The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In ...The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In this study, we sequenced five EV71 circulating strains, isolated from Fuyang, Hefei, Kunming and Shenzhen city of China and named them FY-23, FY-22, H44, K9 and S1 respectively. The sequence alignment demonstrated their genotypes be C4. The genetic distance of the VP1 gene from these isolates suggested that they were highly co-related with genetic identity similar to other previously reported EV71 strains in China. Additionally, these strains were identified to display some obvious proliferation dynamics and plaque morphology when propagated in Vero cells. However, a distinctive difference in pathogenic ability in neonatal mice was found. Some differences in cross neutralization test & immunogenic analysis were also found. All these results are related to the biological characterization of circulating EV71 strains in China and aid in the development of an EV71 vaccine in the future.展开更多
This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formo...This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formof B/C recombinant strains.Envelope sequences ofHIV-1 subtype C and some other subtypes deposited before December 31,2020 were downloaded from the Los Alamos HIV Database and the Chinese National Center for AIDS/STD Control and Prevention Database.The available sequences were screened for quality,and Bayesian analysis was used to build the maximum clade credibility evolutionary tree to analyze and judge the origin and spread of HIV-1 subtype C.HIV-1 subtype C originated in central Africa around 1952,then spread to southern Africa around 1969 and to eastern Africa around 1973.HIV-1 subtype C fromsouthern Africa was introduced into India in 1977.HIV-1 subtype C of eastern Africa was introduced into Brazil in 1987.Indian HIV-1 subtype C was exported to China in three migration events during the period from 1986 to 1989.The two predominant recombinants in China(CRF07_BC and CRF08_BC)emerged in 1988 and 1990,respectively.Other B/C recombinants,namely,CRF64_BC,CRF61_BC and CRF62_BC,originated in 1993,2002 and 2000,respectively.Our study has reconstructed the global origin and evolutionary history of HIV-1 subtype C.In addition,our study demonstrated that the Chinese HIV-1 subtype C originated from three related Indian lineages around the mid to late 1980s and,since then,has formed some B/C recombinants with subtype B that caused a widespread epidemic in China.展开更多
The multifunctional trans-activator Tat is an essential regulatory protein for HIV-1 replication and is characterized by high sequence diversity. Numerous experimental studies have examined Tat in HIV-1 subtype B, but...The multifunctional trans-activator Tat is an essential regulatory protein for HIV-1 replication and is characterized by high sequence diversity. Numerous experimental studies have examined Tat in HIV-1 subtype B, but research on subtype C Tat is lacking, despite the high prevalence of infections caused by subtype C worldwide. We hypothesized that amino acid differences contribute to functional differences among Tat proteins. In the present study, we found that subtype B NL4-3Tat and subtype C isolate HIV1084 i Tat exhibited differences in stability by overexpressing the fusion protein Tat-Flag. In addition, 1084 i Tat can activate LTR and NF-κB more efficiently than NL4-3 Tat. In analyses of the activities of the truncated forms of Tat, we found that the carboxylterminal region of Tat regulates its stability and transactivity. According to our results, we speculated that the differences in stability between B-Tat and C-Tat result in differences in transactivation ability.展开更多
It is well established that different sites within a protein evolve at different rates according to their role within the protein; identification of these correlated mutations can aid in tasks such as ab initio protei...It is well established that different sites within a protein evolve at different rates according to their role within the protein; identification of these correlated mutations can aid in tasks such as ab initio protein structure, structure function analysis or sequence alignment. Mutual Information is a standard measure for coevolution between two sites but its application is limited by signal to noise ratio. In this work we report a preliminary study to investigate whether larger sequence sets could circumvent this problem by calculating mutual information arrays for two sets of drug naive sequences from the HIV gpl20 protein for the B and C subtypes. Our results suggest that while the larger sequences sets can improve the signal to noise ratio, the gain is offset by the high mutation rate of the HIV virus which makes it more difficult to achieve consistent alignments. Nevertheless, we were able to predict a number of coevolving sites that were supported by previous experimental studies as well as a region close to the C terminal of the protein that was highly variable in the C subtype but highly conserved in the B subtype.展开更多
