Effects of single nucleotide polymorphisms in the RANTES promoter region in healthy and HIV-infected indigenous Chinese

The Association between CCL5/RANTES SNPs and Susceptibility to HIV-1 Infection: A Meta-Analysis

Genetic polymorphisms in genes that encode natural ligands of CCR5 (the main human HIV coreceptor), such as CCL5/RANTES, can alter the levels of secretion of these peptides. This article sought to review the relationship between single nucleotide polymorphisms (SNPs) of CCL5/RANTES and HIV-1 disease susceptibility. A meta-analysis was conducted through 17 articles found from January 1999 to December 2022 in the PUBMED, Science Direct, Medline, and SciELO databases. A total of three SNPs were identified and investigated under their dominant genotypic model and through a fixed-effects model. In terms of the SNP rs2107538 (G > A), in Africa and Asia, it has a protective role (OR = 0.56; 95% CI = 0.41-0.76; p = 0.0002, and OR = 0.88; 95% CI = 0.76-1.02; p = 0.08, respectively). In terms of the SNP rs2280788 (C > G), in Europe and America, it shows a higher risk role (OR = 1.92; 95% CI = 1.06-3.47; p = 0.03, and OR = 0.94; 95% CI = 0.94-1.11; p = 0.04, respectively), but in the population of Asia, with its mutant allele, it has a protective role (OR = 0.76; 95% CI = 0.63-0.93; p = 0.007). In terms of the SNP rs2280789 (T > C), no significant associations were found. Both SNPs rs2107538 and rs2280788 have a positive transcriptional effect on the RANTES/CCL5 gene, while SNP rs2280789 causes a decrease in gene expression levels. This study suggests that there is an association between the increased expression of CCL5/RANTES and a lower risk of AIDS. Therefore, further studies are needed to arrive at a definitive conclusion, and these results may help establish scientific bases for effective HIV/AIDS control strategies.

RANTES Gene Polymorphisms Associated with HIV-1 Infections in Kenyan Population

Previous studies have reported that two single nucleotide polymorphisms (SNPs) in the RANTES gene promoter region, -403G/A and -28C/G, are associated with a slower rate of decline in CD4+ T cell count. In addition, as a ligand of the major HIV coreceptor CCR5, it is known to block HIV-CCR5 interactions in the course of the HIV infection cycle. This study was carried out with the aim of determining the occurrence of single nucleotide polymorphisms (SNPs) -403G > A and -28C > G in the promoter region of RANTES, in a subset of the Kenyan population. Genomic DNA was extracted from peripheral blood monocular cells and used to amplify the RANTES gene region. Restriction fragment length polymorphism was used to determine the genotypes of the RANTES gene. Out of 100 HIV infected individuals, 19% had G1 genotypes (403G/G, 28C/G), 30% (403A/A, 28C/C), and 50% (403G/A, 28C/C), while in healthy blood donors 13% had G4 (403G/A, 28C/C) genotypes, 22% (403A/A, 28C/C), and 54% (403G/A, 28C/C). HIV negative blood donors (54%) had higher risk of alteration to risk of HIV transmission compared to those who were HIV infected (50%). However, the risk to transmission and distribution differences was not significant (P = 0.092). The study showed that RANTES polymorphisms -403 and -28 alleles do exist in the Kenyan population.

Impact of genetic variations in C-C chemokine receptors and ligands on infectious diseases

Chemokine receptors and ligands are crucial for extensive immune response against infectious diseases such as malaria, leishmaniasis, HIV and tuberculosis and a wide variety of other diseases. Role of chemokines are evidenced in the activation and regulation of immune cell migration which is important for immune response against diseases. Outcome of disease is determined by complex interaction among pathogen, host genetic variability and surrounding milieu. Variation in expression or function of chemokines caused by genetic polymorphisms could be associated with attenuated immune responses. Exploration of chemokine genetic polymorphisms in therapeutic response, gene regulation and disease outcome is important. Infectious agents in human host alter the expression of chemokines via epigenetic alterations and thus contribute to disease pathogenesis. Although some fragmentary data are available on chemokine genetic variations and their contribution in diseases, no unequivocal conclusion has been arrived as yet. We therefore, aim to investigate the association of CCR5-CCL5 and CCR2-CCL2 genetic polymorphisms with different infectious diseases, transcriptional regulation of gene, disease severity and response to therapy. Furthermore, the role of epigenetics in genes related to chemokines and infectious disease are also discussed.

