Dominant effects of CCR2-CCR5 haplotypes in HIV-1 disease progression.
Three haplotypes for the CCR2-CCR5 region previously have been shown to affect AIDS progression; however, it is not known if the protective and accelerating effects of the haplotypes are relatively constant throughout infection or exert their effects early or late in HIV type 1 infection. The authors report the relative contributions to AIDS progression of CCR2 64I, CCR5 Delta32, and the CCR5 promoter haplotype +.P1.+ in the GRIV cohort, which included patients representing the extremes of the distribution for AIDS progression: rapid progressors (RP) who developed CD4 T-cell counts of <300/ mm within 3 years after the last HIV-1-seronegative test and slow progressors (SP) who were HIV-1 infected for > or =8 years with CD4 T-cell counts of >500/mm. Comparing the RP with a seroconverter control group including intermediate progressors to AIDS, we observed the early protective effect of CCR5 Delta32 (odds ratio = 0.25; P = 0.007) was similar in strength to the early susceptible effect of CCR5 +.P1.+ (odds ratio = 2.1, P = 0.01). Comparison of the intermediate control group to the SP showed weaker and less significant odd ratios, suggesting that the effect of these factors tended to be stronger on early progression; the tendency towards a disproportionately early effect was significant for CCR5 Delta32 (P = 0.04) but not for CCR5 +.P1.+ (P = 0.12). Follow-up of SP demonstrated that these polymorphisms have little effect after 8 years, because the subset of SP who had progression after study entry had the same genotype distribution as the global population of SP, suggesting that factors other than CCR5 or CCR2 genetic variants must be responsible for the long-term maintenance of nonprogression.
Available from: Pere Domingo
- "For CCR5Δ32, we found that there is no signal for non progression. This is in agreement with CCR5Δ32 having a primary effect against rapid progression as pointed out by the GRIV study [42,43]. We acknowledge, however, that in order to see the effect of CCR5Δ32, the use of a larger cohort and/or a Kaplan-Meier plot of patients' evolution since seroconversion under various endpoints could have been useful. "
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ABSTRACT: Tumor necrosis factor alpha (TNF-alpha) is thought to be involved in the various immunogenetic events that influence HIV-1 infection.
We aimed to determine whether carriage of the TNF-alpha-238G>A, -308G>A and -863 C>A gene promoter single nucleotide polymorphisms (SNP) and the CCR5 Delta 32 variant allele influence the risk of HIV-1 infection and disease progression in Caucasian Spaniards. The study group consisted of 423 individuals. Of these, 239 were uninfected (36 heavily exposed but uninfected [EU] and 203 healthy controls [HC]) and 184 were HIV-1-infected (109 typical progressors [TP] and 75 long-term nonprogressors [LTNP] of over 16 years' duration). TNF-alpha SNP and the CCR5 Delta 32 allele were assessed using PCR-RFLP and automatic sequencing analysis methods on white blood cell DNA. Genotype and allele frequencies were compared using the chi 2 test and the Fisher exact test. Haplotypes were compared by logistic regression analysis.
The distribution of TNF-alpha-238G>A, -308G>A and -863 C>A genetic variants was non-significantly different in HIV-1-infected patients compared with uninfected individuals: -238G>A, p = 0.7 and p = 0.3; -308G>A, p = 0.05 and p = 0.07; -863 C>A, p = 0.7 and p = 0.4, for genotype and allele comparisons, respectively. Haplotype analyses, however, indicated that carriers of the haplotype H3 were significantly more common among uninfected subjects (p = 0.04). Among the infected patients, the distribution of the three TNF-alpha genetic variants assessed was non-significantly different between TP and LTNP: -238G>A, p = 0.35 and p = 0.7; -308G>A, p = 0.7 and p = 0.6: -863 C>A, p = 0.2 and p = 0.2, for genotype and allele comparisons, respectively. Haplotype analyses also indicated non-significant associations. Subanalyses in the LTNP subset indicated that the TNF-alpha-238A variant allele was significantly overrepresented in patients who spontaneously controlled plasma viremia compared with those who had a detectable plasma viral load (genotype comparisons, p = 0.02; allele comparisons, p = 0.03). The CCR5 Delta 32 distribution was non-significantly different in HIV-1-infected patients with respect to the uninfected population (p = 0.15 and p = 0.2 for genotype and allele comparisons, respectively) and in LTNP vs TP (p = 0.4 and p = 0.5 for genotype and allele comparisons, respectively).
In our cohort of Caucasian Spaniards, TNF-alpha genetic variants could be involved in the vulnerability to HIV-1 infection. TNF-alpha genetic variants were unrelated to disease progression in infected subjects. The -238G>A SNP may modulate the control of viremia in LTNP. Carriage of the CCR5 Delta 32 variant allele had no effect on the risk of infection and disease progression.
BMC Medical Genetics 04/2010; 11(1):63. DOI:10.1186/1471-2350-11-63 · 2.08 Impact Factor
Available from: Margaret May
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ABSTRACT: Humans differ substantially with respect to susceptibility to human immunodeficiency virus type 1 (HIV-1). We evaluated variants
of nine host genes participating in the viral life cycle for their role in modulating HIV-1 infection. Alleles were assessed
ex vivo for their impact on viral replication in purified CD4 T cells from healthy blood donors (n = 128). Thereafter, candidate alleles were assessed in vivo in a cohort of HIV-1-infected individuals (n = 851) not receiving potent antiretroviral therapy. As a benchmark test, we tested 12 previously reported host genetic variants
influencing HIV-1 infection as well as single nucleotide polymorphisms in the nine candidate genes. This led to the proposition
of three alleles of PML, TSG101, and PPIA as potentially associated with differences in progression of HIV-1 disease. In a model considering the combined effects of
new and previously reported gene variants, we estimated that their effect might be responsible for lengthening or shortening
by up to 2.8 years the period from 500 CD4 T cells/μl to <200 CD4 T cells/μl.
Journal of Virology 10/2005; 79(20):12674-80. DOI:10.1128/JVI.79.20.12674-12680.2005 · 4.44 Impact Factor
Available from: Jean-Yves Springael
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ABSTRACT: It became clear over the recent years that most, if not all, G protein-coupled receptors (GPCR) are able to form dimers or higher order oligomers. Chemokine receptors make no exception to this new rule and both homo- and heterodimerization were demonstrated for CC and CXC receptors. Functional analyses demonstrated negative binding cooperativity between the two subunits of a dimer. The consequence is that only one chemokine can bind with high affinity onto a receptor dimer. In the context of receptor activation, this implies that the motions of helical domains triggered by the binding of agonists induce correlated changes in the other protomer. The impact of the chemokine dimerization process in terms of co-receptor function and drug development is discussed.
Cytokine & Growth Factor Reviews 01/2006; 16(6):611-23. DOI:10.1016/j.cytogfr.2005.05.005 · 5.36 Impact Factor
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