The influence of CCL3L1 gene-containing segmental duplications on HIV-1/AIDS susceptibility

Segmental duplications in the human genome are selectively enriched for genes involved in immunity, although the phenotypic consequences for host defense are unknown. We show that there are significant interindividual and interpopulation differences in the copy number of a segmental duplication encompassing the gene encoding CCL3L1 (MIP-1alphaP), a potent human immunodeficiency virus-1 (HIV-1)-suppressive chemokine and ligand for the HIV coreceptor CCR5. Possession of a CCL3L1 copy number lower than the population average is associated with markedly enhanced HIV/acquired immunodeficiency syndrome (AIDS) susceptibility. This susceptibility is even greater in individuals who also possess disease-accelerating CCR5 genotypes. This relationship between CCL3L1 dose and altered HIV/AIDS susceptibility points to a central role for CCL3L1 in HIV/AIDS pathogenesis and indicates that differences in the dose of immune response genes may constitute a genetic basis for variable responses to infectious diseases.     

CX3CR1-mediated dendritic cell access to the intestinal lumen and bacterial clearance

Dendritic cells (DCs) and macrophages are critical to innate and adaptive immunity to the intestinal bacterial microbiota. Here, we identify a myeloid-derived mucosal DC in mice, which populates the entire lamina propria of the small intestine. Lamina propria DCs were found to depend on the chemokine receptor CX3CR1 to form transepithelial dendrites, which enable the cells to directly sample luminal antigens. CX3CR1 was also found to control the clearance of entero-invasive pathogens by DCs. Thus, CX3CR1-dependent processes, which control host interactions of specialized DCs with commensal and pathogenic bacteria, may regulate immunological tolerance and inflammation.     

Antiretroviral drugs for tuberculosis control in the era of HIV/AIDS

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) has dramatically increased the incidence of tuberculosis (TB) in subSaharan Africa, where up to 60% of TB patients are coinfected with HIV and each year 200,000 TB deaths are attributable to HIV coinfection. Now HIV threatens control of TB in Asia, Eastern Europe, and Latin America. Antiretroviral (ARV) drugs can prevent TB by preserving immunity, but cohort analysis shows that early therapy, plus high levels of coverage and compliance, will be needed to avert a significant fraction of TB cases. However, ARV drugs could enhance the treatment of TB, and TB programs provide an important entry point for the treatment of HIV/AIDS.     

CX3CL1在不同品种鸡骨骼肌发育中的表达模式及相关性分析

趋化因子CX3CL1(chemokine(C-X3-Cmotif)ligand 1)与受体CX3CR1结合后,激活MAPK通路调控骨骼肌细胞的增殖和分化。以矮小品系S2系和隐性白羽鸡作为试验素材,采用Q-PCR技术及SPSS分析软件,研究CX3CL1在2个品种胚胎期至生长期骨骼肌发育中的表达模式及相关性分析。结果表明,在S2系鸡,CX3CL1在胚胎期胸肌组织的表达显著低于出雏后的各个发育时期(P0.05);隐性白羽鸡10胚龄时CX3CL1的表达量显著高于其他胚龄及出雏后4、6和8周的表达(P0.05);除16周龄以外,CX3CL1在隐性白羽鸡胸肌组织各个时期的表达都显著高于S2系(P0.05);CX3CL1的表达与胸肌率的相关性分析表明,CX3CL1的表达与2品种胸肌率呈显著正相关。在腿肌组织中,CX3CL1在S2系和隐性白羽鸡的表达呈现显著的品种差异性,除10胚龄外,CX3CL1在隐性白羽鸡其他发育时期的表达都显著高于S2系。综合CX3CL1在2品种的胸肌和腿肌组织中的发育模式及相关性分析表明,CX3CL1在鸡胚胎期和生长期骨骼肌中的表达存在显著的品种和组织差异性。     

