Prevalence of CCR2-64I, SDF1-3'A and CCR5-Delta32 alleles in healthy Thais.

A genetic survey was performed of 200 healthy Thai blood donors for the frequency of three alleles that influence susceptibility to HIV infection and the rate of progression to HIV disease. The CCR5-Delta32 allele was not detected in this population. The CCR2-64I allele was detected at a frequency similar to that found in other Asian populations (15.7%). SDF1-3'A was detected at 33.2%, supporting a cline of increasing frequency of this allele from African and Caucasian to Asian (particularly Australasian) populations. These results have implications for the role of host genetic background in the biology and pathology of HIV in Thailand, and indicate that a systematic survey of non-Caucasian populations may reveal novel alleles important in HIV disease.     

Distribution of CCR5delta32, CCR2-64I and SDF1-3'A and plasma levels of SDF-1 in HIV-1 seronegative North Indians.

Host genetic factors play an important role in susceptibility to HIV-1 infection and progression to AIDS. Mutations in genes encoding chemokine receptors and their ligands, viz., CCR5delta32, CCR2-64I and SDF1-3'A are implicated to have protective effects against HIV-1 infection and/or disease progression. The distribution of these gene polymorphisms and their role in the course of the disease varies between individuals of different racial, ethnic and risk groups. We have examined the allelic frequencies of CCR5delta32, CCR2-64I and SDF1-3'A in 500 healthy North Indians tested seronegative for HIV-1, by PCR-RFLP. The plasma levels of stromal derived factor (SDF-1) protein were estimated in 75 individuals using ELISA kit. Frequencies of CCR5delta32, CCR2-64I and SDF1-3'A alleles in 500 individuals were 1.5%, 9.1% and 20.4%, respectively. The SDF1-3'A homozygosity was confirmed by PCR product cloning and sequencing. The relative hazard values calculated on the basis of the three locus genotype of each individual revealed high relative hazard values (>0.9). The plasma levels of SDF-1 ranged from 1.77 to 3.42 ng/ml and were comparable between the three genotypes of SDF-1. This is the first study to assess the plasma level of SDF-1 protein in Asian Indians. Low frequency of the protective allele CCR5delta32 observed in this study suggests high vulnerability of North Indians to HIV-1 infection. The precise role of SDF1-3'A in HIV-1 infection needs to be elucidated.     

CCR5△32、CCR5m303、CCR2-64I、SDF1-3''A基因多态性对中国HIV-1感染者预后的影响

目的研究CCR5A32、CCR5m303、CCR2-64I、SDF1—3’A基因多态性对中国HIV-1感染者预后的影响。方法对在深圳地区发现的HIV-1感染者进行流行病学调查，应用PCR／RFLP技术分析感染者CCR5G32、CCR5m303、CCR2-64I、SDF1-3’A4种基因的多态性，对部分人群进行HIV-1血浆病毒载量和CD4^＋细胞计数的检测，判断感染者的潜伏期，使用SPSS11．0统计软件分析基因多态性对感染者病毒载量和潜伏期的影响。结果在189例HIV-1感染者中没有发现CCR5A32和CCR5-m303突变基因型，SDF1—3’A的等位基因频率为26．14％，CCR2—64I的等位基因频率为19．82％。方差分析发现，CCR2-64I基因野生型与杂合型的两组HIV-1感染者人群病毒载量对数的大小差异无统计学意义（P=0．272），两组人群潜伏期的长短差异无统计学意义（P=0．662）。SDF1基因野牛型、杂合型和纯合型的3组HIV-1感染者人群病毒载量对数的大小差异有统计学意义（P=0．001），但3组人群潜伏期的长短差异无统计学意义（P=0．228）。结论CCR2-64I基因突变对中国汉族HIV-1感染者病毒载量没有明显影响，因而也不影响感染者的潜伏期。SDF1-3’A基因突变对于病毒载量有降低作用，但对延长感染者潜伏期可能没有作用。     

Protective effect of CCR2-64I and not of CCR5-delta32 and SDF1-3'A in pediatric HIV-1 infection

