RESUMO
American Tegumentary Leishmaniasis (ATL) is a disease of high severity and incidence in Brazil, in addition to being a worldwide concern in public health. Leishmania amazonensis is one of the etiological agents of ATL, and the inefficiency of control measures, associated with the high toxicity of the treatment and the lack of effective immunoprophylactic strategies, makes the development of vaccines indispensable and imminent. In this light, the present study proposes to elaborate a chimeric protein (rChiP), based on the fusion of multiple epitopes of CD4+/CD8+ T cells, identified in the immunoproteome of the parasites L. amazonensis and L. braziliensis. The designed chimeric protein was tested in the L. amazonensis murine model of infection using the following formulations: 25 µg of the rChiP in saline (rChiP group) and 25 µg of the rChiP plus 25 µg of MPLA-PHAD® (rChiP+MPLA group). After completing immunization, CD4+ and CD8+ T cells, stimulated with SLa-Antigen or rChiP, showed an increased production of nitric oxide and intracytoplasmic pro-inflammatory cytokines, in addition to the generation of central and effector memory T cells. rChiP and rChiP+MPLA formulations were able to promote an effective protection against L. amazonensis infection determined by a reduction in the development of skin lesions and lower parasitic burden. Reduction in the development of skin lesions and lower parasitic burden in the vaccinated groups were associated with an increase of nitrite, CD4+/CD8+IFN-γ+TNF-α+ and CD4+/CD8+CD44highCD62Lhigh/low T cells, IgGTotal, IgG2a, and lower rates of IgG1 and CD4+/CD8+IL-10+. This data suggests that proposed formulations could be considered potential tools to prevent ATL.
Assuntos
Adjuvantes Imunológicos , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Epitopos de Linfócito T , Memória Imunológica , Vacinas contra Leishmaniose , Leishmaniose Cutânea , Animais , Leishmaniose Cutânea/prevenção & controle , Leishmaniose Cutânea/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Camundongos , Vacinas contra Leishmaniose/imunologia , Feminino , Adjuvantes Imunológicos/administração & dosagem , Camundongos Endogâmicos BALB C , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/genética , Leishmania braziliensis/imunologia , Lipídeo A/análogos & derivados , Lipídeo A/imunologia , Anticorpos Antiprotozoários/imunologia , Citocinas/metabolismo , Citocinas/imunologia , Modelos Animais de Doenças , Antígenos de Protozoários/imunologiaRESUMO
BACKGROUND: Leishmania braziliensis, a protozoan prevalent in Brazil, is the known causative agent of cutaneous leishmaniasis (CL). The activation of M1 macrophages is a pivotal factor in the host's ability to eliminate the parasite, whereas M2 macrophages may facilitate parasite proliferation. This study analyzed the clinical outcomes of CL and the patients' immunological profiles, focusing on the prevalence of M1 and M2 macrophages, cytokine production, and annexin-A1 (ANXA1) expression in the lesion. METHODS: Data were obtained by polymerase chain reaction (PCR) and histopathological, immunofluorescence, and cytokine analyses. RESULTS: Patients with exudative and cellular reaction-type (ECR)-type lesions that healed within 90 days showed a significant increase in M1. Conversely, patients with ECR and exudative and granulomatous reaction (EGR)types, who healed within 180 days, showed an elevated number of M2. Cytokines interferon (IFN)-γ and tumor necrosis factor (TNF)-α were higher in ECR lesions that resolved within 90 days (P<0.05). In contrast, IL-9 and IL-10 levels significantly increased in both ECR and EGR lesions that healed after 180 days (P<0.001). The production of IL-21, IL-23 and TGF-ß was increased in patients with ECR or EGR lesions that healed after 180 days (P<0.05). The expression of ANXA1 was higher in M2 within ECR-type lesions in patients who healed after 180 days (P<0.05). CONCLUSIONS: These findings suggest that the infectious microenvironment induced by L. braziliensis affects the differentiation of M1 and M2 macrophages, cytokine release, and ANXA1 expression, thereby influencing the healing capacity of patients. Therefore, histopathological and immunological investigations may improve the selection of CL therapy.
