RESUMO
This study evaluated levels for mRNA expression of 7 cytokines in ocular toxoplasmosis. Peripheral blood mononuclear cells (PBMC) of patients with ocular toxoplasmosis (OT Group, n = 23) and chronic toxoplasmosis individuals (CHR Group, n = 9) were isolated and stimulated in vitro with T. gondii antigen. Negative controls (NC) were constituted of 7 PBMC samples from individuals seronegative for toxoplasmosis. mRNA expression for cytokines was determined by qPCR. Results showed a significant increase in mRNA levels from antigen stimulated PBMCs derived from OT Group for expressing IL-6 (at P < .005 and P < .0005 for CHR and NC groups, respectively), IL-10 (at P < .0005 and P < .005 for CHR and NC groups, respectively) and TGF-ß (at P < .005) for NC group. mRNA levels for TNF-α and IL-12 were also upregulated in patients with OT compared to CHR and NC individuals, although without statistical significance. Additionally, mRNA levels for IL-27 and IFN-γ in PBMC of patients with OT were upregulated in comparison with NC individuals. Differences between OT and NC groups were statistically significant at P < .05 and P < .0005, respectively.
Assuntos
Antígenos de Protozoários/imunologia , Citocinas/genética , Leucócitos Mononucleares/imunologia , RNA Mensageiro/biossíntese , Toxoplasma/imunologia , Toxoplasmose Ocular/imunologia , Citocinas/metabolismo , Expressão Gênica , Humanos , Estudos Prospectivos , Toxoplasmose Ocular/diagnóstico , Toxoplasmose Ocular/parasitologiaRESUMO
TNF-α, IFN-γ, IL-10, IL-17, CD68 and CD57 were evaluated in biopsies of patients with American cutaneous leishmaniasis living in Sorocaba, Brazil. The analyses were performed considering the time of lesions from 23 patients with recent lesions (Group I) and 19 patients with late lesions (Group II). All patients were infected with Leishmania (Viannia) braziliensis. Immunostaining cells for CD68, CD57, TNF- α, IFN-γ, IL-10 and IL-17 were performed by immunohistochemistry. Except for CD68 and IL-17, the distribution of in situ for CD57, IL-10, TNF-α and IFN-γ showed that patients with recent lesions expressed higher levels than those with late lesions. The comparison of cytokine expression/group showed that IL-10 was significantly higher than IL-17 and IFN-γ (similar data were shown in IL-17 compared with TNF-α), suggesting an immunological balance between inflammatory-anti-inflammatory agents. This balance was similar for two groups of patients. In conclusion, these data suggested that (i) patients from Group I had recent lesions (in the beginning of chronic phase) compared to those from Group II and (ii) the modulation of inflammatory response in patients with recent American cutaneous leishmaniasis was correlated with IL-10 expression in skin lesions preventing the development of mucosal forms. The parasite treatment also prevented the evolution of severe forms.
Assuntos
Citocinas/imunologia , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/patologia , Adulto , Antígenos CD/análise , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/análise , Antígenos de Diferenciação Mielomonocítica/imunologia , Brasil , Antígenos CD57/análise , Antígenos CD57/imunologia , Citocinas/análise , Feminino , Humanos , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/parasitologia , Masculino , Pessoa de Meia-IdadeRESUMO
TNFα, IFNγ, IL10, IL17, CD68 and CD57 were evaluated in biopsies of patients with American cutaneous leishmaniasis living in Sorocaba, Brazil. The analyses were performed considering the time of lesions from 23 patients with recent lesions (Group I) and 19 patients with late lesions (Group II). All patients were infected with Leishmania (Viannia) braziliensis. Immunostaining cells for CD68, CD57, TNF α, IFNγ, IL10 and IL17 were performed by immunohistochemistry. Except for CD68 and IL17, the distribution of in situ for CD57, IL10, TNFα and IFNγ showed that patients with recent lesions expressed higher levels than those with late lesions. The comparison of cytokine expression/group showed that IL10 was significantly higher than IL17 and IFNγ (similar data were shown in IL17 compared with TNFα), suggesting an immunological balance between inflammatoryantiinflammatory agents. This balance was similar for two groups of patients. In conclusion, these data suggested that (i) patients from Group I had recent lesions (in the beginning of chronic phase) compared to those from Group II and (ii) the modulation of inflammatory response in patients with recent American cutaneous leishmaniasis was correlated with IL10 expression in skin lesions preventing the development of mucosal forms. The parasite treatment also prevented the evolution of severe forms.
