Presentation of KS tumor lysate is CD91 dependent. The effect of an allogeneic tumor lysate, TNF-α administration, at 10 ng/mL and blockade of CD91 receptors with or without TNF-α. Results from 1 patient with a low CD4 count (patient 12) are shown. CD8 depletion abrogated responses, and no responses to KS lysate were observed in 6 HIV⁺/KSHV–controls. Where δ-cpm < 0 and SI < 1.0 indicates that the background cpm was greater than the observed experimental cpm. Experiments using tumor lysate and monocyte-derived DCs labeled with an isotype antibody (anti-CD3) did not change the observed results when compared with tumor lysate alone.