The impact of HIV infection on regulatory CD4(+)CD25(high) (Treg) lymphocyte subpopulations was evaluated by FOXP3 quantitative reverse transcriptase polymerase chain reaction and by flow cytometry. FOXP3 mRNA was quantified in peripheral blood mononuclear cells or purified CD4(+) lymphocytes from HIV(+) lymphopenic patients. Patients were distributed among clinical stages A, B, and C and received highly active antiretroviral therapy. The frequency of CD4(+)CD25(high) lymphocytes, measured by flow cytometry, was decreased in HIV patients (n = 38) compared with the group of uninfected subjects (n = 39). FOXP3 mRNA levels were found decreased in HIV patients (n = 25) compared with controls (n = 17) when expression of CD3gamma or beta-actin but not that of TATA box binding protein 1 was used for data normalization. Our results are compatible with a decrease of the Treg lymphocytes during HIV infection. The consequences of a Treg decrease are discussed in the context of immunologic anomalies observed during HIV infection.

Finally, fibroblasts and BM-MSCs act at an early stage through blockage of lymphocyte activation, as demonstrated by down-regulation of GZMB (granzyme B) and IL2RA (CD25) expression.

Cloning and expression of chimpanzee FUT3, FUT5, and FUT6 genes confirmed the hypothesis that the gene duplications at the origin of the present human cluster of genes occurred between: (i) the great mammalian radiation 80 million years ago and (ii) the separation of man and chimpanzee 10 million years ago. The phylogeny of fucosyltransferase genes was completed by the addition of the FUT8 family of ␣(1,6)fucosyltransferase genes, which are the oldest genes of the fucosyltransferase family. By analysis of data banks, a new FUT8 alternative splice expressed in human retina was identified, which allowed mapping the human FUT8 gene to 14q23. The results suggest that the fucosyltransferase genes have evolved by successive duplications, followed by translocations, and divergent evolution from a single ancestral gene.Three human ␣(1,3)fucosyltransferase genes FUT3 1 (1), FUT5 (2) and FUT6 (3) are organized in a cluster, within 1 centimorgan, in the short arm of chromosome 19, in the band 19p13.3 (4, 5).Previous cloning of a bovine ␣(1,3)fucosyltransferase gene (futb) gave a single transcript, and the corresponding cognate enzyme had properties in common with the products of the three human FUT3, FUT5, and FUT6 genes. The position of this futb gene in the phylogenetic tree of fucosyltransferases, showed that the separation of the bovine species from the common evolutionary pathway, during the great mammalian radiation some 80 million years ago, occurred before the duplication events, which originated the present cluster of human FUT3, FUT5, and FUT6 genes and suggested that this bovine enzyme is the orthologous homologue of the ancestor of the FUT3, FUT5, and FUT6 human genes (6).The present cloning and expression of three chimpanzee ␣(1,3)fucosyltransferase genes provides evidence for the existence of at least three distinct, but related ␣(1,3)fucosyltransferase enzymes in this species, each one being the orthologous homologue of one of the human FUT3, FUT5, and FUT6 genes. The position of these chimpanzee genes in the fucosyltransferase phylogenetic tree suggests that the separation of man and chimpanzee from the common evolutionary pathway, about 10 million years ago, has occurred after the duplication events, at the origin of the present cluster of FUT3, FUT5, and FUT6 genes. Addition of the FUT8 gene family to the phylogenetic tree suggests that the appearance of this family preceded the ␣(1,2)-and the ␣(1,3)fucosyltransferase gene families, and the analysis of sequences in GenBank TM /EBI, EST, 2 and UniGene data banks allowed us to map the human FUT8 gene to 14q23. EXPERIMENTAL PROCEDURESCloning-PCR was used to amplify the coding regions and immediately adjacent sequences of FUT3, FUT5, and FUT6 from a chimpanzee, with primers containing extra bases with specific restriction sites, already used for the human genes (7,8). PCR products were digested with EcoRI and XbaI for FUT3, HindIII for FUT6, and HindIII and EcoRI for FUT5. Each gene was cloned between the respective restriction sites of pcDNA1 (Invitrogen). T...

Experimental infection of Mauritian cynomolgus macaques by simian immunodeficiency virus is a representative model of HIV infection, currently in favour for evaluating the efficacy of new preventive or curative treatments. Extensive studies of major histocompatibility complex (MHC) polymorphism by microsatellites revealed seven haplotypes (H1-H7). We present statistical evidence of the influence of MHC polymorphism on the set-point plasma viral load (PVL). Our analysis was based on the study of 45 Mauritian cynomolgus macaques inoculated by intravenous or intrarectal injection of a 50 AID50 dose of the SIVmac251 virus. The animals received no treatment before or after the inoculation. MHC polymorphism was investigated by means of 20 microsatellites distributed across the MHC and by DRB genotyping using the DGGE sequencing method. Statistical analysis with UNPHASED: software revealed that two markers located in the class IB region significantly influenced the Log PVL and that three class IB haplotypes were significantly associated with lower (H2 or H6) or higher (H4) set-point Log PVL values. Although the impact of MHC on Log PVL was found to be low (around one Log10), it is important to dispose of animals paired for their MHC genotypes, each animal tested for a given treatment and its untreated control, to minimize the influence of the MHC and clearly reveal the effect of the treatment.