The CCR5Delta32 allele slows disease progression of human immunodeficiency virus-1-infected children receiving antiretroviral treatment

The role of the CCR5Delta32 allele in human immunodeficiency virus (HIV)-1-related disease progression was analyzed for 457 antiretroviral-na?ve children who had participated in the Pediatric AIDS Clinical Trials Group 152 study, which demonstrated that didanosine (ddI) or zidovudine + ddI treatments were superior to zidovudine alone. The CCR5Delta32 allele was detected at an overall frequency of 6.1% (28/457). At study entry, heterozygote children (wild type [wt]/Delta32) had higher baseline median CD4(+) counts/mm(3) than wt/wt children had (1035 vs. 835 cells/mm(3); P=. 043), higher mean weight-for-age Z scores (-0.15 vs. -0.84; P=.01), and a trend toward less cortical atrophy (P=.059). During antiretroviral treatment and study follow-up, there was a trend toward less disease progression and death among heterozygote children than among wt/wt children (P=.056; relative hazard, 0.28; 95% confidence interval, 0.07-1.13) independent of the antiretroviral treatment to which they were randomized.     

Polymorphisms in the CCR5 promoter region influence disease progression in perinatally human immunodeficiency virus type 1-infected children

The effect of CC-chemokine receptor 5 (CCR5) promoter polymorphisms on the natural history of human immunodeficiency virus (HIV) disease was studied in 73 HIV-1-infected children. The CCR5(59338-59537) promoter haplotype, CCR5-59029A/G polymorphism, and CCR5Delta32 and CCR2-64I alterations were investigated. After exclusion of carriers of CCR5Delta32 or CCR2-64I, Kaplan-Meier analysis disclosed that children with the P1/P1(59353C,59356C,59402A) genotype progressed faster to disease than did children with other haplotypes (P=.016). When CCR2-64I carriers were included, this effect had borderline significance (P=.065) and was lost when CCR5Delta32 carriers were also considered (P=.387). The P1/P1 effect was strongest early after infection, when progression to disease was mainly associated with CCR5 coreceptor-using viruses. These results indicate that the P1/P1 genotype is predictive of rapid progression in HIV-1-infected children lacking CCR5Delta32 or CCR5-64I alleles. The observation of a linkage disequilibrium between P1 and 59029A might explain the previously reported association between 59029A homozygosity and rapid disease progression.     

No evidence for an effect of the CCR5 delta32/+ and CCR2b 64I/+ mutations on human immunodeficiency virus (HIV)-1 disease progression among HIV-1-infected injecting drug users

The relationship between CCR5 and CCR2b genotypes and human immunodeficiency virus (HIV)-1 disease progression was studied among the 108 seroconverters of the Amsterdam cohort of injecting drug users (IDUs). In contrast to earlier studies among homosexual men, no effect on disease progression of the CCR5 Delta32/+ and the CCR2b 64I/+ genotypes was found, when progression to AIDS, death, or a CD4 cell count <200/microL was compared by a Cox proportional hazards model. Furthermore, CD4 cell decline (by a regression model for repeated measurements) and virus load in the first 3 years after seroconversion did not differ between the CCR5 and CCR2b wild type and heterozygous genotypes. A nested matched case-control study also revealed no significant effect of the CCR5 and CCR2b mutations. Immunologic differences between IDUs and homosexual men may account for the observed lack of effect. Alternatively, difference in transmission route or characteristics of the HIV-1 variants that circulate in IDUs could also explain this phenomenon.     

The coreceptor mutation CCR5Delta32 influences the dynamics of HIV epidemics and is selected for by HIV

We explore the impact of a host genetic factor on heterosexual HIV epidemics by using a deterministic mathematical model. A protective allele unequally distributed across populations is exemplified in our models by the 32-bp deletion in the host-cell chemokine receptor CCR5, CCR5Delta32. Individuals homozygous for CCR5Delta32 are protected against HIV infection whereas those heterozygous for CCR5Delta32 have lower pre-AIDS viral loads and delayed progression to AIDS. CCR5Delta32 may limit HIV spread by decreasing the probability of both risk of infection and infectiousness. In this work, we characterize epidemic HIV within three dynamic subpopulations: CCR5/CCR5 (homozygous, wild type), CCR5/CCR5Delta32 (heterozygous), and CCR5Delta32/CCR5Delta32 (homozygous, mutant). Our results indicate that prevalence of HIV/AIDS is greater in populations lacking the CCR5Delta32 alleles (homozygous wild types only) as compared with populations that include people heterozygous or homozygous for CCR5Delta32. Also, we show that HIV can provide selective pressure for CCR5Delta32, increasing the frequency of this allele.     

