The recent cloning of MIF receptor fills an important gap in our understanding of the molecular biology and immunology of MIF. The MIF receptor, like MIF, does not fall into any established family of protein mediators...The recent cloning of MIF receptor fills an important gap in our understanding of the molecular biology and immunology of MIF. The MIF receptor, like MIF, does not fall into any established family of protein mediators, providing both new challenges and opportunities for the structural and functional analysis of MIF signal transduction.展开更多
Activation-induced cell death （AICD） of immune cells is widely believed to be crucial for the regulation of immune responses. Although macrophage apoptosis has been observed under a variety of pathological condition...Activation-induced cell death （AICD） of immune cells is widely believed to be crucial for the regulation of immune responses. Although macrophage apoptosis has been observed under a variety of pathological conditions, questions as to whether there is AICD ofmacrophages and how macrophage life span is regulated have not been well addressed. AICD in macrophages requires two signals. One is cell activation triggered by LPS or other bacterial components. The other is an event that exists in AICD-susceptible （primed） but not unsusceptible （resting） macrophages. Here we show that RAW264.7 cell is susceptible to LPS stimulation when it is primed with Salmonella typhimurium, type 5 adenovirus （Ad5） or IFN-γ. We found that the stability of the transcription factor MEF2C is increased in primed RAW264.7 cell. Transfection of a dominant negative form of MEF2C protects primed macrophage from cell death triggered by LPS. Our data demonstrate that the increase of MEF2C protein stability is a key factor in the AICD of macrophage.展开更多
Interaction between cytotoxic T lymphocyte-asso-ciated antigen-4 (CTLA4, CD152) and B7 molecules (B7-1and B7-2) is of importance in the cellular events of lym-phocyte, including antigen-specific T-cell activation andi...Interaction between cytotoxic T lymphocyte-asso-ciated antigen-4 (CTLA4, CD152) and B7 molecules (B7-1and B7-2) is of importance in the cellular events of lym-phocyte, including antigen-specific T-cell activation andinduction of autoreactive T-cell. We describe here the firstintroduction of a murine soluble CTLA4 gene, CTLA4Ig,to Mm1 cells, a macrophagic cell line. CTLA4Ig waJssuccessfully expressed on Mm1 cells and the expressedCTLA4Ig was found to be functionally active in their bind-ing to B7 molecules by flow cytometry and immunofluo-rescence studies- The biological activity of CTLA4Ig fromthe transfected Mm1 cells was studied and showed in-hibitory activity on mixed lymphocyte culture. A highCTLA4Ig producing macrophagic cell line was obtained.As Mm1 cells were regarded as difficult for gene transfec-tion and there had so far been no report on expression ofCTLA4Ig gene on Mm1 cells, these results suggested thatthe CTLA4Ig expressing Mm1 cells could be useful forExpression of CTLA4 on Mml and its biological activityanalysis of CTLA4 and B7 molecule interaction in bothmacrophage and T-cell.展开更多
In order to provide the experimental basis for the further studies on the oncogenic mechanism of the E6 protein from human papillomavirus type 16 （HPV16）, the eukaryotic expression vector pcDNA3.1 （-）/E6 was used ...In order to provide the experimental basis for the further studies on the oncogenic mechanism of the E6 protein from human papillomavirus type 16 （HPV16）, the eukaryotic expression vector pcDNA3.1 （-）/E6 was used for the study on the effect of E6 protein to influence the secretory activity of LPS-induced 3MP-1-macrophages, and the reconstructed plasmid pcDNA3.1 （-）/E6 was transfected into THP-1-macrophages. The expression of E6 gene was assayed in macrophage lysates by using Western blot analysis and the level of TNF-α or IL-1β was examined by ELISA. All of data were analyzed by SPSS12.0. As demonstrated by Western blot analysis, the expression of E6 protein with a molecular weight of about 18 kDa by plasmid pcDNA3.1 （-）/E6 in THP-1-macrophages could be detected. However, as demonstrated by ELISA assay, the level of TNF-α or IL-1β in lysates of THP-1-macrophages showed an obvious difference between the pcDNA3.1 （-）/E6 group and the LPS control group or the pcDNA3.1 （-） control group （P 〈 0.01）, but no significant difference existed between pcDNA3.1 （-） control group and LPS control group （ P 〉 0.05）. All these results illustrate that the transient over-expression of HPV6 E6 protein reduces the production of TNF-α and IL-1β induced by LPS in THP-1-macrophages.展开更多
文摘The recent cloning of MIF receptor fills an important gap in our understanding of the molecular biology and immunology of MIF. The MIF receptor, like MIF, does not fall into any established family of protein mediators, providing both new challenges and opportunities for the structural and functional analysis of MIF signal transduction.