TNF-α, IFN-γ, IL-10, IL-17, CD68 e CD57 foram avaliados em biópsias de pacientes com leishmaniose tegumentar americana residentes em Sorocaba, Brasil. As análises foram realizadas considerando o tempo de lesão de 23 pacientes com lesões recentes (Grupo I) e 19 pacientes com lesões tardias (Grupo II). Todos os pacientes foram infectados com Leishmania (Viannia) braziliensis. As células de imunocoloração para CD68, CD57, TNF-α, IFN-γ, IL-10 e IL-17 foram realizadas por imuno-histoquímica. Exceto para CD68 e IL-17, a distribuição in situ de CD57, IL-10, TNF-α e IFN-γ mostrou que pacientes com lesões recentes expressavam níveis mais altos do que aqueles com lesões tardias. A comparação da expressão / grupo de citocinas mostrou que a IL-10 foi significativamente maior que a IL-17 e IFN-γ (dados semelhantes foram mostrados na IL-17 em comparação com o TNF-α), sugerindo um equilíbrio imunológico entre agentes inflamatórios e anti-inflamatórios . Esse equilíbrio foi semelhante para dois grupos de pacientes. Em conclusão, esses dados sugeriram que (i) pacientes do grupo I apresentavam lesões recentes (no início da fase crônica) em comparação com os do grupo II e (ii) a modulação da resposta inflamatória em pacientes com leishmaniose tegumentar americana recente estava correlacionada com Expressão da IL - 10 em lesões cutâneas impedindo o desenvolvimento de formas mucosas. O tratamento do parasita também impediu a evolução de formas graves.
Assuntos
Parasitos , Imuno-Histoquímica , LeishmaniaRESUMO
The aim of this study was to investigate risk factors for ocular toxoplasmosis (OT) in patients who received medical attention at a public health service. Three hundred and forty-nine consecutive patients, treated in the Outpatient Eye Clinic of Hospital de Base, São José do Rio Preto, São Paulo state, Brazil, were enrolled in this study. After an eye examination, enzyme-linked immunosorbent assay (ELISA) was used to determine anti-Toxoplasma gondii antibodies. The results showed that 25.5% of the patients were seronegative and 74.5% were seropositive for IgG anti-T. gondii antibodies; of these 27.3% had OT and 72.7% had other ocular diseases (OOD). The presence of cats or dogs [odds ratio (OR) 2.22, 95% confidence interval (CI) 1.24-3.98, P = 0.009] and consumption of raw or undercooked meat (OR 1.77, 95% CI 1.05-2.98, P = 0.03) were associated with infection but not with the development of OT. Age (OT 48.2 ± 21.2 years vs. OOD: 69.5 ± 14.7 years, P < 0.0001) and the low level of schooling/literacy (OT vs. OOD: OR 0.414, 95% CI 0.2231-0.7692, P = 0.007) were associated with OT. The presence of dogs and cats as well as eating raw/undercooked meat increases the risk of infection, but is not associated with the development of OT.
