Allelic polymorphism, mRNA and antigen expression of KIR2DL1 in the Chinese Han population

Dual effects of natural killer cells in transplantation for leukemia

Natural killer (NK) cells were originally considered to belong to the innate immune system to play a protective role against tumor cells and viral infections. In human, they can recognize self and non-self HLA class 1 as their ligand. So, analyzing the outcomes of allogeneic hematopoietic stem cell transplantation is a good opportunity to know the antitumor effects and regulatory effects of NK cells through HLA class 1 matching and mismatching of donor and recipient. In this review, I looked back on the main analysis results of the past transplants, summarized our reports consisting of many cases in a single ethnic, and showed that NK cells might work oppositely depending on the type of leukemia. New treatment strategies based on these concepts may offer individualized treatment options and ultimately increase offer the possibility of a cure for patients with leukemia.

Single Nucleotide Polymorphism in KIR2DL1 Is Associated With HLA-C Expression in Global Populations

Regulation of NK cell activity is mediated through killer-cell immunoglobulin-like receptors (KIR) ability to recognize human leukocyte antigen (HLA) class I molecules as ligands. Interaction of KIR and HLA is implicated in viral infections, autoimmunity, and reproduction and there is growing evidence of the coevolution of these two independently segregating gene families. By leveraging KIR and HLA-C data from 1000 Genomes consortium we observed that the KIR2DL1 variant rs2304224 ^* T is associated with lower expression of HLA-C in individuals carrying the ligand HLA-C2 (p = 0.0059). Using flow cytometry, we demonstrated that this variant is also associated with higher expression of KIR2DL1 on the NK cell surface (p = 0.0002). Next, we applied next generation sequencing to analyze KIR2DL1 sequence variation in 109 Euro and 75 Japanese descendants. Analyzing the extended haplotype homozygosity, we show signals of positive selection for rs4806553 ^* G and rs687000 ^* G, which are in linkage disequilibrium with rs2304224 ^* T. Our results suggest that lower expression of HLA-C2 ligands might be compensated for higher expression of the receptor KIR2DL1 and bring new insights into the coevolution of KIR and HLA.

The novel KIR2DL1*00602 allele identified in an individual from a southern Chinese Han population

KIR2DL1*00602 differs from KIR2DL1*00302 by a non-synonymous mutation in exon 7.

Identification and characterization of the novel KIR2DL1*030 allele by sequence-based typing in a southern Chinese Han individual

KIR2DL1*030 differs from KIR2DL1*00302 by a single non-synonymous mutation in exon 4.

Allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population

KIR2DL2 and KIR2DL3 segregate as alleles of the same killer cell immunoglobulin-like receptor (KIR) gene locus. They have been associated with viral infectious diseases and certain cancers and their allelic information may help to better comprehend mechanisms. The allelic polymorphism of KIR2DL2/2DL3 has been shown to influence their binding specificity and affinity to the HLA-C1 ligands. The present study aims to investigate the distribution of the allelic polymorphism of KIR2DL2/2DL3 in a southern Chinese population using sequence-specific primer polymerase chain reaction (PCR-SSP) and PCR-sequence-based typing (SBT) at the entire coding sequence. Of the 306 tested individuals, 1.96% were positive for KIR2DL2 only, 78.10% for KIR2DL3 only, and 19.93% for both KIR2DL2 and 2DL3. KIR2DL3 showed a high degree of diversity in the study population with 15 alleles detected including 8 novel ones. The predominant 2DL3 allele in the study population is 2DL3*00101 (92.81%) followed by 2DL3*00201 (24.18%), 2DL3*023 (4.25%), and 2DL3*00109 (1.31%). The remaining 11 2DL3 alleles all had a frequency below 1%. Three detected 2DL2 alleles were 2DL2*00301 (18.95%), 2DL2*00101 (3.59%), and the novel 2DL2*013 (0.33%). These results provide further insight into the KIR gene diversity in Southern Chinese and may help to better understand the role played by KIR genes in associated diseases.