Minor structural changes in a mutated human melanoma antigen correspond to dramatically enhanced stimulation of a CD4+ tumor-infiltrating lymphocyte line.Sundberg, E.J., Sawicki, M.W., Southwood, S., Andersen, P.S., Sette, A., Mariuzza, R.A.
(2002) J Mol Biol 319: 449-461
- PubMed: 12051920
- DOI: 10.1016/S0022-2836(02)00370-4
- Primary Citation of Related Structures:
- PubMed Abstract:
- Biochemical identification of a mutated human melanoma antigen recognized by CD4+ T cells
Pieper, R., Christian, R.E., Gonzales, M.I., Nishimura, M.I., Gupta, G., Settlage, R.E., Shabanowitz, J., Rosenberg, S.A., Hunt, D.F., Topalian, S.L.
(1999) J Exp Med 189: 757
While most immunotherapies for cancer have focused on eliciting specific CD8+ cytotoxic T lymphocyte killing of tumor cells, a mounting body of evidence suggests that stimulation of anti-tumor CD4+ T cell help may be required for highly effective therapy ...
While most immunotherapies for cancer have focused on eliciting specific CD8+ cytotoxic T lymphocyte killing of tumor cells, a mounting body of evidence suggests that stimulation of anti-tumor CD4+ T cell help may be required for highly effective therapy. Several MHC class II-restricted tumor antigens that specifically activate such CD4+ helper T lymphocytes have now been identified, including one from a melanoma tumor that is caused by a single base-pair mutation in the glycolytic enzyme triosephosphate isomerase. This mutation results in the conversion of a threonine residue to isoleucine within the antigenic epitope, concomitant with a greater than five log-fold increase in stimulation of a CD4+ tumor-infiltrating lymphocyte line. Here, we present the crystal structures of HLA-DR1 in complex with both wild-type and mutant TPI peptide antigens, the first structures of tumor peptide antigen/MHC class II complexes recognized by CD4+ T cells to be reported. These structures show that very minor changes in the binding surface for T cell receptor correspond to the dramatic differences in T cell stimulation. Defining the structural basis by which CD4+ T cell help is invoked in an anti-tumor immune response will likely aid the design of more effective cancer immunotherapies.
Center for Advanced Research in Biotechnology, W. M. Keck Laboratory for Structural Biology, University of Maryland Biotechnology Institute, 9600 Gudelsky Drive, Rockville, MD 20850, USA. firstname.lastname@example.org