Assuntos
Toxoplasmose Ocular/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antiprotozoários/sangue , Brasil/epidemiologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Socioeconômicos , Inquéritos e Questionários , Toxoplasma/imunologia , Toxoplasmose Ocular/imunologiaRESUMO
This study analyzed the synthesis of Interferon gamma (IFN-γ), Tumor Necrosis Factor alpha (TNF-α), and Interleukin 10 (IL-10) in chronically infected patients which developed the symptomatic disease as cerebral or ocular toxoplasmosis. Blood from 61 individuals were divided into four groups: Cerebral toxoplasmosis/AIDS patients (CT/AIDS group) (n = 15), ocular toxoplasmosis patients (OT group) (n = 23), chronic toxoplasmosis individuals (CHR group) (n = 13) and healthy individuals (HI group) (n = 10). OT, CHR, and HI groups were human immunodeficiency virus (HIV) seronegative. The diagnosis was made by laboratorial (PCR and ELISA) and clinical subjects. For cytokine determination, peripheral blood mononuclear cells (PBMC) of each patient were isolated and stimulated in vitro with T. gondii antigen. IFN-γ, TNF-α, and IL-10 activities were determined by ELISA. Patients from CT/AIDS and OT groups had low levels of IFN-γ when were compared with those from CHR group. These data suggest the low resistance to develop ocular lesions by the low ability to produce IFN-γ against the parasite. The same patients, which developed ocular or cerebral toxoplasmosis had higher TNF-α levels than CHR individuals. High TNF-α synthesis contribute to the inflammatory response and damage of the choroid and retina in OT patients and in AIDS patients caused a high inflammatory response as the TNF-α synthesis is not affected since monocytes are the major source this cytokine in response to soluble T. gondii antigens. IL-10 levels were almost similar in CT/AIDS and OT patients but low when compared with CHR individuals. The deviation to Th2 immune response including the production of anti-inflammatory cytokines, such as IL-10 may promote the parasite's survival causing the tissue immune destruction. IL-10 production in T. gondii-infected brains may support the persistence of parasites as down-regulating the intracerebral immune response. All these indicate that OT and CT/AIDS patients produced low levels of IL-10 (Th2 response) and IFN-γ (Th1 response). They produced high TNF-α suggesting a high inflammatory response triggered by the parasite.
Assuntos
Toxoplasmose , Doença , Síndrome da Imunodeficiência Adquirida , NecroseRESUMO
Immunization of BALB/c mice with a plasmid containing the gene for Trypanosoma cruzi trans-sialidase (TS) induced antibodies that inhibited TS enzymatic activity, CD4+ Th1 and CD8+ Tc1 cells, and protective immunity against infection. We used this model to obtain basic information on the requirement of CD4 or CD8 or B-cell epitopes for an effective DNA-induced immunity against T. cruzi infection. For that purpose, mice were immunized with plasmids containing DNA sequences encoding (i) the entire TS protein, (ii) the TS enzymatic domain, (iii) the TS CD4+ T-cell epitopes, (iv) the TS CD8+ T-cell epitope, or (v) TS CD4+ and CD8+ T-cell epitopes. Plasmids expressing the entire TS or its enzymatic domain elicited similar levels of TS-inhibitory antibodies, gamma interferon (IFN-gamma)-producing T cells, and protective immunity against infection. Although the plasmid expressing TS CD4 epitopes was immunogenic, its protective efficacy against experimental infection was limited. The plasmid expressing the CD8 epitope was poorly immunogenic and provided little protective immunity. The reason for the limited priming of CD8+ T cells was due to a requirement for CD4+ T cells. To circumvent this problem, a plasmid expressing both CD4+ and CD8+ T-cell epitopes was produced. This plasmid generated levels of IFN-gamma-producing T cells and protective immunity comparable to that of the plasmid expressing the entire catalytic domain of TS. Our observations suggest that plasmids expressing epitopes recognized by CD4+ and CD8+ T cells may have a better protective potential against infection with T. cruzi.
