Expression of MHCⅠ genes in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila / 生物工程学报

The aim of this study was to investigate the expression of MHCⅠ gene in different tissues of Rana dybowskii under the stress of Aeromonas hydrophila (Ah), and to provide evidence for revealing the anti-infective immune response mechanism of amphibians. The experimental animal model of Aeromonas hydrophila infection was first constructed, and the pathological changes were observed by HE staining. The MHCⅠ gene α1+α2 peptide binding region of Rana dybowskii was cloned by RT-PCR and analyzed by bioinformatics. Real-time PCR was used to detect the transcription level of MHCⅠ in different tissues under Ah stress. After Ah infection, the skin, liver and muscle tissues showed signs of cell structure disappearance and texture disorder. The MHCⅠ gene α1+α2 peptide binding region fragment was 494 bp, encoding 164 amino acids, and homology with amphibians. Above 77%, the homology with mammals was as low as 14.96%, indicating that the α1+α2 region of MHC gene was less conserved among different species. The results of real-time PCR show that the liver, spleen and kidney of the experimental group were under Ah stress. The transcript levels of MHCⅠ gene in skin and muscle tissues were higher than those in the control group at 72 h, but the time to peak of each tissue was different (P<0.01), indicating that the response time of MHCⅠ gene in different tissues was different under Ah stress. This study provides a reference for further exploring the immune function of MHC molecules in anti-infection.

Research on molecular chimeric mice pre-T cells infusion to reduce response to allogeneic T cells stimulation / 国际生物医学工程杂志

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.

The effect of allogeneic MHC Ⅰ gene modification on the immunologic character in bone marrow cells / 中国免疫学杂志

Objective:To observe the effect of allogeneic MHC Ⅰ gene modification on the immunologic character in bone marrow cells and to investigate the mechanism of induce immunologic tolerance of MHC Ⅰ.Methods:The retroviral expression vector of BALB/C mice H 2D d gene was constructed and transducted into C57BL/6 mice bone marrow cells And the expression of H 2D d on the infected cells was detected by FACS technique Then observe the MLR between the BALB/C mice spleen T cells and the C57BL/6 mice bone marrow cells modified with H 2D d gene by MTT assay The cytotoxic activity of BALB/C mice NK cells to the C57BL/6 mice bone marrow cells modified with H 2D d gene was detected by LDH release assay Results:Either stimulation or response ability of the C57BL/6 mice bone marrow cells to the T cell from BALB/C mice spleen was significantly decreased after modified with H 2D d gene The cytotoxic activity of BALB/C mice NK cells to the C57BL/6 mice bone marrow cells modified with allogeneic MHC Ⅰ gene was significantly lower than which to the C57BL/6 mice bone marrow cells non modified Conclusion:It's maybe a way to induce immunologic tolerance in bone marrow transplantation by the means of modify the bone marrow cells with the MHC Ⅰ gene of the recipient