Dendritic cells （DC） are diverse and specialized hematopoietic cells serving as an essential bridge between innate and adaptive immunity. DC exist in all lymphoid and nonlymphoid organs and are amongst the first res...Dendritic cells （DC） are diverse and specialized hematopoietic cells serving as an essential bridge between innate and adaptive immunity. DC exist in all lymphoid and nonlymphoid organs and are amongst the first responders to infection at epithelial surfaces including mucosal tissues. DC of the lung, gut, and vaginal mucosa display different phenotypes and functions reflecting each unique tissue and, in contrast to their counterparts in spleen and lymph nodes, are constantly exposed to both harmful and benign factors of their environments. Mucosal DC recognize and respond to pathogens through engagement of pattern recognition receptors, and activated DC migrate to draining lymph nodes to induce adaptive immune responses. The specialized function of DC aids in the induction of immunity and pathogen control at the mucosa. Such specialization includes the potent antiviral interferon response of plasma- cytoid DC to viral nucleic acids, the ability of mucosal DC to capture organisms in the gut lumen, the capacity of DC to cross-present antigen from other infected cells, and the ability of mucosal DC to initiate lgA class switching in B cells. DC plasticity is also critical in the immune response to mucosal pathogens, as DC can respond to the microen- vironment and sense pathogen-induced stress in neighboring epithelial cells. Finally, DC interact with each other through crosstalk to promote antigen presentation and T-cell immunity. Together, these processes condition mucosal DC for the induction of a tailored immune response to pathogens.展开更多
Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the comple...Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.展开更多
Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis ...Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.展开更多
Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three loblolly p...Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three loblolly pine (Pinus taeda L.) genotypes. Of the antibiotics administered, cefotaxime maximally increased the frequency of callus formation and growth rate of organogenic calli, carbenicillin maximally increased the frequency of shoot regeneration and the average number of adventitious shoots per piece of organogenic callus, ampicillin maximally decreased the rooting frequency of regenerated shoots and mean number of roots per regenerated shoot, in comparison with antibiotic-free media. Compared with the control, ampicillin minimally increased the frequency of callus formation, cefotaxime minimally increased the frequency of shoot regeneration, and carbenicillin mini-mally decreased the rooting frequency of regenerated shoots in three loblolly pine genotypes tested. All three antibiotics in-creased the frequencies of callus formation and shoot regeneration, and reduced the rooting frequency of regenerated shoots suggested that the establishment of an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integra-tion of foreign genes into loblolly pine need to select a suitable antibiotic. This investigation could be useful for optimizing genetic transformation of conifers.展开更多
The balsum pear （Momordica charantia L. ） anthers in the monokaryotic stage of microspore development were cultured in this experiment. Different Plant growth regulators＇ combinations, base media and carbon sources...The balsum pear （Momordica charantia L. ） anthers in the monokaryotic stage of microspore development were cultured in this experiment. Different Plant growth regulators＇ combinations, base media and carbon sources were studied for callus formation and organ differentiation from balsum pear anthers. The result showed that the best media for callus inducement was： MS＋BA 0.5 mg/L＋NAA 0.2 mg/L＋ 2, 4-D 0.5 mg/L＋KT 2.0 mg/L, with 3% sugar and 0.8% agar. The best media to induce roots from balsum pear anther callus was： MS＋NAA 0.05 rag/L＋ KT 0.5 rag/L, with 3% sugar and 0.8% agar. Most of adventitious roots from callus were triploid（2N=3X=33）展开更多
文摘Dendritic cells （DC） are diverse and specialized hematopoietic cells serving as an essential bridge between innate and adaptive immunity. DC exist in all lymphoid and nonlymphoid organs and are amongst the first responders to infection at epithelial surfaces including mucosal tissues. DC of the lung, gut, and vaginal mucosa display different phenotypes and functions reflecting each unique tissue and, in contrast to their counterparts in spleen and lymph nodes, are constantly exposed to both harmful and benign factors of their environments. Mucosal DC recognize and respond to pathogens through engagement of pattern recognition receptors, and activated DC migrate to draining lymph nodes to induce adaptive immune responses. The specialized function of DC aids in the induction of immunity and pathogen control at the mucosa. Such specialization includes the potent antiviral interferon response of plasma- cytoid DC to viral nucleic acids, the ability of mucosal DC to capture organisms in the gut lumen, the capacity of DC to cross-present antigen from other infected cells, and the ability of mucosal DC to initiate lgA class switching in B cells. DC plasticity is also critical in the immune response to mucosal pathogens, as DC can respond to the microen- vironment and sense pathogen-induced stress in neighboring epithelial cells. Finally, DC interact with each other through crosstalk to promote antigen presentation and T-cell immunity. Together, these processes condition mucosal DC for the induction of a tailored immune response to pathogens.
