Prime-Boost Vaccination Using Chemokine-Fused gp120 DNA and HIV Envelope Peptides Activates Both Immediate and Long-Term Memory Cellular Responses in Rhesus Macaques

Figure 2

The immunization strategy elicited mucosal long term memory T-cell immune responses. Production of IFN-𝛾 by CD3⁺CD4⁺ or CD3⁺CD8⁺ memory T cells isolated from colon was analyzed in the vaccinated macaques one year after final peptide-cocktail boost. Lamina propria lymphocytes (LPL) from colon biopsy samples were stimulated with peptide-mix or mitogens for 6 h. Both untreated (control) and stimulated cells were stained for surface markers, followed by fixation, permeabilization, and intracellular staining of IFN-𝛾. Live cells were identified by gating on Aqua-negative cells. The cells gated on CD3⁺CD4⁺ and CD3⁺CD8⁺ were further separated as memory population according to the expression of CD95 (data not shown). The percentage values indicate the population of IFN-𝛾—producing CD3⁺ CD95⁺CD4⁺ or CD3⁺ CD95⁺CD8⁺ lymphocytes.

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