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81.
82.
Comprehensive epitope analysis of human immunodeficiency virus type 1 (HIV-1)-specific T-cell responses directed against the entire expressed HIV-1 genome demonstrate broadly directed responses,but no correlation to viral load 总被引:24,自引:0,他引:24 下载免费PDF全文
Addo MM Yu XG Rathod A Cohen D Eldridge RL Strick D Johnston MN Corcoran C Wurcel AG Fitzpatrick CA Feeney ME Rodriguez WR Basgoz N Draenert R Stone DR Brander C Goulder PJ Rosenberg ES Altfeld M Walker BD 《Journal of virology》2003,77(3):2081-2092
Cellular immune responses play a critical role in the control of human immunodeficiency virus type 1 (HIV-1); however, the breadth of these responses at the single-epitope level has not been comprehensively assessed. We therefore screened peripheral blood mononuclear cells (PBMC) from 57 individuals at different stages of HIV-1 infection for virus-specific T-cell responses using a matrix of 504 overlapping peptides spanning all expressed HIV-1 proteins in a gamma interferon-enzyme-linked immunospot (Elispot) assay. HIV-1-specific T-cell responses were detectable in all study subjects, with a median of 14 individual epitopic regions targeted per person (range, 2 to 42), and all 14 HIV-1 protein subunits were recognized. HIV-1 p24-Gag and Nef contained the highest epitope density and were also the most frequently recognized HIV-1 proteins. The total magnitude of the HIV-1-specific response ranged from 280 to 25,860 spot-forming cells (SFC)/10(6) PBMC (median, 4,245) among all study participants. However, the number of epitopic regions targeted, the protein subunits recognized, and the total magnitude of HIV-1-specific responses varied significantly among the tested individuals, with the strongest and broadest responses detectable in individuals with untreated chronic HIV-1 infection. Neither the breadth nor the magnitude of the total HIV-1-specific CD8+-T-cell responses correlated with plasma viral load. We conclude that a peptide matrix-based Elispot assay allows for rapid, sensitive, specific, and efficient assessment of cellular immune responses directed against the entire expressed HIV-1 genome. These data also suggest that the impact of T-cell responses on control of viral replication cannot be explained by the mere quantification of the magnitude and breadth of the CD8+-T-cell response, even if a comprehensive pan-genome screening approach is applied. 相似文献
83.
Kumi Sumiyoshi Satoshi Kubota Rika A. Furuta Kazuta Yasui Eriko Aoyama Harumi Kawaki Kazumi Kawata Toshihiro Ohgawara Takashi Yamashiro Masaharu Takigawa 《Journal of cell communication and signaling》2010,4(1):5-14
CCN2 plays a central role in the development and growth of mesenchymal tissue and promotes the regeneration of bone and cartilage
in vivo. Of note, abundant CCN2 is contained in platelets, which is thought to play an important role in the tissue regeneration
process. In this study, we initially pursued the possible origin of the CCN2 in platelets. First, we examined if the CCN2
in platelets was produced by megakaryocyte progenitors during differentiation. Unexpectedly, neither megakaryocytic CMK cells
nor megakaryocytes that had differentiated from human haemopoietic stem cells in culture showed any detectable CCN2 gene expression
or protein production. Together with the fact that no appreciable CCN2 was detected in megakaryocytes in vivo, these results suggest that megakaryocytes themselves do not produce CCN2. Next, we suspected that mesenchymal cells situated
around megakaryocytes in the bone marrow were stimulated by the latter to produce CCN2, which was then taken up by platelets.
To evaluate this hypothesis, we cultured human chondrocytic HCS-2/8 cells with medium conditioned by differentiating megakaryocyte
cultures, and then monitored the production of CCN2 by the cells. As suspected, CCN2 production by HCS-2/8 was significantly
enhanced by the conditioned medium. We further confirmed that human platelets were able to absorb/uptake exogenous CCN2 in vitro. These findings indicate that megakaryocytes secrete some unknown soluble factor(s) during differentiation, which factor
stimulates the mesenchymal cells to produce CCN2 for uptake by the platelets. We also consider that, during bone growth, such
thrombopoietic-mesenchymal interaction may contribute to the hypertrophic chondrocyte-specific accumulation of CCN2 that conducts
endochondral ossification. 相似文献
84.
Kanefusa Kato Fujiko Suzuki Rika Morishita Tomiko Asano Tsuneko Sato 《Journal of neurochemistry》1990,54(4):1269-1274
Changes in the concentrations of nervous tissue-related proteins and their isoproteins, such as S-100 proteins (S-100 alpha and S-100 beta), enolase isozymes (alpha-enolase and gamma-enolase), and GTP-binding proteins (Go alpha, Gi2 alpha, and beta-subunits), were determined in the CNS of male rats of various ages (from 2 to 30 months old) by means of enzyme immunoassay. The weights of brains and the concentrations of soluble proteins in the cerebral cortex, cerebellum, and brainstem were constant during the observation period. The concentration of S-100 beta protein, which is predominantly localized in glial cells, increased gradually in the cerebral cortex with age; levels in the 25-month-old rats increased to approximately 150% of the levels in the young (2-month-old) rats. However, the S-100 beta concentrations in the cerebellum and brainstem were relatively constant, showing similar values in rats 2-30 months old. Levels of other proteins, including both neuronal (gamma-enolase and Go alpha) and glial (alpha-enolase and S-100 alpha) marker proteins, did not change significantly with age in the cerebral cortex, cerebellum, and brainstem. These results suggest that there is a close relation between the age-dependent changes of the CNS function and S-100 beta protein levels in the cerebral cortex. 相似文献
85.