High-grade serous ovarian cancer(HGSC)accounts for more than 70%of ovarian cancer-related deaths,yet therapeutic progress remains stagnant.Among the four molecular subtypes reported for HGSC,the C5 subtype is distingu...High-grade serous ovarian cancer(HGSC)accounts for more than 70%of ovarian cancer-related deaths,yet therapeutic progress remains stagnant.Among the four molecular subtypes reported for HGSC,the C5 subtype is distinguished by high proliferation and immune evasion with an unfavorable MHC-I/PD-L1 ratio.However,the molecular drivers of this immune desert state remain largely undefined.Here,we identify RNA-binding proteins(RBPs)as key regulators of immune evasion in C5-HGSC through integrated single-cell and bulk RNA sequencing.We perform a targeted loss-of-function screen in C5-like cell models and find IGF2BP1 as a central mediator of immune evasion in vitro and in vivo.Mechanistically,IGF2BP1 abrogates interferon-gamma signaling by accelerating IRF1 protein degradation,thereby suppressing MHC-I presentation.We also discover that IGF2BP1 decouples PD-L1 expression from IRF1-dependent transcription and reshapes the immune receptor landscape to limit immune cell infiltration and T cell activation.Therapeutically,the small-molecule BTYNB effectively inhibits IGF2BP1 and synergizes with PD-1 blockade to overcome immune evasion in vivo.Multi-spectral imaging confirms these findings in human HGSC tissues and highlights the role of oncofetal RBPs as molecular drivers of the C5-HGSC subtype.This subtype-wide survey uncovers a previously unrecognized RBP–interferon regulatory axis and establishes RBP inhibition as a therapeutic strategy to enhance immune checkpoint therapy in immunologically cold ovarian tumors.展开更多
基金National Science and Technology Major Project (2008ZX10004-014)
文摘The comparative analysis of the biological characterization and the genetic background study of EV71 circulating strains is commonly recognized as basic work necessary for development of an effective EV71 vaccine. In this study, we sequenced five EV71 circulating strains, isolated from Fuyang, Hefei, Kunming and Shenzhen city of China and named them FY-23, FY-22, H44, K9 and S1 respectively. The sequence alignment demonstrated their genotypes be C4. The genetic distance of the VP1 gene from these isolates suggested that they were highly co-related with genetic identity similar to other previously reported EV71 strains in China. Additionally, these strains were identified to display some obvious proliferation dynamics and plaque morphology when propagated in Vero cells. However, a distinctive difference in pathogenic ability in neonatal mice was found. Some differences in cross neutralization test & immunogenic analysis were also found. All these results are related to the biological characterization of circulating EV71 strains in China and aid in the development of an EV71 vaccine in the future.
基金supported by Science Priority Grant(2019SKLID602)the State Key Laboratory of Infectious Disease Prevention and Control,and the National Natural Science Foundation of China(grant number:81861138011).
文摘This study aimed to reconstruct the origin and worldwide epidemic history of human immunodeficiency virus(HIV)1 subtype C and comprehend how HIV-1 subtype C was introduced into and spread throughout China in the formof B/C recombinant strains.Envelope sequences ofHIV-1 subtype C and some other subtypes deposited before December 31,2020 were downloaded from the Los Alamos HIV Database and the Chinese National Center for AIDS/STD Control and Prevention Database.The available sequences were screened for quality,and Bayesian analysis was used to build the maximum clade credibility evolutionary tree to analyze and judge the origin and spread of HIV-1 subtype C.HIV-1 subtype C originated in central Africa around 1952,then spread to southern Africa around 1969 and to eastern Africa around 1973.HIV-1 subtype C fromsouthern Africa was introduced into India in 1977.HIV-1 subtype C of eastern Africa was introduced into Brazil in 1987.Indian HIV-1 subtype C was exported to China in three migration events during the period from 1986 to 1989.The two predominant recombinants in China(CRF07_BC and CRF08_BC)emerged in 1988 and 1990,respectively.Other B/C recombinants,namely,CRF64_BC,CRF61_BC and CRF62_BC,originated in 1993,2002 and 2000,respectively.Our study has reconstructed the global origin and evolutionary history of HIV-1 subtype C.In addition,our study demonstrated that the Chinese HIV-1 subtype C originated from three related Indian lineages around the mid to late 1980s and,since then,has formed some B/C recombinants with subtype B that caused a widespread epidemic in China.
