Definition: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
Input: A CTL antigenic site located between residues 273 and 291 of the E1 envelope protein of RV was identified by 51Cr_release assays employing SPs. Two E 1specific CTL clones were examined for immune recognition of RV wild-type and attenuated vaccine strains and recombinant E1 protein. The exact sequence (273-284) recognized by both clones was delineated by using truncated and overlapping SPs covering these residues. The defined T-cell site overlapped almost completely with a virus neutralizing antibody-binding site previously identified with mouse monoclonal and human antibodies. A series of single aa-substituted SP analogues of E1(273-284) was used to define residues critical for T-cell recognition. Using EBV-BL displaying different HLA-DR haplotypes and -DR4 subtypes as targets to determine MHC class II restriction elements, immune recognition by both T-cell clones was shown to be associated with HLA-DR4. Three HLA-DR4 subtypes (DR4Dw13A, DR4Dw13B, and DR4KT2) sharing a common residue, glutamic acid at position 74 in their ~ 1 chains, were able to present SP E1(273-284) to the T-cell clones.

Analysis of Overlapping T-and B-Cell Antigenic Sites on Rubella Virus E1 Envelope Protein Influence of HLA-DR4 Polymorphism on T-Cell Clonal Recognition