Data/hora: 10/06/2024 10:21:33

Provedor de dados: | 56
País: | Brazil
Título: | Cytokines produced by susceptible and resistant mice in the course of Paracoccidioides brasiliensis infection
Autores: | Calich,V.L.G.; Kashino,S.S.
Data: | 1998-05-01
Ano: | 1998
Palavras-chave: | Murine paracoccidioidomycosis; Genetic resistance; Cytokines; Type-1 cytokines; Type-2 cytokines; Monokines.
Resumo: | Paracoccidioidomycosis (PCM) is the most prevalent deep mycosis in Latin America and presents a wide spectrum of clinical manifestations. We established a genetically controlled murine model of PCM, where A/Sn mice develop an infection which mimics the benign disease (immune responses which favor cellular immunity) and B10.A animals present the progressive disseminated form of PCM (preferential activation of B cells and impairment of cellular immune responses). To understand the immunoregulatory phenomena associated with resistance and susceptibility in experimental PCM, A/Sn and B10.A mice were studied regarding antigen-elicited secretion of monokines (TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt; and TGF-ß) and type-1 (IL-2 and IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt;) and type-2 (IL-4,5,10) cytokines. Total lymph node cells from resistant mice infected ip with P. brasiliensis produced early and sustained levels of IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; and IL-2; type-2 cytokines (IL-4 and IL-5) started to appear 8 weeks after infection. In contrast, susceptible mice produced low levels of IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; concomitant with significant levels of IL-5 and IL-10 early in the infection. In the chronic phase of the disease, susceptible animals presented a transitory secretion of IL-2, and IL-4. In the pulmonary infection IL-4, IL-5 and IL-10 were preferentially detected in the lung cells washings of susceptible animals. After in vitro challenge with fungal antigens, normal peritoneal macrophages from B10.A mice secreted high levels of TGF-ß and low levels of TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt;. In contrast, macrophages from A/Sn animals released high levels of TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt; associated with a small production of TGF-ß. The in vivo depletion of IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; not only abrogated the resistance of A/Sn mice but also diminished the relative resistance of B10.A animals. The in vivo depletion of IL-4 did not alter the disease outcome, whereas administration of rIL-12 significantly enhanced resistance in susceptible animals. Taken together, these results suggest that an early secretion of high levels of TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt; and IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; followed by a sustained secretion of IL-2 and IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; plays a dominant role in the resistance mechanisms to P. brasiliensis infection. In contrast, an early and ephemeral secretion of low levels of TNF-&lt;FONT FACE="Symbol"&gt;a&lt;/font&gt; and IFN-&lt;FONT FACE="Symbol"&gt;g&lt;/font&gt; associated with production of IL-5, IL-10 and TGF-ß characterizes the progressive disease of susceptible animals.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000500003
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1998000500003
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.31 n.5 1998
Fonte: | info:eu-repo/semantics/openAccess