HIV/AIDS患者外周血中4种细胞因子IL-2、IL-4、IL-15和IL-21表达水平及其临床意义研究

目的 观察外周血 4 种细胞因子（IL-2、IL-4、IL-15及IL-21）在HIV感染者/AIDS患者（HIV/AIDS）和正常人表达水平的区别及其与HIV RNA病毒载量和CD3⁺、CD4⁺细胞数量的相关性,分析其与HIV感染的关系和临床意义。方法 40例未经抗病毒治疗的HIV/AIDS 和31名正常人,采用ELISA法检测外周血4种细胞因子（IL-2、IL-4、IL-15及IL-21）,使用流式细胞计数法检测外周血CD3⁺、CD4⁺ T 淋巴细胞数量,实时聚合酶链反应测定血清中HIV RNA水平。结果 未经抗病毒治疗的HIV/AIDS外周血IL-2、IL-15及IL-21水平低于正常人,而IL-4水平高于正常人（P<0.05）。CD3⁺、CD4⁺细胞数量和各细胞因子水平显示出一定的相关关系,IL-2和IL-15水平均与HIV-1 RNA载量呈负相关。结论 提示外周血4种细胞因子都可能参与了HIV感染的致病机制,并与HIV RNA病毒载量及CD3⁺、CD4⁺细胞数量相关。     

Dual infection of the central nervous system by AIDS viruses with distinct cellular tropisms

Human immunodeficiency virus (HIV) is the causative agent of the acquired immune deficiency syndrome (AIDS). A large number of AIDS patients show evidence of neurologic involvement, known as AIDS-related subacute encephalopathy, which has been correlated with the presence of HIV in the brain. In this study, two genetically distinct but related viruses were isolated from one patient from two different sources in the central nervous system: brain tissue and cerebrospinal fluid. Both viruses were found to replicate in peripheral blood lymphocytes, but only virus from brain tissue will efficiently infect macrophage/monocytes. The viruses also differ in their ability to infect a brain glioma explant culture. This infection of the brain-derived cells in vitro is generally nonproductive, and appears to be some form of persistent or latent infection. These results indicate that genetic variation of HIV in vivo may result in altered cell tropisms and possibly implicate strains of HIV with glial cell tropism in the pathogenesis of some neurologic disorders of AIDS.     

Specific tropism of HIV-1 for microglial cells in primary human brain cultures

Human immunodeficiency virus (HIV) frequently causes neurological dysfunction and is abundantly expressed in the central nervous system (CNS) of acquired immunodeficiency syndrome (AIDS) patients with HIV encephalitis or myelopathy. The virus is found mostly in cells of the monocyte-macrophage lineage within the CNS, but the possibility of infection of other glial cells has been raised. Therefore, the effects of different HIV-1 and HIV-2 strains were studied in primary cultures of adult human brain containing microglial cells, the resident CNS macrophages, and astrocytes. These cultures could be productively infected with macrophage-adapted HIV-1 isolates but not with T lymphocyte-adapted HIV-1 isolates or two HIV-2 isolates. As determined with a triple-label procedure, primary astrocytes did not express HIV gag antigens and remained normal throughout the 3-week course of infection. In contrast, virus replicated in neighboring microglial cells, often leading to their cell fusion and death. The death of microglial cells, which normally serve immune functions in the CNS, may be a key factor in the pathogenesis of AIDS encephalitis or myelopathy.     

Scaling Up HIV/AIDS programs to national coverage

The most important issue in the fight against HIV/AIDS is how to scale up existing programs that are only reaching small numbers of people to the national level. Here, I present suggestions on how to tackle the daunting challenge of building truly national HIV/AIDS programs, based on insights gained from participatory, decentralized rural development experiences and from HIV/AIDS programs.     

Monitoring of blood vessels and tissues by a population of monocytes with patrolling behavior

The cellular immune response to tissue damage and infection requires the recruitment of blood leukocytes. This process is mediated through a classical multistep mechanism, which involves transient rolling on the endothelium and recognition of inflammation followed by extravasation. We have shown, by direct examination of blood monocyte functions in vivo, that a subset of monocytes patrols healthy tissues through long-range crawling on the resting endothelium. This patrolling behavior depended on the integrin LFA-1 and the chemokine receptor CX(3)CR1 and was required for rapid tissue invasion at the site of an infection by this "resident" monocyte population, which initiated an early immune response and differentiated into macrophages.     

Structure of a V3-containing HIV-1 gp120 core

The third variable region (V3) of the HIV-1 gp120 envelope glycoprotein is immunodominant and contains features essential for coreceptor binding. We determined the structure of V3 in the context of an HIV-1 gp120 core complexed to the CD4 receptor and to the X5 antibody at 3.5 angstrom resolution. Binding of gp120 to cell-surface CD4 would position V3 so that its coreceptor-binding tip protrudes 30 angstroms from the core toward the target cell membrane. The extended nature and antibody accessibility of V3 explain its immunodominance. Together, the results provide a structural rationale for the role of V3 in HIV entry and neutralization.     

