Cloning of human T cells specific for measles virus haemagglutinin and nucleocapsid.

T cell lines specific for measles virus (MV) were generated from blood of two DR1/DR2 heterozygous healthy donors with a history of past measles infection. The antigenic specificity of 66 T cell clones derived from the lines was studied in a blastogenic assay using whole measles virus and two purified virus components, haemagglutinin and nucleocapsid. Thirty-nine of the clones were specific for one of the two purified antigens. None of the seven synthetic peptides covering 20% of the MV haemagglutinin amino acid sequence stimulated T cell clones with haemagglutinin specificity. Responsiveness of the majority of the clones were restricted by HLA-D/DR antigens, although two clones were isolated that responded only to MV antigens presented by autologous cells. Ten of 11 clones recognizing the nucleocapsid antigen were DR1-restricted, while the haemagglutinin antigen and whole measles virions were recognized more often in association with the DR2 antigen. These results indicate that much of the MV-specific memory T cell response is specific for the haemagglutinin and nucleocapsid virus antigens, with the DR antigen being the main restriction element involved.