Associations of CCR5, CCR2, and stromal cell-derived factor 1 genotypes with human immunodeficiency virus disease progression in patients receiving nucleoside therapy.

Genotype data for CCR5, CCR2, and stromal cell-derived factor 1 (SDF-1) were obtained from 354 human immunodeficiency virus type 1 (HIV-1)-positive subjects who were being treated with nucleosides. Associations with HIV-1 load, HIV syncytium-inducing (SI) phenotype, CD4 cell count, and disease progression were analyzed. No differences in HIV-1 load or CD4 cell count were observed between wild type (+) and variant genotypes. Changes from non-SI to SI viral phenotype were more frequent in heterozygotes with a 32-bp deletion (Delta32) in the CCR5 gene than in + homozygotes (40% vs. 7%; P=.01). In a multivariate analysis, heterozygous CCR5 Delta32 was associated with reduced hazard of progression (hazard ratio, 0.32; P=.02). Subjects homozygous for the SDF-1 3'A variant had more-rapid disease progression (P=.008). The SDF-1 homozygous 3'A variant was related to more-rapid disease progression, and CCR5 Delta32 was associated with reduced rates of hazard for disease progression in nucleoside-treated subjects.     

Rapid determination of the Delta32 deletion in the human CC-chemokine receptor 5 (CCR5) gene without DNA extraction by lightcycler real-time polymerase chain reaction

CCR5 is a major coreceptor for cellular entry of macrophage-tropic isolates of the human immunodeficiency virus (HIV). A 32-base pair deletion of the CCR5 gene (CCR5Delta32) protects against HIV infection because the frame shift leads to a truncated protein not expressed on the cell surface. CCR5Delta32 also delays progression in heterozygous HIV-infected patients and improves responses to antiretroviral therapy. Available methods for CCR5 genotyping, however, are cost expensive and/or time consuming. To improve CCR5 genotyping we studied four primer sets flanking the CCR5Delta32 deletion site using real-time polymerase chain reaction (PCR) on a LightCycler device. Primers amplified fragments of different length depending on the presence or absence of the Delta32 mutation. Next, melting curves of the amplified fragments were analyzed using SYBR green, a conventional double-strand DNA dye. To circumvent initial DNA extraction, we also studied serially diluted "interphase" leukocytes as PCR templates after centrifugation of EDTA blood. Finally, the validity of the new method was checked by analyzing 100 blood samples with known CCR5 genotypes. Amplicons of 82 bp:50 bp and 97 bp:65 bp fragment ratios could easily be discriminated due to the differences in their melting temperatures (3 degrees C and 2 degrees C, respectively). Furthermore, CCR5 genotyping was possible without initial DNA extraction and yielded optimal results at 1:400 to 1:600 dilution of the "interphase" leukocytes. Results of the new LightCycler PCR protocol were identical to conventional CCR5 genotyping but required considerably less time and expenditures. We have established a new real-time PCR protocol, which enables fast, cost-saving, and reliable CCR5 genotyping.     

High prevalence of the CCR5Delta32 HIV-resistance mutation among Estonian HIV type 1-infected individuals

The aim of this survey was to investigate human immunodeficiency virus type 1 (HIV-1) coreceptor, chemokine receptor 5 (CCR5), polymorphism among Estonian HIV-1-infected individuals. Homozygous CCR5Delta32 genotypes have been associated with resistance to HIV-1 infection; however, inconsistent evidence exists as to whether a single copy of a mutant allele among heterozygotes confers protection from HIV-1 infection. In an Estonian population the frequency of the CCR5Delta32 allele has been found to be among the greatest observed to date. Ironically, Estonia is concomitantly characterized by a very high HIV-1 prevalence. We compared the allele frequencies in a healthy control population to the HIV-positive group. The frequency of heterozygous individuals did not differ significantly between the HIV-positive group and the control population. Allele frequencies were analyzed among different risk groups as well as groups with different HIV genetic backgrounds. We did not find a difference between CCR5Delta32 allele frequencies among intravenous drug users (IDUs) and sexually infected persons. Likewise, the distribution of CCR5Delta32 allele frequencies among patients infected with different subtypes did not differ while data from "pure" subtypes A, B, and CRF06_cpx were pooled and evaluated against unique recombinant forms.     