Assuntos
Anexina A1 , Citocinas , Leishmania braziliensis , Leishmaniose Cutânea , Macrófagos , Humanos , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Masculino , Leishmania braziliensis/imunologia , Feminino , Adulto , Macrófagos/imunologia , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Adulto Jovem , AdolescenteRESUMO
The parasite Leishmania (Viannia) braziliensis is widely distributed in Brazil and is one of the main species associated with human cases of different forms of tegumentary leishmaniasis (TL) such as cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML). The mechanisms underlying the pathogenesis of TL are still not fully understood, but it is known that factors related to the host and the parasite act in a synergistic and relevant way to direct the response to the infection. In the host, macrophages have a central connection with the parasite and play a fundamental role in the defense of the organism due to their ability to destroy intracellular parasites and present antigens. In the parasite, some intrinsic factors related to the species or even the strain analyzed are fundamental for the outcome of the disease. One of them is the presence of Leishmania RNA Virus 1 (LRV1), an endosymbiont virus that parasitizes some species of Leishmania that triggers a cascade of signals leading to a more severe TL phenotype, such as ML. One of the strategies for understanding factors associated with the immune response generated after Leishmania/host interaction is through the analysis of molecular patterns after infection. Thus, the gene expression profile in human monocyte-derived macrophages obtained from healthy donors infected in vitro with L. braziliensis positive (LbLRV1+) and negative (LbLRV1-) for LRV1 was evaluated. For this, the microarray assay was used and 162 differentially expressed genes were identified in the comparison LbLRV1+ vs. LbLRV1-, 126 upregulated genes for the type I and II interferons (IFN) signaling pathway, oligoadenylate synthase OAS/RNAse L, non-genomic actions of vitamin D3 and RIG-I type receptors, and 36 down-regulated. The top 10 downregulated genes along with the top 10 upregulated genes were considered for analysis. Type I interferon (IFNI)- and OAS-related pathways results were validated by RT-qPCR and Th1/Th2/Th17 cytokines were analyzed by Cytometric Bead Array (CBA) and enzyme-linked immunosorbent assay (ELISA). The microarray results validated by RT-qPCR showed differential expression of genes related to IFNI-mediated pathways with overexpression of different genes in cells infected with LbLRV1+ compared to LbLRV1- and to the control. No significant differences were found in cytokine levels between LbLRV1+ vs. LbLRV1- and control. The data suggest the activation of gene signaling pathways associated with the presence of LRV1 has not yet been reported so far. This study demonstrates, for the first time, the activation of the OAS/RNase L signaling pathway and the non-genomic actions of vitamin D3 when comparing infections with LbLRV1+ versus LbLRV1- and the control. This finding emphasizes the role of LRV1 in directing the host's immune response after infection, underlining the importance of identifying LRV1 in patients with TL to assess disease progression.
Assuntos
Leishmania braziliensis , Leishmaniavirus , Macrófagos , Humanos , Leishmania braziliensis/genética , Leishmania braziliensis/imunologia , Macrófagos/imunologia , Macrófagos/virologia , Leishmaniavirus/genética , Perfilação da Expressão Gênica , Leishmaniose Cutânea/imunologia , Brasil , Simbiose , Citocinas/metabolismo , Citocinas/genética , Transcriptoma , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/parasitologiaAssuntos
Proteínas de Ligação ao GTP/genética , Interferon gama/genética , Leishmania braziliensis/imunologia , Leishmania donovani/imunologia , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Animais , Proteínas de Ligação ao GTP/metabolismo , Humanos , Imunidade Inata/genética , Imunidade Inata/imunologia , Interferon gama/imunologia , Leishmaniose Cutânea/patologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Transcriptoma/genéticaRESUMO
Intracellular phagosomal pathogens represent a formidable challenge for innate immune cells, as, paradoxically, these phagocytic cells can act as both host cells that support pathogen replication and, when properly activated, are the critical cells that mediate pathogen elimination. Infection by parasites of the Leishmania genus provides an excellent model organism to investigate this complex host-pathogen interaction. In this review we focus on the dynamics of Leishmania amazonensis infection and the host innate immune response, including the impact of the adaptive immune response on phagocytic host cell recruitment and activation. L. amazonensis infection represents an important public health problem in South America where, distinct from other Leishmania parasites, it has been associated with all three clinical forms of leishmaniasis in humans: cutaneous, muco-cutaneous and visceral. Experimental observations demonstrate that most experimental mouse strains are susceptible to L. amazonensis infection, including the C57BL/6 mouse, which is resistant to other species such as Leishmania major, Leishmania braziliensis and Leishmania infantum. In general, the CD4+ T helper (Th)1/Th2 paradigm does not sufficiently explain the progressive chronic disease established by L. amazonensis, as strong cell-mediated Th1 immunity, or a lack of Th2 immunity, does not provide protection as would be predicted. Recent findings in which the balance between Th1/Th2 immunity was found to influence permissive host cell availability via recruitment of inflammatory monocytes has also added to the complexity of the Th1/Th2 paradigm. In this review we discuss the roles played by innate cells starting from parasite recognition through to priming of the adaptive immune response. We highlight the relative importance of neutrophils, monocytes, dendritic cells and resident macrophages for the establishment and progressive nature of disease following L. amazonensis infection.
