Abstract:
The objectives of this study were: 1) to determine the genetic distribution and mutation allele
frequency of CCR5-m303, CCR2-64I, and SDF1-3′A in HIV-1 seropositive and seronegative healthy
donors; 2) to compare the genetic allele frequency in HIV-1 subjects based on CD4+ T cell counts and
disease progression; 3) to established the multiplex PCR technique for the simultaneous detection of
three genetic polymorphisms for CCR5-m303, CCR2-64I, and SDF1-3′A.
In order to determine the host genotype distribution and mutant allele frequency of CCR5-m303,
CCR2-64I, and SDF1-3′A polymorphisms on chemokine receptors in Thai subjects, genomic DNA
were extracted from 93 HIV-1 seronegative blood donors and 93 HIV-1 seropositive subjects using the
QIAamp DNA blood kit. All samples were tested for these three genes by polymerase chain reactionrestriction
fragment length polymorphism (PCR-RFLP) using restriction enzymes. No CCR5-m303
allele was detected in these Thai samples. HIV-1 infected and HIV-1 uninfected subjects exhibited no
significant differences (p>0.05, χ2) in CCR2 genotypes and CCR2-64I allele frequencies. The SDF1-3′
A allele frequency was lower in HIV-1 infected than in HIV-1 uninfected subjects (p=0.05, χ2). A
higher number of the HIV-1 uninfected subjects than the HIV-1 infected subjects were found to be of
the SDF1-3′A/ 3′A genotype. No significant differences in CCR2 and SDF1 genotypes distribution and
mutant allele frequencies were observed as regards the CD4 status of HIV-1 seropositive subjects (p>
0.05, χ2).
Genotype distribution and mutant allele frequencies of these three genetic polymorphisms were
considered as to speed of disease progression. No significant differences were seen in CCR2-64I and
SDF1-3′A allele frequencies between the 17 members of slower progressor group (those in whom the
disease developed slowly) and 14 members of the rapid progressor group (p>0.05, Fischer’s exact test).
There was a higher frequency in the SDF1-3′A/ 3′A genotype in the slower progressors than in the
rapid progressors, but it was not statistically significant (p= >0.05, Fischer’s exact test).
Furthermore, a multiplex PCR-RFLP assay for the simultaneous determination of these three
polymorphisms correlated (with 100% concordant results) to that of the conventional PCR-RFLP in 30
selected samples from HIV-1 seropositive subjects with different levels of CD4+T cells. Therefore, the
multiplex PCR assay may be quick tool for the determination of these polymorphisms in large field
research.