In renewing tissues,mutations conferring selective advantage may result in clonal expansions1-4.In contrast to somatic tissues,mutations driving clonal expansions in spermatogonia(CES)are also transmitted to the next ...In renewing tissues,mutations conferring selective advantage may result in clonal expansions1-4.In contrast to somatic tissues,mutations driving clonal expansions in spermatogonia(CES)are also transmitted to the next generation.This results in an effective increase of de novo mutation rate for CES drivers5-8.CES was originally discovered through extreme recurrence of de novo mutations causing Apert syndrome5.Here,we develop a systematic approach to discover CES drivers as hotspots of human de novo mutation.Our analysis of 54,715 trios ascertained for rare conditions9-13,6,065 control trios12,14-19 and population variation from 807,162 mostly healthy individuals20 identifies genes manifesting rates of de novo mutations inconsistent with plausible models of disease ascertainment.We propose 23 genes hypermutable at loss-of-function(LoF)sites as candidate CES drivers.An extra 17 genes feature hypermutable missense mutations at individual positions,suggesting CES acting through gain of function.CES increases the average mutation rate roughly 17-fold for LoF genes in both control trios and sperm and roughly 500-fold for pooled gain-of-function sites in sperm21.Positive selection in the male germline elevates the prevalence of genetic disorders and increases polymorphism levels,masking the effect of negative selection in human populations.展开更多
Cell competition is now a well-established quality control strategy to optimize cell and tissue fitness in multicellular organisms.While pursuing this goal,it is also effective in selecting against altered/defective c...Cell competition is now a well-established quality control strategy to optimize cell and tissue fitness in multicellular organisms.While pursuing this goal,it is also effective in selecting against altered/defective cells with putative(pre)-neoplastic potential,thereby edging the risk of cancer development.The flip side of the coin is that the molecular machinery driving cell competition can also be co-opted by neoplastic cell populations to expand unchecked,outside the boundaries of tissue homeostatic control.This review will focus on information that begins to emerge regarding the role of cell competition in liver physiology and pathology.Liver repopulation by normal transplanted hepatocytes is an interesting field of investigation in this regard.The biological coordinates of this process share many features suggesting that cell competition is a driving force for the clearance of endogenous damaged hepatocytes by normal donor-derived cells,as previously proposed.Intriguing analogies between liver repopulation and carcinogenesis will be briefly discussed and the potential dual role of cell competition,as a barrier or a spur to neoplastic development,will be considered.Cell competition is in essence a cooperative strategy organized at tissue level.One facet of such cooperative attitude is expressed in the elimination of altered cells which may represent a threat to the organismal community.On the other hand,the society of cells can be disrupted by the emergence of selfish clones,exploiting the molecular bar codes of cell competition,thereby paving their way to uncontrolled growth.展开更多
Large granular lymphocytic leukemia(LGLL)is a relatively uncommon malignancy of the blood system,marked by the clonal expansion of cytotoxic lymphocytes,particularly CD8+T cells(T-LGLL),and in some cases,natural kille...Large granular lymphocytic leukemia(LGLL)is a relatively uncommon malignancy of the blood system,marked by the clonal expansion of cytotoxic lymphocytes,particularly CD8+T cells(T-LGLL),and in some cases,natural killer(NK)cells(NK-LGLL).1 Though rare,LGLL is clinically significant,representing approximately 2%to 6%of all chronic lymphopro-liferative diseases,with a somewhat higher incidence in Asian populations.展开更多
Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruse...Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruses.In order to reduce or eliminate the HIV-1 latent reservoir,characteristics of the latently infected cells need to be intensively studied,and a comprehensive understanding of the heterogenous nature of the latent reservoir will be critical to develop novel therapeutic strategies.Here,we discuss the different cell types and mechanisms contributing to the complexity and heterogeneity of HIV-1 latent reservoirs,and summarize the key challenges to the development of cure strategies for acquired immunodeficiency syndrome(AIDS).展开更多
