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Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (S1, PS2, and PS3) and by the new species, P. lutzii. Considering that genetic differences in the Paracoccidioides genus could elicit distinct immune responses by the host, current research investigated serum IgG levels to antigens from P. brasiliensis B339 (S1), P. brasiliensis LDR3 (PS2), and atypical strain LDR2 ( P. lutzii), in patients with chronic PCM from the northern and west regions of Paraná, Brazil ( n = 35). Cell-free antigen (CFA) and high molecular mass fraction (hMM) were produced from each strain. Samples were analyzed by ELISA and immunodiffusion (ID). ELISA positivity using CFA: B339-100 %, LDR3-83 %, and LDR2-74 %. Response to CFA from B339 was more intense ( p < 0.05), while there was no difference between LDR3-LDR2. IgG anti-hMM was higher for antigens from B339 or LDR3, when compared with LDR2 ( p < 0.05). There was a positive correlation for each strain between CFA-hMM and for hMM between B339-LDR3 and LDR3-LDR2. ID positivity with CFA: B339-63 %, LDR3-66 %, and LDR2-60 %. We conclude that the intensity of reaction of the patients’ sera varies with the strain used; hMM influences tests that use CFA, independently of strain; using ID, positive rates were very similar, but there was a large number of false negative results; ELISA tests using antigens from P. brasiliensis S1 were able to detect a larger number of patients than PS2 and P. lutzii (which had a considerable number of false negative results), and therefore, its use may be more appropriate in this region of Brazil. [ABSTRACT FROM AUTHOR]

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the fungus Paracoccidioides brasiliensis (Pb). The cyclosporin A (CsA) is an immunosuppressant drug that inhibits calcineurin and has been described as a potential antifungal drug. The present study investigated the effect of CsA on the immune response, fungal load/antigenemia in experimental murine PCM. It was used four groups of BALB/c mice: (a) infected with 1 × 10 Pb18 yeast cells (Pb), (b) infected and treated with CsA every other day 10 mg/kg of CsA (s.c.) during 30 days (Pb/CsA), (c) treated with CsA (CsA) and (d) no infected/treated (PBS). The immune response was evaluated by lymphocyte proliferation, DTH assays to exoAgs, ELISA for IgG anti-gp43 (specific immune responses) and cytokine serum levels (IFN-γ, TNF-α, IL-4 and IL-10). Fungal load was determined by lung colony-forming units (CFU) counts, lung and liver histopathology analysis and antigenemia determined by inhibition-ELISA. As expected, CsA was able to inhibit the specific cellular and humoral immune response ( P < 0.05), with decrease in serum IFN-γ, TNF-α and IL-4 levels ( P < 0.05). Cyclosporin A treatment also resulted in significantly decreased lung Pb CFU ( P < 0.05) as well as a lower number of yeasts in the lung and liver ( P < 0.05) by histopathology. In concordance, the decreased antigenemia was observed in Pb/CsA group ( P < 0.05). In conclusion, even with immunosuppressive action, treatment with CsA results in decreased lung fungal load/antigenemia in experimental PCM in BALB/c mice. Further study is required to determine whether this represents less severe disease or protection by CsA. [ABSTRACT FROM AUTHOR]

Histoplasma capsulatum var. capsulatum is a thermally dimorphic fungus that causes histoplasmosis. Fungal hemagglutination activity and cases of reactive hemophagocytic syndrome (RHS) have been reported in the disseminated form of disease. In the present study, soluble components of H. capsulatum var. capsulatum have been investigated for hemagglutinin activity and the capacity to induce hemophagocytosis in the mouse system. To analyze hemagglutinating activity, mouse red blood cells (RBC) (1% v/v in PBS) were incubated (37°C, 1 h) with cell-free antigen (CFAg) from H. capsulatum var. capsulatum (isolate IMT/HC128) (RBC-CFAg) or previously heated CFAg (56°C, 30 min) (RBC-hCFAg) or as control with PBS (RBC-PBS). Hemophagocytosis was analyzed by incubating BALB/c mouse peritoneal phagocytic cells (5 x 106 cells) with syngeneic RBC, sensitized or not with CFAg. In addition, mouse polyclonal antibodies were raised against syngeneic RBC-CFAg (anti-RBCCFAg) and used to analyze CFAg chromatographic fractions (Sephadex G75/120) by immunoenzymatic assay (ELISA). Hemagglutinin activity was observed with RBC-CFAg, but not with RBC-hCFAg or RBC. Also, hemophagocytosis was observed with RBCCFAg, but not with RBC. The anti-RBC-CFAg antibodies reacted with CFAg fractions corresponding to a molecular mass (MM) higher than 150 kDa. In conclusion, the yeast form of H. capsulatum var. capsulatum releases thermolabile soluble components with hemagglutinin activity and it has been demonstrated for the first time that soluble components of the same fungus induce syngeneic hemophagocytosis in the in vitro mouse system. Also, indirect analysis with antibodies suggests that high-MM components (> 150 kDa) are responsible for the interaction with RBC. [ABSTRACT FROM AUTHOR]