Mannose-binding lectin in severe acute respiratory syndrome coronavirus infection

Little is known about the innate immune response to severe acute respiratory syndrome (SARS) coronavirus (CoV) infection. Mannose-binding lectin (MBL), a key molecule in innate immunity, functions as an ante-antibody before the specific antibody response. Here, we describe a case-control study that included 569 patients with SARS and 1188 control subjects and used in vitro assays to investigate the role that MBL plays in SARS-CoV infection. The distribution of MBL gene polymorphisms was significantly different between patients with SARS and control subjects, with a higher frequency of haplotypes associated with low or deficient serum levels of MBL in patients with SARS than in control subjects. Serum levels of MBL were also significantly lower in patients with SARS than in control subjects. There was, however, no association between MBL genotypes, which are associated with low or deficient serum levels of MBL, and mortality related to SARS. MBL could bind SARS-CoV in a dose- and calcium-dependent and mannan-inhibitable fashion in vitro, suggesting that binding is through the carbohydrate recognition domains of MBL. Furthermore, deposition of complement C4 on SARS-CoV was enhanced by MBL. Inhibition of the infectivity of SARS-CoV by MBL in fetal rhesus kidney cells (FRhK-4) was also observed. These results suggest that MBL contributes to the first-line host defense against SARS-CoV and that MBL deficiency is a susceptibility factor for acquisition of SARS. © 2005 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio

Polymorphisms of PTPN11 coding SHP-2 as biomarkers for ulcerative colitis susceptibility in the Japanese population.

OBJECTIVE: To identify genetic determinants of inflammatory bowel disease (IBD), we examined an association between polymorphisms of both the programmed cell death 1 gene (PDCD1) and the src homology 2 domain-containing tyrosine phosphatase 2 gene (PTPN11) and susceptibility to IBD. METHODS: Study subjects comprised 114 patients with ulcerative colitis (UC), 83 patients with Crohn\u27s disease, and 200 healthy control subjects. Five single nucleotide polymorphisms (SNPs) in PDCD1 and PTPN11 were detected by polymerase chain reaction restriction fragment length polymorphism. Subsequently, haplotypes composed of the two SNPs in PTPN11 were constructed. RESULTS: The frequencies of the Hap 1 haplotype and its homozygous Hap 1/Hap 1 diplotype of PTPN11 were significantly increased in UC patients compared to control subjects (P = 0.011 and P = 0.030, respectively). While no association was found for PDCD1 for UC or CD and none for PTPN11 for CD. CONCLUSION: PTPN11 is a genetic determinant for the pathogenesis of UC, and haplotyping of PTPN11 may be useful as a genetic biomarker to identify high-risk individuals susceptible to UC

Analysis of a new potentially regulatory polymorphism in the PDCD1 gene in systemic lupus erythematosus

Poster no. 9

p21 gene polymorphisms in systemic lupus erythematosus

Objective. Cyclin-dependent kinase inhibitor 1A (p21) is a negative regulator in the cell cycle. Development of sex-linked lupus-like syndrome in p21 -/- mice and reduced p21 gene expression in patients with systemic lupus erythematosus (SLE) compared with those in healthy controls suggested that p21 is a susceptibility gene of SLE. We investigated the same by a case-control association study. Methods. Six single nucleotide polymorphisms, p21US G/A, p21DS C/A, p21-1022 G/A, p21C31 C/A, p21In2 G/C and p21UTR T/C, were genotyped in 516 SLE patients and 693 healthy controls. Association of genotypes and alleles with disease, disease phenotypes, haplotypes construction, linkage disequilibrium analysis and p21 mRNA expression were performed. Results. We found a significant association of p21US A allele (OR = 0.23, 95% CI: 0.14-0.38, P < 0.001) and p21-1022 A allele (OR = 1.95, 95% CI: 1.37-2.78, P < 0.001) with SLE. We identified significant differences in the frequencies of haplotypes ht1-A CACCC, which contains p21US A allele, and ht2-GC A CCC, which contains p21-1022 A allele, between SLE patients and controls (P < 0.0001). Besides, the p21US GA was associated with SLE patients suffering from arthritis (P = 0.003). We also observed differential p21 mRNA expressions among different genotypes of p21US and p21-1022 which were statistically significant. Conclusion. Our results suggested that the p21US A allele and p21-1022 A allele were both associated with the development of SLE, and the p21US A allele was associated with arthritis in SLE patients. © 2007 Oxford University Press.link_to_OA_fulltex