Figure 2: SAG increases MHC class I mediated antigen presentation and upregulates expression of MHC class I. MΦs isolated from BALB/c and C57BL/6 mice, cultured in presence or absence of SAG for 24 h. (a) To study the antigen presenting function, peritoneal MΦs from BALB/c and C57BL/6 mice either kept untreated or treated with SAG for 24 h, were used as antigen presenting cells to drive the T-cell hybridoma in presence of appropriate peptide and IL-2 secretion was tested on IL-2-dependent cell line (HT-2). The growth of HT-2 was studied using 3H-Thymidine incorporation. The studies showed that class I but not class II restricted presentation was significantly ( ) enhanced upon SAG treatment both in normal and infected MΦ. (b) To study the expression of MHC I molecules, untreated (filled histogram) and SAG-treated (open histogram) MΦs from BALB/c mice were stained with FITC labeled anti-Dd (BD Pharmingen) according to manufacturer’s instruction and either analyzed on flow cytometer or examined under a confocal laser scanning microscope. The studies showed that class I expression was significantly ( ) enhanced upon SAG treatment. Antigen presentation assay was performed at least thrice and the results are presented as mean ± SD. For flow cytometry and confocal microscopy, representative data of 3 similar experiments is presented here.