Fig. 3

Antigen presentation activity of murine DCs and MΦs against BCG infection. (A) Detection of murine DCs and MΦs Ag-presenting activity ex vivo. LN DCs and MΦs from the inguinal LN were harvested and sorted at various time points groups after s.c injection of mice (n = 5) with BCG. Cells were then serially diluted and used to directly stimulate DE10 T-cell hybridomas. In vivo formation of Ag85A peptide-MHC complexes on LN DCs and MΦs from mice injected with Ag85A protein or BCG were estimated by measuring IL-2 production in DE10 T-cell hybridoma culture supernatants ex vivo. (B) Analysis of costimulatory molecules on MΦs following BCG infection. Inguinal LNs were obtained at different time points group following s.c infection of mice with 1 × 10⁸ CFU BCG (n = 5), and MΦs were sorted and stained with a panel of mAbs to detect cell-surface expression of CD40, CD80, CD86 and MHC II using FACS. The experiment was repeated at least three times. (C) Expression of MHC II and CIITA by MΦs following BCG infection. Inguinal LNs were obtained from mice of four group (n = 5) at different time points following s.c injection of 1 × 10⁸ CFU BCG, transcription levels of MHC II, total CIITA, CIITA types I and IV were analysed using real-time PCR. The results are representative of three independent experiments and presented as means ± SEM. Statistical significance was determined using Student’s t-test (*P < 0.05, **P < 0.01)