KIR-like activating natural killer cell receptors and their association with complicated malaria in north India.

Killer immunoglobulin-like receptors (KIRs) genomic regions have been suggested to influence malaria pathogenesis and infection susceptibility. KIRs are known as activating natural killer (NK) cell receptors, which upon binding to their corresponding human leukocyte antigen (HLA) ligands cause lysis of any infected cell. We have examined the potential association of KIR genes with complicated malaria (CM) among north Indians in this study and further evaluated the KIR receptor-HLA ligand association on the severity of the disease considering the uncomplicated malaria (UCM) subjects as control. Molecular profiling of KIR and HLA was carried out using the PCR-SSP method. Susceptible association was found for individuals possessing KIR2DS2 (OR=1.76, p-value=0.0390), KIR2DL1 (OR=2.87, p-value=0.0005) and KIR2DL3 (OR=2.74, p-value=0.0011) genes with CM. This was supported by the strong linkage disequilibrium observed for 2DS2-2DL2 (D́=0.87, r2=0.54) with CM. Whereas the receptor-ligand association has revealed risk association against KIR2DS2-HLAC1 (OR=2.08, p-value=0.0229), KIR2DL3-HLAC1 (OR=1.79, p-value=0.0301), and KIR2DL1-HLAC2 (OR=2.10, p-value=0.0175) combinations for complicated malaria. The frequency of different KIR genes are more or less similar to that observed in African population showing not much genetic diversity at KIR level in context to malarial infection. In conclusion, our data indicates KIR gene loci differentially influenced the malarial outcome in north Indians and in particular the KIR2DS2 gene appeared to be associated with disease severity.

Associations of killer cell immunoglobulin like receptors with rheumatoid arthritis among North Indian population.

INTRODUCTION: Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease of unknown etiology. Killer cell immunoglobulin-like receptors (KIR) expressed on surface of natural killer cells and CD28 null T-cells which are present in synovial membrane of RA. The present study has evaluated associations of KIR genes with RA among North Indian population from Uttar Pradesh. MATERIALS AND METHODS: KIR genotypes were determined in 100 RA cases and 100 healthy controls using sequence specific primer polymerase chain reaction (PCR-SSP) method. RESULTS: RA cases positive for KIR3DS1 (OR = 1.17, p-value = 0.0498) and KIR2DS2 (OR = 2.21, p-value = 0.0120) showed risk associations. While, KIR2DL2 (OR = 0.40, p-value = 0.0026), KIR2DL3 (OR = 0.44, p-value = 0.0283) and KIR3DL1 (OR=0.32, p-value = 0.0012) showed protective associations. Increased incidence of BB genotype (45%) was revealed among cases. Risk association was noted against telomeric region (OR = 2.12, p = 0.0120) genes for RA. Pair-wise linkage disequilibrium (LD) analysis among RA cases revealed KIR2DS1-2DL1 (D' = 0.83, r(2) = 0.36), KIR3DL1-3DS1 (D' = 1, r(2) = 0.58) and KIR2DL1-2DL2 (D' = 1, r(2)=0.61) to be in significant LD. KIR3DS1 and KIR2DS3 genes showed significant risk associations among RA patients with extra-articular manifestations (OR = 5.14, p-value = 0.0018; OR = 3.79, p-value = 0.0106) and in limited range of motion in affected joints (OR = 14.91, p-value = 0.0001; OR = 2.95, p-value=0.0126). CONCLUSION: The KIR activating genes have risk association with RA in the present study.

Identification of new primer binding site mutations at TH01 and D13S317 loci and determination of their corresponding STR alleles by allele-specific PCR.

Several commercial multiplex PCR kits for the amplification of short tandem repeat (STR) loci have been extensively applied in forensic genetics. Consequently, large numbers of samples have been genotyped, and the number of discordant genotypes observed has also increased. We observed allele dropout with two novel alleles at the STR loci TH01 and D13S317 during paternity testing using the AmpFℓSTR Identifiler PCR Amplification Kit. The lost alleles reappeared when alternative PCR primer pairs were used. A sequence analysis revealed a G-to-A substitution 82 bases downstream of the last TCAT motif of the repeat region at the TH01 locus (GenBank accession: D00269) and a G-to-T substitution 90 bases upstream of the first TATC motif of the repeat region at the D13S317 locus (GenBank accession: G09017). The frequencies of these two point mutations were subsequently investigated in the Chinese population using sequence-specific primer PCR (SSP-PCR), but neither of these mutations was detected in any of the samples tested. In addition, the DNA samples in which the mutations were identified were amplified to type the point mutations by SSP-PCR to determine the corresponding STR alleles at the two loci. Subsequently, the amplified PCR products with different point mutations and STR repeat numbers were directly sequenced because this strategy overcomes the appearance overlapping peaks generated by different STR alleles and accurately characterizes genotypes. Thus, our findings not only provide useful information for DNA databases and forensic identification but also establish an effective strategy for typing STR alleles with primer binding site mutations.

Association between disease susceptivity of chronic HBV infection and SNP G-944C in CⅡTA gene promoter Ⅳ / 第三军医大学学报

0.05). Conclusion The polymorphism of G-944C in CⅡTA gene promoter Ⅳ was associated with the susceptivity of chronic HBV infection, but was not associated with severity of diseases. The individuals with chronic HBV infection of CC genotype are of less possibility to develop chronic liver disease than those of other genotypes.

Research on genetic polymorphisms of HLA-DRB1 and DQB1 in the Hans of Zunyi / 中国免疫学杂志

Objective:To investigate frequencies and polymorphism of HLA-DRB1 and DQB1 allele in the Hans of Zunyi area.Methods:Polymerase chain reaction-sequence specific primers(PCR-SSP) were used to type HLA-DRB1 and DQB1 genes of 200 unrelated healthy Han individuals in Zunyi area.Results:13 HLA-DRB1 and 7 HLA-DQB1 alleles were obtained at low resolution level in all subjects.The allele DRB1*09,DRB1*08 and DQB1*05 were showed high distributing frequencies;The allele DRB1*10 and DQB1*04 were scarcely found with low distributing frequencies.Comparied with Northern and Southern Han people,it would seem that Han people in Zunyi are more closely related to the Southern ones.The allele B*07 was scarcely found in the Southern Han with a high distributing frequency(GF=2.0%).Conclusion:HLA-DRB1 and DQB1 of Han people in Zunyi have plenty of polymorphisms.They seem to distribute in line with the Southern Han's characteristics but have their own territory feature with a high B*07 frequency.