ROLE OF GAMMA-INTERFERON AND TUMOR-NECROSIS-FACTOR-ALPHA DURING T-CELL-INDEPENDENT AND T-CELL-DEPENDENT PHASES OF MYCOBACTERIUM-AVIUM INFECTION

• Tipo: Artigo em Revista Científica Internacional
• Data: 1994

Autores

APPELBERG, R (Autor) ICBAS; CASTRO, AG (Autor) Outra; PEDROSA, J (Autor) Outra; SILVA, RA (Autor) Outra; ORME, IM (Autor) Outra; MINOPRIO, P (Autor) Outra

Revista

Título: Infection and Immunity

Vol. 62

Páginas: 3962-3971

ISSN: 0019-9567

Editora: American Society for Microbiology

Indexação

ISI Web of Knowledge - 139 Citações

Scopus - 129 Citações

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

Outras Informações

ID Authenticus: P-001-JNB

Abstract (EN): To design an effective immunotherapy for Mycobacterium avium infections, the protective host response to the infection must be known. Here we analyzed the role of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF alpha) in the innate and acquired responses to M. avium infections in mice. T-cell depletion studies showed that CD4(+) T cells were required for control of the infection. CD4(+)-depleted mice showed enhanced bacterial proliferation and at the same time showed a reduction in the level of expression of both IFN-gamma and TNF-alpha mRNAs in spleen cells. In contrast, M. bovis BCG immunization restricted M. avium proliferation and at the same time promoted expression of the mRNAs for the two cytokines. In vivo depletion studies using specific monoclonal antibodies showed that both IFN-gamma and TNF-alpha are involved in an early protection possibly involving NK cells, and furthermore, IFN-gamma is involved in the later T-cell-protective response to infection. In vivo neutralization of IFN-gamma during M. avium infection also blocked the priming for enhanced TNF-ol secretion triggered by endotoxin. Both cytokines were found to be involved in the resistance expressed in BCG immunized animals and exhibited additive bacteriostatic effects in vitro on bone marrow-derived macrophages infected with different strains of M. avium. These data suggest that both cytokines act in an additive or synergistic fashion in the induction of bacteriostasis and that IFN-gamma is also involved in priming TNF-alpha secretion.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10