Recognition of Escape Variants in ELISPOT Does Not Always Predict CD8+ T-Cell Recognition of Simian Immunodeficiency Virus-Infected Cells Expressing the Same Variant Sequences.

Human immunodeficiency virus (HIV)'s tremendous sequence variability is a major obstacle for the development of cytotoxic-T-lymphocyte-based vaccines, especially since much of this variability is selected for by CD8+ T cells. We investigated to what extent some of the variants was, however, markedly reduced. These mutations which reduced avidity also abrogated recognition by epitope-specific CD8+ T cells in a viral suppression assay. Our results indicate that "cross-reactive" CD8+ T-cell responses identified in ELISPOT and ICS assays using a single high concentration of variant peptide often fail to predict the recognition of cells infected with variant viruses. [ABSTRACT FROM AUTHOR]