The Effects of RANTES Polymorphisms on Susceptibility to HIV-1 Infection and Disease Progression: Evidence from an Updated Meta-Analysis

Associations of regulated on activation, normal T cell expressed and secreted (RANTES) -403G/A, -28C/G, and In1.1T/C polymorphisms with HIV-1 infection and the progression of HIV-1 disease have been widely reported with inconsistent results. To clarify this situation, we performed an updated meta-analysis of all available studies from PubMed, EMBASE, and the China National Knowledge Infrastructure. A total of 24 eligible studies involving more than 10,000 subjects were included. By using the healthy controls, we found that -403G/A polymorphism was significantly associated with reduced susceptibility to HIV-1 infection in G/A+A/A versus GG (odds ratio [OR] = 0.755, 95% confidence interval [CI] = 0.581-0.982); and a significantly decreased risk was also found for -28C/G polymorphisms (G vs. C, OR = 0.804, 95% CI = 0.696-0.927; G/G+C/G vs. C/C, OR = 0.826, 95% CI = 0.704-0.969). Whereas for In1.1T/C polymorphism, increased risk of HIV-1 infection was revealed (C vs. T, OR = 1.216, 95% CI = 1.047-1.430; T/C vs. T/T, OR = 1.68, 95% CI = 1.263-2.234; T/C+T/T vs. C/C, OR = 1.466, 95% CI = 1.147-1.875). Subgroup analyses by ethnicity showed significant association among Asians, but not among Caucasians. When HIV-1-exposed seronegative (HESN) controls were used, no significant association was detected. Moreover, -403G/A and -28C/G polymorphisms were also not associated with long-term nonprogressive HIV-1 infection (all p > .05). This meta-analysis suggests that RANTES -403G/A and -28C/G polymorphisms confer possible protection against HIV-1 infection, whereas In1.1T/C polymorphism may increase risk of HIV-1 infection, especially in Asians. These results may contribute to finding a theoretical basis for effective control strategies against HIV/AIDS. Further investigations are needed to validate our conclusions.

Frequency of RANTES gene polymorphisms and their association with incidence of malaria: a longitudinal study on children in Iganga district, Uganda

BACKGROUND

The severity and outcome of malaria is influenced by host immunity in which chemokines such as Regulated upon Activation, Normal T cell Expressed and Secreted (RANTES) play an important role. Previous studies show that variations in the RANTES gene affect RANTES protein production, hence altering host immunity. In this study, the relationship between presence of mutations in RANTES and incidence of malaria in a cohort of children living in a malaria-endemic area of Uganda was determined.

METHODS

This was a longitudinal study comprising of 423 children aged between 6 months and 9 years, who were actively followed up for 1 year. Malaria episodes occurring in the cohort children were detected and the affected children treated with national policy drug regimen. Mutations in the RANTES gene were determined by PCR-RFLP method and their frequencies were calculated. A multivariate negative binomial regression model was used to estimate the impact of RANTES mutations on malaria incidence. In all statistical tests, a P-value of <0.05 was considered as significant.

RESULTS

The frequencies of the -403A and In1.1C allele were 53.7 and 19.2 %, respectively. No mutations were found at the -28 locus. After adjustment of incidence rates for age, blood group, insecticide-treated bed net (ITN) use, malaria history and the sickle cell trait, 1n1.1T/C heterozygotes and homozygotes showed a non-significant trend towards higher incidence rates compared to wild-type individuals (IRR = 1.10; P = 0.55 and IRR = 1.25; P = 0.60, respectively). Similarly, there was no significant difference in malaria incidence rates between RANTES -403G/A heterozygotes or homozygotes and those without mutations (IRR = 1.09; P = 0.66 and IRR = 1.16; P = 0.50, respectively). No relation was seen between RANTES polymorphisms, baseline parasite densities and the time to first re-infection after administration of anti-malaria drugs.