Transmission of HIV in Belle Glade, Florida: lessons for other communities in the United States

The high cumulative incidence of AIDS and the large percentage of AIDS patients with no identified risks in Belle Glade, Florida, were evaluated through case interviews and neighborhood-based seroepidemiologic studies. It was found that of 93 AIDS patients reported between July 1982 and 1 August 1987, 34 could be directly linked to at least one other AIDS patient or to a person with AIDS-related complex by sexual contact, sharing of needles during intravenous drug abuse (or both), or perinatal exposure; of 877 randomly selected adults, 28 had antibodies to HIV; no person over age 60 and none of 138 children aged 2 to 10 years had antibodies to HIV; no clustering of infected persons within households occurred, except in sex partners; and HIV-seropositive adults were more likely than HIV-seronegative adults to be from Haiti, have a lower income, report sex with intravenous drug abusers, and have a history of previous treatment for sexually transmitted diseases. The presence of antibodies to five arboviruses prevalent in South Florida or the Caribbean did not correlate significantly with HIV infection. The high cumulative rate of AIDS in Belle Glade appears to be the result of HIV transmission through sexual contact and intravenous drug abuse; the evidence does not suggest transmission of HIV through insects.     

中国荷斯坦牛CXCR1基因遗传多态性与体细胞评分的关联分析

【目的】研究中国荷斯坦奶牛CXCR1基因的多态性及其与体细胞评分(Somaticcellscore,SCS)的关系,寻找与中国荷斯坦牛SCS相关的分子遗传标记,加快抗病育种进程。【方法】采用PCR-SSCP技术对来自30个公牛家系的610头中国荷斯坦牛CXCR1基因进行多态性检测,利用最小二乘均数法对CRCR1基因的多态位点与SCS进行相关分析,利用PHASE软件对4个多态位点进行单倍型分析。【结果】检测到4个SNPs,在5侧翼区发现了3个SNPs(-1830(A/G)、-1768(T/A)、-344(T/C)),在编码区783(C/A)位点为新发现的SNP。-1830(A/G)位点AA基因型个体SCS极显著低于AG基因型个体(P0.01),-1768(T/A)位点TT基因型个体SCS极显著低于TA基因型个体(P0.01),-344(T/C)位点TT基因型个体SCS极显著低于TC、CC个体(P0.01)。783(C/A)位点基因型个体的SCS差异不显著。单倍型Haplo2(ATTA)纯合基因型的SCS极显著低于Haplo1(ATCA)、Haplo3(GACA)和Haplo4(GATA)单倍型纯合基因型(P0.01)。【结论】-1830(A/G)位点AA基因型、-1768(T/A)位点TT基因型和-344(T/C)位点TT基因型以及单倍型Haplo2(ATTA)纯合体对中国荷斯坦牛的SCS具有较大的遗传效应,可作为分子标记应用于奶牛乳房炎抗性的筛选。     

Reconstruction and future trends of the AIDS epidemic in the United States

There has been considerable uncertainty in estimates of past and current human immunodeficiency virus (HIV) infection rates in the United States. Statistical estimates of historical infection rates can be obtained from acquired immunodeficiency syndrome (AIDS) incidence data and the incubation period. However, this approach is subject to a number of sources of uncertainty and two other approaches, epidemic models of HIV transmission and surveys of HIV prevalence, are used to corroborate and refine the statistical estimates. Analyses suggest the HIV infection rate in the United States grew rapidly in the early 1980s, peaked in the mid-1980s, and subsequently declined markedly. Due both to the decline in the underlying infection rate and to the development of effective therapies that may delay AIDS diagnosis, overall AIDS incidence may plateau during the next 5 years. However, the number of individuals with advanced HIV disease without a diagnosis of AIDS who could potentially benefit from therapy is expected to increase 40% by 1995 as infected individuals progress to more advanced stages of HIV disease. Thus, although the overall HIV infection rate has declined, the demands on the U.S. health care system for treatment and care of HIV-infected individuals remain enormous.     

