Objective To research the effect of molecular chimeric mice pre-T cells on proliferation ability of allogeneic mouse T cells.Methods The MHC-Ⅰ gene (H-2Kband H-2Db gene) were extracted and amplified by RT-PCR,the identified pre-T cells were transfected by the constructed eukaryotic expression vector of C57BL/6mouse MHC-I (pIRES-H-2Db and pIRES-H-2Kb),non-transfected group and sham pIRES-transfected control group were set.The molecular chimeric cells were transfused back to BALB/c mouse.After 7 days,T lymphocyte cells of each group were extracted,the ability of molecular chimeric cells inducing spleen T lymphocyte response to allogeneic T cells was observed through mixed lymphocyte culture (MLC).Results Sequencing of the plasmid we have constructed showed that insertion sequence contained C57BL/6 mice H-2Kb and H-2Db series which could be retrieved from GenBank.The result of flow cytometry analysis indicated that H-2Kb and H-2Db protein had an increased expression in pre-T cells,the difference with other two groups was statistically significant (P＜0.05).The result of MLC demonstrated that the stimulation index (SI) of T lymphocyte in co-injection transfected pIRES-H-2Kb and pIRES-H-2Db pre-T cells group (0.764±0.074) were significantly decreased compared with non-transfected group(0.983±0.081)and sham pIRES-transfected group(0.994±0.142) (P＜0.05).Conclusions The molecular chimeric pre-T cells infusion can reduce spleen T lymphocyte response to allogeneic T cells and it may induce immune tolerance in vivo.

Objective:To investigate the effect of human Leptin on the proliferation of human circulating T lymphocytes in vitro and the influence of Leptin on the action of PHA on the proliferation of human circulating T lymphocytes.Methods:PBMC were isolated from hepartinized venous blood of normal donors by density-gradient sedimentation over Ficoll-Hypaque and cultured in the 1640 complete medium.T lymphocytes were then obtained by depleting the monocyte and B cell populations.Cells were then cultured in the 1640 complete medium for 56 h in the presence of PHA.The proliferative effect was assessed by means of incorporation of thymidine.TdR was added and cultured for 16 hours.Cells were then processed in the harvester to measure the incorporation of [()~3H] thymidine.Radioactivity was determined by liquid scintillation counter.Results:The results showed that Leptin alone did not affect the proliferation of T lymphocytes,but it could enhance the effect of PHA on the proliferation of T lymphocytes at the concentrations of PHA from 2-8 ?g/ml.A dose-response studies of T lymphocyte proliferation showed that the maximal effect of Leptin were observed at 10 nmol/L.Leptin did not affect the proliferation of T lymphocytes when the concentrations of PHA were over 8 ?g/ml.Conclusion:The studies demonstrated that Leptin alone did not affect the proliferation of lymphocytes,but it could enhance the action of PHA on cell growth in a dose-dependent manner.