Carbohydrate-rich high-molecular-mass antigens are strongly recognized during experimental Histoplasma capsulatum infection

• Published in: Revista da Sociedade Brasileira de Medicina Tropical
• Main Authors: Fabrine Sales Massafera Tristão, Paula César Leonello, Luciene Airy Nagashima, Ayako Sano, Mário Augusto Ono, Eiko Nakagawa Itano
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedade Brasileira de Medicina Tropical (SBMT) 2012
• Subjects: Antígenos solúveis; Histoplasmose; Imunocomplexos; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.1590/S0037-86822012000200018; https://doaj.org/article/08e1ba4c803e421ea4688dd020aea4f6

INTRODUCTION: During histoplasmosis, Histoplasma capsulatum soluble antigens (CFAg) can be naturally released by yeast cells. Because CFAg can be specifically targeted during infection, in the present study we investigated CFAg release in experimental murine histoplasmosis, and evaluated the host humoral immune response against high-molecular-mass antigens (hMMAg. >150 kDa), the more immunogenic CFAg fraction. METHODS: Mice were infected with 2.2x10(4) H. capsulatum IMT/HC128 yeast cells. The soluble CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg circulating immune complexes (CIC) levels were determined by enzymelinked immunosorbent assay, at days 0, 7, 14, and 28 post-infection. RESULTS: We observed a progressive increase in circulating levels of CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg CIC after H. capsulatum infection. The hMMAg showed a high percentage of carbohydrates and at least two main immunogenic components. CONCLUSIONS: We verified for the first time that hMMAg from H. capsulatum IMT/HC128 strain induce humoral immune response and lead to CIC formation during experimental histoplasmosis.