CONCLUSIONS

This study showed that the -403A mutation occurs in nearly half of the study population and the In1.1C allele occurs in one in every four children. Despite the high frequency of these mutations, there was no clear association with malaria incidence. Other studies evaluating more markers, that could potentially modulate RANTES gene transcription alongside other genetic modifiers of malaria susceptibility, may provide further explanations to these less dramatic findings.

Association between chemotactic chemokine ligand 5 -403G/A polymorphism and risk of human immunodeficiency virus-1 infection: a meta-analysis

Background

The association between chemotactic chemokine ligand 5 (CCL5) -403G/A gene polymorphism and human immunodeficiency virus-1 (HIV-1) infection has been illustrated among several case-control studies, but the conclusions are still inconsistent. Here we performed a meta-analysis to estimate the association.

Methods

The published studies based upon the association between CCL5 -403G/A polymorphism and HIV-1 infection were retrieved from PubMed, Embase, and China National Knowledge Infrastructure database. Quantitative synthesis, including pooled odds ratios (ORs) and 95% confidence intervals (CIs), was performed for all genetic models.

Results

A total of ten studies consisting of 5,127 subjects were included for this meta-analysis. There was no association found between -403G/A polymorphism and HIV-1 infection in the overall analysis under any genetic models. Further stratified by ethnicity, our analysis showed that -403A/A polymorphism significantly decreased the susceptibility to HIV-1 infection in three models: the dominant model (AA+AG vs GG: OR =0.44, 95% CI =0.21–0.94) among Africans, the homozygous model (AA vs GG: OR =0.62, 95% CI =0.242–0.90), and the recessive model (AA vs GG+AG: OR =0.62, 95% CI =0.45–0.93) among Asians.

Conclusion

We found that only Asians and Africans with CCL5 -403A/A polymorphism could be resistant to HIV-1 infection. However, further studies should be performed to evaluate this association on ethnic basis against control groups consisting of individuals who have once been exposed to HIV-1 but are seronegative.

Gene polymorphisms in CCR5, CCR2, SDF1 and RANTES among Chinese Han population with HIV-1 infection

Chemokines and chemokine receptors are crucial for immune response in HIV-1 infection. Although many studies have been done to investigate the relationship between chemokines and chemokine receptor gene polymorphisms and host's susceptibility to HIV-1 infection, the conclusions are under debate. In the present study, a cohort of 287 HIV-1 seropositive patients, 388 ethnically age-matched healthy controls and 49 intravenous drug users (IDUs) HIV-1 exposed seronegative individuals (HESN) from Chinese Han population were enrolled in order to determine the influence of host genetic factors on HIV-1 infection. Seven polymorphisms on four known chemokines/chemokine receptor genes (CCR5Δ32, CCR5 m303, CCR5 59029A/G, CCR2 64I, RANTES -403A/G, RANTES -28C/G and SDF1 3'-A) were screened. CCR5Δ32 and CCR5 m303 were absent or infrequent in Chinese Han population, which may not be hosts' genetic protective factors for HIV-1 infection. Our results showed the CCR5 59029A/G, CCR2 64I and SDF1 3'-A were not associated with host's resistance to HIV-1 infection. The frequency of RANTES -403A allele was significantly lower in HIV-1 patients than in healthy blood donors (p=0.0005) and HESN group (p=0.035), which implied the association between A allele and reduced HIV-1 infection risk. Different genetic models were assessed to investigate this association (AA vs. GG+AG, OR=0.38 95% CI, 0.22-0.65 p=0.0004; A vs. G, OR=0.66 95% CI, 0.52-0.84 p=0.0006), which supported this association, either. The genotype and allele distribution of RANTES -28 between HIV-1 patients and healthy controls (genotype profile: p=0.072; allele profile: p=0.027) or HIV-1 seronegative group (genotype profile: p=0.036; allele profile: p=0.383) were both at the marginal level of significance, which were not observed after Bonferroni correction. All these results suggest the RANTES -403A may be associated with reduced susceptibility to HIV-1 infection, while the RANTES -28 locus not. By lack of the patients' clinical information, whether these polymorphisms affect AIDS disease progression and their role in different HIV-1 infection routes could not performed in present study and needs to be assessed in ongoing studies.

