Screening assays and methods of using same for screening to identify modulator agents or compounds that affect matrix metalloproteinase-2 (MMP-2) mediated activation of toll-like receptor-2 (TLR-2) are described herein. Pharmaceutical and immunogenic compositions comprising agents or compounds that modulate MMP-2 mediated activation of TLR-2 are also encompassed. Methods for modulating MMP-2 mediated activation of TLR-2 using MMP-2 peptides in pharmaceutical and immunogenic compositions, as well as vaccines, are also envisioned. Melanoma is an exemplary tumor type that expresses MMP-2 and for which such pharmaceutical and immunogenic compositions, as well as vaccines, would confer benefit to patients. Also encompassed are methods for reducing MMP-2 mediated activation of TLR-2 and downstream signaling therefrom so as to achieve more effective T cell responses to MMP-2 expressing tumors.