Epitope specificity of T cells induced by chemo-vaccination.

<p><b>A</b>: T cell specificities in PrEP-protected macaques 4284 and 35451 change rapidly during SHIV exposures and PrEP, while they remain more consistent in infected control macaque AG94, and in 4284 after infection. T cell specificities were determined by IFNγ-ELISPOT with 14 peptide pools represented by the indicated colors. The pie charts depict percentages of contributions to the T cell response. Arrows indicate time point of virus exposures, adjacent numbers indicate how many exposures were given. Seroconversion is recorded by “Y”; numbers indicates the study week of seroconversion. <b>B</b>: T cells induced by chemo-vaccination appear focused on epitopes derived from the <i>pol</i> region. IFNγ-ELISPOT responses to 14 peptide pools were combined for the indicated gene products; their contribution to the response (all 14 peptide pools) was calculated. All IFNγ-ELISPOT results from week 1–41 are depicted. N refers to number of macaques in the 4 specified groups. P-values were obtained by unpaired, two-sided student's t-tests comparing all results before infection (12 time-points from 3 chemo-vaccinated macaques, filled circles and open diamonds combined) to those after infection (56 time-points from 5 macaques in control or PrEP-infected groups, open circles and filled triangles combined).