HIGH MOLECULAR WEIGHT ANTIGENIC COMPONENTS OF PARACOCCIDIOIDES BRASILIENSIS: PARTIAL CHARACTERIZATION AND IMPLICATIONS FOR TH1 RESPONSE

Abstract

Paracoccidioidomycosis (PCM) is a chronic infection caused by the fungi Paracoccidioides brasiliensis or P. lutzii, whose host defense is mediated by Th1 lymphocytes. This study aimed to purify and evaluate the effect of high molecular weight (hMM) components of P. brasiliensis on the cellular immune response. The soluble antigens of the fungus (Pb18) were submitted to Sephadex G-200 column chromatography followed by HPLC, obtaining the F17 fraction (~380 kDa) and its F17-IV subfraction (~70 kDa), both reactive to sera from patients with PCM. The fractions were tested in vitro with the splenic cells of infected mice, resulting in lymphoproliferative response and increased levels of INF-γ and IL-10, without IL-4 alteration. These findings indicate the activation of the Th1 immune response and suggest that the ~380 kDa fraction can degrade generating active subcomponents of ~70 kDa. The ~70 kDa subcomponent appears to be distinct from the gp70 described in the literature, given its ability to induce INF-γ. The results point to the immunogenic potential of these components, highlighting their relevance for the development of vaccines or therapies against PCM.

DOI: https://doi.org/10.56238/sevened2024.039-009