IFN-γ secretion by splenocytes exposed to soluble and transfected HIV-v polypeptides. Splenocytes of HLA-A*0201 transgenic mice immunised with HIV-v or NRP-v were exposed in vitro to Vpr (A), Vif (B), Rev (C) and Nef (D) polypeptides as well as polypeptides transfected in syngeneic T1 (T1-Vpr, T1-Vif, T1-Rev and T1-Nef) and allogeneic JURKAT (Ju-Vpr, Ju-Vif, Ju-Rev and Ju-Nef) cells. IFN-γ production is represented as the net increment in IFN-γ production (pg/ml) over the response to the negative control antigens Lysozyme or non-transfected cells (25 ±10 pg/ml for soluble Lysozyme, 316 ±43 pg/ml for T1 cells, and 19 ±6 pg/ml for JURKAT cells, average ± SEM). Con A was used as a standard positive control to confirm assay validity. A positive response, indicated by an asterisk (*), was defined as an increment of at least 30% over the control group’s response with a statistical significance of p < 0.05. Splenocytes from each individual were assayed separately in quadruplicate wells. This graph is a representative of three independent experiments.