文摘In renewing tissues,mutations conferring selective advantage may result in clonal expansions1-4.In contrast to somatic tissues,mutations driving clonal expansions in spermatogonia(CES)are also transmitted to the next generation.This results in an effective increase of de novo mutation rate for CES drivers5-8.CES was originally discovered through extreme recurrence of de novo mutations causing Apert syndrome5.Here,we develop a systematic approach to discover CES drivers as hotspots of human de novo mutation.Our analysis of 54,715 trios ascertained for rare conditions9-13,6,065 control trios12,14-19 and population variation from 807,162 mostly healthy individuals20 identifies genes manifesting rates of de novo mutations inconsistent with plausible models of disease ascertainment.We propose 23 genes hypermutable at loss-of-function(LoF)sites as candidate CES drivers.An extra 17 genes feature hypermutable missense mutations at individual positions,suggesting CES acting through gain of function.CES increases the average mutation rate roughly 17-fold for LoF genes in both control trios and sperm and roughly 500-fold for pooled gain-of-function sites in sperm21.Positive selection in the male germline elevates the prevalence of genetic disorders and increases polymorphism levels,masking the effect of negative selection in human populations.
文摘Cell competition is now a well-established quality control strategy to optimize cell and tissue fitness in multicellular organisms.While pursuing this goal,it is also effective in selecting against altered/defective cells with putative(pre)-neoplastic potential,thereby edging the risk of cancer development.The flip side of the coin is that the molecular machinery driving cell competition can also be co-opted by neoplastic cell populations to expand unchecked,outside the boundaries of tissue homeostatic control.This review will focus on information that begins to emerge regarding the role of cell competition in liver physiology and pathology.Liver repopulation by normal transplanted hepatocytes is an interesting field of investigation in this regard.The biological coordinates of this process share many features suggesting that cell competition is a driving force for the clearance of endogenous damaged hepatocytes by normal donor-derived cells,as previously proposed.Intriguing analogies between liver repopulation and carcinogenesis will be briefly discussed and the potential dual role of cell competition,as a barrier or a spur to neoplastic development,will be considered.Cell competition is in essence a cooperative strategy organized at tissue level.One facet of such cooperative attitude is expressed in the elimination of altered cells which may represent a threat to the organismal community.On the other hand,the society of cells can be disrupted by the emergence of selfish clones,exploiting the molecular bar codes of cell competition,thereby paving their way to uncontrolled growth.
文摘Large granular lymphocytic leukemia(LGLL)is a relatively uncommon malignancy of the blood system,marked by the clonal expansion of cytotoxic lymphocytes,particularly CD8+T cells(T-LGLL),and in some cases,natural killer(NK)cells(NK-LGLL).1 Though rare,LGLL is clinically significant,representing approximately 2%to 6%of all chronic lymphopro-liferative diseases,with a somewhat higher incidence in Asian populations.
基金This work was supported by grants from the National Special Research Program of China for Important Infectious Diseases(No.2018ZX10302103 and No.2017ZX10202102)National Natural Science Foundation of China(No.81672024)+1 种基金Natural Science Foundation of Guangdong Province of China(No.2017A030306005)Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06S638)。
文摘Antiretroviral therapy(ART)can effectively inhibit human immunodeficiency virus-1(HIV-1)replication,but is not curative due to the existence of a stable viral latent reservoir harboring replication-competent proviruses.In order to reduce or eliminate the HIV-1 latent reservoir,characteristics of the latently infected cells need to be intensively studied,and a comprehensive understanding of the heterogenous nature of the latent reservoir will be critical to develop novel therapeutic strategies.Here,we discuss the different cell types and mechanisms contributing to the complexity and heterogeneity of HIV-1 latent reservoirs,and summarize the key challenges to the development of cure strategies for acquired immunodeficiency syndrome(AIDS).