Genetic influence of CCR5, CCR2, and SDF1 variants on human immunodeficiency virus 1 (HIV-1)-related disease progression and neurological impairment, in children with symptomatic HIV-1 infection

The role that host genetics plays in the modification of the rate of human immunodeficiency virus 1 (HIV-1)-related disease progression was evaluated in a seroprevalent cohort of 1049 children with symptomatic HIV-1 infection who participated in 2 clinical trials in the United States. Variants including CCR2-V64I, CCR5-wt/Delta32, CCR5-59029-G/A, CCR5-59353-T/C, CCR5-59356-C/T, and SDF1-3'-G/A were identified by polymerase chain-reaction genotyping. Children with the CCR5-wt/Delta32 genotype experienced significantly delayed disease progression, including less neurocognitive impairment. In the CCR5-wt/wt group, the most rapid disease progression was in those with the CCR5-59029-A/A genotype, which was present in 23% of the children. Although the SDF1-3'-A/A variant was associated with more-rapid disease progression, it occurred in <2% of the children studied. Modest or little impact was associated with the CCR5-59353, CCR5-59356, or CCR2 genotypes. Thus, in children with the CCR5-wt/wt genotype, variants at CCR5-59029 have the broadest impact on disease progression. These data suggest that, in children, host genetics plays an important role in HIV-1-related disease progression and neurological impairment.     

Differential CCR5Delta32 allelic frequencies in juvenile idiopathic arthritis subtypes: evidence for different regulatory roles of CCR5 in rheumatological diseases

BACKGROUND: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease of childhood and is characterized by persistent arthritis for at least 6 weeks. Its aetiopathogenesis is unknown but there is strong evidence that there is a substantial genetic component. Chemokine receptors genes are among the candidate genes for association with arthritis and other inflammatory diseases. The CC chemokine receptor 5 (CCR5)Delta32 polymorphism has been associated with rheumatoid arthritis (RA), conferring a protective effect. OBJECTIVE: To determine whether the CCR5Delta32 polymorphism is associated with JIA and RA in Brazilian patients. METHODS: We investigated 203 RA patients, 101 JIA patients, and 104 healthy individuals by amplification of the CCR5Delta32 deletion. We compared the allelic frequencies among these groups, as well as among different JIA subtypes. RESULTS: The frequency of the Delta32 allele was higher in JIA patients (9.4%) as compared to control subjects (3.8%) and RA patients (3.2%). Grouping the patients according to JIA subtypes, we observed a higher CCR5Delta32 allelic frequency in the subtypes with a greater inflammatory component: 4.1% in oligoarticular (n = 49), 11.2% in polyarticular (n = 40) [9.5% in rheumatoid factor negative (RF-) and 33.3% in RF positive (+)], and 25% in systemic JIA (n = 12). CONCLUSIONS: This study suggests that in JIA, unlike in RA, CCR5Delta32 does not have a protective effect, but instead it could be a factor associated with more inflammatory forms of the disease. These observations give rise to new questions about the mechanism and the cellular types involved in JIA as well as about the aetiology of JIA.     