Assuntos
Imunidade Adaptativa , Sistema Imunitário/parasitologia , Imunidade Inata , Leishmania braziliensis/patogenicidade , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Fagocitose , Fagossomos/parasitologia , Animais , Doença Crônica , Interações Hospedeiro-Parasita , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/metabolismo , Leishmaniose Mucocutânea/imunologia , Leishmaniose Mucocutânea/metabolismo , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/metabolismo , Fagossomos/imunologia , Fagossomos/metabolismoRESUMO
The severity of lesions that develop in patients infected by Leishmania braziliensis is mainly associated with a highly cytotoxic and inflammatory cutaneous environment. Recently, we demonstrated that senescent T and NK cells play a role in the establishment and maintenance of this tissue inflammation. Here, we extended those findings using transcriptomic analyses that demonstrate a strong co-induction of senescence and pro-inflammatory gene signatures in cutaneous leishmaniasis (CL) lesions. The senescence-associated signature was characterized by marked expression of key genes such as ATM, Sestrin 2, p16, p21 and p38. The cell type identification from deconvolution of bulk sequencing data showed that the senescence signature was linked with CD8+ effector memory and TEMRA subsets and also senescent NK cells. A key observation was that the senescence markers in the skin lesions are age-independent of patients and were correlated with lesion size. Moreover, a striking expression of the senescence-associated secretory phenotype (SASP), pro-inflammatory cytokine and chemokines genes was found within lesions that were most strongly associated with the senescent CD8 TEMRA subset. Collectively, our results confirm that there is a senescence transcriptomic signature in CL lesions and supports the hypothesis that lesional senescent cells have a major role in mediating immunopathology of the disease.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Imunossenescência/genética , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/etiologia , Leishmaniose Cutânea/patologia , Transcriptoma , Biomarcadores , Biópsia , Biologia Computacional/métodos , Citocinas/genética , Citocinas/metabolismo , Bases de Dados Genéticas , Suscetibilidade a Doenças/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/metabolismo , Leishmaniose Cutânea/metabolismo , Carga Parasitária , Pele/patologiaRESUMO
The golden hamster is a suitable model for studying cutaneous leishmaniasis (CL) due to Leishmania (Viannia) braziliensis. Immunopathological mechanisms are well established in the L. (L.) major-mouse model, in which IL-4 instructs a Th2 response towards progressive infection. In the present study, we evaluated the natural history of L. braziliensis infection from its first stages up to lesion establishment, with the aim of identifying immunological parameters associated with the disease outcome and parasitism fate. To this end, hamsters infected with 104, 105, or 106 promastigotes were monitored during the first hours (4h, 24h), early (15 days, 30 days) and late (50 days) post-infection (pi) phases. Cytokines, iNOS and arginase gene expression were quantified in the established lesions by reverse transcription-quantitative PCR. Compared to the 105 or 106 groups, 104 animals presented lower lesions sizes, less tissue damage, and lower IgG levels. Basal gene expression in normal skin was high for TGF-ß, and intermediary for TNF, IL-6, and IL-4. At 4hpi, no cytokine induction was observed in the 104 group, while an upregulation of IL-6, IL-10, and IL-4 was observed in the 106 group. At 15dpi, lesion appearance was accompanied by an increased expression of all assessed cytokines, markedly in the 105 and 106 groups. Upregulation of all investigated cytokines was observed in the late phase, although less expressive in the 104 group. IFN-γ was the depending variable influencing tissue damage, while IL-6 was associated to parasite load. The network correlating gene expression and clinical and laboratorial parameters indicated inoculum-independent associations at 15 and 30dpi. A strong positive network correlation was observed in the 104 group, but not in the 105 or 106 groups. In conclusion, IL-4, IL-6, IL-10, and TGF-ß are linked o L. braziliensis progression. However, a balanced cytokine network is the key for an immune response able to reduce the ongoing infection and reduce pathological damage.
