Identification of a Human Cyclin D1-Derived Peptide that Induces Human Cytotoxic CD4 T Cells

Abstract

Cyclin D1 is over-expressed in various human tumors and therefore can be a potential oncogenic target antigen. However, only a limited number of T cell epitopes has been characterized. We aimed at identifying human cyclin D1-derived peptides that include both CD4 and CD8 T cell epitopes and to test if such multi-epitope peptides could yield improved cytotoxic CD8 T cell responses as well as cytotoxic CD4 T cells. Five HLA-DR.B1-binding peptides containing multiple overlapping CD4 epitopes and HLA-A0201-restricted CD8 T cell epitopes were predicted by computer algorithms. Immunogenicity of the synthetic peptides was assessed by stimulating T cells from healthy donors in vitro and the epitope recognition was measured by IFN-γ ELISPOT and 51Chromium release assays. A HLA-DR.B1 peptide, designed “DR-1”, in which a HLA-A0201-binding epitopes (D1-1) was imbedded, induced CD3 T cell responses against both DR-1 and D1-1 peptides in IFN-γ ELISPOT assay. This suggested processing of the shorter D1-1 epitope from the DR-1 sequence. However, only DR-1-stimulated CD4 or CD3 T cells possessed cytotoxicity against peptide-pulsed autologous DCs and a cancer cell line, that expresses a high level of cyclin D1. Monoclonal antibody to HLA-DR abrogated the epitope-specific responses of both CD3 and CD4 T cells, demonstrating class II-mediated killing. Our studies suggest a possible role of CD4 T cells in anti-tumor immunity as cytotoxic effectors against HLA-DR expressing cancers and provide a rationale for designing peptide vaccines that include CD4 epitopes.

Therapeutic bispecific T-cell engager antibody targeting the intracellular oncoprotein WT1

“…16), Prame-435 (ref. 17); or Ewings sarcoma epitope EW 18 that are also presented by HLA-A*02:01, or to A*02:01 − HL60 cells. The T-cell response against SET-2 showed recognition of other yet-to-be defined epitopes that are neither WT1 nor HER2/Neu.…”

“…Microtiter plates were incubated for 20 h at 37 °C and then extensively washed with PBS/0.05% Tween and 100 μl/well biotinylated detection antibody against human IFN-γ (2 μg/ml; 7-B6-1; Mabtech) was added. Plates were incubated for an additional 2 h at 37 °C and spot development was done as described 18 . Spot numbers were automatically determined with the use of a computer-assisted video image analyzer with KS ELISPOT 4.0 software (Carl Zeiss Vision).…”

Regulation of CD4 T cells and their effects on immunopathological inflammation following viral infection

“…This could only be achieved by selective CD4 T-cell vaccination. However, single induction of CD4 T-cell responses (in the complete absence of CD8 T-cell responses) is difficult to achieve in nature, as many CD4 T-cell epitopes contain shorter overlapping CD8 T-cell epitopes, 15,20,[38][39][40][41][42] ensuring that both cytotoxic CD8 T cells and helper CD4 T cells are generated following antigen challenge.…”

Spontaneous Peripheral T-cell Responses toward the Tumor-Associated Antigen Cyclin D1 in Patients with Clear Cell Renal Cell Carcinoma

“…Cyclin D1 induces T-cell responses in mantle cell lymphoma and colon cancer, and antibodies in prostate cancer (46)(47)(48)(49), and was identified as a target for immunotherapy in mantel cell lymphoma (50).…”