吸毒人群和HIV-1感染者人群DC-SIGN/DC-SIGNR基因多态性分析

目的 研究等位基因DC-SIGN/DC-SIGNR在人类免疫缺陷病毒Ⅰ型(HIV-1)感染者与HIV-1阴性吸毒人群中的分布,筛选出HIV-1抗性基因.方法 选择深圳市戒毒所HIV抗体阴性戒毒者的样本257份,HIV-1感染者的样本220份.提取外周血基因组DNA,对DC-SIGN/DC-SIGNR颈区基因进行特异性聚合酶链反应(PCR)扩增,PCR扩增产物行琼脂糖凝胶电泳检测和基因序列测定分析.结果 通过统计学分析发现,DGSIGNR颈区中杂合子7/5、7/6和7/7在HIV阴性吸毒者中出现的频率为13.33%、7.50%、49.4%,在HIV-1感染者中出现的频率为11.05%、4.65%、51.74%,两者无明显差异.说明DC-SIGN在吸毒者与HIV-1感染者中的基因型及等位基因的分布无明显差异.结论 深圳市吸毒人群中DC-SIGNR和DC-SIGN基因型分布和等位基因出现频率,与HIV-1感染者无显著性差异,推测DC-SIGNR和DC-SIGN基因多态性对HIV-1易感性无明显影响.     

树突状细胞表面特异性非整联蛋白同源物基因多态性与丙型肝炎病毒感染的相关性

目的 研究丙型肝炎患者树突状细胞表面特异性非整联蛋白同源物(DC-SIGNR)外显子4基因颈区重复序列的遗传多态性分布,探讨DC-SIGNR基因多态性与HCV病毒基因分型及HCV载量的关系. 方法采用PCR结合DNA测序对268例丙型肝炎患者DC-SIGNR重复序列多态性进行基因分型和测序分析,同时检测患者的HCV病毒载量及HCV病毒基因分型.组间两两比较用LSD法.结果 DC-SIGNR基因型或等位基因与HCV基因分型的相关性不显著.HCV载量携带7等位基因的患者为(4.6722±1.9766)log10拷贝/ml,携带9等位基因的患者为(5.3073±1.6795)log10拷贝/ml,P=0.036,两组差异有统计学意义.7/7基因型的患者HCV载量水平为(4.5974±2.0067)log10拷贝/ml,9/7基因型的患者组为(5.2771±1.8587)log10拷贝/ml,P=0.025,两组差异有统计学意义.提示HCV更易与携带较长DC-SINGR等位基因的患者结合.结论 DC-SIGNR遗传多态性可能与HCV在个体内的复制有关,但与HCV基因分型不相关.     

树突状细胞表面特异性非整联蛋白同源物基因多态性与丙型肝炎病毒感染的相关性

目的 研究丙型肝炎患者树突状细胞表面特异性非整联蛋白同源物(DC-SIGNR)外显子4基因颈区重复序列的遗传多态性分布,探讨DC-SIGNR基因多态性与HCV病毒基因分型及HCV载量的关系. 方法采用PCR结合DNA测序对268例丙型肝炎患者DC-SIGNR重复序列多态性进行基因分型和测序分析,同时检测患者的HCV病毒载量及HCV病毒基因分型.组间两两比较用LSD法.结果 DC-SIGNR基因型或等位基因与HCV基因分型的相关性不显著.HCV载量携带7等位基因的患者为(4.6722±1.9766)log10拷贝/ml,携带9等位基因的患者为(5.3073±1.6795)log10拷贝/ml,P=0.036,两组差异有统计学意义.7/7基因型的患者HCV载量水平为(4.5974±2.0067)log10拷贝/ml,9/7基因型的患者组为(5.2771±1.8587)log10拷贝/ml,P=0.025,两组差异有统计学意义.提示HCV更易与携带较长DC-SINGR等位基因的患者结合.结论 DC-SIGNR遗传多态性可能与HCV在个体内的复制有关,但与HCV基因分型不相关.     

