The Study In Treatment With Cord Blood-derived DCs Pulsed With Tumor Antigen Peptides Against Nasopharyngeal Carcinoma

Objective: To observe the activation effect on cytotoxic T lymphocytes (CTL) by cord blood-derived dendritic cells (DCs) pulsed with mild acid eluted tumor antigen peptides presented on nasopharyngeal carcinoma cells surface. Assess the specific anti-tumor response in vitro induced by the CTL.Methods: CBMNC were collected by centrifugal in density gradient (Ficoll-Hypaque) from healthy human cord blood. The adherent fraction of CBMNC was cultured with the presence of relevant cytokines (rhGM-CSF1000u/ml and rhIL-4 500u/ml) to generate DCs, and analyze its characteristics. Tumor cells of nasopharyngeal carcinoma were treated with citrate-phosphate buffer (pH3.3) at room temperature for 5 min. FCM was used to analyze the elution effect of tumor antigen peptides. The acid eluted peptides were subsequently purified through OASIS-HLB column. DCs pulsed with these peptides were also co-cultured with naive T cells derived from PBMNC. Its stimulating index (SI)was detected by 3H-TdR assay. MTT assay was employed to test the inhibition rates of tumor specific CTL on CNE cells.Result: After adherent treatment ,CBMNC cultured in the above medium cytokines highly expressed differential antigens of DC (CD86, GD1 , CD40, HLA-DR).Mild acid could elute tumor antigen peptides from CNE cells effectively. Dendritic cells (DCs) pulsed with mild acid eluted tumor antigen peptides presented on CNE cells' surface could activate CD8+CTL and induce specific anti-tumor immunity effectively, while the unpulsed DCs group and inactivated T cells group couldn't. Tumor antigen peptides after eluted could be presented again on CNE surface after being cultured for 48 hours.Conclusion: We could get DCs from CBMNC after adherent treatment and being cultured in the above medium cytokines. Dendritic cells (DC) pulsed with mild acid-eluted tumor antigen peptides presented on CNE tumor cells' surface could induce specific anti-tumor immunity effectively. Tumor cells after eluted could be eluted again after being cultured again.