Assuntos
Citocinas/metabolismo , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/metabolismo , Leishmaniose Cutânea/parasitologia , Transdução de Sinais , Animais , Biomarcadores , Biologia Computacional/métodos , Cricetinae , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Expressão Gênica , Interações Hospedeiro-Parasita/imunologia , Imunomodulação , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Carga ParasitáriaRESUMO
Cutaneous leishmaniasis (CL) patients present an exacerbated inflammatory response associated with tissue damage and ulcer development. Increasing numbers of patients have exhibited treatment failure, which remains not well understood. We hypothesized that adjuvant anti-inflammatory therapy would benefit CL patients. The aim of the present study was to investigate the contribution of Notch signalling and gamma-secretase activity to the inflammatory response observed in CL patients. Notch signalling is a molecular signalling pathway conserved among animal species. Gamma-secretase forms a complex of proteins that, among other pathways, modulates Notch signalling and immune response. We found that Notch 1 cell receptor signalling protects against the pathologic inflammatory response, and JLK6, a gamma-secretase inhibitor that does not interfere with Notch signalling, was shown to decrease the in-vitro inflammatory response in CL. Our data suggest that JLK6 may serve as an adjuvant treatment for CL patients.
Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Leishmaniose Cutânea/imunologia , Monócitos/imunologia , Receptores Notch/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Antígenos de Protozoários/imunologia , Células Cultivadas , Estudos Transversais , Citocinas/metabolismo , Diaminas/farmacologia , Humanos , Inflamação , Leishmania braziliensis/imunologia , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/metabolismo , Leishmaniose Cutânea/parasitologia , Monócitos/metabolismo , Monócitos/parasitologia , Inibidores de Proteases/farmacologia , Receptor Notch1/metabolismo , Transdução de Sinais , Tiazóis/farmacologiaRESUMO
Cutaneous leishmaniasis is a localized infection controlled by CD4+ T cells that produce IFN-γ within lesions. Phagocytic cells recruited to lesions, such as monocytes, are then exposed to IFN-γ which triggers their ability to kill the intracellular parasites. Consistent with this, transcriptional analysis of patient lesions identified an interferon stimulated gene (ISG) signature. To determine whether localized L. braziliensis infection triggers a systemic immune response that may influence the disease, we performed RNA sequencing (RNA-seq) on the blood of L. braziliensis-infected patients and healthy controls. Functional enrichment analysis identified an ISG signature as the dominant transcriptional response in the blood of patients. This ISG signature was associated with an increase in monocyte- and macrophage-specific marker genes in the blood and elevated serum levels IFN-γ. A cytotoxicity signature, which is a dominant feature in the lesions, was also observed in the blood and correlated with an increased abundance of cytolytic cells. Thus, two transcriptional signatures present in lesions were found systemically, although with a substantially reduced number of differentially expressed genes (DEGs). Finally, we found that the number of DEGs and ISGs in leishmaniasis was similar to tuberculosis-another localized infection-but significantly less than observed in malaria. In contrast, the cytolytic signature and increased cytolytic cell abundance was not found in tuberculosis or malaria. Our results indicate that systemic signatures can reflect what is occurring in leishmanial lesions. Furthermore, the presence of an ISG signature in blood monocytes and macrophages suggests a mechanism to limit systemic spread of the parasite, as well as enhance parasite control by pre-activating cells prior to lesion entry.