基金supported by grants from the National Natural Science Foundation of China (No.81571987 and 81371820)the Ph.D. Candidate Research Innovation Fund of Nankai University (2015) (No.68150003)
文摘The multifunctional trans-activator Tat is an essential regulatory protein for HIV-1 replication and is characterized by high sequence diversity. Numerous experimental studies have examined Tat in HIV-1 subtype B, but research on subtype C Tat is lacking, despite the high prevalence of infections caused by subtype C worldwide. We hypothesized that amino acid differences contribute to functional differences among Tat proteins. In the present study, we found that subtype B NL4-3Tat and subtype C isolate HIV1084 i Tat exhibited differences in stability by overexpressing the fusion protein Tat-Flag. In addition, 1084 i Tat can activate LTR and NF-κB more efficiently than NL4-3 Tat. In analyses of the activities of the truncated forms of Tat, we found that the carboxylterminal region of Tat regulates its stability and transactivity. According to our results, we speculated that the differences in stability between B-Tat and C-Tat result in differences in transactivation ability.
文摘It is well established that different sites within a protein evolve at different rates according to their role within the protein; identification of these correlated mutations can aid in tasks such as ab initio protein structure, structure function analysis or sequence alignment. Mutual Information is a standard measure for coevolution between two sites but its application is limited by signal to noise ratio. In this work we report a preliminary study to investigate whether larger sequence sets could circumvent this problem by calculating mutual information arrays for two sets of drug naive sequences from the HIV gpl20 protein for the B and C subtypes. Our results suggest that while the larger sequences sets can improve the signal to noise ratio, the gain is offset by the high mutation rate of the HIV virus which makes it more difficult to achieve consistent alignments. Nevertheless, we were able to predict a number of coevolving sites that were supported by previous experimental studies as well as a region close to the C terminal of the protein that was highly variable in the C subtype but highly conserved in the B subtype.
基金supported by grants from the Deutsche Forschungsgemeinschaft(DFG)to Nadine Bley,Stefan Hüttelmaier,and Wolfgang Sippl(DFG-FOR5433,468534282)Nadine Bley and Stefan Hüttelmaier(DFG_GRK2751,449501615)+1 种基金The authors would like to thank Prof.Iain McNeish(Imperial College London,UK)for providing ID8 and ID8-TP53 knockout cell lines36 Furthermore,the authors would like to thank the Core Facility Imaging(CFI)providing all devices and technical support for imaging,FACS and flow cytometry as well as RNA sequencing,scRNA sequencing and data analyses.
文摘High-grade serous ovarian cancer(HGSC)accounts for more than 70%of ovarian cancer-related deaths,yet therapeutic progress remains stagnant.Among the four molecular subtypes reported for HGSC,the C5 subtype is distinguished by high proliferation and immune evasion with an unfavorable MHC-I/PD-L1 ratio.However,the molecular drivers of this immune desert state remain largely undefined.Here,we identify RNA-binding proteins(RBPs)as key regulators of immune evasion in C5-HGSC through integrated single-cell and bulk RNA sequencing.We perform a targeted loss-of-function screen in C5-like cell models and find IGF2BP1 as a central mediator of immune evasion in vitro and in vivo.Mechanistically,IGF2BP1 abrogates interferon-gamma signaling by accelerating IRF1 protein degradation,thereby suppressing MHC-I presentation.We also discover that IGF2BP1 decouples PD-L1 expression from IRF1-dependent transcription and reshapes the immune receptor landscape to limit immune cell infiltration and T cell activation.Therapeutically,the small-molecule BTYNB effectively inhibits IGF2BP1 and synergizes with PD-1 blockade to overcome immune evasion in vivo.Multi-spectral imaging confirms these findings in human HGSC tissues and highlights the role of oncofetal RBPs as molecular drivers of the C5-HGSC subtype.This subtype-wide survey uncovers a previously unrecognized RBP–interferon regulatory axis and establishes RBP inhibition as a therapeutic strategy to enhance immune checkpoint therapy in immunologically cold ovarian tumors.