Association between regulated upon activation, normal T cells expressed and secreted (RANTES) -28C/G polymorphism and susceptibility to HIV-1 infection: a meta-analysis

BACKGROUND

Many studies have investigated the distributions of RANTES genotypes between HIV-1 infected patients and uninfected individuals. However, no definite results have been put forward about whether the RANTES -28C/G polymorphism can affect HIV-1 susceptibility.

METHODS

We performed a meta-analysis of 12 studies including 7473 subjects for whom the RANTES -28C/G polymorphism was genotyped. Odds ratios (ORs) with 95% confidence intervals (CIs) were employed to assess the association of the polymorphism with HIV-1 susceptibility. By dividing the controls into healthy controls and HIV-1 exposed but seronegative (HESN) controls, we explored the both allelic and dominant genetic models.

RESULTS

By using the healthy controls, we found a marginally significant association between the -28C/G polymorphism and susceptibility to HIV-1 infection in the allelic model (OR = 0.82, 95%CI = 0.70-0.97). But sensitivity analysis suggested that the association was driven by one study. We further performed stratified analysis according to ethnicity. The -28G allele decreased susceptibility to HIV-1 infection in the allelic model among Asians (OR = 0.79, 95%CI = 0.66-0.94). By using the HESN controls, no association between the polymorphism -28C/G and the susceptibility to HIV-1 infection was revealed in either the allelic model (OR = 0.84, 95%CI = 0.60-1.17) or the dominant model (OR = 0.77, 95%CI = 0.54-1.10).

CONCLUSIONS

Our findings suggested that the RANTES -28G allele might play a role in resistance to HIV-1 infection among Asians. Additional well-designed studies were required for the validation of this association.

Association of the CCR5Δ32 polymorphism and its ligand RANTES-403G/A polymorphism with coronary artery disease: a meta-analysis

INTRODUCTION

To explore the relationship between polymorphisms in the RANTES and CCR5 genes and the risk of coronary artery disease (CAD).

MATERIALS AND METHODS

We conducted a meta-analysis on two genetic variants (RANTES-403G/A and CCR5Δ32). Publication bias was tested by the Egger's regression test and Begg's test. Sensitivity analysis and subgroup analyses were performed to explore the heterogeneity among studies.

RESULTS

No significant association of RANTES-403G/A polymorphism and CAD risk was observed (dominant model: RR=1.02, 95%CI=0.90-1.06; recessive model: RR=1.27, 95%CI=0.90-1.80). However, after excluding the study conducted by Yangsoo et al., the pooled relative ratio (RR) in the dominant model suggested that the RANTES-403G/A polymorphism was positively associated with CAD risk. The subgroup analyses found that a positive relationship between the polymorphism and CAD risk was restricted to the Caucasian population. A meta-analysis of studies on the CCR5Δ32 polymorphism showed no significant association with CAD risk both in dominant (RR=1.05, 95%CI=0.92-1.21) and recessive (RR=1.27, 95%CI=0.90-1.80) models. Moreover, no association was identified in the subgroup analyses.

CONCLUSIONS

The RANTES-403G/A polymorphism is not associated with CAD risk, but does most likely increase CAD risk in Caucasians. Moreover, no relationship between the CCR5∆32 polymorphism and risk of CAD was found.