Assuntos
Interferon gama/sangue , Interferon gama/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Pele/imunologia , Linfócitos T CD4-Positivos/imunologia , Estudos de Casos e Controles , Humanos , Inflamação/imunologia , Leishmaniose Cutânea/sangue , Macrófagos/imunologia , Monócitos/imunologiaRESUMO
BACKGROUND: Cytokines and growth factors involved in the tissue inflammatory process influence the outcome of Leishmania infection. Insulin-like growth factor (IGF-I) constitutively present in the skin may participate in the inflammatory process and parasite-host interaction. Previous work has shown that preincubation of Leishmania (Leishmania) amazonensis with recombinant IGF-I induces accelerated lesion development. However, in human cutaneous leishmaniasis (CL) pathogenesis, it is more relevant to the persistent inflammatory process than progressive parasite proliferation. In this context, we aimed to investigate whether IGF-I was present in the CL lesions and if this factor may influence the lesions' development acting on parasite growth and/or on the inflammatory/healing process. Methodology. Fifty-one CL patients' skin lesion samples from endemic area of L. (Viannia) braziliensis infection were submitted to histopathological analysis and searched for Leishmania and IGF-I expression by immunohistochemistry. RESULTS: In human CL lesions, IGF-I was observed preferentially in the late lesion (more than 90 days), and the percentage of positive area for IGF-I was positively correlated with duration of illness (r = 0.42, P < 0.05). IGF-I was highly expressed in the inflammatory infiltrate of CL lesions from patients evolving with good response to therapy (2.8% ± 2.1%; median = 2.1%; n = 18) than poor responders (1.3% ± 1.1%; median: 1.05%; n = 6; P < 0.05). CONCLUSIONS: It is the first time that IGF-I was detected in lesions of infectious cutaneous disease, specifically in American tegumentary leishmaniasis. IGF-I was related to chronicity and good response to treatment. We may relate this finding to the efficient anti-inflammatory response and the known action of IGF-I in wound repair. The present data highlight the importance of searching nonspecific factors besides adaptive immune elements in the study of leishmaniasis' pathogenesis.
Assuntos
Fator de Crescimento Insulin-Like I/metabolismo , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Pele/patologia , Adolescente , Adulto , Animais , Brasil , Feminino , Interações Hospedeiro-Parasita/imunologia , Humanos , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Pessoa de Meia-Idade , Pele/imunologia , Pele/microbiologia , Cicatrização/imunologia , Adulto JovemRESUMO
BACKGROUND: In this study, we determined the accuracy of anti-Leishmania IgG and IgG subclasses to distinguish clinical forms of American tegumentary leishmaniasis (ATL) and and determined the relationship between antibodies levels with cytokine production and severity of ATL. METHODS: Participants were 40 patients with cutaneous leishmaniasis (CL), 20 patients with mucosal leishmaniasis (ML), 20 patients with disseminated leishmaniasis (DL), and 20 individuals with subclinical Leishmania braziliensis infection (SC). Diagnosis was performed by DNA of L. braziliensis or IFN-γ production in SC. IgG and subclasses of IgG to soluble Leishmania antigen and cytokine levels in supernatants of mononuclear cells were detected by ELISA. RESULTS: IgG was detected in 95%, 95%, and 100% of patients with CL, ML, and DL, respectively. Higher levels of anti-Leishmania IgG and IgG2 were seen in DL compared to CL, ML, and SC. ROC analysis confirmed the ability of IgG to distinguish DL from the other clinical forms. A direct correlation was observed between IgG titers and levels of IFN-γ and CXCL10 in CL and DL, and IgG2 antibodies were correlated with the number of lesions in DL. CONCLUSIONS: High anti-Leishmania IgG and IgG2 levels are characteristic of DL, and while IgG was correlated with pro-inflammatory cytokines, IgG2 was direct correlated with the number of lesions.
Assuntos
Imunoglobulina G/imunologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Adulto , Biomarcadores/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Leishmaniose Cutânea/diagnóstico , Masculino , Pessoa de Meia-IdadeRESUMO
In cutaneous leishmaniasis, the immune response is not only protective but also mediates immunopathology. We previously found that cytolytic CD8 T cells promote inflammatory responses that are difficult to treat with conventional therapies that target the parasite. Therefore, we hypothesized that inhibiting CD8 T-cell cytotoxicity would reduce disease severity in patients. IL-15 is a potential target for such a treatment because it is highly expressed in human patients with cutaneous leishmaniasis lesions and promotes granzyme Bâdependent CD8 T-cell cytotoxicity. Here we tested whether tofacitinib, which inhibits IL-15 signaling by blocking Jak3, might decrease CD8-dependent pathology. We found that tofacitinib reduced the expression of granzyme B by CD8 T cells in vitro and in vivo systemic and topical treatment, with tofacitinib protecting mice from developing severe cutaneous leishmaniasis lesions. Importantly, tofacitinib treatment did not alter T helper type 1 responses or parasite control. Collectively, our results suggest that host-directed therapies do not need to be limited to autoimmune disorders and that topical tofacitinib application should be considered a strategy for the treatment of cutaneous leishmaniasis disease in combination with antiparasitic drugs.
