-I were observed in M0, M1 and CTRL than in CTRH. Limitations: Three patients were not assessed at M1, decreasing the number of evaluated patients from 14 to 11. Conclusion: High-serum levels of interleukin-6 were observed during ENL, primarily in patients with more severe reactions; levels decreased after specific therapy, suggesting a role for this cytokine in pathogenesis and its utility as an ENL biomarker. Further studies should explore whether interleukin-6 could also be used as a predictive marker for ENL or as a specific target for its treatment.

Made available in DSpace on 2021-06-25T10:15:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 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. Lauro de Souza Lima Institute São Paulo State University (UNESP) Medical School Graduate Program in Health Sciences School of Medicine Pontifícia Universidade Católica do Paraná Leprosy Laboratory Oswaldo Cruz Institute-Fiocruz Laboratory of Immunogenetics Department of Basic Health Sciences Maringá State University (UEM) São Paulo State University (UNESP) Medical School

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 Krox‐20, Sox‐10, c‐Jun and p75NTR in SC culture and mice sciatic nerves, both infected by ML Thai‐53 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 (NU ‐Foxn1 (nu)) infected with ML were evaluated after 6 and 9 months. In vitro results demonstrate downregulation of Krox‐20 and Sox‐10 along with the increase in p75NTR‐immunolabelled cells. Concurrently, sciatic nerves of infected mice showed a significant decrease in Krox‐20 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 non‐myelinating phenotype in SCs, with possible implications for the repair of adult peripheral nerves.

Leprosy remains a health problem in several countries. Current management of patients with leprosy is complex and requires multidrug therapy. Nonetheless, antibiotic treatment is insufficient to prevent nerve disabilities and control Mycobacterium leprae. Successful infectious disease treatment demands an understanding of the host immune response against a pathogen. Immune-based therapy is an effective treatment option for malignancies and infectious diseases. A promising therapeutic approach to improve the clinical outcome of malignancies is the blockade of immune checkpoints. Immune checkpoints refer to a wide range of inhibitory or regulatory pathways that are critical for maintaining self-tolerance and modulating the immune response. Programmed cell-death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), cytotoxic T-lymphocyte-associated protein 4, and lymphocyte-activation gene-3 are the most important immune checkpoint molecules. Several pathogens, including M. leprae, are supposed to utilize these mechanisms to evade the host immune response. Regulatory T cells and expression of co-inhibitory molecules on lymphocytes induce specific T-cell anergy/exhaustion, leading to disseminated and progressive disease. From this perspective, we outline how the co-inhibitory molecules PD-1, PD-L1, and Th1/Th17 versus Th2/Treg cells are balanced, how antigen-presenting cell maturation acts at different levels to inhibit T cells and modulate the development of leprosy, and how new interventions interfere with leprosy development.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:48:39Z No. of bitstreams: 1 S0004-282X2012000400012.pdf: 6275055 bytes, checksum: f1da7c7bf148b57ff37227a29524c38c (MD5) Made available in DSpace on 2013-08-22T18:48:39Z (GMT). No. of bitstreams: 1 S0004-282X2012000400012.pdf: 6275055 bytes, checksum: f1da7c7bf148b57ff37227a29524c38c (MD5) Previous issue date: 2012-04-01 Made available in DSpace on 2013-09-30T19:38:39Z (GMT). No. of bitstreams: 2 S0004-282X2012000400012.pdf: 6275055 bytes, checksum: f1da7c7bf148b57ff37227a29524c38c (MD5) S0004-282X2012000400012.pdf.txt: 26569 bytes, checksum: 112a6cf6f0c5a005293149edcd7f43de (MD5) Previous issue date: 2012-04-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:10:22Z No. of bitstreams: 2 S0004-282X2012000400012.pdf: 6275055 bytes, checksum: f1da7c7bf148b57ff37227a29524c38c (MD5) S0004-282X2012000400012.pdf.txt: 26569 bytes, checksum: 112a6cf6f0c5a005293149edcd7f43de (MD5) Made available in DSpace on 2014-05-20T15:10:22Z (GMT). No. of bitstreams: 2 S0004-282X2012000400012.pdf: 6275055 bytes, checksum: f1da7c7bf148b57ff37227a29524c38c (MD5) S0004-282X2012000400012.pdf.txt: 26569 bytes, checksum: 112a6cf6f0c5a005293149edcd7f43de (MD5) Previous issue date: 2012-04-01 Neurotrofinas são fatores de crescimento com papel fundamental na fisiopatologia neural. Esses mediadores modulam funcionalmente fibras nociceptivas. Mudanças em sua expressão têm sido relacionadas à perda precoce da nocicepção na hanseníase. Este estudo investigou a expressão de NGF, BDNF e NT3 em nervos dérmicos de pacientes hansenianos. A caracterização de fibras nervosas não mielinizadas foi feita por p75NTR e marcadores axonais NF-L e PGP 9.5. Os parâmetros clínicos de dano neural foram avaliados por monofilamentos Semmes-Wenstein. Nossos achados demonstram diminuição de NGF nos pacientes dimorfos em comparação aos controles. Resultados similares foram observados para PGP 9.5 (dimorfos: p