树突状细胞表面特异性非整联蛋白外显子4在中国裔丙型肝炎患者中的遗传多态性

目的探讨树突状细胞表面特异性非整联蛋白（DC—SIGN）及其同源物（DC-SIGNR）外显子4遗传多态性在中国裔丙型肝炎患者中是否存在遗传易感性。方法采用PCR结合DNA测序对300例丙型肝炎患者和520名健康人的DC-SIGN和DC-SIGNR外显子4重复序列多态性进行基因分型和测序分析。结果DC—SIGN外显子4基因型与等位基因频率在丙型肝炎患者和健康人群间差异无统计学意义（P〉0．05）。DC-SIGNR外显子4等位基因的频率差异也无统计学意义（P〉0．05）；但9／5基因型分布频率在丙型肝炎患者和健康人群间的差异有统计学意义（P〈0．05）。结论DC-SIGN外显子4遗传多态性与HCV感染易感性无明显相关性；9／5基因型DC-SIGNR外显子4在丙型肝炎患者中的分布频率较高，可能与HCV感染的易感性相关，值得进一步研究。     

HIV-1的基因重组：分子机制及生物学特征

基因重组是导致HIV—1多态性不断增加的重要进化机制。重组发生在病毒基因组的逆转录过程中，通过模板选择来实现。新的重组病毒可能具有传播优势，从而成为流行重组形式（circulatingrecombinant forms，CRFs）。全世界现已发现43种CRFs，此数量还会不断增加。HIV-1基因重组将有利于病毒复制和传播的突变联合起来，使病毒能更快地逃避药物选择和宿主免疫压力。因此，基因重组在HIV-1的分子进化、适应宿主和逃避药物治疗等方面都是不可或缺的部分。目前对HIV-1基因重组产生和发展的机制及重组毒株的生物学特征了解得还不是很清楚。本文对HIV-1基因重组的分子机制及其对传播及致病特征的影响进行综述。     

血红素加氧酶1基因启动子区多态性与冠心病的相关性及其对血清胆红素水平的影响

目的探讨冠心病患者血红素加氧酶1启动子区(GT)n重复序列多态性与冠心病的相关性及其对血清胆红素水平的影响。方法采用聚合酶链反应-非变性聚丙烯酰胺凝胶电泳法检测337例冠心病患者和240例健康对照者血红素加氧酶1启动子区(GT)n重复序列多态性,同时测定血清胆红素水平。结果冠心病组与对照组LL基因型及L等位基因频率分布差异显著(P<0.05);L等位基因频率在冠心病不同病变程度之间分布差异显著(P<0.05),且LL基因型频率在多支血管病变组较单支和双支血管病变组高(P<0.05);LL基因型者胆红素水平较SS基因型者明显下降(P<0.001)。结论血红素加氧酶1启动子区(GT)n重复序列多态性与冠心病的发生发展及冠状动脉狭窄程度有关,L等位基因是冠心病的一个危险因素,可能与该基因多态性所致血清胆红素水平降低有关。     

广西西部地区吸毒人群HIV-1毒株基因序列测定和亚型分析

目的了解吸毒人群HIV-1流行毒株的亚型类型和变异特征，为艾滋病的疫苗预防、诊治提供依据。方法采集血清和外周血单个核细胞，用ELISA法检测HIV-1的抗体；PEIA检测HIV-1血清亚型；PCR扩增HIV-1膜蛋白基因片段，荧光标记未端终止物循环测序法进行测序反应，自动DNA序列分析仪测定产物序列。结果HIV-1毒株至少有C、E两个亚型。C为优势亚型，其株间基因离散率最大为2．93％，与A亚型等其他9个亚型参考株相比较，基因离散率为12．42～19．05％，gp120 V3环多肽序列相似。还可能存在其它亚型或混合感染。结论吸毒人群HIV-1流行毒株亚型呈现多样性，应加强对HIV-1亚型及其变异的监测和研究，指导疫苗预防、诊断和治疗。     

白细胞介素-10基因多态性与慢性乙型肝炎病毒感染的相关性

HBV感染结局的多样性除与病毒因素有关外,还与宿主遗传背景密切相关。细胞因子在宿主清除病毒的免疫反应中发挥重要作用,其遗传多态性可能影响HBV感染后的不同转归,甚至影响抗病毒治疗的反应。IL-10是一种重要的细胞因子,可抑制免疫细胞的活化,具有潜在的抗炎和抗纤维化作用。IL-10基因启动子区有3个多态性     

