OBJECTIVETo investigate the role of CD40 ligand (CD40L) in dendritic cells (DC) of CEA transgenic mice and to evaluate the specific cellular immunity induced by activated DC.

METHODSBone marrow cells of the CEA transgenic mice were used to generate immature dendritic cells under the condition of GM-CSF and IL-4. CD40L was added to activate dendritic cells into mature phenotype. Dendritic cells cancer vaccine was pulsed with CEA526-533 peptide which made the vaccine specific for cancer immunity. The immunophenotype molecules were identified by flow cytometry. The cytokines produced by cells were determined by ELISA. T cells proliferation was measured by (3)H-thymidine essays.

RESULTSImmunophenotype molecules expressions of CD40L-activated dendritic cells were significantly higher than those in control group. IL-12 secretion by CD40L-activated dendritic cells was (937.81+/-51.99) pg/10(6) DC, significantly higher than that in control group [(83.06+/-8.58) pg/10(6) DC, P<0.01]. CD8(+) T cells proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.05), and the secretion of IFN-gamma was(33.900+/-4.550) ng/L, significantly higher than that in control group [(5.226+/-0.460) ng/L, P<0.01]. Splenocytes proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.01), and the secretion of IFN-gamma was (69.802+/-11.407) ng/L, significantly higher than that in control group [(2.912+/-0.562) ng/L, P<0.01].

CONCLUSIONThe method of using CD40L to stimulate bone marrow-delivered dendritic cells promotes the maturation and activation of dendritic cells, which enhances the cellular immunity in CEA transgenic mice.