Toxoplasma gondii antigen SAG2A differentially modulates IL-1ß expression in resistant and susceptible murine peritoneal cells.

The cell surface of Toxoplasma gondii is covered by antigens (SAGs) from the SRS family anchored by glycosylphosphatidylinositol (GPI) and includes antigens from the SAG2 family. Among these, the SAG2A surface antigen shows great potential in activating humoral responses and has been used in characterizing the acute phase of infection and in the serological diagnosis of toxoplasmosis. In this study, we aimed to evaluate rSAG2A-induced proteins in BALB/c and C57BL/c mice macrophages and to evaluate the phenotypic polarization induced in the process. We treated the peritoneal macrophages from mouse strains that were resistant or susceptible to T. gondii with rSAG2A to analyze their proteomic profile by mass spectrometry and systems biology. We also examined the gene expression of these cells by RT-qPCR using the phenotypic markers of M1 and M2 macrophages. Differences were observed in the expression of proteins involved in the inflammatory process in both resistant and susceptible cells, and macrophages were preferentially induced to obtain a pro-inflammatory immune response (M1) via the overexpression of IL-1ß in mice susceptible to this parasite. These data suggest that the SAG2A antigen induces phenotypic and classical activation of macrophages in both resistant and susceptible strains of mice during the acute phase of the disease.

Immunoblotting using Strongyloides venezuelensis larvae, parthenogenetic females or eggs extracts for the diagnosis of experimentally infected immunosuppressed rats.

The nematode Strongyloides stercoralis is responsible for strongyloidiasis in humans. Diagnosis of infection occurs through detection of larvae in feces, but low elimination of larvae often hampers the detection of disease, particularly in cases of patient immunosuppression. Immunodiagnostic tests have been developed; however obtaining S. stercoralis larvae for the production of homologous antigen extract is technically difficult. Thus, the use different developmental forms of Strongyloides venezuelensis has become an alternative method for the production of antigen extracts. The aim of this study was to evaluate immunoblotting using alkaline extracts from S. venezuelensis L3 larvae, parthenogenetic females or eggs to test detection of experimental strongyloidiasis associated with immunosuppression. Immunocompetent and immunosuppressed male rats were experimentally infected, and serum sample from all animals were obtained at 0, 5, 8 13, and 21 days post infection (d.p.i.). Immunoblotting was evaluated for use in detection of anti-S. venezuelensis IgG in both experimental rat groups. The larval extract immunoblotting profile had the most immunoreactive fractions in the immunosuppressed group beginning at 5 d.p.i., while the immunocompetent group reactivity began on 8 d.p.i. Immunoreactive protein fractions of 17 kDa present in larval alkaline extract presented as possible markers of infection in immunosuppressed rats. It is concluded that all extracts using immunoblotting have diagnostic potential in experimental strongyloidiasis, particularly larval extract in immunosuppressed individuals.