Circulating CD4+ T-cells that produce IL-4 or IL-17 when stimulated by Melan-A but not by NY-ESO-1 have negative impacts on survival of stage IV melanoma patients

Item does not contain fulltextPurpose: We initially observed that the presence of circulating NY-ESO-1- and/or Melan-A-specific T-cells in stage IV melanoma patients was significantly associated with prolonged survival. Here we report on how the phenotypes and functions of these T-cells differentially impact survival in patients pre-selected for NY-ESO-1 and/or Melan-A reactivity. Experimental Design: We assayed functional antigen-reactive T-cells recognizing NY-ESO-1 and/or Melan-A after in vitro stimulation using overlapping peptide pools. After restimulation, we assayed six cytokines simultaneously by intracellular cytokine staining. This allowed us to analyze the functional antigen-response of both CD4+ and CD8+ T-cells at the single-cell level. Results: We observed that NY-ESO-1 stimulated mainly CD4+ T-cells, whereas Melan-A more often stimulated CD8+ T-cells. NY-ESO-1-reactivity was not associated with an additional impact on survival whether CD4+ or CD8+ T-cells or both were responding. In contrast, recognition of Melan-A by CD4+ T-cells was associated with reduced survival in our cohort of patients pre-selected for NY-ESO-1 and/or Melan-A reactivity i.e. in patients with exceptionally long survival. We further observed a negative effect on survival in patients with CD4+ T-cells producing IL-4 and IL-17 upon Melan-A stimulation. Their prognosis was comparable to patients without any Melan-A reactivity. Conclusions: The nature and prognostic impact of specific T cell responses is different according to targeted antigen. Independent from phenotype and functional aspects, NY-ESO-1-reactivity is associated with good prognosis. For Melan-A, antigen-specific CD8+, but not CD4+ responses are associated with prolonged survival