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.

Objective:To understand the loss to follow-up of children born to pregnant women with HIV infection (HIV-exposed children) and analyze its influencing factors in China in 2019.Methods:The data were collected from the follow-up records of pregnant women with HIV infection and their children reported by the national "Management Information System for the Prevention of HIV, syphilis and Hepatitis B Mother-to-Child Transmission" in 2019. HIV-exposed children were defined as those who were not followed up after birth or who were not followed up at 18 months of age and who were not followed up at 21 months of age. The univariate and multivariate influencing factors of loss to follow-up of children born to HIV-infected pregnant women were analyzed by χ2 test and logistic regression model. SPSS 25.0 software was used for statistical analysis. Results:The number of HIV-infected pregnant women was 5 039, the number of live-born children was 5 035, the number of loss to follow-up children within 18 months of age was 283, and the loss to follow-up rate children was 5.62%(283/5 035). The results of multivariate logistic regression analysis showed that the rate of loss to follow-up of exposed children born to pregnant women who worked as farmers (animal husbandry and fishery) (a OR=0.34, 95% CI: 0.22-0.53), unmarried (a OR=0.47, 95% CI: 0.24-0.93), first marriage (a OR=0.38, 95% CI: 0.22-0.67), remarriage (a OR=0.36, 95% CI: 0.20-0.67) and cohabiting (a OR=0.47, 95% CI: 0.23-0.97), and knew they had HIV infection before this pregnancy (a OR=0.53, 95% CI: 0.40-0.70) was lower. Han nationality (a OR=1.52, 95% CI: 1.09-2.13), primary school (a OR=2.06, 95% CI: 1.10-3.89) and junior middle school (a OR=1.81, 95% CI: 1.03-3.17) educational level, non-use of antiviral drugs (a OR=6.21, 95% CI: 4.32-8.93) and delivery in township (street) level midwifery institutions (a OR=5.72, 95% CI: 1.61-20.27) had higher rates of loss to follow-up among infants born to HIV-infected pregnant women. Conclusions:HIV-exposed children still have a specific rate of loss to follow-up in China in 2019. In order to further reduce the rate of loss to follow-up, it is of great significance to improve the detection rate of HIV before pregnancy and the rate of antiviral drugs used in pregnant women with HIV infection, which is of great significance for the effective implementation of comprehensive intervention measures of prevention of mother-to-child transmission of HIV.