Population-level HIV declines and behavioral risk avoidance in Uganda

Uganda provides the clearest example that human immunodeficiency virus (HIV) is preventable if populations are mobilized to avoid risk. Despite limited resources, Uganda has shown a 70% decline in HIV prevalence since the early 1990s, linked to a 60% reduction in casual sex. The response in Uganda appears to be distinctively associated with communication about acquired immunodeficiency syndrome (AIDS) through social networks. Despite substantial condom use and promotion of biomedical approaches, other African countries have shown neither similar behavioral responses nor HIV prevalence declines of the same scale. The Ugandan success is equivalent to a vaccine of 80% effectiveness. Its replication will require changes in global HIV/AIDS intervention policies and their evaluation.     

A whole-genome association study of major determinants for host control of HIV-1

Understanding why some people establish and maintain effective control of HIV-1 and others do not is a priority in the effort to develop new treatments for HIV/AIDS. Using a whole-genome association strategy, we identified polymorphisms that explain nearly 15% of the variation among individuals in viral load during the asymptomatic set-point period of infection. One of these is found within an endogenous retroviral element and is associated with major histocompatibility allele human leukocyte antigen (HLA)-B*5701, whereas a second is located near the HLA-C gene. An additional analysis of the time to HIV disease progression implicated two genes, one of which encodes an RNA polymerase I subunit. These findings emphasize the importance of studying human genetic variation as a guide to combating infectious agents.     

几种林木浸提液对小麦籽粒发芽的影响

对5种植物天然浸提液M1、M2、M3、M4和M5分别按280、200、120和40 g/L的浓度,对小麦种子萌发抑制效应进行试验.结果表明,5种天然材料的浸提液对小麦籽粒的萌发均具有抑制效应,其中M1的抑制作用较为持久,M4、M5和M2次之,M3较为短暂;各材料的抑制作用强度为:M1＞M4＞M5＞M2＞M3;浓度的抑制作用强度为:280 g/L＞200 g/L＞120 g/L＞40 g/L.     

中国肝细胞癌p53基因热点突变R249S的载体构建及其在细胞中的表达

抑癌基因p53突变是人肝细胞癌（Hepatocellular carcinoma，HCC）中常见的现象，中国江苏启东地区的HCC患者中p53基因的第249位密码子突变AGG→AGT/Arg→Ser（R249S）被认为是热点突变。本研究以人肝cDNA为模板，扩增人全长p53基因，将其克隆到pCMV-Myc载体中。利用定点突变引物以pC-MV-p53为模板，构建R249S定点突变体pCMV-R249S，转染p53缺陷型的H1299细胞系。Western Blot检测表明，克隆在pCMV-Myc载体中的p53基因和249位密码子热点突变的p53基因都可以在H1299细胞系中表达。     

Global AIDS epidemic: time to turn the tide

HIV/AIDS is catastrophic both from a public health perspective and in terms of its impact on economic and social stability in many of the most severely affected nations, including virtually all of southern Africa. A public health response alone is insufficient to address this devastating epidemic. Political leadership at the highest levels is needed to mobilize a multisectoral response to the impact of HIV/AIDS on educational systems, industry, agriculture, the military, and other sectors. With a few notable exceptions, political response was slow to mobilize in the early years of the epidemic, but response has dramatically improved in the past 18 months. The Joint United Nations Programme on HIV/AIDS (UNAIDS) is involved in ongoing efforts to encourage political leaders to make a multisectoral response to the epidemic a major focus of their national plans.     

Synthetic peptide immunoassay distinguishes HIV type 1 and HIV type 2 infections

Efforts to solve the epidemiologic puzzle of AIDS in Africa are complicated by the presence of multiple human retroviruses. Simple serologic tests that unambiguously distinguish among infections by these retroviruses are essential. To that end, a partially conserved immunoreactive epitope was identified in the transmembrane glycoproteins of human immunodeficiency viruses (HIV) types 1 and 2. Synthetic peptides derived from these conserved domains were used in sensitive and specific immunoassays that detect antibodies in sera from patients infected with HIV-1 or HIV-2. By making single amino acid substitutions in the HIV-1 peptide, it was possible to demonstrate HIV-1 strain-specific antibody responses to this epitope. Such custom-designed peptides synthesized from this domain are likely to detect newly discovered HIV types, define infection with specific HIV strains, and allow detection of group-common antibodies.