Investigation On Specific Killing U937 Cell Reaction With CTL Induced By Dendritic Cell Pulsed With Frozen-thawed Antigen

Dendritic cells (DC) are the most potent antigen presenting cells (APC), which are named for their stretching out many dendritic or pseudopodial apophysis in maturation. Compared with other antigen presenting cells, DC could highly stimulate naive T cell proliferate, accelerate help T cell and cytotoxic T cell generate, facilitate B cell develop, differentiate and activating. Otherwise phagocyte and B cell could only stimulate activated and memory T cell, so DC are considered to be the initiation of organism immunity, which play a unique role in inducing the immunity. Consequently, dendritic cell immunotherapy is being aggressively investigated as a mechanism to enhance immune responses for cancer.DC-based specific active immunotherapy include:1)DC induced by tumor associated antigen(peptide)in vitro.2)the gene coding TAA or cytokine transfer to DC.3) fuse tumor cell and DC in vitro,get DC-tumor cell chimera,vaccine to the body.4) applicating DC directly.Basing on the internal and external previous experimental results, we investigate the effects of dendritic cell pulsed with U937 cell frozen-thawed antigen on inducing the cytotoxic T lymphocyte (CTL) to get specific anti-tumor activity in vitro.DC was generated from human bone marrow mononuclear cell (BMMC) in the presence of granulocyte/macrophage-colony stimulating factor (GM-CSF), interleukin-4 (EL-4) in vitro. DC pulsed with U937 frozen-thawed antigen, and co-culture to induce T cell into specific CTL. We observe the effects of CTL induced by DC pulsed with U937 cell frozen-thawed antigen killing U937 cell specially and the influence of dendritic cell affecting the funtion and CD expression on CTL.Through experiment above, we found that the CD la expression on DC pulsed with U937 frozen-thawed antigen has increased obviously than the uncultured (P<0.01). TheCDla, CD86, CD lle and HLA-DR expression on DC pulsed with LJ937 frozen-thawed antigen have increased obviously than the uncultured (P<0.01). The CD86 and CD 14 expression on DC pulsed with U937 frozen-thawed antigen have no difference compared to the uncultured (P>0.05). There are more CD3+CD8+ T cells in the CTL induced by DC pulsed with U937 frozen-thawed antigen than the T cell uncultured (P<0.01).The CTL induced by DC pulsed with U937 frozen-thawed antigen had more significant activity in killing U937 cell than killing K562 cell (P<0.01),and The CTL induced by DC pulsed with U937 frozen-thawed antigen was also more effective to kill U937 cell than the CTL induced by DC simply,T cell co-cultured with IL-2 and T cell simply(P<0.01).So we conclude that the DC generated from human bone marrow mononuclear cell (BMMC) in the presence of granulocyte/ macrophage -colony stimulating factor (GM-CSF), interleukin-4 (EL-4) was CD14~CDla+ DC, and it could also induce the cytotoxic T lymphocyte (CTL) to get specific anti-tumor activity in intro. Otherwise, the increasing of CD3+CD8+ T cells in the CTL induced by DC pulsed with U937 frozen-thawed antigen implied the main role of the CD3+CD8+ T cells in the anti-tumor immunity.