The Experimental Study In Treatment With DCs Against Retinoblastoma

Retinoblastoma is a kind of common ophthalmic malignant tumors. especially in children. It is easy to displace in early time. The rate of disability and mortality is high. It is a tast to be fulfilled to seek an effective clinical protocol to treat the patients with retinoblastoma. dendritic cells are potent antigen presenting cells that uptake and process antigens, present antigens to naive T lymphocytes, activate antigen-specific T lymphocytes and prime specific immune response. The experimental results in vitro and in vivo indicate that DCs pulsed with tumor antign induce antigen-specific protective and antitumor immunity, furthermore, the curative effect of some patients with a few kinds of cancers observed in phase I clinical trial is satisfactory . There have not been any reports of the research on retinoblastoma in this field in both experiment and clinical trial so far.PURPOSES: Injection of human cord blood mononuclear cells(hu-CBMNC) can result in a stable long-term reconstitution of a functional human immune system in mice with severe combined immunodeficiency (SCID). This experimental model was used to assess the ability of dendritic cells (DCs) pulsed with antigen of SoRb-70 cells to against retinoblastoma (RB).Methods (1) six to 8-week-old SCIDmice were maintained under special pathogen-free (SPF) conditions. CBMNC were collected from heparinized cord blood. SCID mice were injected intraperitoneally with 2 x 10 CBMNC resuspend-ed in 0.5ml phosphate-buffered saline (PBS) . At 2 weeks after reconstitution , only mices that tested positive for human Ig in serum were considered for the study. (2) For production of tumor , SoRb-70 cells were injucted subcutaneously into the flanks of SCID mice. The tumor voloum (v) were monitored every 2 days (3) The incubation condition of DCs from CBMNC was rhGM-CSF 2000u/ml andrhIL-4 500u/ml. The culture time of DCs was 3-4weeks. (4) CBMNC co-cultured with DCs pulsed with SoRb-70 frozen repeatedly generated respectivedly from adult peripheral blood and killed the SoRb-70 cells. (5) Hu-CBMNC-SCID mice beared prostate cancer were given DCs pulsed with SoRb-70 cells frozed repeatedly generated from human cord blood with different cell quantity. The SCID mice in control group were given NS/esreogen. The tumor volume and survival time and compared with the control groups by X~2 test.Results: 1. DCs pulsed with tumor cells mixture as a source of undefined tumor antigen can induce an effective antitumor immune response. 2. The mice in intravenous groups (10~6,10~7) and in intratumoral grop led to significant regression of established tumors and significant prolonger survival.Conclusions: The results indicate that DCs plused with tumor cells mixture as a source of tumor antigen can induce an effective antitumor immune response. These findings provide a rational and protocol for the use of cultured DCs in immu-notherapy of retinoblastoma.