Assuntos
Antiparasitários/uso terapêutico , Granzimas/antagonistas & inibidores , Leishmaniose Cutânea/tratamento farmacológico , Piperidinas/uso terapêutico , Pirimidinas/uso terapêutico , Linfócitos T Citotóxicos/efeitos dos fármacos , Transferência Adotiva , Animais , Antiparasitários/farmacologia , Biópsia , Modelos Animais de Doenças , Quimioterapia Combinada/métodos , Granzimas/metabolismo , Humanos , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/imunologia , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Camundongos , Carga Parasitária , Piperidinas/farmacologia , Pirimidinas/farmacologia , Índice de Gravidade de Doença , Pele/efeitos dos fármacos , Pele/imunologia , Pele/parasitologia , Pele/patologia , Linfócitos T Citotóxicos/imunologia , Células Th1/efeitos dos fármacos , Células Th1/imunologiaRESUMO
Leishmania braziliensis is the main causative agent of American tegumentary leishmaniasis in Brazil. Current treatment includes different drugs that have important side effects and identification of cases of parasite resistance to treatment support the search for new therapeutic strategies. Recent findings have indicated that CXCL10, a chemokine that recruits and activates Th1 cells, NK cells, macrophages, dendritic cells and B lymphocytes, is a potential alternative to treat Leishmania infection. Here, we tested CXCL10 immunotherapy against experimental infection caused by an antimony-resistant isolate of Leishmania braziliensis. Following infection, mice were treated with CXCL10 for 7 days after onset of lesions. We demonstrate that mice treated with CXCL10 controlled lesion progression and parasite burden more efficiently comparing to controls. An increased IFN-γ, IL-10, TGF-ß and low IL-4 production combined with a distinct inflammatory infiltrate composed by activated macrophages, lymphocytes and granulomas was observed in the CXCL10-treated group comparing to controls. However, CXCL10 and Glucantime combined therapy did not improve CXCL10-induced protective effect. Our findings reinforce the potential of CXCL10 immunotherapy as an alternative treatment against infection caused by L. braziliensis resistant to conventional chemotherapy.
Assuntos
Quimiocina CXCL10/uso terapêutico , Fatores Imunológicos/uso terapêutico , Leishmania braziliensis/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Animais , Antimônio/farmacologia , Brasil , Feminino , Interleucina-10/imunologia , Leishmania braziliensis/imunologia , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/imunologia , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/farmacologia , Células Th1/imunologiaRESUMO
BACKGROUND: Leishmania skin test (LST) evaluates the delayed type hypersensitivity to Leishmania antigens (LA) and has been used for diagnosis of cutaneous leishmaniasis (CL). In CL patients LST is usually positive but a small percentage have negative LST. The aim of this study was to determine the clinical and immunologic features and response to antimony therapy in LST-negative CL patients. METHODS: We compare the clinical presentation, response to therapy, and immune response of CL patients with negative vs positive LST. RESULTS: The clinical presentation was similar in both groups but LST-negative patients had a lower cure rate. In the lesions, LST-negative patients displayed less inflammation and necrosis, and higher frequency of CD8+ T cells. Mononuclear cells from LST-negative patients had a poor T helper 1 cell (Th1) response but levels of interleukin-1ß (IL-1ß), IL-6, IL-17, granzyme B, and metalloproteinase-9 (MMP-9) were similar to the LST-positive group upon stimulation with LA. Leishmania internalization and killing by macrophages were similar in both groups. Cure of disease was associated with restoration of Th1 response. CONCLUSIONS: In LST-negative patients, impaired Th1 response is associated with therapeutic failure. Increased frequency of CD8+ T cells and high production of inflammatory cytokines, granzyme B, and MMP-9 contributes to immunopathology.
