Cloning, expression, and characterization of novel GH5 endoglucanases from Thermobifida alba AHK119.

Thermobifida alba AHK119 exhibits sufficient filter paper-degradation activity in its culture supernatant. AHK119-bMs (1365 bp) and AHK119-E5 (1425 bp), which encode novel GH5 family endoglucanases, were cloned from the genomic DNA of T. alba AHK119. AHK119-bMs and AHK119-E5 consisted of 454 and 474 amino acid residues, respectively, in which the catalytic domain (CD) and carbohydrate-binding module (CBM) were connected by an accessary module (linker region). The amino acid sequences of CD and CBM of AHK119-bMs were most identical to those of endo-ß-mannanases (Man5As) from Thermobifidafusca TM51, T. halotolerans YIM90462, and T.cellulosilytica TB100. In contrast, the amino acid sequences of CD and CBM of AHK119-E5 were most identical to those of endo-1,4-ß-glucanases (cellulases; Cel5As) from T. fusca and T. halotolerans YIM90462. However, the linker region of both the genes shared low identities with those of Man5As and Cel5As. AHK119-bMs showed broader specificities toward cellulosic substrates than Man5As, whereas AHK119-E5 showed higher activity toward insoluble cellulosic substrates than toward soluble ones, which was conflicting when compared with other Cel5As. In addition, AHK119-bMs and AHK119-E5 showed different requirements for metal ions from those of Man5As and Cel5As, respectively. Therefore, both the enzymes were identified as novel GH5 endoglucanases, and the accessary modules seemed to play important roles in their enzymatic properties.

Human leukocyte antigen class I polymorphisms influence the mild clinical manifestation of Plasmodium falciparum infection in Ghanaian children.

A prospective study that included 429 children for active detection of mild malaria was conducted in a coastal region of Ghana to reveal whether the incidence of malaria is affected by human leukocyte antigen (HLA) polymorphism. During 12 months of follow-up, 85 episodes of mild clinical malaria in 74 individuals were observed, and 34 episodes among them were accompanied with significant parasitemia at >5000 infected red blood cells per cubic millimeter. Attributable and relative risks conferred by genetic factors in the HLA region were evaluated by comparison of the incidence in children, stratified by carrier status, of a given allele of HLA-A, -B, -DRB1 and TNFA promoter polymorphism. HLA-B*35:01 reduced the incidence by 0.178 events per person per year (0.060 versus 0.239 for B*35:01-positive and -negative subpopulations, respectively), and a relative risk of 0.25, which remained statistically significant after Bonferroni's correction for multiple testing (p(c) = 8.2 × 10(-5)). Further, HLA-B*35:01 and -B*53:01 exhibited opposite effects on the incidence of malaria with significant parasitemia. When parasite densities in different HLA carriers status were compared, HLA-A*01 conferred an increase in parasite load (p = 6.0 × 10(-7)). In addition, we found a novel DRB1 allele that appears to have emerged from DRB1*03:02 by single nucleotide substitution.

Genetic polymorphisms in CTLA4 and SLC4A2 are differentially associated with the pathogenesis of primary biliary cirrhosis in Japanese patients.

BACKGROUND: Anti-gp210 and anti-centromere antibodies are different risk factors for the progression of primary biliary cirrhosis (PBC). In order to dissect the genetic basis for the production of these autoantibodies, as well as the development and progression of PBC in Japanese patients, we examined single nucleotide polymorphisms (SNPs) in cytotoxic T-lymphocyte antigen 4 (CTLA4) and solute carrier family 4 anion exchanger, member 2 (SLC4A2), which have been associated with the pathogenesis of PBC in Caucasian patients. METHODS: Four SNPs for both CTLA4 and SLC4A2 were genotyped, using the polymerase chain reaction-restriction fragment length polymorphism method and TaqMan assay, in 450 Japanese PBC patients and 371 sex-matched healthy controls. RESULTS: The CTLA4 rs231775, rs3087243, and rs231725 SNPs were significantly associated with PBC susceptibility. The CTLA4 rs231725 SNP was significantly associated with progression to late-stage disease. The CTLA-4 haplotype 1 (rs231775 G, rs231777 C, rs3087243 G, rs231725 A; GCGA) was a risk factor for PBC susceptibility but a protective factor for PBC progression. Conversely, the CTLA-4 haplotype 2 (ACAG) was a protective and risk factor, respectively, for PBC susceptibility and progression. In addition, the CTLA4 rs231777 SNP and haplotype 3 (ATGG) was significantly associated with anti-gp210 antibody production, while SLC4A2 haplotype 4 (rs2069443 A, rs2303933 G, rs2303937 A, rs2303941 T; AGAT) and haplotype 3 (AAGC) were significantly associated with PBC susceptibility and anti-centromere antibody production, respectively. CONCLUSIONS: CTLA4 and SLC4A2 genetic polymorphisms are differentially associated with PBC development and progression, as well as anti-gp210 or anti-centromere antibody production, in Japanese PBC patients.

Analysis of HLA-DRB1 polymorphisms in Japanese patients with primary biliary cirrhosis (PBC): The HLA-DRB1polymorphism determines the relative risk of antinuclear antibodies for disease progression in PBC.

AIMS: Anti-gp210 and anti-centromere antibodies are different risk factors for the progression of primary biliary cirrhosis (PBC). However, the association of human leukocyte antigen (HLA) polymorphisms with these risk factors is unknown. METHODS: We determined the HLA-DRB1 genotype in 334 Japanese PBC patients and studied their serum antibodies to gp210 and centromere during the 1-452-month observation period. RESULTS: Anti-gp210 (odds ratio [OR] 46.56, 95% confidence interval [CI], 9.20-850.1) and anti-centromere antibodies (OR, 2.36, 95% CI, 1.28-4.35) were significant risk factors for jaundice- and nonjaundice-type progression, respectively. HLA-DRB1*0405 and *0803 predisposed patients to anti-gp210 (OR, 1.61, 95% CI, 1.08-2.39) and anti-centromere (OR, 2.30, 95% CI, 1.41-3.73) antibody production, respectively. HLA-DRB1*1502 and *0901 patients were predisposed to nonjaundice-type progression (OR, 1.98, 95% CI, 1.13-3.40 and OR, 1.78, 95% CI, 1.02-3.03), while HLA-DRB1*0803 and *0405 patients were predisposed to disease development (OR, 2.24, 95% CI, 1.48-3.41 and OR, 1.53, 95% CI, 1.11-2.11, respectively). Stratifying patients by HLA-DRB1 alleles revealed that anti-gp210 antibodies was a strong risk factor, regardless of the HLA-DRB1 alleles for jaundice-type progression, while anti-centromere antibodies was a significant risk factor for nonjaundice-type progression in patients with HLA-DRB1*0405 (OR, 6.89, 95% CI, 2.18-26.56) and -DRB1*0803 (OR, 5.42, 95% CI, 1.47-24.62) but not other HLA-DRB1 alleles. CONCLUSIONS: HLA-DRB1 polymorphisms are significantly associated with not only disease development and progression but also antinuclear antibody production and the determination of the relative risk of antinuclear antibodies that contribute to PBC disease progression.