AIM:To determine the changes of CD8+ T subsets especially CD8+CD28-T regulatory cells in rat model of experimental colitis induced by 2,4-dinitrofluorobenzene (DNFB). METHODS:The rat model of experimental colitis was ...AIM:To determine the changes of CD8+ T subsets especially CD8+CD28-T regulatory cells in rat model of experimental colitis induced by 2,4-dinitrofluorobenzene (DNFB). METHODS:The rat model of experimental colitis was induced by enema with DNFB.Ten days later,colonic intraepithelial and splenic lymphooltes were isolated from colitis animals (n=16) and controls (n=8).The proportion of CD8+ T cells,CD8+CD28+ T cells and CD8+CD28-T regulatory cells were determined by flow cytometry. RESULTS:The model of experimental colitis was successfully established by DNFB that was demonstrated by bloody diarrhea,weight loss and colonic histopathology.The proportion of CD8+ T cells in either splenic or colonic intraepithelial lymphocytes was not significantly different between colitis animals and controls (spleen:34.6±7.24 % vs 33.5±9.41%, colon:14.0±8.93 % vs 18.0±4.06 %,P>0.05).But CD8+CD28- T regulatory cells from colitis animals were significantly more than those from controls (spleen:11.3±2.26 % vs 5.64±1.01%, colon:6.50±5.37 % vs 1.07±0.65 %,P<0.05).In contrast, CD8+CD28+ T cells from colitis animals were less than those from controls (spleen:23.3±6.14 % vs 27.8±9.70 %,P=0.06; colon:7.52±4.18 % vs 16.9±4.07 %,P<0.05).The proportion of CD8+CD28-T regulatory cells in splenic and colon intraepithelial CD8+ T cells from colitis animals was higher than that from controls (spleen:33.3±5.49 % vs 18.4±7.26 %, colon:46.0±14.3 % vs6.10±3.72 %,P<0.005). CONCLUSION:Experimental colitis of rats can be induced by DNFB with simplicity and good reproducibility.The proportion of CD8+CD28-T regulatory cells in rats with experimental colitis is increased,which may be associated with the pathogenesis of colitis.展开更多
Allergic contact dermatitis is a delayed hypersensitivity reaction, which results from skin exposure to low molecular weight chemicals such as haptens. To clarify the pathogenic mechanism, electrospray ionization mass...Allergic contact dermatitis is a delayed hypersensitivity reaction, which results from skin exposure to low molecular weight chemicals such as haptens. To clarify the pathogenic mechanism, electrospray ionization mass spectrometry （ESI-MS） and hydrogen/deuterium （H/D） exchange, as well as UV spectroscopy, were applied to determine the interaction between the model protein cytochrome c （cyt c） and the hapten 2,4- dinitro-fiuorobenzene （DNFB）. The ESI-MS results demonstrate that the conformation of cyt c can change from native folded state into partially unfolded state with the increase of DNFB. The equilibrium state H/D exchange followed by ESI-MS further confirms the above results. UV spectroscopy indicates that the strong- field coordination between iron of heme （prosthetic group） and His18 or Met80 of cyt c is not obviously affected by the hapten.展开更多
基金the National Natural Science Foundation of China,No.30240051
文摘AIM:To determine the changes of CD8+ T subsets especially CD8+CD28-T regulatory cells in rat model of experimental colitis induced by 2,4-dinitrofluorobenzene (DNFB). METHODS:The rat model of experimental colitis was induced by enema with DNFB.Ten days later,colonic intraepithelial and splenic lymphooltes were isolated from colitis animals (n=16) and controls (n=8).The proportion of CD8+ T cells,CD8+CD28+ T cells and CD8+CD28-T regulatory cells were determined by flow cytometry. RESULTS:The model of experimental colitis was successfully established by DNFB that was demonstrated by bloody diarrhea,weight loss and colonic histopathology.The proportion of CD8+ T cells in either splenic or colonic intraepithelial lymphocytes was not significantly different between colitis animals and controls (spleen:34.6±7.24 % vs 33.5±9.41%, colon:14.0±8.93 % vs 18.0±4.06 %,P>0.05).But CD8+CD28- T regulatory cells from colitis animals were significantly more than those from controls (spleen:11.3±2.26 % vs 5.64±1.01%, colon:6.50±5.37 % vs 1.07±0.65 %,P<0.05).In contrast, CD8+CD28+ T cells from colitis animals were less than those from controls (spleen:23.3±6.14 % vs 27.8±9.70 %,P=0.06; colon:7.52±4.18 % vs 16.9±4.07 %,P<0.05).The proportion of CD8+CD28-T regulatory cells in splenic and colon intraepithelial CD8+ T cells from colitis animals was higher than that from controls (spleen:33.3±5.49 % vs 18.4±7.26 %, colon:46.0±14.3 % vs6.10±3.72 %,P<0.005). CONCLUSION:Experimental colitis of rats can be induced by DNFB with simplicity and good reproducibility.The proportion of CD8+CD28-T regulatory cells in rats with experimental colitis is increased,which may be associated with the pathogenesis of colitis.
基金This work was supported by the National Natural Science Foundation of China （No.20473020）.
文摘Allergic contact dermatitis is a delayed hypersensitivity reaction, which results from skin exposure to low molecular weight chemicals such as haptens. To clarify the pathogenic mechanism, electrospray ionization mass spectrometry （ESI-MS） and hydrogen/deuterium （H/D） exchange, as well as UV spectroscopy, were applied to determine the interaction between the model protein cytochrome c （cyt c） and the hapten 2,4- dinitro-fiuorobenzene （DNFB）. The ESI-MS results demonstrate that the conformation of cyt c can change from native folded state into partially unfolded state with the increase of DNFB. The equilibrium state H/D exchange followed by ESI-MS further confirms the above results. UV spectroscopy indicates that the strong- field coordination between iron of heme （prosthetic group） and His18 or Met80 of cyt c is not obviously affected by the hapten.