Assuntos
Doença de Chagas/prevenção & controle , Epitopos de Linfócito T/imunologia , Glicoproteínas/imunologia , Neuraminidase/imunologia , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Vacinas de DNA/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Sequência de Bases , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Epitopos de Linfócito T/genética , Feminino , Glicoproteínas/genética , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/genética , Plasmídeos/genética , Trypanosoma cruzi/enzimologia , Trypanosoma cruzi/genética , VacinaçãoRESUMO
In the presence of sialic acid donors Trypanosoma cruzi acquires up to 10(7) sialic acid residues on its surface, in a reaction catalyzed by its unique trans-sialidase. Most of these sialic acid residues are incorporated into mucin-like glycoproteins. To further understand the biological role of parasite sialylation, we have measured the amount of mucin in this parasite. We found that both epimastigote and trypomastigote forms have the same number of mucin molecules per surface area, although trypomastigotes have less than 10% of the amount of glycoinositol phospholipids, the other major surface glycoconjugate of T. cruzi. Based on the estimated surface area of each mucin, we calculated that these molecules form a coat covering the entire trypomastigote cell. The presence of the surface coat is shown by transmission electron microscopy of Ruthenium Red-stained parasites. The coat was revealed by binding of antibodies isolated from Chagasic patients that react with high affinity to alpha-galactosyl epitopes present in the mucin molecule. When added to the trypomastigote, these antibodies cause an extensive structural perturbation of the parasite coat with formation of large blebs, ultimately leading to parasite lysis. Interestingly, lysis is decreased if the mucin coat is heavily sialylated. Furthermore, addition of MgCl2 reverses the protective effect of sialylation, suggesting that the sialic acid negative charges stabilize the surface coat. Inhibition of sialylation by anti-trans-sialidase antibodies, found in immunized animals, or human Chagasic sera, also increase killing by anti-alpha-galactosyl antibodies. Therefore, the large amounts of sialylated mucins, forming a surface coat on infective trypomastigote forms, have an important structural and protective role.
Assuntos
Anticorpos Antiprotozoários/toxicidade , Antígenos de Protozoários/imunologia , Mucinas/fisiologia , Trissacarídeos/imunologia , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/imunologia , Animais , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Glicosilfosfatidilinositóis/metabolismo , Humanos , Imunidade Inata , Mucinas/metabolismo , Mucinas/ultraestrutura , Ácido N-Acetilneuramínico/metabolismo , Propriedades de Superfície , Trypanosoma cruzi/metabolismo , Trypanosoma cruzi/ultraestruturaRESUMO
Trypanosoma cruzi. the protozoan parasite that causes Chagas' disease, does not synthesize sialic acid, but expresses a trans-sialidase (TS) that catalyzes the transfer of sialic acid from host glycoconjugates to the parasite surface. Here, we review studies that characterize the immune response to the catalytic domain of the enzyme in humans during Chagas' disease or in mice following immunization with the TS gene. In both cases, there are antibodies that strongly inhibit the enzymatic activity and generation of interferon-gamma-producing T cells.
Assuntos
Doença de Chagas/imunologia , Neuraminidase/administração & dosagem , Trypanosoma cruzi/imunologia , Vacinas de DNA/administração & dosagem , Animais , Doença de Chagas/enzimologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/imunologiaRESUMO
Immunization with naked DNA represents an attractive strategy for development of vaccines against a variety of infections including those caused by protozoan parasites. Recently, we have described that immunization with a plasmid containing the trans-sialidase (TS) gene induced protective immunity against Trypanosoma cruzi infection in BALB/c mice. The present study was aimed at examining and comparing the effectiveness of immunization using either plasmid or recombinant delivered antigens in a mouse strain highly susceptible to infection (A/Sn). Two plasmids were generated containing the coding region for the catalytic domain of TS. TS gene was inserted into pcDNA3 vector with or without the coding region for TS signal peptide. These two plasmids were found to be equally immunogenic at inducing antibodies to TS or inhibition of T. cruzi infection. A third plasmid, in which the TS gene was inserted into the vector VR1012, was as immunogenic as the two others. Immunization with a TS recombinant protein in alum generated a significantly higher antibody response as measured by ELISA or inhibition of TS enzymatic activity. Most relevant, this immunization reduced the mortality due to acute infection.