基金a grant （No. 30330260） from National Natural Science Foundation of China.
文摘Activation-induced cell death （AICD） of immune cells is widely believed to be crucial for the regulation of immune responses. Although macrophage apoptosis has been observed under a variety of pathological conditions, questions as to whether there is AICD ofmacrophages and how macrophage life span is regulated have not been well addressed. AICD in macrophages requires two signals. One is cell activation triggered by LPS or other bacterial components. The other is an event that exists in AICD-susceptible （primed） but not unsusceptible （resting） macrophages. Here we show that RAW264.7 cell is susceptible to LPS stimulation when it is primed with Salmonella typhimurium, type 5 adenovirus （Ad5） or IFN-γ. We found that the stability of the transcription factor MEF2C is increased in primed RAW264.7 cell. Transfection of a dominant negative form of MEF2C protects primed macrophage from cell death triggered by LPS. Our data demonstrate that the increase of MEF2C protein stability is a key factor in the AICD of macrophage.
文摘Interaction between cytotoxic T lymphocyte-asso-ciated antigen-4 (CTLA4, CD152) and B7 molecules (B7-1and B7-2) is of importance in the cellular events of lym-phocyte, including antigen-specific T-cell activation andinduction of autoreactive T-cell. We describe here the firstintroduction of a murine soluble CTLA4 gene, CTLA4Ig,to Mm1 cells, a macrophagic cell line. CTLA4Ig waJssuccessfully expressed on Mm1 cells and the expressedCTLA4Ig was found to be functionally active in their bind-ing to B7 molecules by flow cytometry and immunofluo-rescence studies- The biological activity of CTLA4Ig fromthe transfected Mm1 cells was studied and showed in-hibitory activity on mixed lymphocyte culture. A highCTLA4Ig producing macrophagic cell line was obtained.As Mm1 cells were regarded as difficult for gene transfec-tion and there had so far been no report on expression ofCTLA4Ig gene on Mm1 cells, these results suggested thatthe CTLA4Ig expressing Mm1 cells could be useful forExpression of CTLA4 on Mml and its biological activityanalysis of CTLA4 and B7 molecule interaction in bothmacrophage and T-cell.
文摘In order to provide the experimental basis for the further studies on the oncogenic mechanism of the E6 protein from human papillomavirus type 16 （HPV16）, the eukaryotic expression vector pcDNA3.1 （-）/E6 was used for the study on the effect of E6 protein to influence the secretory activity of LPS-induced 3MP-1-macrophages, and the reconstructed plasmid pcDNA3.1 （-）/E6 was transfected into THP-1-macrophages. The expression of E6 gene was assayed in macrophage lysates by using Western blot analysis and the level of TNF-α or IL-1β was examined by ELISA. All of data were analyzed by SPSS12.0. As demonstrated by Western blot analysis, the expression of E6 protein with a molecular weight of about 18 kDa by plasmid pcDNA3.1 （-）/E6 in THP-1-macrophages could be detected. However, as demonstrated by ELISA assay, the level of TNF-α or IL-1β in lysates of THP-1-macrophages showed an obvious difference between the pcDNA3.1 （-）/E6 group and the LPS control group or the pcDNA3.1 （-） control group （P 〈 0.01）, but no significant difference existed between pcDNA3.1 （-） control group and LPS control group （ P 〉 0.05）. All these results illustrate that the transient over-expression of HPV6 E6 protein reduces the production of TNF-α and IL-1β induced by LPS in THP-1-macrophages.