R5 HIV productively infects Langerhans cells,and infection levels are regulated by compound CCR5 polymorphisms

Langerhans cells (LCs) are suspected to be initial targets for HIV after sexual exposure (by becoming infected or by capturing virus). Here, productive R5 HIV infection of LC ex vivo and LC-mediated transmission of virus to CD4+ T cells were both found to depend on CCR5. By contrast, infection of monocyte-derived dendritic cells and transfer of infection from monocyte-derived dendritic cells to CD4+ T cells were mediated by CCR5-dependent as well as DC-specific ICAM-3-grabbing nonintegrin-dependent pathways. Furthermore, in 62 healthy individuals, R5 HIV infection levels in LCs ex vivo were associated with CCR5 genotype. Specifically, genotyping for ORF Delta 32 revealed that LCs isolated from ORF Delta 32/wt individuals were significantly less susceptible to HIV when compared with LCs isolated from ORFwt/wt individuals (P = 0.016). Strikingly, further genetic analyses of the A-2459G CCR5 promoter polymorphism in ORF Delta 32/wt heterozygous individuals revealed that LCs isolated from -2459A/G + ORF Delta 32/wt individuals were markedly less susceptible to HIV than were LCs from -2459A/A + ORF Delta 32/wt individuals (P = 0.012). Interestingly, these genetic susceptibility data in LCs parallel those of genetic susceptibility studies performed in cohorts of HIV-infected individuals. Thus, we suggest that CCR5-mediated infection of LCs, and not capture of virus by LCs, provides a biologic basis for understanding certain aspects of host genetic susceptibility to initial HIV infection.     

Allelic distribution of CCR5 and CCR2 genes in an Italian population sample

Genetic polymorphisms of CCR5 and CCR2 human chemokine receptors have been associated with resistance during HIV-1 infection and disease progression. The protective effect of mutant alleles at these loci has important implications in AIDS pathogenesis. Chemokine receptors have a role in viral entry into target cells as well as in immune response modulation. In the present report, we studied the frequency of CCR5delta32 and CCR264I allelic variants among a representative sample of the Italian population. Observed allelic frequencies were 0.0454 and 0.0655, respectively. In both cases, genotype distribution was in equilibrium as predicted by the Hardy-Weinberg equation. Taken as a whole, about 21% of the population sample was found to be heterozygous for one or another of those two mutated alleles. Distribution of CCR5delta32 and CCR264I allelic variants within a population can be considered as a measure of genetic susceptibility to HIV infection and disease progression.     

CCR5Delta32 and promoter polymorphisms are not correlated with initial virological or immunological treatment response.

OBJECTIVE: Natural genetic polymorphisms within the CCR5 gene and promoter have been linked to patterns of HIV-1 clinical disease progression in untreated individuals. The objective of this retrospective study was to assess the influence of the CCR5Delta32 mutation and promoter polymorphisms on virological and immunological treatment outcome in 436 antiretroviral-naive individuals initiating their first therapy, over a mean follow-up time of 22 months. METHODS: Genotypes for the CCR5Delta32 and promoter were determined by polymerase chain reaction amplification of human DNA from plasma, followed by gel electrophoresis for CCR5Delta32 or DNA sequencing for the promoter polymorphisms. Time to virological failure [defined as the second plasma viral load > or = 400 copies HIV-1 RNA/ml) and immunological failure (defined as time to achieve two successive CD4 cell counts below baseline) were analyzed by Kaplan-Meier methods. RESULTS: The five most common CCR5 promoter polymorphisms were observed at positions 208(G/T), 303(A/G), 627(C/T), 676(A/G), and 927(C/T). Allele frequencies were 0.24(208T), 0.38(303G), 0.44(627T), 0.35(676G) and 0.18(927T). The CCR5Delta32 allele frequency was 0.08. The promoter polymorphisms existed in strong linkage disequilibrium with each other and the Delta32. No significant effect of the individual CCR5Delta32 or promoter polymorphisms could be demonstrated with respect to time to treatment failure as defined by virological or immunological parameters (P > or = 0.07). Similarly, when combined CCR5Delta32 and promoter genotypes were analyzed in order to account for linkage disequilibrium, no significant effect was observed on time to virological or immunological failure (P > 0.6). CONCLUSION: CCR5Delta32 and promoter genotypes may not be of clinical relevance in predicting initial virological or immunological response to antiretroviral therapy.     

Host genetic background at CCR5 chemokine receptor and vitamin D receptor loci and human immunodeficiency virus (HIV) type 1 disease progression among HIV-seropositive injection drug users.