Assuntos
Leishmania braziliensis/imunologia , Leishmaniose Cutânea/parasitologia , Células Th1/imunologia , Adolescente , Adulto , Idoso , Antimônio , Brasil , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Feminino , Granzimas , Humanos , Inflamação , Leishmania/imunologia , Leishmaniose Cutânea/patologia , Masculino , Metaloproteinase 9 da Matriz , Pessoa de Meia-Idade , Necrose , Pele/parasitologia , Pele/patologia , Adulto JovemRESUMO
The development of senescence in tissues of different organs and in the immune system are usually investigated independently of each other although during ageing, senescence in both cellular systems develop concurrently. Senescent T cells are highly inflammatory and secrete cytotoxic mediators and express natural killer cells receptors (NKR) that bypass their antigen specificity. Instead they recognize stress ligands that are induced by inflammation or infection of different cell types in tissues. In this article we discuss data on T cell senescence, how it is regulated and evidence for novel functional attributes of senescent T cells. We discuss an interactive loop between senescent T cells and senescent non-lymphoid cells and conclude that in situations of intense inflammation, senescent cells may damage healthy tissue. While the example for immunopathology induced by senescent cells that we highlight is cutaneous leishmaniasis, this situation of organ damage may apply to other infections, including COVID-19 and also rheumatoid arthritis, where ageing, inflammation and senescent cells are all part of the same equation.
Assuntos
Linfócitos T CD8-Positivos/citologia , Senescência Celular/fisiologia , Células Matadoras Naturais/imunologia , Leishmaniose Cutânea/imunologia , Receptores de Células Matadoras Naturais/imunologia , Envelhecimento/imunologia , Artrite Reumatoide/imunologia , COVID-19/imunologia , Humanos , Leishmania braziliensis/imunologia , SARS-CoV-2/imunologiaRESUMO
Photodynamic inactivation of Leishmania has been shown to render them non-viable, but retain their immunological activities. Installation of dual photodynamic mechanisms ensures complete inactivation of species in the Leishmania subgenus, raising the prospect of their safe and effective application as whole-cell vaccines against leishmaniasis. Here, we report the successful extension of this approach to L. braziliensis in the Viannia subgenus, viz. genetic engineering of promastigotes for cytosolic accumulation of UV-sensitive uroporphyrin (URO) and their loading with red light excitable phthalocyanines (PC) that was cationized by chemical engineering. The transgenic strategy used previously produced L. braziliensis transfectants, which gave the same phenotype of aminolevulinate (ALA)-inducible uroporphyria as found in Leishmania subgenus, indicative of pre-subgenus evolutionary origin for similar genetic deficiencies in porphyrin/heme biosynthesis. In the present study, 12 independent clones were obtained and were invariably ALA-responsive, albeit to different extent for uroporphyrinogenesis and UV-inactivation. In a separate study, L. braziliensis was also found, like other Leishmania spp., to take up diamino-PC (PC2) for red light inactivation. In vitro interactions of a highly uroporphyrinogenic clone with primary macrophages were examined with the intervention of URO/PC2-medated double-photodynamic inactivation to ascertain its complete loss of viability. Doubly sensitized L. braziliensis transfectants were photo-inactivated before (Strategy #1) or after (Strategy #2) loading of macrophages. In both cases, macrophages were found to take up L. braziliensis and degrade them rapidly in contrast to live Leishmania infection. The effector functions of macrophages became upregulated following their loading with L. braziliensis photodynamically inactivated by both strategies, including CD86 expression, and IL6 and NO production. This was in contrast to the immunosuppressive infection of macrophages with live parasites, marked by IL10 production. The results provide evidence that photodynamically inactivated L. braziliensis are susceptible to the degradative pathway of macrophages with upregulation of immunity relevant cytokine and co-stimulatory markers. The relative merits of the two loading strategies with reference to previous experimental vaccination were discussed in light of the present findings with L. braziliensis.
