Distinct
glycolipid profiles are described in microorganisms, which have been shown to modulate the innate immune system. We tested the hypothesis that
glycosphingolipids from Paracoccidioides brasiliensis have immunomodulatory properties on monocytes and dendritic cells of two groups of healthy individuals, one cured of
paracoccidioidomycosis in the past (CUR-I) and the other nonexposed to P. brasiliensis (HNE-I). Two classes of
glycosphingolipids purified from yeast cells were evaluated: a neutral
glycosphingolipid,
monohexosylceramide (CMH), and acidic glycosylinositolphosphorylceramides (GIPCs). Both
glycosphingolipids affected the functioning of innate immunity cells, interfering with the
antigen presenting process: P. brasiliensis yeast cells phagocytosis,
IL-10 secretion, and costimulatory molecules and recognition receptors expression by monocytes were altered, while dendritic cell antigen presentation to autologous T cells was markedly down-modulated as shown by reduced T-cell proliferative responses. The mechanisms by which CMH and GIPCs exert their effects differ since the target cells did not always respond similarly to the challenge with the
glycosphingolipids. Moreover, CUR-I and HNE-I presented different responses to the
glycosphingolipids. Differences not only in the
glycosphingolipid structure (such as the polar head group or the
ceramide moiety), but also in the innate immunity properties of CUR-I and HNE-I, may underlie these differences and contribute to individual's susceptibility or resistance to develop
paracoccidioidomycosis.