Genetic correlates influencing immunopathogenesis of HIV infection

Variability to HIV infection, its progression as well as responsiveness to antiretroviral therapy (ART) is observed among individuals including viraemia controllers or exposed uninfected, rapid versus slow progressors and ART responders compared to non responders. This differential responsiveness/vulnerability to HIV-1 is governed by multiple host genetic factors that include HLA, cytokines, chemokines, their receptors and others. This review highlights the influence of these genetic factors on HIV/AIDS outcome; however, in India, the information in this area is very limited and most of these genetic studies have been conducted in Caucasian and South African populations. Considering, the population specific differences in the frequencies of protective or susceptibility favouring alleles and their influence on the disease outcome, it is of utmost importance to strengthen ongoing efforts towards defining largely unknown genetic propensity in Indian population, particularly by recruitment of large cohorts of well categorized exposed uninfected individuals, rapid, long term non progressors and elite viraemic controllers. Multi-parametric analysis of these potentially interactive immunogenetic variables in these cohorts may help to define potential targets for diagnostics and therapy in a population specific manner.

RANTES gene polymorphisms (-403G>A and -28C>G) associated with hepatitis B virus infection in a Saudi population

Besides the host immune response, genetic and environmental factors play crucial roles in the manifestation of hepatitis B virus (HBV) infection. "Regulated on activation normal T-cell expressed and secreted" factor (RANTES) plays a vital role in CD4(+), CD8(+) T-lymphocyte and dendritic cell activation and proliferation in inflammation. Single nucleotide polymorphisms (SNPs) in the RANTES gene are associated with several viral and non-viral diseases. Association studies have invariably indicated a lack of association between RANTES gene SNPs and HBV infection in ethnic populations, even though RANTES gene SNPs exhibit distinct ethnic distributions. Despite the high prevalence of HBV infections in Saudi Arabia, no studies have been made concerning a possible relationship between RANTES gene polymorphisms and susceptibility to and progression of HBV infection. We examined -403G>A and -28C>G RANTES gene variants in 473 healthy controls and 484 HBV patients in ethnic Saudi populations. Significant differences were found in the genotype and allele distributions of the SNPs between the controls and the HBV patients. Both SNPs were significantly linked to viral clearance in these subjects. Our data demonstrate for the first time in a Saudi population, a relationship between the RANTES gene polymorphisms and the clinical course of HBV infection and underscore the importance of evaluating the genetic background of the affected individual to determine how it may affect disease progression.

Gene expression variability within and between human populations and implications toward disease susceptibility

Variations in gene expression level might lead to phenotypic diversity across individuals or populations. Although many human genes are found to have differential mRNA levels between populations, the extent of gene expression that could vary within and between populations largely remains elusive. To investigate the dynamic range of gene expression, we analyzed the expression variability of ∼18, 000 human genes across individuals within HapMap populations. Although ∼20% of human genes show differentiated mRNA levels between populations, our results show that expression variability of most human genes in one population is not significantly deviant from another population, except for a small fraction that do show substantially higher expression variability in a particular population. By associating expression variability with sequence polymorphism, intriguingly, we found SNPs in the untranslated regions (5′ and 3′UTRs) of these variable genes show consistently elevated population heterozygosity. We performed differential expression analysis on a genome-wide scale, and found substantially reduced expression variability for a large number of genes, prohibiting them from being differentially expressed between populations. Functional analysis revealed that genes with the greatest within-population expression variability are significantly enriched for chemokine signaling in HIV-1 infection, and for HIV-interacting proteins that control viral entry, replication, and propagation. This observation combined with the finding that known human HIV host factors show substantially elevated expression variability, collectively suggest that gene expression variability might explain differential HIV susceptibility across individuals.

Many human genes have population-specific expression levels, which are linked to population-specific polymorphisms and copy-number variations. However, it is unclear whether human genes show similar dynamic range of expression between populations. In this work we analyzed HapMap gene expression compendium, and quantified the between-population and within-population expression variability for ∼18,000 human transcripts. We first concluded that the majority of the human genes have similar levels of within-population variability. However, a small fraction (∼4%) does show much higher expression variability in one population, and the deviation is consistently associated with increased SNP heterozygosity in their UTR regulatory regions. We further showed that genes with the greatest within-population expression variability are significantly enriched for chemokine signaling associated with HIV-1 infection. Combined with the finding that human HIV-1 host factors tend to have increased expression variability within populations, our analysis may explain, at least in part, different susceptibility to HIV infection within the human population. This work provides a fresh angle for analyzing gene expression variations in populations.