Photosynthetic responses to photosynthetically active radiation and temperature including chilling‐light stress on the heteromorphic life history stages of a brown alga,Cladosiphon okamuranus (Chordariaceae) from Ryukyu Islands,Japan 下载免费PDF全文
Rika Fukumoto Iris Ann Borlongan Gregory N. Nishihara Hikaru Endo Ryuta Terada 《Phycological Research》2018,66(3):209-217
Photosynthetic responses to temperature and photosynthetically active radiation (PAR) were investigated on the heteromorphic life history stages (macroscopic and microscopic stages) of an edible Japanese brown alga, Cladosiphon okamuranus from the Ryukyu Islands. Measurements were carried out by using optical dissolved oxygen sensors and a pulse‐amplitude modulated fluorometer. Maximum net photosynthetic rates and other parameters of the Photosynthesis – PAR curves at 28°C were somewhat similar in both life history stages, without characteristic photoinhibition at 1000 μmol photons m?2 s?1. Results of oxygenic gross photosynthesis and dark respiration experiments over a temperature range of 8–40°C revealed similar temperature optima for both stages (29.7°C, macroscopic stage; 30.3°C, microscopic stage), which support their observed occurrences in the habitat during summer. Maximum quantum yields of photosystem II (PSII ) (F v /F m ) were relatively stable at low temperatures with the highest at 15.1°C for the macroscopic stage and at 16.5°C for the microscopic stage; but dropped at higher temperatures especially above 28°C. Continuous exposures (6 h) to 200 and 1000 μmol photons m?2 s?1 at 8, 16, and 28°C revealed greater depressions in effective quantum yields of PSII (Φ PSII ) of the microscopic stage at 8°C, as well as its F v /F m that barely increased after 6 h of dark acclimation. Whereas post‐dark acclimation F v /F m of both stages exposed to low PAR fairly recovered at 28°C, suggesting their photosynthetic tolerance to such high temperature. Under natural conditions, both heteromorphic stages of C. okamuranus may persist throughout the year in this region. Beyond its northern limit of distribution, the microscopic stage of this species may suffer from photodamage, as enhanced by low winter temperatures; hence, its restricted occurrence. 相似文献
86.
Hojun Rim Masayoshi Uefune Rika Ozawa Junji Takabayashi 《Arthropod-Plant Interactions》2018,12(4):495-503
Nesidiocoris tenuis Reuter (Heteroptera: Miridae) is an omnivorous mirid bug that preys on diverse generalist herbivorous arthropods. N. tenuis adults are attracted to volatiles from plants induced by their prey, such as tobacco cutworms (CCW) (Spodoptera litura larvae) and two-spotted spider mites (Tetranychus urticae). N. tenuis adults also induce volatiles when they infest plants. In this study, we focused on olfactory responses of N. tenuis males and females to volatiles from eggplants and sesame plants induced by conspecifics of the same or different gender by using a Y-tube olfactometer. Males were attracted to volatiles from plants of both species induced by either males or females. The male preference was biased to volatiles from plants of both species induced by females, probably because the biased response would facilitate their mate-finding. Females were attracted only to volatiles from plants of both species induced by females. Mating occurs multiple times in this species. Thus, the responses would indirectly affect mating of males and females. Slight but significant qualitative and quantitative differences were detected between the volatiles of plants of both species induced by N. tenuis females and those of the plants induced by conspecific males. N. tenuis might use such differences in their gender-specific responses. 相似文献
87.
88.
Association of the hypha‐related protein Pra1 and zinc transporter Zrt1 with biofilm formation by the pathogenic yeast Candida albicans 下载免费PDF全文
89.
Genetic characterization of hemagglutinin protein of measles viruses in Hokkaido district,Japan, 2006–2015 下载免费PDF全文
Masahiro Miyoshi Rika Komagome Hiroki Yamaguchi Setsuko Ishida Hideki Nagano Motohiko Okano 《Microbiology and immunology》2018,62(6):411-417
90.
Resisting annihilation: relationships between functional trait dissimilarity,assemblage competitive power and allelopathy 下载免费PDF全文
Rika M. W. Muhl Daniel L. Roelke Tamar Zohary Maria Moustaka‐Gouni Ulrich Sommer Gábor Borics Ursula Gaedke Frances G. Withrow Joydeb Bhattacharyya 《Ecology letters》2018,21(9):1390-1400
Allelopathic species can alter biodiversity. Using simulated assemblages that are characterised by neutrality, lumpy coexistence and intransitivity, we explore relationships between within‐assemblage competitive dissimilarities and resistance to allelopathic species. An emergent behaviour from our models is that assemblages are more resistant to allelopathy when members strongly compete exploitatively (high competitive power). We found that neutral assemblages were the most vulnerable to allelopathic species, followed by lumpy and then by intransitive assemblages. We find support for our modeling in real‐world time‐series data from eight lakes of varied morphometry and trophic state. Our analysis of this data shows that a lake's history of allelopathic phytoplankton species biovolume density and dominance is related to the number of species clusters occurring in the plankton assemblages of those lakes, an emergent trend similar to that of our modeling. We suggest that an assemblage's competitive power determines its allelopathy resistance. 相似文献