HXTCs release multiple proinflammatory cytokines and are polyclonal. (a) IL-2 and (b) TNF-a release by HXTCs in response to no antigen (neg), Gag, Pol, and Nef PepMix was measured by ELISA as described in the Materials and Methods section (representative of n = 3, error bars represent SD). (c) Vβ usage of HXTCs was analyzed using a flow cytometry–based assay, IOTest Beta Mark TCR V Kit (BD Biosciences). (d) HXTCs were tested against the Nef group M consensus region broken up into peptide pools containing seven to eight peptides each in an IFN-γ ELIspot assay. *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001, and ****P ≤ 0.0001.