CCR5, RANTES and SDF-1 polymorphisms and mother-to-child HIV-1 transmission

Summary Among 288 HIV-1-infected, breastfeeding women who received zidovudine prophylaxis and were followed with their infants in Nairobi, we found no associations between maternal genetic polymorphisms in CCR5 (59029G/A, 59353T/C, 59356T/C, 59402G/A), RANTES (-403G/A) and SDF-1 (3'801G/A) and mother-to-child HIV-1 transmission; plasma, cervical and breastmilk viral loads; or breastmilk chemokine concentrations.

Association of RANTES -403 G/A, -28 C/G and In1.1 T/C polymorphism with HIV-1 transmission and progression among North Indians

The relationships between host immune factors and HIV-1 disease progression are still in dispute. The RANTES SNPs exhibit distinct ethnic distribution and are associated with different effects on the course of HIV infection. Therefore, impact of RANTES gene polymorphism on HIV-1 transmission and progression needs to be evaluated. The RANTES genotypes were identified by PCR-RFLP method and confirmed by sequencing in HIV-1 seronegative (HSN; n=315), HIV-1 exposed seronegative (HES; n=47) and HIV-1 seropositive (HSP; n=196) patients classified into different clinical stages (i.e. Stages I, II, III). Fisher exact test was used for statistical analysis and Arlequin software for haplotype analysis. RANTES allele -403G, -28C and In1.1 T were the predominant allele in the subject studied. HSP group have higher frequency of RANTES In1.1 T allele compared with HSN (91.32% vs. 86.19%; P=0.013) and HES (91.32% vs. 78.72%; P=0.001). Higher frequency of RANTES In1.1 C allele in Stage III was observed, compared with Stage I (14.28% vs. 6.39%) and was significantly associated with high risk (P=0.047, OR=2.439, C.I.=1.061-5.609). Haplotype II (ACT) was significantly higher in HSP compared with HSN (9.69% vs. 1.58%) and associated with high risk (P<0.001, OR=6.655, C.I.=2.443-18.132). There were no significant differences in RANTES -403 A/G and -28 C/G genotype and allele distribution in all the groups compared. Our results implicate that RANTES In1.1 T allele and haplotype II (ACT) may be a risk factor for HIV-1 transmission while RANTES In1.1 C allele may be risk factor for disease progression among North Indians.

RANTES-403 polymorphism is associated with reduced risk of gastric cancer in women

BACKGROUND

Men are more susceptible to gastric cancer (GC) than women. However, the genetic factors associated with the sex difference are not well understood. Chemokines have been shown to modulate tumor behavior, and the sex-specific effect of the chemokine polymorphisms on the host susceptibility to several diseases has been reported. We aimed to determine the role of chemokine polymorphisms on host susceptibility to GC, with special interest on their sex-specific effect.

METHODS

A hospital-based case-control study, including 177 patients with GC and 217 age-matched unaffected healthy controls, was performed in three major tertiary care hospitals. Genotyping for regulated upon activation, normal T-cell expressed and secreted (RANTES) -403 A/G and -28 C/G, CC chemokine receptor 5 (CCR5) deletion, and CCR2-V64I was performed using peripheral blood DNA.

RESULTS

The RANTES -403 GA and AA genotypes were independently associated with a 2.3-fold reduced risk of developing GC (OR=0.44, 95% CI 0.22-0.90, P=0.025) compared with GG genotype in women, but not in men. The RANTES -28C/G and CCR2-V64I polymorphisms were not associated with different risk of developing GC. The tumor stage, histological features, and survival rate were not different when stratified by RANTES -403 and -28 and CCR2-V64I genotypes.

CONCLUSIONS

Our data indicate that women who inherit A allele at RANTES -403 may be at reduced risk of GC.

