Rhaphidophora korthalsii (Araceae) is a root-climber plant which has been widely used in Chinese traditional medicine for cancer and skin disease treatment. Previous reports have recorded its immunomodulatory effects on mice splenocyte and human peripheral blood. This study investigated the potential immunostimulatory effect of Rhaphidophora korthalsii on human PBMC enriched NK cell.
The ever-increasing number of tumor-associated antigens has provided a major stimulus for the development of therapeutic peptides vaccines. Tumor-associated peptides can induce high immune response rates and have been developed as vaccines for several types of solid tumors, and many are at various stages of clinical testing. MAGED4B, a melanoma antigen, is overexpressed in oral squamous cell carcinoma (OSCC) and this expression promotes proliferation and cell migration. In this study, we have identified 9 short peptides derived from MAGED4B protein that are restricted in binding to the HLA subtypes common in the Asian population (HLA-A2, A11, and A24). The peptides had good binding affinity with the MHC-Class I molecules and stimulated ex-vivo IFN-gamma and Granzyme-B production in blood samples from OSCC patients, suggesting that they are immunogenic. Further, T cells stimulated with peptide-pulsed dendritic cells showed enhanced T-cell cytotoxic activity against MAGED4B-overexpressing OSCC cell lines. In summary, we have identified MAGED4B peptides that induce anti-tumor immune responses advocating that they could be further developed as vaccine candidates for the treatment of OSCC.