Immunity and Treatment of Sporotrichosis

Abstract

Species of the Sporothrix complex are the etiological agents of sporotrichosis, an important subcutaneous mycosis with several clinical forms and an increasing incidence around the world that affects humans and other mammals. The immunological mechanisms involved in the prevention and control of this mycosis are not entirely understood. Many reports have suggested that cell-mediated immunity has an essential role in the development of the disease, being the primary response controlling it, while only recent data supports that the humoral response is essential for the appropriate control. This mycosis is a challenge for diagnosis since the culture and isolation of the organism are time-consuming and complicated; reasons that have led to the study of fungus antigenic molecules capable of generating a detectable humoral response. The treatment for this disease includes the use of several antifungal drugs like itraconazole, amphotericin B, caspofungin, fluconazole, and the combination between them among others such as the extract of Vismia guianensis.

Keywords: antifungal; host-defense; immunity; sporotrichosis.

Figure 1

Host immune response against Sporothrix spp. (1) Infection with Sporothrix occurs by the traumatic inoculation of yeasts, conidia, or hyphae. Once the fungus crosses the primary barriers of the immune system, (2) components of the pathogen trigger the innate immune response including cells and molecules to attack the invader. (3) Several molecules of the fungus active T cells by being presented as antigens (i.e., peptides of Gp70). (4) Protective antibodies against the fungus are generated. All of this is for the clearance of the pathogen. MNC: Mononuclear cells. PMNC: Polymorphonuclear cells. NK: Natural Killer cells. Black arrows: infection sequence. Red arrows: increased production and participation during infection. Orange arrow: increased secretion during infection.