The effect of polymorphisms on genes encoding the CCR5 chemokine receptor and vitamin D receptor (VDR) in human immunodeficiency virus (HIV) type 1 disease progression was analyzed in a cohort of 185 HIV-seropositive injection drug users. Results confirmed a lack of association in patients with HIV disease between CCR5 wtDelta32 heterozygosity and a slow progression to AIDS and to a CD4 cell count <200 cells/microL. In contrast, a more rapid disease progression was associated with the VDR-BB genotype. A higher proportion of this genotype was found in patients with <200 CD4 cells/microL (P=.009; odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3-4.7), as well as a faster progression both to AIDS (1993 CDC classification [CDC 1993]) and to a CD4 cell count <200 cells/microL. When the analysis was restricted to patients with a VDR-bb genetic background, patients with CCR5 wtDelta32 heterozygosity were overrepresented in CDC 1993 nonprogressors (P=.033; OR, 0.28; 95% CI, 0.08-0.92) and in those with >200 CD4 cells/microL (P=.062; OR, 0.26; 95% CI, 0.06-1.08). Also, patients with CCR5 wtDelta32 heterozygosity showed a slow progression both to AIDS CDC 1993 and to a CD4 cell count <200 cells/microL.     

CCR△532 mutation does not influence the susceptibility to HCV infection, severity of liver disease and response to therapy in patients with chronic hepatitis C

AIM: To study whether CCR5Delta32 mutation was associated with viral infection and severity of liver disease. METHODS: Two hundred and fifty two histologically proven, chronic HCV patients (mean age: 41 +/- 14 years; M/F: 164/88) were genotyped. PCR based genotyping of 32 bp deletion at the CCR5 locus was done. Four-hundred and eight matched healthy controls were studied to assess susceptibility to HCV infection. To assess correlation of immune gene polymorphism with severity of HCV related liver disease, patients with chronic HCV infection were divided into those with a fibrosis score of <= 2 (mild) or > 2 (severe) and histological activity index (HAI) of <= 5 or > 5. For correlation between CCR5Delta32 mutations and response to therapy, 129 patients who completed therapy were evaluated. RESULTS: The majority (89.4%) of the patients were infected with genotype 3. The frequency of homozygous CCR5Delta32 mutants was comparable to HCV patients as compared to the healthy controls (0.7% vs 0%, P = 0.1). Further more, the frequency of CCR5Delta32 mutation was comparable in patients with mild or severe liver disease. (P = NS). There was also no association observed with response to therapy and CCR5Delta32 mutation. CONCLUSION: CCR5Delta32 mutation does not have a role in disease susceptibility, severity or response to therapy in patients with chronic hepatitis C infection.     

Reduced prevalence of the CCR5 delta32 heterozygous genotype in human immunodeficiency virus-infected individuals with AIDS dementia complex.

Heterozygosity for a 32-bp deletion in the CCR5 gene (CCR5 Delta32), which encodes the coreceptor for macrophage-tropic non-syncytium-inducing (NSI) human immunodeficiency virus type 1 (HIV-1) variants, results in a lower CCR5 expression and reduced NSI HIV-1 replication. Because infection of macrophages and microglial cells by NSI HIV-1 is considered to be instrumental for the development of AIDS dementia complex (ADC), we studied whether the CCR5 Delta32 heterozygous genotype correlated with a reduced frequency of ADC. Two (4.1%) of 49 patients with ADC versus 27 (14. 5%) of 186 AIDS patients without ADC were heterozygous for CCR5 Delta32 (P=.05). In contrast, a point mutation in the first transmembrane domain of CCR2 (CCR2 64I) did not show this protective effect (P=.57). The reduced prevalence of the CCR5 Delta32 allele among patients with ADC may indicate a reduced or absent reservoir of macrophage-tropic NSI HIV-1 in the brain of CCR5 Delta32 heterozygotes.     

