Figure 1: Immunization with an adenovirus encoding the multiepitope gene (Ad5-HIVBr18) elicits higher proliferative responses when compared to other regimens. BALB/c mice (6 per group) were immunized intramuscularly (IM) with the DNA vaccine HIVBr18 (3 doses); or received 2 doses of 2x108 PFU of recombinant adenovirus (Ad5) by intramuscular (IM) or subcutaneous (SC) route; or received a heterologous prime-boost regimen based on a DNA prime (IM), Ad5 boost (IM or SC). Control groups received pVAX1 plasmid and/ or Ad5-▀gal.Two weeks after the last immunization; splenocytes from each immunized group were pooled, labeled with CFSE (1.25ÁM) and cultured for 5 days, in the presence of 5ÁM of pooled HIV-1 peptides. Cells were analyzed by flow cytometry and CFSE dilution on gated CD3+CD4+M or CD3+CD8+ cells was used as readout for antigen-specific proliferation. Cutoff values were 1.7% for CD4+ and 1.5% for CD8+ T cells. Only significant differences with the DNA immunized group are depicted (*p<0.05 and ***p<0.001). DNA= HIVBr18; Ad5= adenovirus 5 encoding HIVBr18.