人工合成HIV多肽的抗原性比较研究

为了建立检测HIV感染的敏感方法,根据文献报道的HIV-1和HIV-2基因组核苷酸序列、氨基酸序列,利用计算机分析其亲水性和抗原决定簇位点,自行设计合成了HIV-1gp41、gp120、P24和HIV-2pg36区域的10条多肽,以此多肽作抗原包被反应板,建立了检测HIV抗体的间接ELISA方法,同时检测10份抗HIV-1阳性病人血清和4份抗HIV-2     

血红素氧合酶1基因启动子区(GT)n重复序列多态性与广东潮汕人群冠心病易感性的关系

目的 探讨血红素氧合酶1基因启动子区(GT)n重复序列多态性与广东潮汕人群冠心病易感性的关系.方法 采用荧光标记PCR和毛细管电泳相结合技术检测血红素氧合酶1基因启动子区(GT)n重复序列多态性在300例冠心病患者以及性别、年龄相匹配的182例对照者中等位基因和基因型频率分布差异,重复次数n≤25为S型等位基因,n＞25为L型等位基因.Logistics回归分析基因型与吸烟、高血压、糖尿病、高血脂、家族史等冠心病危险因素间的交互作用.结果 等位基因和基因型频率在冠心病组与对照组中分布差异无显著性,基因型与吸烟(OR为1.790,95%CI为1.110-2.886)、高血压(OR为1.552,95%CI为1.045-2.304)、糖尿病(OR为1.727,95%CI为1.018-2.928)交互作用增加个体冠心病患病风险,SL+LL基因型与吸烟作用最为显著(OR为2.517, 95%CI为1.206-5.253).结论 血红素氧合酶1基因启动子区(GT)n重复序列多态性可作为潮汕人群伴危险因素个体冠心病易感风险评估的分子标记.     

Chimpanzee DC-SIGN alleles predict the existence of A and B isoforms, but do not support a role for resistance to HIV infection

We report here the gene sequence for DC-SIGN (CD209) from chimpanzees. DC-SIGN is a C-type lectin expressed by dendritic cells. It is involved in DC-T cell interactions as well as in HIV-1 and SIV transmission. We have cloned two new alleles for chimpanzee DC-SIGN. The coding sequences are highly homologous to the two previously described chimpanzee alleles. We confirm the existence of a polymorphism within the repeat region of DC-SIGN. In humans polymorphisms in the repeat region have been associated with resistance to HIV infection. However, we have not been able to correlate the number of repeats with susceptibility of chimpanzees to HIV infection. The actual impact of DC-SIGN variability in HIV infection therefore remains to be determined.     

Repeat-region polymorphisms in the gene for the dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin-related molecule: effects on HIV-1 susceptibility

In 1716 individuals--801 human immunodeficiency virus (HIV)-1-seropositive individuals, 217 high-risk HIV-1-seronegative individuals, and 698 general HIV-1-seronegative individuals--from a Seattle cohort and a Multicenter AIDS Cohort Study cohort, the association between HIV-1 susceptibility and repeat-region polymorphisms in the gene for the dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin-related molecule (DC-SIGNR) was investigated; 16 genotypes were found in the DC-SIGNR repeat region. The DC-SIGNR homozygous 7/7 repeat was found to be associated with an increased risk of HIV-1 infection (17.5% in high-risk HIV-1-seronegative individuals vs. 28.5% in HIV-1-seropositive individuals; P=.0015), whereas the DC-SIGNR heterozygous 7/5 repeat tended to be correlated with resistance to HIV-1 infection (35.5% in high-risk HIV-1-seronegative individuals vs. 27.6% in HIV-1-seropositive individuals; P=.0291). These findings suggest that DC-SIGNR polymorphisms may influence susceptibility to HIV-1.     