Leprosy is a complex infectious disease influenced by genetic and environmental factors. The genetic contributing factors are considered heterogeneous and several genes have been consistently associated with susceptibility like PARK2, tumor necrosis factor (TNF), lymphotoxin-alpha (LTA) and vitamin-D receptor (VDR). Here, we combined a case-control study (374 patients and 380 controls), with meta-analysis (5 studies; 2702 individuals) and biological study to test the epidemiological and physiological relevance of the interleukin-10 (IL-10) genetic markers in leprosy. We observed that the -819T allele is associated with leprosy susceptibility either in the case-control or in the meta-analysis studies. Haplotypes combining promoter single-nucleotide polymorphisms also implicated a haplotype carrying the -819T allele in leprosy susceptibility (odds ratio (OR)=1.40; P=0.01). Finally, we tested IL-10 production in peripheral blood mononuclear cells stimulated with Mycobacterium leprae antigens and found that -819T carriers produced lower levels of IL-10 when compared with non-carriers. Taken together, these data suggest that low levels of IL-10 during the disease outcome can drive patients to a chronic and unprotective response that culminates with leprosy.

Submitted by Priscila Medeiros (pribio0912@gmail.com) on 2022-04-08T19:06:47Z No. of bitstreams: 1 j.meegid.2016.01.015.pdf: 726803 bytes, checksum: e916615e7bde4e864ce9b94fe1bfaf37 (MD5) Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2022-04-19T12:50:24Z (GMT) No. of bitstreams: 1 medeiros_p_posprint_bot_thegata.pdf: 726803 bytes, checksum: e916615e7bde4e864ce9b94fe1bfaf37 (MD5) Made available in DSpace on 2022-04-19T12:50:24Z (GMT). No. of bitstreams: 1 medeiros_p_posprint_bot_thegata.pdf: 726803 bytes, checksum: e916615e7bde4e864ce9b94fe1bfaf37 (MD5) Previous issue date: 2016-04 Outra Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 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. Versão final do editor Instituto Lauro de Souza Lima Faculdade de Medicina de Botucatu - FMB FAPESP: 2009/16873-8 FAPESP: 576051/2008-0 FAPESP: 2014/04143-3

Made available in DSpace on 2018-11-26T16:16:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-01. Added 1 bitstream(s) on 2019-10-09T18:25:36Z : No. of bitstreams: 1 S0074-02762015000500655.pdf: 1108367 bytes, checksum: 138ebf10244ef2d71fb00581b96ff2c9 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) AMC-UvA 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. Univ Estadual Paulista, Fac Med Botucatu, Programa Posgrad Doencas Trop, Botucatu, SP, Brazil Univ Santo Amaro, Sao Paulo, SP, Brazil Fac Anhanguera Bauru, Bauru, SP, Brazil Inst Lauro Souza Lima, Equipe Tecn Imunol, Bauru, SP, Brazil Univ Sao Paulo, Fac Odontol Bauru, Dept Microbiol & Imunol, Bauru, SP, Brazil Univ Amsterdam, Acad Med Ctr, Dept Pathol, NL-1105 AZ Amsterdam, North Holland, Netherlands Univ Birmingham, Sch Immun & Infect, Birmingham, W Midlands, England Univ Estadual Paulista, Fac Med Botucatu, Programa Posgrad Doencas Trop, Botucatu, SP, Brazil FAPESP: 2009/01436-1

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.

The immunosuppression observed in systemic mycosis can be related to primary lymphoid organs damage. Thus, our laboratory has studied the effects of the Paracoccidioides brasiliensis infection on the thymus of mice. Here, thymuses of susceptible and resistant mice were evaluated after inoculation with highly and slightly virulent isolates of the fungus. All groups presented thymic atrophy, loss of corticomedullary delimitation and increase of apoptotic index. However, mice inoculated with high virulent strain showed earlier and stronger alterations suggesting that thymic atrophy can be directly related to the fungal virulence and to the immunosuppression.A imunossupressão observada em micoses sistêmicas pode estar relacionada a danos nos órgãos linfóides primários. Assim, nosso laboratório tem estudado uma possível ação do Paracoccidioides brasiliensis sobre o timo de camundongos. Neste estudo, analisamos o timo de camundongos susceptíveis e resistentes ao fungo utilizando cepas de alta e baixa virulência. Todos os grupos apresentaram atrofia tímica, perda de delimitação corticomedular e aumento da taxa de apoptose. Entretanto, as alterações foram mais precoces e pronunciadas em camundongos inoculados com a cepa virulenta do fungo, sugerindo que a virulência fúngica pode estar diretamente ligada à atrofia tímica e indução de imunossupressão.

