Figure 3.

Reduced TCR activation threshold and enhanced antigen-specific T-cell response by CompK. (A) Decreased threshold of TCR activation by viral antigen via CompK treatment. CD8+ T cells specific to HPV E7 antigen were cocultured with E7 or control peptide pulsed T2 cells for 18 hours in the presence of different concentrations of E7 peptides and 0.5 µM CompK; IFN-γ release was measured at the end of the study. (B) Required presence of APCs (T2 cells) in increased IFN-γ production by CompK. HPV E7 peptide was presented with either HLA-A2 dimer or T2 cells to stimulate E7-specific CD8+ T cells for 72 hours followed by measurement of IFN-γ release. (C) Significant synergy of IFN-γ production by CFET-specific T cells by combination of CompK and anti-PD1. CFET-specific T cells were cocultured with CFET pulsed APCs in the presence of different concentrations of CompK, along with 5 µg/mL anti-PD1 for 24 hours, followed by measurement of IFN-γ secretion. (D) Augmented tumor lysis by tumor antigen-specific T cells. Study was conducted by coculturing T cells with engineered TCR specific to NY-ESO-1 and sarcoma cells with endogenous expression of HLA-A2 restricted NY-ESO-1. IFN-γ secretion was analyzed at the end of the study. All studies were repeated three times and representative graphs are shown here. APCs, antigen-presenting cell; CFET, cytomegalovirus, Epstein-Barr virus, influenza and tetanus toxin; CompK, compound K; DMSO, dimethyl sulfoxide; HPV, human papillomavirus; IFN-γ, interferon gamma; TCR, T-cell receptor; aPD1, anti PD1.