We used cutaneous delayed-type hypersensitivity responses, a powerful in vivo measure of cell-mediated immunity, to evaluate the relationships among cell-mediated immunity, AIDS, and polymorphisms in CCR5, the HIV-1 coreceptor. There was high concordance between CCR5 polymorphisms and haplotype pairs that influenced delayed-type hypersensitivity responses in healthy persons and HIV disease progression. In the cohorts examined, CCR5 genotypes containing -2459G/G (HHA/HHA, HHA/HHC, HHC/HHC) or -2459A/A (HHE/HHE) associated with salutary or detrimental delayed-type hypersensitivity and AIDS phenotypes, respectively. Accordingly, the CCR5-Δ32 allele, when paired with non-Δ32-bearing haplotypes that correlate with low (HHA, HHC) versus high (HHE) CCR5 transcriptional activity, associates with disease retardation or acceleration, respectively. Thus, the associations of CCR5-Δ32 heterozygosity partly reflect the effect of the non-▵32 haplotype in a background of CCR5 haploinsufficiency. The correlations of increased delayed-type hypersensitivity with -2459G/G-containing CCR5 genotypes, reduced CCR5 expression, decreased viral replication, and disease retardation suggest that CCR5 may influence HIV infection and AIDS, at least in part, through effects on cell-mediated immunity.

No abstract

No abstract

Mannose-binding lectin (MBL) plays an important role in the innate immune defense against invading microorganisms. Deficiency of functional MBL is linked to polymorphisms in the MBL2 gene. The aim of the study was to determine the influence of MBL2 polymorphisms in susceptibility to HTLV-1 infection. A total of 43 HTLV-1 infected subjects and 127 healthy controls were evaluated for polymorphisms in the coding region of MBL2 gene. The point mutations in exon 1 at codon 54 (allele B) and codon 52 (allele D) and the wild type allele A were detected by PCR-RFLP. The frequency of the allele A, B and D was 66%, 29% and 5% among HTLV-1 infected subjects and 79%, 18% and 3% among healthy controls, respectively. Genotype and allele frequencies were statistically different between both groups, being the allele B more frequent among HTLV-1 infected subjects than in controls (29% and 18%, respectively; p=0.032). Moreover, the homozygous genotype BB was observed in 14% of HTLV-1 patients and only 3% of controls (p=0.016), and it was associated with an almost five-fold higher risk of OR=4.98, 95%CI=1,63). Our results suggest that carriers of the MBL2 allele B are more susceptible to HTLV-1 infection. Further studies with a large number of individuals are ongoing to confirm the impact of MBL polymorphisms as genetic determinant of HTLV-1 susceptibility.