Immunotherapeutic targeting of established sarcoma in Swiss mice by tumor-derived antigen-pulsed NLGP matured dendritic cells is CD8+ T-cell dependent.

OBJECTIVE

Neem leaf glycoprotein (NLGP) matures human myeloid and mouse bone marrow-derived dendritic cells (DCs). (NLGP) also therapeutically restricts the mouse established sarcoma growth by activating CD8(+) T cells along with increased proportion of tumor residing CD11c(+) DCs. Here, we intended to find out whether CD8(+) T cells become cytotoxic to sarcoma cells after presentation of sarcoma antigen by NLGP-matured DCs to restrict murine sarcoma growth.

METHODS

NLGP was prepared from matured neem(Azadirachta indica) leaves. Solid sarcoma tumor in Swiss mice was developed by subcutaneous inoculation of sarcoma cells. GMCSF-IL-4 generated DCs were matured with NLGP and pulsed with sarcoma antigen for immunotherapy. Status of CD8+CD69+T cells was studied by flow cytometry and secretion of cytokines was measured by ELISA. RT-PCR was used to monitor the status of perforin, granzyme B.

RESULTS

NLGP-matured sarcoma antigen-pulsed DCs (DCNLGPTAg) inhibit mouse sarcoma growth. DCNLGPTAg immunization enhances CD8(+) T-cell number within tumor-infiltrating lymphocytes and tumor-draining lymph nodes along with increased perforin and granzyme B expression. Antigen-specific T-cell proliferation and IFN-γ secretion were significantly higher in DCNLGP- and DCNLGPTAg-immunized mice groups. In vivo CD8(+) T-cell depletion abrogated the DCNLGPTAg-mediated tumor growth restriction.

CONCLUSIONS

DCNLGPTAg restricts CD8(+) T-cell-dependent mouse established sarcoma growth, related to the optimum antigen presentation by DCs to CD8(+) T cells.