The effects of chemokine and chemokine receptor genetic polymorphisms such as stromal derived factor 1 (SDF1-3'A), CCR2-64I, and CCR5-delta32 associated with HIV-1 transmission and/or rate of disease progression in infected study subjects remain highly controversial and have been analyzed primarily only in adults. We have investigated whether these polymorphisms may provide similar beneficial effects in children exposed to HIV-1 perinatally. The prevalence of CCR2-64I allele was significantly increased (p = .03) and the CCR2-64I genotype distribution was not in Hardy-Weinberg equilibrium, among HIV-1-exposed uninfected infants. Moreover, in the HIV-1-infected group, a delay to AIDS progression was observed among carriers of CCR2-64I allele. This is the first report that suggests a protective role of CCR2-64I allele in mother-to-infant HIV-1 transmission and documents a delay in disease progression, after the child has been infected with HIV-1. However, SDFI-3'A and CCR5-delta32 alleles did not modify the rate of HIV-1 transmission or disease progression in HIV-1-infected children.     

Distribution of three HIV-1 resistance-conferring polymorphisms (SDF1-3'A, CCR2-641, and CCR5-delta32) in global populations

Chemokine receptors (CCR5, CXCR4 and CCR2) have been shown to be important co-receptors for HIV infection. Mutations at CCR5 (CCR5-delta2), CCR2 (CCR2-641), and stromal-derived factor SDF1 (SDF1-3'A), a primary ligand for CXCR4, are known to have protective effects against HIV-1 infection and the onset of AIDS symptoms. We studied the three-locus genotype frequency distributions in 70worldwide populations from a sample of 2341 individuals without any known history of HIV-1 infection and AIDS symptoms. From these data, we estimated the risk of AIDS onset (relative hazard, RH) of each population. This survey shows that the substantial allele frequency differences of each of these mutations translate into an extensive variation in relative hazards for AIDS in worldwide populations. However, no evidence of natural selection against the mutant gene carriers is detected. Finally, the combined three-locus genotype data predict the highest relative hazard (RH) in South-East Asia and Africa where AIDS is known to be more prevalent.     

Role of the CCR5 delta 32 allele in resistance to HIV-1 infection in west Africa

OBJECTIVE: To determine the frequency of the mutant CCR5 delta 32 allele in high-risk HIV-seronegative Africans as compared with the general African population, and to assess its in vitro protective efficacy against HIV-1 infection. STUDY DESIGN: In the homozygous form, the CCR5 delta 32 allele confers resistance to macrophage-tropic (M-tropic) strains of HIV-1. Assuming that genetic characteristics favoring HIV resistance would prevail in a high-risk HIV-seronegative population, we examined the CCR5 genotypes of female commercial sex workers (CSWs) from Dakar, Senegal, who have remained uninfected for an elongated period. METHODS: The CCR5 genetic profile of study participants was determined by polymerase chain reaction (PCR) amplification of genomic DNA followed by sequencing. Peripheral blood mononuclear cells (PBMCs) were infected with different strains of HIV-1 and monitored by p24 enzyme-linked immunosorbent assay (ELISA). RESULTS: We confirmed the presence of two CCR5wt/delta 32 genotypes among 139 individuals (1.44%). PBMCs from these 2 heterozygous individuals were also found to be less susceptible to in vitro infection by an M-tropic HIV-1 primary isolate. CONCLUSIONS: Evidence was found of an increased prevalence of the CCR5wt/delta 32 genotype in a high-risk HIV-seronegative cohort in West Africa. Furthermore, reduced susceptibility to HIV-1 infection among heterozygous individuals supports a role for 32-bp CCR5 deletion in HIV-1 resistance.     

中国HIV-1感染疾病长期不进展者CCR2-64I、SDF1-3′A和CCR5△32的基因变异研究

目的探讨CCR2-64I、SDF1-3′A、CCR5△32基因变异对中国HIV-1感染疾病长期不进展者(long-term nonprogressors,LTNPs)疾病进程的影响.方法收集17例中国HIV-1感染LTNPs和39例中国HIV-1感染疾病典型进展者(typical progressors,TPs)的抗凝全血标本,用全自动核酸提取仪提取基因组DNA,采用PCR/RFLP技术对CCR2、SDF1、CCR5基因进行检测分析.结果LTNP组的CCR2-64I、SDF1-3′A基因突变率分别为50%和62.5%,TP组的CCR2-64I和SDF1-3′A基因突变率分别为23.08%、33.33%,LTNP组CCR2-64I、SDF1-3′A基因突变率明显高于TP组(P＜0.05);LTNP组有1例CCR5△32杂合突变,未发现纯合变异,而TP组未发现CCR5△32突变.结论CCR2-64I、SDF1-3′A和CCR5△32基因突变可能是中国HIV-1感染者疾病长期不进展的保护性因素之一.     