The polymorphisms in DC-SIGNR affect susceptibility to HIV type 1 infection

Dendritic cell-specific intercellular adhesion molecule-3 (ICAM-3) grabbing nonintegrin (DC-SIGN) and its homologue DC-SIGNR (DC-SIGN related) have been thought to play an important role in establishing HIV infection by enhancing trans-infection of CD4(+)T cells in the regional lymph nodes. To identify polymorphisms associated with HIV-exposed seronegative (ESN) individuals in Thais, genomic DNA from 102 HIV-seronegative individuals of HIV-seropositive spouses, 305 HIV-seropositive individuals, and 290 HIV-seronegative blood donors was genotyped for two single nucleotide polymorphisms (SNPs) in DC-SIGN promoter (-139A/G and 336A/G), a repeat number of 69 bp in Exon 4 of DC-SIGN and DC-SIGNR, and one SNP in Exon 5 of DC-SIGNR (rs2277998A/G). We found that the proportion of individuals possessing a heterozygous 7/5 and 9/5 repeat and A allele at rs2277998 of DC-SIGNR in HIV-seronegative individuals of HIV-seropositive spouses was significantly higher than HIV-seropositive individuals [p = 0.0373, OR (95% CI) = 0.57 (0.32,1.01); p = 0.0232, OR (95% CI) = 0.38 (0.15,0.98); and p = 0.0445, OR (95% CI) = 0.61 (0.37,1.02), respectively]. Analysis after stratifying by gender showed that these associations were observed only in females but not in males. Moreover, HIV-seropositive females tend to have a homozygous 7/7 repeat more frequently than HIV-seronegative females with a marginal level of significance [p = 0.0556, OR (95% CI) = 1.79 (0.94,3.40)]. Haplotype analysis showed that the proportion of individuals possessing the 5A haplotype in HIV-seronegative females was significantly higher than HIV-seropositive females [p = 0.0133, OR = 0.50 (0.27,0.90)]. These associations suggest that DC-SIGNR may affect susceptibility to HIV infection by a mechanism that is different in females and males. Further studies are warranted to investigate the mechanisms of their function.     

DC-SIGNR, a DC-SIGN homologue expressed in endothelial cells, binds to human and simian immunodeficiency viruses and activates infection in trans

DC-SIGN, a C-type lectin expressed on the surface of dendritic cells (DCs), efficiently binds and transmits HIVs and simian immunodeficiency viruses to susceptible cells in trans. A DC-SIGN homologue, termed DC-SIGNR, has recently been described. Herein we show that DC-SIGNR, like DC-SIGN, can bind to multiple strains of HIV-1, HIV-2, and simian immunodeficiency virus and transmit these viruses to both T cell lines and human peripheral blood mononuclear cells. Binding of virus to DC-SIGNR was dependent on carbohydrate recognition. Immunostaining with a DC-SIGNR-specific antiserum showed that DC-SIGNR was expressed on sinusoidal endothelial cells in the liver and on endothelial cells in lymph node sinuses and placental villi. The presence of this efficient virus attachment factor on multiple endothelial cell types indicates that DC-SIGNR could play a role in the vertical transmission of primate lentiviruses, in the enabling of HIV to traverse the capillary endothelium in some organs, and in the presentation of virus to CD4-positive cells in multiple locations including lymph nodes.     

Protective role of DC-SIGN (CD209) neck-region alleles with <5 repeat units in HIV-1 transmission

To investigate the role that DC-SIGN neck-region length variation plays in HIV-1 transmission, we studied 530 HIV-1-positive and 341 HIV-1-negative individuals in China. The carrier frequency of a DC-SIGN allele with <5 repeat units in the neck-region was 0.9% in HIV-1-positive and 3.8% in HIV-1-negative individuals (P=.007), an observation suggesting that this DC-SIGN variation plays a role in HIV-1 transmission. These naturally occurring DC-SIGN neck-region variants were significantly more frequent in the Chinese population than in the US population (P <.001) and in a worldwide population (P=.006).     