Iron is essential for all organisms and its availability can control the growth of microorganisms; therefore, we examined the role of iron metabolism in multibacillary (MB) leprosy, focusing on the involvement of hepcidin. Erythrograms, iron metabolism parameters, pro-inflammatory cytokines and urinary hepcidin levels were evaluated in patients with MB and matched control subjects. Hepcidin expression in MB lesions was evaluated by quantitative polymerase chain reaction. The expression of ferroportin and hepcidin was evaluated by immunofluorescence in paucibacillary and MB lesions. Analysis of hepcidin protein levels in urine and of hepcidin mRNA and protein levels in leprosy lesions and skin biopsies from healthy control subjects showed elevated hepcidin levels in MB patients. Decreases in haematologic parameters and total iron binding capacity were observed in patients with MB leprosy. Moreover, interleukin-1 beta, ferritin, soluble transferrin receptor and soluble transferrin receptor/log ferritin index values were increased in leprosy patients. Hepcidin was elevated in lepromatous lesions, whereas ferroportin was more abundant in tuberculoid lesions. In addition, hepcidin and ferroportin were not colocalised in the biopsies from leprosy lesions. Anaemia was not commonly observed in patients with MB; however, the observed changes in haematologic parameters indicating altered iron metabolism appeared to result from a mixture of anaemia of inflammation and iron deficiency. Thus, iron sequestration inside host cells might play a role in leprosy by providing an optimal environment for the bacillus.

Leprosy is an infectious disease caused by Mycobacterium leprae. Tumor necrosis factor (TNF) plays a key role in the host response. Some association studies have implicated the single nucleotide polymorphism TNF -308G>A in leprosy susceptibility, but these results are still controversial. We first conducted 4 association studies (2639 individuals) that showed a protective effect of the -308A allele (odds ratio [OR] = 0.77; P = .005). Next, results of a meta-analysis reinforced this association after inclusion of our new data (OR = 0.74; P = .04). Furthermore, a subgroup analysis including only Brazilian studies suggested that the association is specific to this population (OR = 0.63; P = .005). Finally, functional analyses using whole blood cultures showed that patients carrying the -308A allele produced higher TNF levels after lipopolysaccharide (LPS) (6 hours) and M. leprae (3 hours) stimulation. These results reinforce the association between TNF and leprosy and suggest the -308A allele as a marker of disease resistance, especially among Brazilians.

Apoptosis eliminates pathogen-infected cells. Its modulation can influence the course of infections, permitting the survival of intracellular pathogens. In leprosy, which presents several clinical manifestations related to bacillary burden and host immune status, the mechanisms responsible for the persistence of the bacillus are unknown. Few studies have focused on apoptosis over the disease spectrum and as a defense mechanism against Mycobacterium leprae. We evaluated apoptosis using terminal transferase dUTP nick end labeling and the expression of Bcl-2 by immunohistochemistry in skin lesions from 11 tuberculoid and 15 lepromatous leprosy patients. Each specimen was evaluated by determining the number of positive cells in 10 fields at × 400 magnification. We observed a higher number of apoptotic cells in tuberculoid lesions in comparison with lepromatous leprosy (42.5 cells per 10 fields vs. 11.5 cells per 10 fields, P

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, a low virulence mycobacterium, and the outcome of disease is dependent on the host genetics for either susceptibility per se or severity. The IFNG gene codes for interferon-γ (IFN-γ), a cytokine that plays a key role in host defense against intracellular pathogens. Indeed, single nucleotide polymorphisms (SNPs) in IFNG have been evaluated in several genetic epidemiological studies, and the SNP +874T>A, the +874T allele, more specifically, has been associated with protection against infectious diseases, especially tuberculosis. Here, we evaluated the association of the IFNG locus with leprosy enrolling 2,125 Brazilian subjects. First, we conducted a case–control study with subjects recruited from the state of Sao Paulo, using the +874 T>A (rs2430561), +2109 A>G (rs1861494) and rs2069727 SNPs. Then, a second study including 1,370 individuals from Rio de Janeiro was conducted. Results of the case–control studies have shown a protective effect for +874T carriers (ORadjusted = 0.75; p = 0.005 for both studies combined), which was corroborated when these studies were compared with literature data. No association was found between the SNP +874T>A and the quantitative Mitsuda response. Nevertheless, the spontaneous IFN-γ release by peripheral blood mononuclear cells was higher among +874T carriers. The results shown here along with a previously reported meta-analysis of tuberculosis studies indicate that the SNP +874T>A plays a role in resistance to mycobacterial diseases.

The effect of HeNe laser on the extracellular matrix deposition, chemokine expression and angiogenesis in experimental paracoccidioidomycotic lesions was investigated. At days 7, 8 and 9 postinfection the wound of each animal was treated with a 632.8 nm HeNe laser at a dose of 3 J cm(-2). At day 10 postinfection, the wounds were examined by using histologic and immunohistochemical methods. Results revealed that laser-treated lesions were lesser extensive than untreated ones, and composed mainly by macrophages and lymphocytes. High IL-1beta expression was shown in the untreated group whereas in laser-treated animals the expression was scarce. On the other hand, the expression of CXCL-10 was found to be reduced in untreated animals and quite intensive and well distributed in the laser-treated ones. Also, untreated lesions presented vascular endothelial growth factor (VEGF) in a small area near the center of the lesion and high immunoreactivity for hypoxia-inducible factor-1 (HIF-1), whereas laser-treated lesions expressed VEGF surrounding blood vessels and little immunoreactivity for HIF-1. Laser-treated lesions presented much more reticular fibers and collagen deposition when compared with the untreated lesion. Our results show that laser was efficient in minimizing the local effects observed in paracoccidioidomycosis and can be an efficient tool in the treatment of this infection, accelerating the healing process.