The effects of RANTES/CCR5 promoter polymorphisms on HIV disease progression in HIV-infected Koreans

Recent studies have reported that two single nucleotide polymorphisms (SNPs) in the RANTES gene promoter region, -403G/A and -28C/G, are associated with a slower rate of decline in CD4(+) T-cell number, whereas genetic polymorphisms within the CCR5 promoter are linked to acceleration of AIDS progression. In this study, we investigated the distribution of SNPs in the RANTES and CCR5 promoters and the association between these SNPs and HIV-1 disease progression in HIV-infected Koreans. Twenty-seven long-term non-progressors (LTNPs), 29 AIDS patients and 39 HIV-uninfected persons were enrolled in this study. SNPs for the RANTES and CCR5 promoters were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and a direct sequencing method. In the analysis of RANTES promoter polymorphisms, the genotypic and allelic frequencies of the RANTES -28G mutation were significantly lower in HIV-infected patients than in HIV-uninfected persons (P = 0.005 and P = 0.001, respectively). The genotypic frequencies of RANTES -28G and -403A mutations did not differ significantly between LTNPs and AIDS patients. The frequencies of three CCR5 promoter polymorphisms, designated 59029 G/A, 59353T/C, and 59402G/A, did not differ significantly between HIV-uninfected and HIV-infected patients. However, the allelic frequency of CCR559353C was significantly higher in AIDS patients than in LTNPs (P = 0.003). These results suggest that RANTES-28G and CCR5 59353C mutations might be associated with HIV infection or pathogenesis in the Korean population.

Host factors influencing susceptibility to HIV infection and AIDS progression

Transmission of HIV first results in an acute infection, followed by an apparently asymptomatic period that averages ten years. In the absence of antiretroviral treatment, most patients progress into a generalized immune dysfunction that culminates in death. The length of the asymptomatic period varies, and in rare cases infected individuals never progress to AIDS. Other individuals whose behavioral traits put them at high-risk of HIV transmission, surprisingly appear resistant and never succumb to infection. These unique cases highlight the fact that susceptibility to HIV infection and progression to disease are complex traits modulated by environmental and genetic factors. Recent evidence has indicated that natural variations in host genes can influence the outcome of HIV infection and its transmission. In this review we summarize the available literature on the roles of cellular factors and their genetic variation in modulating HIV infection and disease progression.

Polymorphisms in CCL2&CCL5 chemokines/chemokine receptors genes and their association with diseases

BACKGROUND

Chemokines and chemokine receptors are major mediators of leukocyte trafficking into the sites of the immune response. They participate in defence against microbial infection, in Th1/Th2 polarization of the immune response, allograft rejection and angiogenesis/angiostasis as well as in tumorigenesis and metastasis. To date, several functional polymorphisms of chemokine and chemokine receptor genes have been discovered that are able to deregulate chemokine system and, therefore, they may interfere with the pathogenesis of a large number of inflammatory and other diseases. In this review we focus on the known polymorphisms of two chemokines: CCL2, CCL5 and their corresponding receptors (CCR2, CCR5) and we also discuss their associations with susceptibility and progression to selected immune-mediated diseases.

METHODS AND RESULTS

Based on relevant literature this article gives a short overview of case-control and family studies regarding effect of the genetic factors on diseases such as coronary artery disease, systemic lupus erythematosus, diabetes mellitus, lung diseases and others.

CONCLUSION

Recent advance in the identification of chemokine genetic background of the diseases could provide opportunity for pharmacological treatment. However, we need more information about posttranscriptional events to understand functional relevance of polymorphisms and to discovery new avenues to blocking disease development.

