Antigen provoking gamma interferon production in response to Mycobacterium bovis BCG and functional difference in T-cell responses to this antigen between viable and killed BCG-immunized mice.
AUTOR(ES)
Kawamura, I
RESUMO
It has been shown that gamma interferon (IFN-gamma)-producing CD4+ T cells, which are generated only by immunization with viable bacteria, exert a significant role in protective immunity against mycobacteria in mice. In this study, we have tried to determine the antigen recognized by the T cells in search of a possible protective antigen. T cells from viable Mycobacterium bovis BCG-immunized mice were stimulated with several antigens, and IFN-gamma production was measured. Purified protein derivative and viable and killed BCG lysates caused significant IFN-gamma production, and almost the same level of IFN-gamma activity was detected in both groups stimulated with viable and killed BCG lysates. However, heat shock protein (HSP) 65 and HSP 70 were not a major antigen for IFN-gamma production. The antigen provoking IFN-gamma production is localized mainly in the membrane fraction of BCG cells, and the approximate molecular size was 18 kDa. On the other hand, T cells from killed BCG-immunized mice never responded to this antigen for IFN-gamma production, whereas they could mount a delayed-type hypersensitivity response. These results showed that the antigen provoking IFN-gamma production was present in killed as well as viable BCG. In addition to the antigen presentation by antigen-presenting cells, some kinds of differentiation factor (such as monokines) that are produced only by stimulation with viable cells seemed to be necessary for the development of IFN-gamma-producing T cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=303122Documentos Relacionados
- Antigen-reactivity pattern of T-cell hybridomas from Mycobacterium bovis BCG-infected mice.
- Mycobacterium bovis BCG Producing Interleukin-18 Increases Antigen-Specific Gamma Interferon Production in Mice
- Mycobacterium bovis BCG-induced human T-cell clones from BCG-vaccinated healthy subjects: antigen specificity and lymphokine production.
- Increased gamma-delta T-lymphocyte response to Mycobacterium bovis BCG in major histocompatibility complex class I-deficient mice.
- Ineffective Cellular Immune Response Associated with T-Cell Apoptosis in Susceptible Mycobacterium bovis BCG-Infected Mice