The immunosuppression observed in systemic mycosis can be related to primary lymphoid organs damage. Thus, our laboratory has studied the effects of the Paracoccidioides brasiliensis infection on the thymus of mice. Here, thymuses of susceptible and resistant mice were evaluated after inoculation with highly and slightly virulent isolates of the fungus. All groups presented thymic atrophy, loss of corticomedullary delimitation and increase of apoptotic index. However, mice inoculated with high virulent strain showed earlier and stronger alterations suggesting that thymic atrophy can be directly related to the fungal virulence and to the immunosuppression. A imunossupressão observada em micoses sistêmicas pode estar relacionada a danos nos órgãos linfóides primários. Assim, nosso laboratório tem estudado uma possível ação do Paracoccidioides brasiliensis sobre o timo de camundongos. Neste estudo, analisamos o timo de camundongos susceptíveis e resistentes ao fungo utilizando cepas de alta e baixa virulência. Todos os grupos apresentaram atrofia tímica, perda de delimitação corticomedular e aumento da taxa de apoptose. Entretanto, as alterações foram mais precoces e pronunciadas em camundongos inoculados com a cepa virulenta do fungo, sugerindo que a virulência fúngica pode estar diretamente ligada à atrofia tímica e indução de imunossupressão.

Literature has shown that immunosuppression observed in systemic mycosis can be related to damage in primary lymphoid organs. We have studied the immunopathological alterations induced experimentally by Paracoccidioides brasiliensis in these organs. In this work, thymic alterations induced in BALB/c mice during acute and chronic stages of infection are described. It was observed that P. brasiliensis is able to invade the thymic microenvironment, inducing severe atrophy characterized by degeneration of the cortical area, organ weight decrease, loss of corticomedullary delimitation and increase in histiocyte number. Occurrence of polymorphonuclear infiltration in the subcapsular area was also observed. Our results demonstrate that P. brasiliensis induces profound thymic atrophy and raises the question of whether this could be a fungal strategy to achieve successful establishment in the host over the long term.

Orientador: Liana Maria Cardoso Verinaud Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia Resumo: O Resumo poderá ser visualizado no texto completo da tese digital Abstract: The Abstract is available with the full electronic digital document Mestrado Imunologia Mestra em Genética e Biologia Molecular CAPES FAPESP CNPQ

Submitted by Mariane Bertolucci Casalenovo null (mary_bc14@hotmail.com) on 2017-09-14T00:20:08Z No. of bitstreams: 1 DISSERTAÇÃO FINAL.pdf: 10749096 bytes, checksum: 4412c078d6e18d64f519d7ac0952d26d (MD5) Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-09-15T13:49:22Z (GMT) No. of bitstreams: 1 casalenovo_mb_me_bot.pdf: 10749096 bytes, checksum: 4412c078d6e18d64f519d7ac0952d26d (MD5) Made available in DSpace on 2017-09-15T13:49:22Z (GMT). No. of bitstreams: 1 casalenovo_mb_me_bot.pdf: 10749096 bytes, checksum: 4412c078d6e18d64f519d7ac0952d26d (MD5) Previous issue date: 2017-08-03 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A infecção por Mycobacterium leprae (M. leprae) desencadeia alterações no status funcional das células de Schwann (SCs), responsáveis pela produção da bainha de mielina e homeostasia neural. Estudos prévios indicam que lesões nos nervos periféricos modulam a expressão de fatores-chave envolvidos na diferenciação e maturação das SCs. Na hanseníase, alterações funcionais nessas células podem estar envolvidas na patogênese do dano neural. O presente estudo buscou determinar a expressão dos fatores de transcrição KROX-20, SOX-10, JUN e do receptor p75NTR, envolvidos nos processos de diferenciação e maturação de SCs. Os dados foram obtidos a partir de cultura primária de SCs murinas expostas ao M. leprae durante sete e 14 dias, com diferentes multiplicidades de infecção (MOI 100:1, MOI 50:1). Os mesmos fatores foram avaliados in vivo, em nervos ciáticos de camundongos nude (NUFoxn1nu), após seis e nove meses de infecção. Comparando-se grupos experimentais em relação aos controles, nossos resultados em cultura de SCs demonstram redução significativa de KROX-20 e SOX-10, bem como elevação na frequência de células imunomarcadas por p75NTR. Paralelamente, nervos ciáticos de camundongos nude infectados por M. leprae apresentaram queda de KROX-20 e aumento de p75NTR, quando comparados aos animais não infectados. Em conjunto, nossos resultados corroboram achados prévios sobre a interferência de M. leprae na expressão de fatores-chave envolvidos na maturação celular, favorecendo a manutenção de fenótipo não mielinizante nas SCs, com possíveis implicações na reparação de nervos periféricos adultos. Mycobacterium leprae infection (M. leprae) triggers changes in the functional status of Schwann cells (SCs), which are responsible for the production of myelin sheath and neural homeostasis. Previous studies indicate that peripheral nerve injury modulates the expression of key factors involved in the differentiation and maturation of SCs. In leprosy, functional changes in these cells may be involved in the pathogenesis of neural damage. The present study sought to determine the expression of the transcription factors KROX-20, SOX-10, JUN and the neurotrophic receptor p75NTR, involved in the differentiation and maturation processes of SCs. Data were obtained from primary murine SCs culture exposed to M. leprae for seven and 14 days, with different multiplicities of infection (MOI 100:1, MOI 50:1). The same factors were evaluated in vivo on sciatic nerve of nude mice (NU-Foxn1nu), after six and nine months of infection. By comparing experimental groups versus controls, our SC culture results demonstrate significant reduction of KROX-20 and SOX-10, as well as elevation in the frequency of cells immunolabelled by p75NTR. In parallel, sciatic nerves of nude mice infected with M. leprae showed a decrease in KROX-20 and an increase of p75NTR when compared to uninfected animals. Our results corroborate previous findings on M. leprae interference in the expression of key factors involved in cell maturation, favoring the maintenance of a non-myelinating phenotype in SCs, with possible implications for the repair of adult peripheral nerves.