Analysis of genetic polymorphisms in CCR5, CCR2, stromal cell-derived factor-1, RANTES, and dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin in seronegative individuals repeatedly exposed to HIV-1

To determine the influence of host genetics on human immunodeficiency virus (HIV) type 1 infection, we examined 94 repeatedly exposed seronegative (ES) individuals for polymorphisms in multiple genes and compared the results with those for 316 HIV-1-seropositive and 425 HIV-1-seronegative individuals. The frequency of homozygous C-C chemokine receptor (CCR) 5- Delta 32 was higher in ES (3.2%) than in HIV-1-seropositive individuals (0.0%; P=.012). However, the CCR5-59029A, CCR2-64I, stromal cell-derived factor (SDF)-1-3'A, RANTES (regulated on activation, normally T cell-expressed and -secreted)-403A, and RANTES-28G polymorphisms were not associated with resistance to HIV-1 infection. Furthermore, we identified novel variants in the DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin) repeat region and observed that heterozygous DC-SIGN reduced the risk of HIV-1 infection (3.2% in ES individuals vs. 0.0% in HIV-1-seropositive individuals; P=.011).     

Subset of DC-SIGN(+) dendritic cells in human blood transmits HIV-1 to T lymphocytes

The dendritic cell (DC)-specific molecule DC-SIGN is a receptor for the HIV-1 envelope glycoprotein gp120 and is essential for the dissemination of HIV-1. DC-SIGN is expressed by DCs, both monocyte-derived DCs and DCs in several tissues, including mucosa and lymph nodes. To identify a DC-SIGN(+) DC in blood that may be involved in HIV-1 infection through blood, we have analyzed the expression of DC-SIGN in human blood cells. Here we describe the characterization of a subset of DCs in human blood, isolated from T-/NK-/B-cell-depleted peripheral blood mononuclear cells (PBMCs) on the basis of expression of DC-SIGN. This subset coexpresses CD14, CD16, and CD33 and is thus of myeloid origin. In contrast to CD14(+) monocytes, DC-SIGN(+) blood cells display a DC-like morphology and express markers of antigen-presenting cells, including CD1c, CD11b, CD11c, CD86, and high levels of major histocompatibility complex (MHC) class I and II molecules. This DC population differs from other described CD14(-) blood DC subsets. Functionally, DC-SIGN(+) blood DCs are able to stimulate proliferation of allogeneic T cells and can produce tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) upon activation with lipopolysaccharide (LPS). When they encounter HIV-1, low amounts of these blood DC-SIGN(+) DCs enhance infection of T lymphocytes in trans, whereas blood monocytes and CD14(-) blood DCs are not capable of transmitting HIV-1. Therefore DC-SIGN(+) blood DCs can be the first target for HIV-1 upon transmission via blood; they can capture minute amounts of HIV-1 through DC-SIGN and transfer HIV-1 to infect target T cells in trans.     

Identification of the DC-SIGN-interactive domains on the envelope glycoprotein of HIV-1 CRF07_BC

DC-SIGN, a C-type lection expressed on dendritic cells, enhances HIV-1 infection in cis and in trans. HIV-1 circulating recombinant form (CRF) 07_BC viruses have been the predominant strain found among injection drug users in southern China and Taiwan. The goal of this study was to map the DC-SIGN-interactive domain on the gp120 of CRF07_BC. Pseudotyped viruses containing single (N233Q, N275Q, N330Q, N351Q, N355Q, N381Q, and N387Q), double (N233Q + N275Q, N233Q + N351Q, N275Q + N351Q), or triple (N233Q + N275Q + N351Q) N-glycan mutant gp120 were generated. Capture assays showed that the DC-SIGN-binding capacity of pseudoviruses with N275Q or N351Q decreased significantly. Rabbit antisera against synthetic peptides covering the N275 (R72 antiserum) or N351 (R77 antiserum) region blocked the interaction between wild-type gp120 and DC-SIGN in the capture assay. Furthermore, pseudotype viruses containing gp120 from five different CRF07_BC isolates were generated and R72 and R77 antisera blocked their interactions with DC-SIGN (80% for R72 and 40% for R77, respectively) in the capture assays. In conclusion, the N275 and N351 glycan sites on the CRF07_BC gp120 play an important role in mediating the interaction between gp120 and DC-SIGN. This information is valuable for developing both therapeutic and preventive agents for HIV-1 infection.