中国HIV-1感染疾病长期不进展者CCR2-64I、SDF1-3’A和CCR5Δ32的基因变异研究

目的 探讨CCR2-641、SDF1-3’A、CCR5Δ32基因变异对中国HIV—1感染疾病长期不进展者（long-term nonprogressors，LTNPs）疾病进程的影响。方法 收集17例中国HIV-1感染LTNPs和39例中国HIV-1感染疾病典型进展者（typical progressors，TPs）的抗凝全血标本，用全自动核酸提取仪提取基因组DNA，采用PCR／RFLP技术对CCR2、SDF1、CCR5基因进行检测分析。结果 LTNP组的CCR2-64I、SDF1-3’A基因突变率分别为50％和62．5％，TP组的CCR2-64I和SDF1-3’A基因突变率分别为23．08％、33．33％，LTNP组CCR2—64I、SDF1-3’A基因突变率明显高于TP组（P〈0．05）；LTNP组有1例CCR5Δ32杂合突变，未发现纯合变异，而TP组未发现CCR5Δ32突变。结论 CCR2-64I、SDF1-3’A和CCR5Δ32基因突变可能是中国HIV-1感染者疾病长期不进展的保护性因素之一。     

Distribution of two HIV-1-resistant polymorphisms (SDF1-3'A and CCR2-64I alleles) in the Polish population

Chemokine receptors (CCR2 and CXCR4) are used as coreceptors for entry of human immunodeficiency virus (HIV) into the target cells. Mutations in CCR2 (CCR2-64I) and stromal-derived factor SDF1 (SDF1-3'A), the primary ligand for CXCR4, exhibited a protective effect against the onset of acquired immune deficiency syndrome (AIDS). The frequency of the SDF1-3'A and CCR2-64I alleles were determined in blood donors from 16 provinces, covering the entire territory of Poland. Of 1063 individuals, 274 (25.8%) were carriers of the SDF1-3'A allele; 36 of them (3.4%) were homozygotes (SDF-3'A/A) while 238 (22.4%) were heterozygotes (SDF-3'G/A), resulting in a 14.6% frequency of the SDF1-3'A allele. Moreover, in the same group of individuals, 234 (22.0%) carried the CCR2-64I allele; 6 of them (0.6%) were homozygotes (CCR2-64I/I), and 228 (21.4%) were heterozygotes (CCR2-64V/I), resulting in an 11.3% frequency of the CCR2-64I allele. The highest frequencies of the SDF1-3'A allele were found in the northeastern provinces and in one of the western provinces of Poland. In contrast, allelic frequencies of CCR2-64I varied slightly among different provinces. The different pattern of prevalence of the SDF1-3'A and CCR2-64I alleles in Poland might suggest that the CCR2-64I allele was spread much earlier than the SDF1-3'A allele in the population of Poland.     

辅助受体CCR5、CCR2及细胞趋化因子SDF1基因多态性与HIV-1异性传播的关系

目的 进一步阐述CCR5、CCR2和SDFl基因多态性与HIV-1异性传播的关系。方法 通过PCR／RFLP技术分析CCR5、CCR2和SDF1基因的多态性，继而分析基因多态性与HIV-1异性传播的关系。结果 在收集到的70对异性配对病例中，未能在汉族人群发现CCR5基因缺失突变，维吾尔族人CCR5Δ32基因频率为6．5％(6／92)，未发现纯合突变。有暴露史而未感染HIV-1者CCR2-64I基因频率明显高于受暴露后感染病毒者，说明CCR2-64I对异性传播可能具有一定保护作用。对SDFl基因的多态性研究发现，将病毒传播给配偶的指标病例(先感染：HIV-1一方)SDF-3′A的基因频率高于未发生传播者(较接近于统计学检验水准)，SDFl-3′A似乎是危险因素。结论 CCR5Δ32对汉族人群的HIV-1异性传播无明显意义，CCR2-64I对HIV-1异性传播可能具有一定的保护作用，而SDFl-3′A则有可能是危险因素，但有必要扩大样本量对后二者作进一步的深入研究。     

Frequency of CCR5 gene 32-basepair deletion in Chilean HIV-1 infected and non-infected individuals