Submitted by Giovanna Valle Germano null (giovannagermano@hotmail.com) on 2017-08-22T19:29:55Z No. of bitstreams: 1 Dissertação versão permanente.pdf: 1257043 bytes, checksum: ed6cb7dcdfd7b4069bf40cae205d3396 (MD5) Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-08-23T18:43:19Z (GMT) No. of bitstreams: 1 germano_gv_me_bot.pdf: 1257043 bytes, checksum: ed6cb7dcdfd7b4069bf40cae205d3396 (MD5) Made available in DSpace on 2017-08-23T18:43:19Z (GMT). No. of bitstreams: 1 germano_gv_me_bot.pdf: 1257043 bytes, checksum: ed6cb7dcdfd7b4069bf40cae205d3396 (MD5) Previous issue date: 2017-07-28 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) A hanseníase, causada pelo Mycobacterium leprae, ainda é considerada um relevante problema de saúde pública no Brasil, afetando o sistema nervoso periférico o que pode resultar em incapacidades físicas. É considerada uma doença complexa e durante a interação patógeno-hospedeiro o background genético do hospedeiro pode determinar o curso da doença que se apresenta de modo espectral abrangendo desde lesões localizadas até a doença disseminada com elevado índice bacilar. Neste estudo, avaliamos na população brasileira a associação com hanseníase do SNP -336A/G (rs4804803) no gene CD209, responsável por codificar o receptor DC-SIGN que está presente na superfície das células dendríticas e que participa do reconhecimento do M. leprae. A população de estudo incluiu 835 indivíduos do município de Rondonópolis-MT (424 controles e 411 casos). O genótipo GG deste SNP foi associado com a forma multibacilar da hanseníase (OR 4.52; IC 1.01-20.09; p=0.0472) e o alelo A foi associado com a proteção contra a forma multibacilar (OR 0.22; IC 0.05-0.98; p=0.0478). Realizamos estudos funcionais empregando células dendríticas estimuladas com antígenos do bacilo e verificamos que os carreadores do alelo G expressaram níveis menores dos receptores DC-SIGN e CD80 e secretaram menos TNF e mais TGF-β1 frente a antígenos do bacilo. Em conjunto, esses dados sugerem menor eficiência dos portadores do alelo G em ativar a resposta imune eficaz contra o M. leprae. Leprosy, caused by Mycobacterium leprae, is still considered a relevant public health problem in Brazil, affecting the peripheral nervous system which can result in physical disabilities. It is considered a complex disease and during pathogenhost interaction the genetic background of the host determine the course of the disease that presents in a spectral range from localized lesions to the disseminated disease with high bacillary index. In this study, we evaluated in the Brazilian population the association with leprosy of -336A/G (rs4804803) SNP in the CD209 gene. This gene encodes DC-SIGN receptor, that is present on the surface of dendritic cells and participates in the recognition of M. leprae. The study population included 835 individuals (424 controls and 411 cases). The GG genotype of this SNP was associated with the multibacillary form of leprosy (OR 4.52, CI 1.01-20.09, p = 0.0472) and the A allele was associated with protection against multibacillary form (OR 0.22, IC 0.05-0.98, p = 0.0478). We performed functional studies using dendritic cells stimulated with bacillus antigens and found that carriers of the G allele expressed lower levels of DC-SIGN and CD80 receptors and secreted less TNF and more TGF-β1 against bacilli antigens. Together, these data suggest a lower efficiency of the G allele carriers in activating the effective immune response against M. leprae.