Polymorphism of RANTES chemokine gene promoter is not associated with long-term nonprogressive HIV-1 infection of more than 16 years

To examine whether polymorphisms of the RANTES chemokine gene promoter are associated with long-term nonprogressive HIV-1 infection in white Spanish subjects, we performed a cross-sectional genetic association case-control study. Two-hundred sixty-seven white Spaniards were studied: 58 were HIV-1-infected long-term nonprogressors (LTNPs) of more than 16 years, 109 were HIV-1-infected usual progressors (UPs), and 100 were control subjects. Three RANTES single nucleotide polymorphisms (SNPs) at positions -28C>G, -109T>C, and -403G>A were assessed. The prevalence of the CCR5Delta 32 allele was also examined. Genotyping was performed using polymerase chain reaction and automatic sequencing analysis methods. Genotype and allele frequencies between the 3 groups were compared by the chi2 test and the Fisher exact test. The distribution of allelic variants of RANTES in controls, UPs, and LTNPs, respectively, was 3%, 2%, and 5% for -28G; 4%, 2%, and 2% for -109C; and 18%, 18%, and 18% for -403A (P = not significant). The differences were still nonsignificant when we exclusively analyzed individuals not carrying the CCR5Delta32 allele. We conclude that LTNP of more than 16 years is not associated with SNPs in the RANTES gene promoter in white Spanish HIV-1-infected subjects.

Protective effects of IL4-589T and RANTES-28G on HIV-1 disease progression in infected Thai females

OBJECTIVE

To evaluate the effect of polymorphisms in interleukin-4 (IL4) and RANTES promoters on disease progression in HIV-1 infected Thais.

DESIGN

Antiretroviral (ARV) drug-free HIV-1 infected females from the prospective cohort.

METHODS

A total of 246 DNA samples were genotyped for IL4 and RANTES promoter polymorphisms by PCR-RFLP. Associations of genotype with HIV-1 disease progression were assessed with respect to baseline clinical data including plasma HIV-1 load, CD4 cell counts, and proportion of symptomatic/AIDS, and survival status during 3 years of follow-up.

RESULTS

Patients with homozygous IL4-589T allele showed a significantly lower HIV-1 viral load (P = 0.005) and a higher CD4 cell count (P = 0.003) than the other patients with heterozygous IL4-589C/T or homozygous IL4-589C allele. Kaplan-Meier analysis demonstrated an apparent but insignificant trend towards better survival in homozygous IL4-589T patients. On the other hand, patients with RANTES-28G allele showed a significantly better survival while those with RANTES In1.1C allele without RANTES-28G showed a significantly poorer survival compared with those who did not possess either RANTES In1.1C or RANTES-28G (P = 0.02), although those polymorphisms only weakly associated with baseline viral load and CD4 cell counts.

CONCLUSIONS

Our results implicate the significant protective effect of IL4-589T and RANTES-28G on HIV disease progression in Thais. In contrast, RANTES In1.1C without RANTES-28G had an accelerating effect on HIV disease progression.

Global human genetics of HIV-1 infection and China

Genetic polymorphisms in human genes can influence the risk for HIV-1 infection and disease progression, although the reported effects of these alleles have been inconsistent. This review highlights the recent discoveries on global and Chinese genetic polymorphisms and their association with HIV-1 transmission and disease progression.

Functional analysis of naturally occurring mutations in the open reading frame of CCR5 in HIV-infected Chinese patients and healthy controls

We studied polymorphism of the HIV coreceptor CC chemokine receptor (CCR) 5 in 1099 Chinese adults residing in Hong Kong, including 785 HIV-negative healthy donors and 314 HIV-positive patients. Ten mutants in the CCR5 open reading frame were identified, 7 of which were nonsynonymous. The frequencies of these alleles did not show a significant difference between HIV patients and healthy controls. G106R, Delta32, R223Q, 299(FS), and S336I were cloned from prevalent mutant genes, and their effects on HIV infection were analyzed by a series of in vitro experiments to determine their transcription levels, expression levels, conformational changes, and HIV coreceptor function. R223Q is the most prevalent CCR5 mutant in ethnic Chinese, with a frequency of 0.046, which does not affect HIV infection in vitro, however. The S336I mutant also does not affect its transcription, expression, or HIV coreceptor function. Similar to 299(FS), the mutant G106R located in the third transmembrane domain results in diminished HIV coreceptor function in vitro through conformation changes in ECL2.