OBJECTIVETo investigate the frequencies of three point mutations, CGT52TGT, GGC54GAC and GGA57GAA, in exon 1 of mannan-binding lectin (MBL) structural gene in Chinese Uyghur population.

METHODSBlood samples were collected from a Uyghur population in Xinjiang Uyghur Autonomous Region, and the genomic DNA was extracted from the leucocytes and the target gene fragment amplified by PCR. The three point mutations in exon 1 of MBL gene were detected by fluorogenic probe hybridization technique with visual monitoring.

RESULTSIn 95 Uyghur individuals, 2 were identified as homozygous for codon 54 mutations, 28 were heterozygous for codon 54 mutation, and no CGT52TGT and GGA57GAA point mutations were found.

CONCLUSIONThe frequencies of CGT52TGT, GGC54GAC and GGA57GAA mutant alleles in exon 1 of MBL structural gene are 0, 0.168 and 0 respectively in the Chinese Uyghur population.

Adolescent ; Adult ; Base Sequence ; China ; Exons ; genetics ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Mannose-Binding Lectin ; blood ; genetics ; Middle Aged ; Point Mutation ; Polymerase Chain Reaction

OBJECTIVETo study the correlations of mannose-binding lectin (MBL) gene promoter polymorphisms and plasma MBL concentrations to the susceptibility to HIV infection in northern Chinese Han population.

METHODSThis case-control study included 115 HIV-infected patients and 115 non-infected healthy individuals, in whom the MBL gene promoter polymorphisms were detected using pyrosequencing technique and plasma MBL concentrations measured using enzyme-linked immunosorbent assay (ELISA).

RESULTSThe MBL promoter genotypes of LY/LY, LY/LX, HY/LY, HY/HY and LX/LX were detected in 66 (57.40%), 25 (21.70%), 17 (14.80%), 5 (4.30%) and 2 (1.70%) among the HIV-infected patients, and in 77 (67.00%), 23(20.00%), 12 (10.40%), 0 (0.00%), and 3 (2.60%) among the healthy individuals, respectively. The frequencies of haplotypes LY, HY and LX were 75.70%, 11.70% and 12.60% among the patients, and 82.20%, 5.20% and 12.60% among the healthy individuals, respectively, showing significant difference in the halpotype between the two groups (P=0.041). The average plasma MBL concentration was significantly lower in HIV-infected group than in the healthy individuals (1775.14-/+786.31 vs 3672.21-/+597.13 microg/L, P=0.001).

CONCLUSIONThe genotypes of LY/LY and LY/LX and the haplotypes of LY and HY are predominant in northern Chinese Han population, and the plasma MBL concentration in HIV infected patients is generally only 50% of that in healthy individuals. We therefore presume that MBL promoter polymorphisms and plasma MBL concentration can be associated with the susceptibility to HIV infection in this population, and individuals with low plasma MBL concentration are more susceptible to HIV infection.

Adult ; Asian Continental Ancestry Group ; genetics ; Case-Control Studies ; China ; Female ; Genetic Predisposition to Disease ; Genotype ; HIV Infections ; blood ; ethnology ; genetics ; Humans ; Male ; Mannose-Binding Lectin ; blood ; genetics ; Middle Aged ; Polymorphism, Single Nucleotide ; Promoter Regions, Genetic ; genetics

Diisocyanate (DI) is the most common cause of occupational asthma (OA) in Korea. Mannose-binding lectin (MBL) initiates the lectin complement activation pathway following oxidative stress and plays an important role in the regulation of inflammatory processes. To determine whether there is a genetic association between MBL2 polymorphisms and DI-OA, 99 patients with DI-OA, 99 asymptomatic exposed controls (AECs) and 144 unexposed normal controls were enrolled in this study. Three polymorphisms (-554 G>C, - 431A>C and - 225 G>C) in the MBL2 promoter were genotyped, and serum MBL levels were determined by enzyme-linked immunosorbent assay. Functional variabilities in the promoter polymorphisms were analyzed by a luciferase reporter assay and electrophoretic mobility shift assay (EMSA). A significantly higher frequency of haplotype (ht) 2 [CAG] was noted in the DI-OA group compared with the AEC group (P=0.044). The patients with DI-OA carrying ht2 [CAG] had significantly lower PC20 methacholine levels (P<0.001) than the non-carriers. The serum MBL levels were significantly higher in the DI-exposed subjects (both the DI-OA patients and AECs) carrying ht1 [GAG] (P=0.028). Luciferase activity was significantly enhanced in ht1 [GAG] compared with ht2 [CAG] in human hepatocarcinoma cells (Hep3B) (P=0.002). The EMSA showed that a - 554G probe produced a specific shifted band compared with the - 554C probe. These findings suggest that decreased serum MBL levels due to polymorphisms of the MBL2 gene may increase susceptibility to the development of DI-OA in DI-exposed individuals.
Adult ; Alleles ; Asthma, Occupational/diagnosis/*etiology ; Cell Line ; Female ; Forced Expiratory Volume ; Gene Frequency ; Genotype ; Haplotypes ; Humans ; Immunoglobulin E/immunology ; Immunoglobulin G/immunology ; Isocyanates/*adverse effects/immunology ; Male ; Mannose-Binding Lectin/blood/*genetics ; Middle Aged ; *Polymorphism, Genetic ; Polymorphism, Single Nucleotide ; Protein Binding ; Transcriptional Activation ; Young Adult