Expression of CD23 and CD11b molecules by macrophage populations in the course of pulmonary infection with Paracoccidioides brasiliensis conidia in susceptible and resistant mice

Abstract

We have been studying the expression of CD11b, CD23 and other cellular markers of macrophage populations in the inflammatory events in the lung of mice inflamed with β- glucan enriched-Paracoccidioides brasiliensis cell wall fraction. In this paper, we used flow eytometry and RT-PCR to analyse the expression of those molecules in the macrophages obtained from mice with diferente degrees of resistance or susceptibility against P. brasiliensis. When β-glucan enriched-cell wall fraction, or viable conidia, was introduced by intranasal or intraperitoneal routes, the expression of CD23 was significant higher in macrophages obtained from susceptible mice. In the other hand, the expression of CD11b/CD18 was enhanced in macrophages obtained from both resistant and susceptible mice. The expression of CD23 or CD11b/CD18 was up or down-regulated in vitro by the addition of recombinant IL-4 or IFN-ϒ. Despite of these findings, proinflammatory macrophage subpopulations from both mice strains had no significant diferences concerning CD11b or CD23 mRNA expression when infected with conidia by intranasal route. Our results indicated that CD23₊ macrophages could be related to the initial inflammatory events in the lung of susceptible mice, which seemed to be not involved with alterations in the level of mRNA expression.