TCR CDR3-antigen chemical complementarity associated with poor ovarian cancer outcomes: A vestigial immune response to early cancer antigens?

Ovarian cancer continues to present significant challenges for early detection and treatment, indicating a need for novel approaches to improve disease outcomes. In this report, we applied a previously described algorithm for detecting chemical complementarity between candidate cancer antigens and complementarity determining region-3 (CDR3) amino acid sequences from tumor resident T-cell receptors. Current literature indicates an association between high CDR3-cancer antigen complementarity and improved survival outcomes. For example, high CDR3-BRAF electrostatic complementarity is associated with a better melanoma outcome. However, such CDR3-cancer antigen chemical complementarity in ovarian cancer was largely associated with worse outcomes. Specifically, high CDR3-MAGEB4 and CDR3-TDRD1 electrostatic complementarity was associated with lower ovarian cancer disease free survival (DFS). Additionally, high CDR3-MAGEB4 and CDR3-TDRD1 electrostatic complementarity was associated with decreased MAGEB4/TDRD1 gene expression and gene copy numbers, consistent with a selection against ovarian cancer cells expressing these antigens. However, when TDRD1 was split into fragments, high CDR3-TDRD1 hydrophobicity complementarity, for a specific TDRD1 fragment, was associated with increased DFS and higher immune marker expression levels. This dichotomy highlights the myriad of opportunities to establish risk stratifications and to identify potential, actionable cancer antigens using immunogenomic parameters.