Biomedical subjects

Li-An Fan

Publications and source records attributed to Li-An Fan.

3 recordsLinked to original sources

PubMed2004

[A genomewide scan for the susceptibility gene loci to ankylosing spondylitis in Chinese Han population].

Ankylosing spondylitis (AS) is a common inflammatory arthritis, with a prevalence of 1@1000-3@1000 in Caucasian and 2@1000 in Chinese population. The recognition of the association of HLA-B27 with AS confirmed the importance of heritable factors in the disease. Whole-genome scans showed that some affected-sibling-pair families with AS not only demonstrated strong linkage to the MHC locus, but also identified other regions with suggestive or stronger linkage on chromosomes 1p, 2q, 9q, 10q, 16q and 19q. In order to localize the regions containing genes that determine susceptibility to AS in Chinese Han population, a genomewide screen was performed in nine Chinese families with AS, including 29 affected individuals. LINKAGE and GENEHUNTER packages were used for parametric (LOD) and non-parametric (NPL) analysis. The significant two-point LOD score value with D6S276 (at 44.9 cM from the 6p terminal) was 3.8821 in parametric analysis. Fine mapping showed LOD scores of D6S1691 (at 42.7 cM) and D6S1618 (at 47.6 cM) around D6S276 were 1.5717 and 2.0056, respectively. Single point NPL score of D6S276, D6S1691 and D6S1618 were 2.6053, 2.7490, 2.0202, respectively, and minimum P value were 0.0072, 0.0047, and 0.0265, respectively. Using multipoint NPL, the maximum LOD score values, NPL score and minimum P value obtained near D6S276 were 5.0623, 3,7561, and 0.000233, respectively. As a result, the strong linkage of the D6S276 with AS was found, the region of D6S1691-D6S276-D6S1618 existed a susceptibility gene of AS. In addition, the LOD scores of D3S1292, D4S1535 and D18S64 were larger than 1.0, so they might be some suggestive linkage markers with AS.

China↗

PubMed2004

[Analysis on HLA-E polymorphism in Guangdong Han population].

To investigate the distribution of HLA-E alleles and linkage between HLA-E and HLA-A or -B loci in Chinese Han in Guangdong area, HLA-E alleles were detected by using PCR-SSP in 150 unrelated healthy individuals from Guangzhou area; HLA-A, -B antigens typing in 106 individuals was carried out with NIH standard microlymphocytoxic method. Analysis of linkage was performed between HLA-E and HLA-A, -B. The results showed that three alleles of HLA-E could be detected in this population. They are E * 0101, E * 01031, E * 01032, with the frequency of 45.33%, 32.33%, 22.33% respectively. No E * 0102 and E * 0104 could be detected in all of these individuals. The analysis of linkage on two loci between HLA-E and HLA-A or -B showed that no significant difference could be found between expected frequencies and observed frequencies except B15/E * 01032 and A2/E * 01032. In conclusion, the high conservative polymorphism of HLA-E suggests that it's biological characteristic is different from that of classical HLA class Ia molecules.

Alleles↗

PubMed2003

[Expression of human KIR2DL1-Ig fusion protein in COS-7 cells].

AIM: To express, purify and identify the KIR2DL1-IgG Fc fusion protein. METHODS: Extracellular region of KIR2DL1 cDNA was amplified by RT-PCR from peripheral blood mononuclear cells, and cloned this fragment into fusion expression vector CD5lnegl. The recombinant vector CD5lnegl-KIR2DL1 was obtained after restriction endonuclease digestion and sequencing. COS-7 cells were transfected with this eukaryotic expression vector CD5lnegl-KIR2DL1 constructed in our Laboratory through DEAE-dextran/chloroquine method. The expressed KIR2DL1-IgGFc fusion protein in COS-7 cell culture surpernatant was identified by ELISA with mAb EB6 and HRP-anti-hIgFc mAb and Western blot. RESULTS: Restriction endonuclease digestion and sequencing indicated that the CD5lnegl-KIR2DL1 had been constructed successfully. The fusion protein could be detected by ELISA in COS-7 cell culture surpernatant. Western blot analysis also showed that the fusion protein could react to both EB6 and anti-hIgFc mAb. There was only one specific band at the position of the relative molecular mass (M(r)) 73 000, and it was equivalent to the expected value. CONCLUSION: KIR2DL1-IgG Fc fusion protein expressed in COS-7 cells successfully and the protein can mimic the natural KIR2DL1 protein and is used as a potential tool in the recognition of its ligands.

Animals↗