Figure 4. MPER-dependent CD4 T_H activation, proliferation and IFNγ secretion in MHC H-2^b and H-2^d congenic strains.

A. MPER-induced proliferation of purified CD4 cells from immunized BALB/c and BALB.B mice (taken 10d after 5^th immunizations with experimental regimen). In vitro re-stimulations were done using 5 μM of the MPER 656 peptide with the various denoted cell fractions used as APCs, and proliferation was measured by [³H] thymidine incorporation, as described in the Materials and Methods section. The CD4 T-cell proliferation index shown was calculated as the cpm ratio of peptide re-stimulated groups: control (unstimulated) groups. B. MPER-dependent proliferation of CD4 splenic subsets from immunized mice (10d after 5^th immunizations with the experimental regimen) was measured by CFSE analysis. Numbers shown represent the percentage of dividing cells (i.e. denoted CFSE low). C. MPER-dependent T_H effector activation (CD69 expression), proliferation (BrdU incorporation) and cytokine expression (IFNγ intracellular staining), were measured by flow cytometry. Numbers shown are MPER-induced T_H effector CD4 cells/10⁶ total CD4 cells.