A 32-basepair deletion polymorphism in the CCR5 chemokine receptor gene (CCR5Delta32) has been identified and shown to have functional significance in determining susceptibility to infection by human immunodeficiency virus type 1 (HIV-1) and possibly in influencing disease progression in HIV-1 positive individuals. These findings led to an interest in studies of DeltaCCR5 allele geographical distribution in human population, for complete understanding of the role of CCR5 in HIV-1 epidemiology. Inter-population variation in CCR5Delta32 frequency may be a significant factor in the prediction of AIDS endemicity. In this report we assessed the frequency of DeltaCCR5 in a Chilean population (63 HIV-1 infected and 62 non-infected individuals). No homozygous CCR5Delta32 individual was identified, and no significant difference was observed between HIV-1 infected (3/63) and non-infected (3/62) individuals for the heterozygote CCR5Delta32 state. This is the first evidence of the contribution of DeltaCCR5 allele to the genetic background of the Chilean population, which is characterized by intense ethnic admixture and by gene flow from the European Spanish gene pool.     

Coregulation of HIV-1 dependency factors in individuals heterozygous to the CCR5-delta32 deletion

Background

CCR5-delta32 heterozygous individuals are susceptible to HIV-1. However, it is not clear if there is a relevant protective effect against transmission and a beneficial effect in terms of HIV progression which cannot be attributed to CCR5 surface density alone. Therefore we investigated HIV-1 dependency factors (HDF) which might be differently regulated in CCR5 wild type (WT) and CCR5-delta32 heterozygous individuals.

Methods

We examined CD34+ hematopoietic progenitor cells derived from bone marrow samples from 19 healthy volunteers, 12 individuals with CCR5 WT and 7 with heterozygous CCR5-delta32 deletion. Samples were analyzed using a global gene expression oligonucleotide microarray (HG-U133plus 2.0, Affymetrix Inc.).

Results

A total of 205 genes were found with altered expression (3fold difference, present call rate of 75%, p?<?0.05) and 7 of these had a connection to HIV-1 pathogenesis. In 4 genes: TOP1, CXCR2, SREBF2, and TAP we found a different regulation which was consistent with a supposed beneficial effect for CCR5-delta32 heterozygotes.

Conclusion

The CCR5-delta32 deletion is associated with other HDFs in HIV-1 pathogenesis as a possible explanation for beneficial effects regarding the deletion leading to a variant expression profile in heterozygous carriers of this mutation.

     

Frequency of CCR5-Delta32 deletion in human immunodeficiency virus type 1 (HIV-1) in healthy blood donors, HIV-1-exposed seronegative and HIV-1-seropositive individuals of southern Brazilian population

The frequency of CCR5-Delta32 allele in human immunodeficiency virus type 1 (HIV-1) infection in the southern Brazilian population was determined in a cross-sectional study carried out from October 2001 to June 2004. Genomic DNA was extracted from peripheral blood cells of 134 healthy blood donors, 145 HIV-1-exposed seronegative individuals, 152 HIV-1-seropositive asymptomatic individuals, and 478 HIV-1-seropositive individuals with AIDS. A fragment with 225 base-pairs of the CCR5 gene was amplified by polymerase chain reaction. The CCR5-Delta32 homozygous deletion was observed in 2 (1.5%) blood donors and in 1 (0.7%) individual HIV-1-exposed seronegative, and was absent among all the HIV-1-seropositive individuals (Fisher's exact test, p=0.0242). The frequency of the homozygous CCR5-Delta32 deletion in the HIV-1-exposed did not differ when compared with that observed in the HIV-1 seronegative blood donors (Fisher's exact test, p=0.6093; OR: 2.18, 95% CI: 0.11-129.6). The wild-type genotype CCR5/CCR5 frequency was higher among the HIV-1-seropositive with AIDS compared to HIV-1 seropositive asymptomatic individuals (Chi-square test, p=0.0263; OR: 2.02, 95% CI: 1.03-3.97). The absence of the homozygous deletion of CCR5-Delta32 among HIV-1-seropositive individuals underscored that this genotype is an important genetic factor associated with the decreased susceptibility to HIV-1 infection. The higher frequency of heterozygosity for the CCR5-Delta32 and the CCR5-Delta32 allele in HIV-1 seropositive asymptomatic compared to HIV-seropositive with AIDS individuals also underscored that this deletion could be associated with the delay of the HIV-1 disease progression in this population. However, the low frequency of CCR5-Delta32 homozygosity observed among HIV-1-exposed seronegative individuals shows that the allele could not explain, by itself, the natural resistance to HIV-1 infection and different mechanisms of protection against HIV-1 infection that must be involved in this population.     

