Characterizing alleles with large deletions using region specific extraction.

Two novel HLA class II alleles, DRB4*03:01N and DQB1*03:276N, containing large deletions were identified during routine typing. Extraction of DNA encompassing the deletions was carried out with a panel of capture oligonucleotides followed by whole genome amplification. Next generation DNA sequencing was then used to characterize the sequences.

Allelic variation of killer cell immunoglobulin-like receptor 2DS5 impacts glycosylation altering cell surface expression levels.

Natural killer cell stimulatory receptor gene, KIR2DS5, is polymorphic. While KIR2DS5*002 is most frequently observed, other alleles have also been found. The proteins encoded by these alleles (KIR2DS5*002-*009) are expressed at varying levels on the surface of NKL and Jurkat transfectants.

Extracellular domain alterations impact surface expression of stimulatory natural killer cell receptor KIR2DS5.

In the human killer cell immunoglobulin-like receptors, KIR2DL2, and KIR2DL3, a triad of amino acids in the D1 domain interact to stabilize protein structure. Substitution of any one of these residues caused significant loss of cell surface expression. Although KIR2DS4 and KIR2DS5, two homologous receptors, differ for this triad, flow cytometry analysis of NK and T cell lines transfected with stimulatory KIR genes KIR2DS4 (allele *001) and KIR2DS5 (allele *002) demonstrated cell surface expression.

Promoter variants of KIR2DL5 add to diversity and may impact gene expression.

Sequencing of polymerase chain reaction (PCR)-amplified genomic DNA encompassing the putative proximal promoter and the coding region was used to identify KIR2DL5 alleles from 77 unrelated Caucasian individuals. PCR and sequencing were used to link each new allele to its neighboring KIR locus to identify 2DL5A or 2DL5B loci. Allele 2DL5A*001 was found in 24 of the 37 2DL5 positive individuals; 2DL5B*0020101 and 2DL5A*0050101 were also observed.

Limited allelic diversity of stimulatory two-domain killer cell immunoglobulin-like receptors.

Genomic sequencing was used to characterize most of the coding regions of the five two-domain stimulatory killer cell immunoglobulin-like receptor (KIR) loci from 80 unrelated, primarily Caucasian, individuals. Specific loci were present in from 26% (KIR2DS3) to 98% (KIR2DS4) of individuals. The number of known alleles present varied from one (KIR2DS1, KIR2DS5) to five (KIR2DS4).

Three common alleles of KIR2DL4 (CD158d) encode constitutively expressed, inducible and secreted receptors in NK cells.

Genetic polymorphism of KIR2DL4 results in alleles with either 9 or 10 consecutive adenines in exon 6, which encodes the transmembrane domain. "10A" alleles encode a membrane-expressed receptor that is constitutively expressed on resting CD56bright NK cells and on CD56dim cells after culture. However, in some individuals with the 10A allele, KIR2DL4 cannot be detected on their resting CD56bright NK cells.