Characterization of MHC class I restricted cytotoxic T cell responses to tax in HTLV-1 infected patients with neurologic disease.

To understand the nature of the cytotoxic T cell response generated in human T lymphotropic virus type 1 (HTLV-1)-infected patients with HTLV-1-associated myelopathy/tropical spastic paraparesis, we cloned CTL from the peripheral blood and cerebrospinal fluid from patients with neurologic diseases and demonstrated the presence of HLA-A2, A3, and B14 restricted responses to the HTLV-1 p40x (tax) protein. We identified the minimal amino acid residues within the epitopes required for binding and recognition by HLA-A2- and B14-restricted CTL, identified the critical residues within the peptide sequence defining the HLA-A2-restricted response, and demonstrated that CTL can lyse T cells infected with HTLV-1. This study shows that the CTL response to HTLV-1 tax in patients with neurologic diseases is heterogenous in nature and is not confined to patients of a single HLA haplotype or to a specific region of the tax protein.