Prevalence of CCR2–64I,SDF1–3′A and CCR5‐Δ32 alleles in healthy Thais

A genetic survey was performed of 200 healthy Thai blood donors for the frequency of three alleles that influence susceptibility to HIV infection and the rate of progression to HIV disease. The CCR5‐Δ32 allele was not detected in this population. The CCR2–64I allele was detected at a frequency similar to that found in other Asian populations (15.7%). SDF1–3′A was detected at 33.2%, supporting a cline of increasing frequency of this allele from African and Caucasian to Asian (particularly Australasian) populations. These results have implications for the role of host genetic background in the biology and pathology of HIV in Thailand, and indicate that a systematic survey of non‐Caucasian populations may reveal novel alleles important in HIV disease.     

Distribution of CCR2 polymorphism in HIV-1-infected and healthy subjects in North India

Substitution of V64I in CCR2 relates to delayed progression to AIDS and protects against HIV-1 infection. We examined the distribution of V64I in HIV-infected and healthy North Indian subjects. No significant difference in the allele or genotype distribution of CCR2 V64I polymorphism was observed, indicating that there is no association between CCR2 V64I polymorphism and susceptibility to HIV infection in North Indian population.     

Causal pathways of the effects of age and the CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles on AIDS development

OBJECTIVE: To investigate the causal pathways by which age and the CCR5-Delta32, CCR2-64I, and SDF-1 3'A alleles influence progression to AIDS. DESIGN: Analysis of follow-up data from 2 cohort studies among homosexual men (n=400), having >10 years of follow-up. METHODS: The effects of the 4 cofactors on the CD4 and HIV-1 RNA trajectories after seroconversion were modeled in a random-effects model. A proportional hazards model was used to investigate their effect on the risk of AIDS after correction for CD4 cell count and RNA level. This approach allows investigation as to whether they influence AIDS progression by affecting CD4 count and RNA level or by other pathways. RESULTS: Persons of younger age or having the CCR2-64I or SDF-1 3'A mutation have significantly higher CD4 levels. Persons with the CCR5-Delta32 deletion or CCR2-64I mutation have significantly lower RNA levels. After correction for both CD4 count and RNA level, only the SDF-1 3'A mutation significantly increases the AIDS risk. CONCLUSIONS: Age and the CCR5-Delta32 deletion and CCR2-64I mutation influence AIDS progression by affecting CD4 and HIV-1 RNA. The SDF-1 3'A allele increases the AIDS risk, but this effect is countered by its effect on CD4 and HIV-1 RNA level.     

Distribution of CCR2-64I and SDF1-3'A alleles and HIV status in 7 ethnic populations of Cameroon

Limited information is available on the prevalence among rural Africans of host genetic polymorphisms conferring resistance to HIV-1 infection or slowing HIV disease progression. We report the allelic frequencies of the AIDS-related polymorphisms CCR2-64I, SDF1-3'A, and CCR5-Delta32 in 321 volunteers from 7 ethnic groups in Cameroon. Allelic frequencies differed among the 7 ethnic groups, ranging from 10.8% to 31.3% for CCR2-64I and 0.0% to 7.1% for SDF1-3'A. No CCR5-Delta32 alleles were found. HIV seroprevalence was 6.9% in the total population and peaked at younger ages in girls and women than in boys and men. Among 15- to 54-year-olds, HIV seroprevalence varied from 2.0% to 11.1% among the village populations. Conditional logistic regression analysis using data from boys and men aged 15 to 54 years showed the number of CCR2-64I alleles to be a significant risk factor for HIV seropositivity (odds ratio per allele adjusted for age and matched on ethnic group = 6.3, 95% confidence interval: 1.3-30.3); this association was not found in women. The findings are consistent with the hypothesis that CCR2-64I alleles may delay HIV disease progression without affecting susceptibility to infection among men. We did not observe this relation among women, and other factors, such as multiple pregnancies or maternal stressors (eg, breastfeeding), may have masked any protective effect of CCR2-64I alleles. Further study of this issue among women is warranted. SDF1-3'A did not differ between HIV-seropositive and HIV-seronegative individuals but was associated with increasing age among HIV-seronegative women, suggesting a protective effect against HIV-1 infection.