CCR5 promoter polymorphisms in a Kenyan perinatal human immunodeficiency virus type 1 cohort: association with increased 2-year maternal mortality

The CCR5 chemokine receptor acts as a coreceptor with CD4 to permit infection by primary macrophage-tropic human immunodeficiency virus type 1 (HIV-1) strains. The CCR5Delta32 mutation, which is associated with resistance to infection in homozygous individuals and delayed disease progression in heterozygous individuals, is rare in Africa, where the HIV-1 epidemic is growing rapidly. Several polymorphisms in the promoter region of CCR5 have been identified, the clinical and functional relevance of which remain poorly defined. We evaluated the effect of 4 CCR5 promoter mutations on systemic and mucosal HIV-1 replication, disease progression, and perinatal transmission in a cohort of 276 HIV-1-seropositive women in Nairobi, Kenya. Mutations at positions 59353, 59402, and 59029 were not associated with effects on mortality, virus load, genital shedding, or transmission in this cohort. However, women with the 59356 C/T genotype had a 3.1-fold increased risk of death during the 2-year follow-up period (95% confidence interval [CI], 1.0-9.5) and a significant increase in vaginal shedding of HIV-1-infected cells (odds ratio, 2.1; 95% CI, 1.0-4.3), compared with women with the 59356 C/C genotype.     

A deletion in the chemokine receptor 5 (CCR5) gene is associated with tickborne encephalitis

Tickborne encephalitis (TBE) virus infections can be asymptomatic or cause moderate to severe injuries of the central nervous system. Why some individuals develop severe disease is unknown, but a role for host genetic factors has been suggested. To investigate whether chemokine receptor CCR5 is associated with TBE, CCR5Delta32 genotyping was performed among Lithuanian patients with TBE (n=129) or with aseptic meningoencephalitis (n=76) as well as among control subjects (n=134). We found individuals homozygous for CCR5Delta32 (P= .026) only among patients with TBE and a higher allele prevalence among patients with TBE compared with the other groups studied. CCR5Delta32 allele prevalence also increased with the clinical severity of disease.     

CD4 T cell surface CCR5 density as a host factor in HIV-1 disease progression

OBJECTIVE AND DESIGN: We have recently shown that the number of CCR5 molecules at the surface of peripheral blood CD4 T cells (CCR5 density) correlates with the viral RNA plasma level in HIV-1-infected individuals. As viral load is a strong predictor of outcome in HIV infection, the present study examines the correlation between CCR5 density and HIV-1 disease progression. METHODS: Using a quantitative flow cytometry assay, we measured CCR5 density in HIV-1-infected adults and control healthy volunteers. The CCR5 genotype (presence of a Delta 32 allele) was also determined. RESULTS: CCR5 density was stable over time on non-activated, HLA-DR(-)CD4 T cells of infected individuals. In a study cohort of 25 patients, asymptomatic and non-treated, we observed a correlation between CCR5 density on HLA-DR(-)CD4 T cells and the CD4 T cell slope (P = 0.026), which was independent of the presence or absence of the Delta 32CCR5 deletion. In particular, slow progressors expressed lower CCR5 densities than non-slow progressors (P = 0.004) and non-infected control subjects (P = 0.002). CONCLUSION: These results are compatible with the hypothesis that CCR5 density, which is a key factor of HIV-1 infectability, determines in-vivo HIV production, and thereby the rate of CD4 cell decline. Consequently, CCR5 density quantitation could be a new valuable prognostic tool in HIV-1 infection. Moreover, these data emphasize the therapeutic potential of treatments that reduce functional CCR5 density.     

CD4+ T cell surface CCR5 density as a determining factor of virus load in persons infected with human immunodeficiency virus type 1

The intensity of expression of the chemokine receptor CCR5 is involved in in vitro cell infectability by human immunodeficiency virus (HIV)-1 R5 isolates. Because CCR5 expression varies among individuals, the hypothesis that this expression could determine virus load in HIV-1-infected persons was tested. The mean number of CCR5 molecules per cell was measured on peripheral blood CD4+ T lymphocytes (CCR5 density) from HIV-1-infected, asymptomatic, nontreated adults. There was a strong correlation between HIV RNA plasma level and CCR5 density (P=.009) that was independent of cell activation and was not due to an HIV-induced CCR5 up-regulation. These data are compatible with the hypothesis that CCR5 density is a key factor governing cell infectability and in vivo virus production and explain the protective effect of the Delta32CCR5 deletion, which results in low CCR5 expression. CCR5 density might be of critical predictive value in HIV infection.