Assuntos
Indóis/farmacologia , Leishmania braziliensis/efeitos dos fármacos , Leishmania braziliensis/efeitos da radiação , Macrófagos/imunologia , Macrófagos/parasitologia , Fármacos Fotossensibilizantes/farmacologia , Uroporfirinas/farmacologia , Ácido Aminolevulínico/farmacologia , Animais , Animais Geneticamente Modificados , Feminino , Humanos , Imunidade Inata , Técnicas In Vitro , Isoindóis , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Vacinas Protozoárias/imunologia , Raios UltravioletaRESUMO
Leishmania (Viannia) braziliensis is the main agent of mucocutaneous Leishmaniasis, a neglected tropical disease that affects thousands of people in Brazil. It has been shown that complement plays a critical role at early stages of Leishmania infection and that is involved in the invasion of macrophages by the promastigotes. Ficolins and collectins are soluble pattern recognition and triggering molecules of the lectin complement pathway. We investigated here whether lectin pathway activators ficolin-1, ficolin-2, ficolin-3 and CL-11 bind to live L. braziliensis promastigotes in vitro. Promastigote forms in the stationary growth phase were incubated with normal human serum (NHS) or recombinant ficolins 1, 2 and 3, MBL and CL-11, and protein binding was evaluated by confocal microscopy and flow cytometry. Ficolins 1, 2 and 3, MBL and CL-11 were able to bind to the surface of live promastigotes after incubation with either NHS or recombinant proteins. A partial inhibition by N-acetyl-d-glucosamine characterizing the participation of acetylated groups in the deposition of ficolins and CL-11 to glycoconjugates on the surface of L. braziliensis was observed. These evidences highlight a role for the lectin pathway in the innate response to L. braziliensis.
Assuntos
Colectinas/fisiologia , Lectinas/fisiologia , Leishmania braziliensis/imunologia , Proteínas do Sistema Complemento/fisiologia , Humanos , Imunidade Inata , FicolinasRESUMO
Leishmania are obligate protozoan parasites responsible for substantial public health problems in tropical and subtropical regions around the world, with L. braziliensis being one of the causative agents of American Tegumentary Leishmaniasis. Macrophages, fundamental cells in the innate inflammatory response against Leishmania, constitute a heterogeneous group with multiple activation phenotypes and functions. The outcome of this infection depends largely on the activation status of macrophages, the first line of mammalian defense and the major target cells for parasite replication. The importance of lipids, the major components of cell membranes, goes beyond their basic structural functions. Lipid bioactive molecules have been described in Leishmania spp., and in the recent years the knowledge about the biological relevance of lipids in particular and their relationship with the immune response is expanding. The present work analyzes the biological effects of L. braziliensis lipids from lysed promastigotes (PRO) to mimic rapid modulatory processes that could occur in the initial steps of infection or the effects of lipids from lysed and incubated promastigotes (PROinc), simulating the parasite lipid degradation processes triggered after parasite lysis that might occur in the mammalian host. To perform these studies, lipid profiles of PRO and PROinc were compared with lipids from amastigotes under similar conditions (AMA and AMAinc), and the effect of these lipid extracts were analyzed on the induction of an inflammatory response in murine peritoneal macrophages: LB induction, COX-2, iNOS and Arginase expression, TNF-α, IL-10 and NO production, Arginase activity and M1/M2 markers mRNA induction.
Assuntos
Antígenos de Protozoários/imunologia , Leishmania braziliensis/imunologia , Leishmaniose/imunologia , Lipídeos/imunologia , Ativação de Macrófagos/imunologia , Animais , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Poorly controlled diabetes mellitus leads to several comorbidities, including susceptibility to infections. Hyperglycemia increases phagocyte responsiveness, however immune cells from people with diabetes show inadequate antimicrobial functions. We and others have shown that aberrant production of leukotriene B4 (LTB4) is detrimental to host defense in models of bacterial infection. Here, we will unveil the consequences of high glucose in the outcome of Leishmania braziliensis skin infection in people with diabetes and determine the role of LTB4 in human phagocytes. We show that diabetes leads to higher systemic levels of LTB4, IL-6 and TNF-α in cutaneous leishmaniasis. Only LTB4 correlated with blood glucose levels and healing time in diabetes comorbidity. Skin lesions of people with leishmaniasis and diabetes exhibit increased neutrophil and amastigote numbers. Monocyte-derived macrophages from these individuals showed higher L. braziliensis loads, reduced production of Reactive Oxygen Species and unbalanced LTB4/PGE2 ratio. Our data reveal a systemic inflammation driven by diabetes comorbidity in opposition to a local reduced capacity to resolve L. braziliensis infection and a worse disease outcome.