Orientador: Liana Maria Cardoso Verinaud Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia Resumo: O timo é o órgão linfoide primário responsável pela maturação e desenvolvimento dos linfócitos T, e para exercer tal função seu microambiente necessita estar preservado. Apesar de sua importância, o timo sofre involução tanto em condições fisiológicas, como no envelhecimento, quanto em condições patológicas, como durante infecções. Estudos de nosso laboratório têm demonstrado que a infecção experimental por Paracoccidioides brasiliensis, o agente causal da micose sistêmica de maior prevalência na América do Sul e Central ¿ a paracoccidiodomicose, induz atrofia tímica. Neste estudo investigamos a participação dos mecanismos de morte celular e das vias inflamatórias na involução tímica em camundongos experimentalmente infectados com P. Brasiliensis. Observamos acentuada perda celular nos timos desses animais, tanto nas subpopulações de células epiteliais tímicas quantos nas subpopulações de timócitos. Tal perda celular resulta do aumento nas taxas de apoptose dessas células. A participação de mediadores de inflamação intratímica foi observada nesse processo, com aumento da produção de citocinas pró-inflamatórias, destacando-se IL-1? na fase precoce da infeção e IFN-? e TNF-? na fase tardia. Além disso, observamos a ativação intratímica do inflamassoma NLRP3, complexo macromolecular envolvido na ativação de caspases inflamatórias. Coletivamente, nossos resultados mostram que o patógeno se mantém viável e se multiplica no microambiente tímico, causando desequilíbrio molecular que afeta as células presentes no estroma, tais alterações comprometem a função tímica com saída prematura de linfócitos na fase precoce e queda na exportação de tais células na fase tardia. Acreditamos que tais resultados podem contribuir para o entendimento da imunossupressão periférica observada na clínica da paracoccidioidomicose Abstract: The thymus is a primary lymphoid organ responsible for the maturation and development of T lymphocytes, to do this the thymic microenvironment needs to be preserved. Despite its importance, thymic involution occurs both in physiological conditions, as in aging, and in pathological conditions as seen in infections. Studies from our group have shown that experimental infection with Paracoccidioides brasiliensis, the causal agent of paracoccidioidomycosis, the most prevalent systemic mycosis on South and Central America, induces thymic atrophy. Here we investigated the participation of cell death mechanisms and inflammatory pathways on the thymic involution seen in P. brasiliensis experimentally infected mice. We observed marked cell loss on the thymus of those animals, in both thymic epithelial cells subpopulations and thymocytes subpopulations. This cell loss is due to the increase in apoptosis rates of these cells. The participation of intrathymic inflammatory mediators was observed in this process, with increased production of pro-inflammatory cytokines, highlighting IL-1? at the early stage of infection and IFN-? and TNF-? in the late phase. In addition, we observed intrathymic activation of the inflammasome NLRP3, a macromolecular complex involved in the activation of inflammatory caspases. Collectively, our data show that the pathogen remains viable and is able to multiply in the thymic microenvironment, causing molecular imbalance that affects the cells present in the stroma, such alterations compromises thymic function leading to premature egress at the early stage of infection and reduction of thymic export on the late phase. We believe that these results can contribute to a better understanding of peripheral immunosuppersion observed in clinical paracoccidioidomycosis Doutorado Imunologia Doutor em Genética e Biologia Molecular FAPESP 2012/22131-7 CAPES

A hanseníase é uma doença crônica causada por Mycobacterium leprae e apresenta diversas formas clínicas. O entendimento da interação parasita-hospedeiro na hanseníase evidenciou que ocorre a persistência assintomática do patógeno, caracterizando um estado de latência. Os fatores mais importantes relacionados com a permanência do patógeno são: a patogenicidade do agente infeccioso e o perfil da resposta imune, no qual os eventos de migração celular, produção de citocinas, as células efetoras e reguladoras são extremamente relevantes. As células T reguladoras (Treg) desempenham papel central na regulação da resposta imune em infecções crônicas o que favorece a persistência do patógeno. A importância de células T reguladores na hanseníase ainda é pouco conhecida. Neste trabalho investigou-se a presença de células T reguladoras em lesões e sangue periférico de indivíduos com hanseníase. Inicialmente avaliou-se a proliferação e a produção de citocinas por células mononucleares do sangue periférico (PBMC) de pacientes com hanseníase. Os resultados evidenciaram que não há diferenças quanto à proliferação de células T e produção de IFN-γ e TNF-α por células desses pacientes, mas a produção de IL-4 e IL-5 foi detectada apenas entre os pacientes com hanseníase virchoviana. Em relação à presença de células T reguladoras, os resultados evidenciaram aumento no número de linfócitos T CD4+CD25+FoxP3+ no sangue periférico de pacientes com hanseníase virchoviana. As células T reguladoras dos pacientes com hanseníase apresentaram elevada expressão de moléculas co-inibitórias PD-1, CTLA-4, GITR e ICOS. De modo relevante, as células T CD4+CD25+ isolados de pacientes com hanseníase virchoviana apresentaram maior atividade supressora quando comparado às células isoladas de pacientes com hanseníase tuberculóide. As células T CD4+CD25+ de pacientes com hanseníase virchoviana inibiram a proliferação de PBMC alogênico e a produção de IFN-γ e TNF-α. Os resultados demonstraram também que nas amostras de lesão de pele de pacientes com hanseníase virchoviana há acúmulo de células CD25+ produtoras de IL-10 e TGF-β, enquanto que estas células não foram detectadas nas lesões de pacientes com hanseníase tuberculóide. Dessa forma, os resultados descritos indicam que pacientes com hanseníase virchoviana apresentam aumento no número de células T reguladoras circulantes e no infiltrado inflamatório, e estas células apresentaram maior atividade supressora. O acúmulo de células T reguladoras no sítio da infecção pode ser correlacionado com o controle da resposta imune e conseqüente persistência de M. leprae. Leprosy is caused by Mycobacterium leprae and its clinical features depend on the host immune background. The understanding of parasite-host interactions in leprosy have highlighted asymptomatic persistence of the pathogen, which indicates that this infection becomes latent. The most important factors related to the permanence of pathogens are: the pathogenicity of the infectious agents; the profile of the immune response developed by the host whose events of cellular migration, cytokines production, and the effector and regulatory cells are extremely relevant. The regulatory T cells (Treg) seem to play a central role in the regulation of the immune response in chronic infections, which favors the persistence of the pathogen. Herein, we analyzed the relation between tuberculoid and lepromatous leprosy with the presence and function of T regulatory cells from peripheral blood mononuclear cells (PBMC) and skin lesions from these patients. First, the proliferation and cytokine production of PBMC isolated from leprosy patients were analyzed. We did not observe any difference in the proliferation ability or IFN-γ and TNF-α release; however, the production of IL-4 and IL-5 was detected only in patients with lepromatous leprosy. Furthermore, T CD4+CD25+FoxP3+ cells were detected in the PBMC of patients with leprosy and these cells from lepromatous patients showed high expression of co-inhibitory molecules such as PD-1, GITR, CTLA-4 and ICOS. T CD4+CD25+cells isolated from patients with lepromatous leprosy were significantly more suppressive than the cells obtained from tuberculoid patients. In addition, TCD4+CD25+ cells isolated from patients with lepromatous leprosy inhibited allogeneic PBMC proliferation and their production of IFN-γ and TNF-α. The results also demonstrated that IL- 10 and TGF-ß were co-expressed with CD25+ cells at the inflammatory infiltrate of skin lesions from lepromatous patients, but similar results were not detected among tuberculoid patients. Thus, these results indicate that lepromatous leprosy patients have an enhanced presence of Treg cells with a suppressive ability in the blood and in the inflammatory infiltrate. The accumulation of Treg cells at the infection sites might be associated to the control of immune response and consequently to Mycobacterium leprae presistence.

