Antitumor Effect Of Human PBMC On Colon Carcinoma Cells(sw1116) Induced By CpGODN,IL-2 And Tumor Cell Antigens

Background: CpG oligodeoxynucleotides, a fairly new class of reagentsthat mimicbacterial DNA, have been shown to induce a potent Thl-orientedresponse that leadsto tumor eradication and protective immunity. Moreover,although CpGODN mayinitially produce inflammation by way of the innatesystem, an ensuing adaptive immune response has been demonstrated thatleads to immunologic memory and tumor-specific T-cell immunity. In cancerimmunotherapy, CpG ODNs have been used as monotherapy, adjuvantfor vaccination, and in combination with chemotherapy, radiation treatment,antibody therapy, cellular vaccines. The immune effects of CpG ODNs may beconsidered in two stages: an early stage of innate immune activation and a laterstage of enhancement of adaptive immune responses. Within minutes ofexposure of plasmacytoid DCs to CpGS the ODNs appear to entertumor-specific T-cell immunity. In cancer immunotherapy, CpG ODNs havebeen used as monotherapy, adjuvant for vaccination, and in combinationwithchemotherapy, radiation treatment, antibodytherapy, cellular vaccines. Theimmuneeffects of CpG ODNs may be considered in two stages: an earlystage of innateimmune activation and a later stage of enhancement of adaptiveimmune responses.Within minutes of exposure of plasmacytoid DCs to CpG, the ODNs appear to enteran endosomal compartment where they interact withTLR9, leading to the activation of cell signaling pathways that culminate inthe expression of costimulatory molecules upregulation of the chemokinereceptor that causes cell trafficking to the T-cell zone of the lymph nodes, andsecretion of Thl-promoting chemokines.Plasmacytoid DCs secrete typeI IFN and mature into highly effectiveantigen-presenting cells.These CpG-induced type I IFNs, cytokines and chemokines triggera wide range of secondary effects, including NK cell activation and enhancedexpression of Fc receptors on effector cells such as polymorphonuclear with aresultant increase in antibodydependent cellular cytotoxicity (ADCC). Thestudy was designed to investigate the function of the effect of CpGODN on thedifferentiation of PBMC, and antitumor activity of human peripheral blood ofimmune cellsThe research aim is to testify the feasibility of CpG ODN as thenew immune therapy。Methods:1. To test lymphocyte proliferation, MTTmethod after human PBMC was incubated with CpG2006,IL-2 and tumorcell antigens. 2. To measure cytokine release byELISA on human PBMCinduced by CpG ODN,IL-2 and tumor cell antigens. including IFN-a.,IL-12, IFN-γand TNF-a.. 3. To analysis cell surface marker of humanPBMC include CD4+T and CD8+T lymphocyte by flow cytometry. 4.To testeffect of human PBMC on Colon carcinoma cells (sw1116) induced by CpGODN,IL-2 and tumor cell antigens。Results:1 .InVitro, CpG ODN,IL-2 andtumor cell antigens together could induce human lymphocyte proliferation .The effect of stimulation is dependent on its dosage. 2,CpG2006,IL-2 andtumor cell antigens together could induced CD4+T and CD8+T cellup-regulated. Expression of CD3+ onT cell was up-regulated too. 3,Lysis of human PBMC on colon carcinoma cells induced by CpG ODN,IL-2 andtumor cell antigens together is stronger than which indued by everyone of itsalone .4,the PBMC come from patients with tumor can be inducedeighther ,and equal to the contract PBMC come from the Healthy. Conclusions:CpG ODN,IL-2 and tumor cell antigens together causing them to up-regulateco-stimulatory could activate cells of the adaptive immune system(lymphocytes) in a sequence-dependent manner. CpG ODN could induceantitumor effect of human PBMC on colon carcinoma cells.