Role of Yersinia pseudotuberculosis outer proteins (Yops) in murine humoral immune response

The infection of mice with the wild-type (WT) strain of Y. pseudotuberculosis did not induce polyclonal activation of B lymphocytes. Suppression in the production of certain isotypes of Ig was observed, provoked mainly by YopH, YopJ and YpkA. The WT strain induced a progressive increase in the serum-specific IgG, which peaked after 4 weeks after infection, IgM being produced only after 1 week. Autoantibodies against phosphorylcholine, myelin, thyroglobulin and cardiolipin could be detected in the serum of mice infected with the WT strain. The infection of mice provoked suppression in the production of immunoglobulins by splenic B cells and that YopH, YopJ and YpkA must be involved here.

Malaria at Humaita county, Amazonas state, Brazil: XVII - immune response in patients with Plasmodium falciparum according to gametocytes

Em agosto de 1983, os Autores, estudaram 36 doentes com infecção causada pelo Plasmodium falciparum e 14 indivíduos normais, nascidos na região de Humaitá, que nunca tiveram malária, sem esplenomegalia, com exame parasitológico de sangue e hemaglutinação passiva negativas. Todos eles foram submetidos à observação clínica completa, exame hematológico, exame parasitológico de sangue e tipagem de linfócitos. Os linfócitos foram isolados e congelados em nitrogênio líquido, para posterior tipagem pela formação de rosetas. Os doentes foram classificados em dois grupos de acordo com a presença (13 doentes), ou ausência (23 doentes) de gametócitos antes do tratamento. Houve predomínio de formas graves no grupo de doentes sem gametócitos. Os resultados mostraram diminuição do número de linfócitos T em ambos os grupos de doentes, com ou sem gametócitos antes do tratamento, enquanto que o número de linfócitos B foi normal apenas no grupo de doentes com gametócitos. Essas observações, assim como as que foram relatadas pelos Autores anteriormente, permitem associar a presença de gametócitos circulantes com o número normal de células B em doentes com formas leves de malária causada pelo Plasmodium falciparum.

Experimental infection of Leishmania chagasi in immunosuppressed balb/c mice: cellular immune response and parasite burden

The immune response to leishmaniasis can result in a polarization of a subpopulation of T lymphocytes, which leads to a different cell phenotype and results in immune protection or exacerbation of the disease. Leishmanias persist in the body both in asymptomatic infections and after treatment, representing risks in terms of immunosuppression. The objective of this study was to evaluate the effects of infection and immunosuppression by dexamethasone associated with pentoxifylline on animal weight, spleen weight, the parasitic load in the spleen and liver, as well as the production of IFN-gamma and IL-10 in spleen cell culture of Balb/c mice infected with Leishmania chagasi. The infection did not alter animal weight gain, but spleen weight and size increased. The immunosuppression, induced by dexamethasone associated with pentoxifylline, affected animal weight gain and weight and size of the spleen (in infected and not infected animals). The immunosuppression did not significantly alter the course of the parasite burden in the spleen and liver. Dexamethasone and pentoxifylline affected the studied cytokine production, but not influenced on Th1/Th2 response in infected animals.

Vaccine immune response and interference of colostral antibodies in calves vaccinated against rabies at 2, 4 and 6 months of age born from antirabies revaccinated females

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efficiency of Matricaria chamomilla CH12 and number of doses of rabies vaccine on the humoral immune response in cattle

This study evaluated the effect of Matricaria chamomilla and vaccination frequency on cattle immunization against rabies. Four groups (n = 15/group) were treated with or without Matricaria chamomilla CH12 and vaccinated with one or two doses of rabies vaccine (30 day interval). No effect of chamomile was found on cattle immunization against rabies; however, antibody titers were protective in cattle vaccinated twice, while 93.3% of cattle vaccinated only once had titers under 0.5 UI/ml after 60 days. In conclusion, the use of chamomile did not alter the Immoral immune response in cattle, and two vaccine doses are suggested for achieving protective antibody titers.

Curcumin modulates the immune response associated with LPS-induced periodontal disease in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of TLR-2 in the immune response in the infection induced by fungus Sporothrix schenckii

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immune response and performance of growing Santa Ines lambs to artificial Trichostrongylus colubriformis infections

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunization with pVAXhsp65 Decreases Inflammation and Modulates Immune Response in Experimental Encephalomyelitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relation of pretreatment sequence diversity in NS5A region of HCV genotype 1 with immune response between pegylated-INF/ribavirin therapy outcomes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evaluation of the Naturally Acquired Antibody Immune Response to the Pv200L N-terminal Fragment of Plasmodium vivax Merozoite Surface Protein-1 in Four Areas of the Amazon Region of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detection of Cryptosporidium parvum oocysts in calf fecal samples by direct immunofluorescence assay

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Demonstration of antibody and cellular immune response to brain extract in West and Lennox-Gastaut syndromes

Investigamos a resposta imunológica celular e humoral frente a extrato salino de tecido cerebral em 9 pacientes com síndrome de Lennox-Gastaut, 15 pacientes com síndrome de West e 20 crianças normais. A técnica de imunodifusão dupla em gel de agar (Ouchterlony) evidenciou em todos os pacientes, altos níveis de um anticorpo precipitante contra o extrato salino de tecido cerebral. O teste de inibição de migração de leucócitos com o mesmo antígeno mostrou-se positivo na maioria dos pacientes. O possível papel destas respostas autoimmunes na patogenia das sindromes de West e Lennox-Gastaut é discutido.

Correlation among immune response, morphogenesis of the granulomatous reaction and spleen lymphoid structure in murine experimental paracoccidioidomycosis

We studied the correlation among cellular immune response, the pattern of lung granulomatous lesions and alterations in spleen lymphoid structure in Swiss mice inoculated intravenously with Paracoccidioides brasiliensis strain 18. The animals were evaluated at 24, 48 and 96 h after infection and further studied weekly for 18 weeks by: (i) the macrophage migration inhibition test with phytohemagglutinin (PHA) and P. brasiliensis antigen (PbAg); and (ii) histopathology of the lung and spleen lesions. One group of animals was gamma -irradiated (8 Gy), infected under the same conditions and evaluated for the pattern of lung granulomatous lesions and spleen lymphoid structure at 24, 48 and 96 h after infection. During the first week of infection, the non-irradiated animals presented a positive response to PHA and PbAg, compact granulomas in the lungs and a typical hyperplasia of the spleen white pulp. However, from weeks 2 to 5, a depression of the cell-mediated immunity (CMI) response to PHA and PbAg was observed in association with granulomas presenting only large mononuclear cells and lacking both giant cells and a peripheral halo of small mononuclear cells. This pattern of granuloma formation was similar to that seen in gamma -irradiated animals, whose cells involved in CMI were absent. After week 7, the non-irradiated animals showed granulomas characterized by the presence of giant cells and a peripheral halo of small mononuclear cells. This type of granuloma was formed concomitantly with recovery of the CMI and of the lymphoid structure of the spleen. The results showed a correlation among granulomas composed of large mononuclear cells, hypoplasia of the splenic tissue and impaired CMI. This correlation indicated that although granuloma morphogenesis per se does not depend on the activation of CMI, this response is important at later stages during modulation of the cellular composition of the granulomas.