Made available in DSpace on 2016-07-01T13:10:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-12. Added 1 bitstream(s) on 2016-07-01T13:14:17Z : No. of bitstreams: 1 000866541.pdf: 1198385 bytes, checksum: 265d4dc3d78da2996e89f94af5e66b2d (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação Paulista Contra a Hanseníase hanseníase é uma doença de caráter complexa causada pelo Mycobacterium leprae, que é um patógeno intracelular obrigatório com predileção por macrófagos na pele e células de Schwann nos nervos periféricos. O genoma altamente conservado do bacilo sugere que o patógeno não seja o responsável pela variedade de fenótipos clínicos e biológicos observada na doença, atribuindo grande importância aos fatores genéticos do hospedeiro. Estudos de ligação do tipo genome-wide apontaram um locus de susceptibilidade para a doença na região cromossômica 10p13 e o gene GATA3, localizado na região 10p15, é um forte candidato a fazer parte dessa associação devido à sua localização no genoma e ao seu papel na resposta imune. O GATA-3 é um fator de transcrição clássico na diferenciação de células Th2, no entanto, sabe-se hoje que essa proteína possui outras funções importantes para o sistema imune. Nós empregamos a estratégia de estudo de associação do tipo caso-controle em série, utilizando duas amostras populacionais do Brasil com 1.633 indivíduos, para testar sete variantes genéticas do GATA3. Um estudo funcional também foi conduzido para avaliar o efeito dos polimorfismos associados sobre a expressão de GATA-3 e produção de citocinas. O alelo A do polimorfismo rs10905284 foi associado com resistência para a hanseníase em ambas as amostras. Na análise combinando as duas amostras este efeito do alelo A foi confirmado (OR 0,67; IC95%: 0,54-0,84; p=0,0004). A análise funcional mostrou que os indivíduos portadores do genótipo AA expressam altos níveis da proteína GATA-3 nos linfócitos. Portanto, nós confirmamos que o marcador rs10905284 está associado à hanseníase na população brasileira e influencia os níveis de expressão do fator de transcrição GATA-3 Leprosy outcome is a complex trait and the host-pathogen-environment interaction defines the emergence of the disease. The causative agent of the disease, Mycobacterium leprae, exhibits a conserved genome and could not be accountable for the variety of outcomes observed from exposition, infection and disease. Thus, host genetic risk factors have been successfully associated to leprosy. The 10p13 chromosomal region was linked to leprosy in familial studies and the GATA3 gene is a strong candidate to be part of this association due to its locus and the role that exerts in the immune response. The GATA-3 is a transcription factor involved in the Th2 cell differentiation, however, today it is recognized the ample role of this protein in the immune response. Here, we applied a stepwise strategy to test genetic variants at GATA3 in two case-control samples from Brazil comprising a total of 1,633 individuals. A functional investigation was also conducted to evaluate the effect of the polymorphisms on the GATA-3 protein and the cytokines production. The A allele of rs10905284 marker was associated to leprosy resistance in both samples. In the analysis combining the two samples this effect was reinforced (OR 0,67; CI95%: 0,54-0,84; p=0,0004). The functional analysis 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 in the Brazilian population and influences the levels of this transcription factor.