文摘Strategies to fill the huge gap in supply versus demand of human organs include bioartificial organs, growing humanized organs in animals, cell therapy, and implantable bioengineered constructs. Reproducing the complex relations between different cell types, generation of adequate vasculature, and immunological complications are road blocks in generation of bioengineered organs, while immunological complications limit the use of humanized organs produced in animals. Recent developments in induced pluripotent stem cell (iPSC) biology offer a possibility of generating human, patient-specific organs in non-human primates (NHP) using patient-derived iPSC and NHP-derived iPSC lacking the critical developmental genes for the organ of interest complementing a NHP tetraploid embryo. The organ derived in this way will have the same human leukocyte antigen (HLA) profile as the patient. This approach can be curative in genetic disorders as this offers the possibility of gene manipulation and correction of the patient's genome at the iPSC stage before tetraploid complementation. The process of generation of patient-specific organs such as the liver in this way has the great advantage of making use of the natural signaling cascades in the natural milieu probably resulting in organs of great quality for transplantation. However, the inexorable scientific developments in this direction involve several social issues and hence we need to educate and prepare society in advance to accept the revolutionary consequences, good, bad and ugly.
文摘Among orchids, Cymbidiums have got a very high demand in both cut flower and pot plant trade. In the present study the effect of some polysaccharides such as chitosan and NAG （n-acetyl-glucosamine） on organogenesis in protocorm-like-bodies （PLBs） of C. insigne was studied. Synthetic phytohormones such as BA and TDZ （cytokinins） and NAA （auxin） were used for comparison. PLBs of C. insigne were explanted on modified Murashige and Skoog medium supplemented with the single addition of chitosan and NAG, and the combination of BA （benzyladenine） and NAA （1-naphthaleneacetic acid） also with the combination of NAA and TDZ （thidiazuron） among different concentrations. Combination treatments of auxin and cytokinins, the highest percentage of PLBs formation was 73% and shoot formation was 67% when cultured on the medium supplemented with 1.0 mg L1 BA without NAA. Combination treatment of NAA and TDZ, the PLBs formation was 90% and shoot formation was 60% obtained from medium supplemented with 1.0 mg Lt of NAA ＋ 0.1 mg L^-1 TDZ. Single addition of chitosan and NAG with modified MS medium was more effective for new PLBs and shoot formation. The highest percentage of PLBs formation was 87% and shoot formation was 80% obtained from the medium supplemented with 0.1 mg L^-1 chitosan. On the other hand, the PLBs formation rate reached 93% and shoot formation rate was 87% obtained from the medium supplemented with 0.01 mg L^-1 NAG. Application of polysaccharides to in vitro orchid PLBs allows developing new PLBs and shoot to form plantlet without synthetic phytohormones.
文摘Three antibiotics ampicillin, carbenicillin, and cefotaxime were evaluated for their effects on induction, growth, and differentiation of organogenic calli, as well as rooting of regenerated shoots of three loblolly pine (Pinus taeda L.) genotypes. Of the antibiotics administered, cefotaxime maximally increased the frequency of callus formation and growth rate of organogenic calli, carbenicillin maximally increased the frequency of shoot regeneration and the average number of adventitious shoots per piece of organogenic callus, ampicillin maximally decreased the rooting frequency of regenerated shoots and mean number of roots per regenerated shoot, in comparison with antibiotic-free media. Compared with the control, ampicillin minimally increased the frequency of callus formation, cefotaxime minimally increased the frequency of shoot regeneration, and carbenicillin mini-mally decreased the rooting frequency of regenerated shoots in three loblolly pine genotypes tested. All three antibiotics in-creased the frequencies of callus formation and shoot regeneration, and reduced the rooting frequency of regenerated shoots suggested that the establishment of an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integra-tion of foreign genes into loblolly pine need to select a suitable antibiotic. This investigation could be useful for optimizing genetic transformation of conifers.
基金The authors would like to thank Dr. WANG Xiao-rong and DENG Qun-xian for their help in the tests. This study was supported by the Education Bureau Science Foundation of Sichuan Province （No. 2005A003） and the Sichuan Agricultural University Science Foundation （No. 3305）.
文摘The balsum pear （Momordica charantia L. ） anthers in the monokaryotic stage of microspore development were cultured in this experiment. Different Plant growth regulators＇ combinations, base media and carbon sources were studied for callus formation and organ differentiation from balsum pear anthers. The result showed that the best media for callus inducement was： MS＋BA 0.5 mg/L＋NAA 0.2 mg/L＋ 2, 4-D 0.5 mg/L＋KT 2.0 mg/L, with 3% sugar and 0.8% agar. The best media to induce roots from balsum pear anther callus was： MS＋NAA 0.05 rag/L＋ KT 0.5 rag/L, with 3% sugar and 0.8% agar. Most of adventitious roots from callus were triploid（2N=3X=33）
