Abstract
The transition of Candida albicans from commensalism to pathogenicity is associated with the immune status of the host; resistance to fungus involves macrophages (Mϕ) and polymorphonuclear neutrophils (PMN), which act as effector cells. T-cell function is also involved. Previously, we found that in Wistar rats exposed to chronic varied stress (CVS) immediately after C. albicans infection (Ca-S group) some functions of phagocytic cells, such as killer activity and NO production, were strongly modified compared with unstressed, infected animals (Ca group). We examined the phenotypic and functional changes of these effector cells recruited at the site of C. albicans infection. The recruitment of peritoneal cells (PC) was markedly reduced in Ca-S animals and the arrival of Mϕ and PMN was selectively diminished after CVS exposure. The integrin CD11b/CD18, implicated in migration and C. albicans phagocytosis, was downregulated in Mϕ of Ca-S animals. The activation markers CD54 and MHC-II were upregulated in Mϕ after fungal contact. The expression of CD54 was only changed in Ca-S rats. Finally, TNF-α production was reduced in PC of Ca-S animals, suggesting an impairment of functional activity. Taken together, the phenotypic and functional changes detected in effector cells may account for the decreased resistance to candidiasis seen in conjunction with CVS. The changes seen also expand our knowledge of the role of Mϕ in the control of C. albicans dissemination.