A hanseníase é uma doença dermato-neurológica complexa que apresenta múltiplas formas clínicas e o diagnóstico diferencial requer expertise clínica. As manifestações clínicas da hanseníase são definidas de acordo com o tipo de resposta imune do paciente, a qual pode ser celular/Th1 na doença paucibacilar (PB) ou humoral/Th2 na doença multibacilar (MB). A multidrogaterapia (MDT) é considerada eficaz, todavia, pouco se sabe sobre seu impacto na resposta imune de pacientes com hanseníase PB e MB. Não existe um teste laboratorial único adequado para o diagnóstico de todas as formas clínicas da hanseníase e que possa contribuir para o diagnóstico diferencial. Este estudo avaliou o impacto da MDT nas respostas imune celular e humoral de pacientes PB e MB recém-diagnosticados, não tratados em dois momentos após a conclusão da MDT utilizando um painel de proteínas recombinantes do M. leprae (rMLs). Ao diagnóstico, pacientes PB produziram IFN para todas as rMLs, pacientes MB produziram baixos níveis de IFN. Cerca de 4-8 meses após o término da MDT observou-se aumento nos níveis de IFN em pacientes PB e MB (p

Made available in DSpace on 2015-01-26T13:21:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-31Bitstream added on 2015-01-26T13:30:39Z : No. of bitstreams: 1 000797469_20150731.pdf: 232290 bytes, checksum: 8b79e45ee61c9f4bcba697b70de0dd8d (MD5) Bitstreams deleted on 2015-08-03T12:21:06Z: 000797469_20150731.pdf,. Added 1 bitstream(s) on 2015-08-03T12:22:20Z : No. of bitstreams: 1 000797469.pdf: 489622 bytes, checksum: 0ef36ba06e14e49b785561d2153aacbb (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Os macrófagos desempenham um papel importante na eliminação do M. Leprae (ML). Estas células participam do reconhecimento de patógenos e ativação do sistema imune, no entanto na hanseníase virchowiana elas se tornam alvos, servindo de habitat para o bacilo, que ali se protege da ação do sistema imune. Assim, este estudo teve por objetivo avaliar a função macrofágica de pacientes com hanseníase virchowiana (LLP) em termos de expressão de marcadores de superfície e produção de mediadores inflamatórios. Além disso, considerando o possível envolvimento dos inflamassomas na resposta dos macrófagos ao ML, foi avaliada a expressão de genes do complexo do inflamassoma. Para tanto, macrófagos diferenciados a partir de monócitos sanguíneos de LLP e indivíduos saudáveis (HC) foram cultivados com ML. A expressão dos marcadores de ativação CD40 e ICAM, e dos receptores do tipo Toll envolvidos no reconhecimento do ML, TLR1 e TLR2, foi avaliada por citometria de fluxo. A produção de citocinas pró (TNF e IL-1β) e anti-inflamatórias (IL-10 e IL-1RA) foi determinada por ELISA e a produção de H2O2 foi avaliada por ensaio colorimétrico. A expressão relativa dos genes NLRP1, NLRP3, NLRC4, CASP1, IL1B e IL18 foi avaliada por PCR em tempo real. ML induziu expressão semelhante de CD40 e ICAM em HC e LLP, assim como dos TLR1 e TLR2. TNF e IL-1β mostraram comportamento diferente, sendo que o ML estimulou uma produção significativa de TNF em HC e LLP, mas não induziu a secreção de IL-1β. H2O2 não foi significativamente induzida pelo ML em LLP. Nenhuma diferença foi encontrada para as citocinas anti-inflamatórias entre HC e LLP. A análise da expressão de genes relacionados aos inflamassomas mostrou que ML é capaz de induzir o gene da IL-1β, mas não dos receptores analisados. Os dados aqui reportados mostrando deficiência na secreção de IL-1β em macrófagos estimulados com ML e a baixa quantidade de H2O2 produzida ... Macrophages play a major role in the elimination of M. leprae (ML). These cells participate in pathogen recognition and activation of the immune system. However in the lepromatous leprosy macrophages become targets, serving as habitat for the bacillus that protects itself from the action of the immune system. This study aimed to evaluate the macrophage function in lepromatous leprosy patients (LLP) in term of surface molecules expression and cytokine and H2O2 production. Moreover, considering the possible involvement of inflammasome complex in macrophage response against ML, inflammasome genes expression was evaluated. ML induced surface expression of activation markers CD40 and ICAM in healthy controls (HC) and LLP macrophages in a similar way, as well as TLRs involved in ML recognition (TLR1 and TLR2). Pro-inflammatory cytokines TNF and IL-1β showed a different behavior. ML was able to induce TNF in HC and LLP, but not IL-1β. Similarly, ML induced significant production of H2O2 in HC but not in LLP macrophages. No difference was found in the production of anti-inflammatory molecules IL-10 and IL1RA in HC and LLP macrophages stimulated with ML. When inflammasome genes expression was analyzed an up-regulation of IL1B gene was observed in both HC and LLP macrophages stimulated with ML. Together, our data indicate that the deficiency in the production of IL-1β and H2O2 in lepromatous leprosy patients combined with IL1B gene expression induction by M. leprae suggested that even if surface recognition of ML and general activation of macrophages are apparently normal, the bacteria is able to inhibits the pathways leading to I IL-1β and H2O2 production, possibly affecting inflammasome activation