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KIR genotype lacking of some conserved genes
Abstracts
S23
2 21-P
KIR GENOTYPE LACKING OF SOME CONSERVED GENES M.R. Uribe,1 S. Adams,2 E. Pae,3 D. Stroncek,4 F. Marincola5, 1DTM-HLA Lab, NIH, Bethesda, MD, USA; 2Fenway Community Health Center KIR genotyping is performed in our laboratory using a commercial low resolution PCR-SSP method. Cell lines from the 10th International Workshop were used to validate this test prior to implementation. KIR haplotypes differ in the number and type of genes present. Genes KIR3DL3 and KIR3DL2 on the centromeric and telomeric ends respectively, and KIR 3DP1-KIR2DL4 in the central region are present on virtually all haplotypes and have therefore been termed framework genes. To date we have performed more than 100 KIR genotypes. Recently we discovered a KIR genotype from an HIV infected patient that was lacking of KIR 3DL1/KIR3DS1, and two of the frame work genes, KIR2DL4 and KIR3DP1. We hypothesize that this genotype is the result of truncated KIR haplotypes that were produced by a non-reciprocal recombination event. Recently a new allele KIR3DP1*004 that associates with gene duplications of KIR3DP1, KIR2DL4, and KIR3DL1/KIR3DS1 was described. Non-reciprocal recombination has been postulated as the event that generated the haplotype containing a region of three duplicated genes. Two haplotypes with very different gene content resulted from this event; one containing duplicated genes, and one lacking of otherwise conserved genes. Rare KIR haplotypes, where some conserved genes are absent, have also been described previously in three other healthy individuals when performing population studies. The frequency of KIR haplotypes lacking of KIR3DL1/KIR3DS1, KIR2DL4 and KIR3DP1 may be higher than described, since these events have been detected when performing genotype testing, where only homozygous haplotypes with deleted genes can be detected. Further characterization of truncated KIR haplotypes may help to elucidate any functional consequences associated with this event.
2 22-P
KIR GENE CONTENT AND HIV PROGRESSION M.R. Uribe,1 S. Adams,1 L. Shupert,2 D. Stroncek,1 M. Connors,2 F. Marincola1, 1DTM HLA Lab., NIH, Bethesda, MD, USA; 2NIAID, NIH Several clinical correlations reported point to the importance of the KIR receptors in viral infections. We performed SSP-PCR low resolution KIR genotyping in 48 HIV⫹ individuals; 26 long term nonprogressors, or slow progressors (LTNP/SP) and 22 progressors(P). Seventy five percent were predetermined to be HLA- B57 (17 LTNP/SP, and 19 P ).HLA typing was performed by low resolution SSP-PCR. Data obtained was analyzed for association with KIR gene content (group A /B haplotypes), and presence of individual activating KIR genes with the corresponding HLA-KIR ligands. We found that 69% of the LTNP/SP had KIR genotypes with two or more stimulatory KIR genes (group B haplotypes), while only 45% of the progressors were in this group (table 1). No significant association was observed with individual activating genes and disease progression (table 2). Since individual NK clones express different activating and inhibitory KIRs, we hypothesize that individuals with several activating KIR genes have a higher probability of expressing them on any given NK cell than individuals with fewer activating KIRs. It is important to perform KIR genotyping at the allele level, since variation in gene content and allelic diversity may affect NK cell function. HLA-B57 allele typing will be informative to elucidate any additional correlation. TABLE 1 Disease Progression LTNP/SP P Total TABLE 2
Group A Haplotypes 8 (31%) 12 (55%) 20
Group B Haplotypes 18 (69%) 10 (45%) 28
Total 26 22 48
Disease Progression
KIR2DS1
KIR2DS2
KIR2DS3
KIR2DS4
KIR2DS5
KIR3DS1
LTNP/SP (HLA ligand) P (HLA ligand)
50% 13/26 (11/13) 27% 6/22 (5/6)
46% 12/26 (11/12) 36% 8/22 (7/8)
23% 6/26 (?) 27% 6/22 (?)
88%23/26 (1/23) 91%20/22 (2/ 20)
42%11/26 (?) 27%6/22 (?)
42% 11/26 (11/11) 27% 6/22 (5/6)
S23
2 21-P
KIR GENOTYPE LACKING OF SOME CONSERVED GENES M.R. Uribe,1 S. Adams,2 E. Pae,3 D. Stroncek,4 F. Marincola5, 1DTM-HLA Lab, NIH, Bethesda, MD, USA; 2Fenway Community Health Center KIR genotyping is performed in our laboratory using a commercial low resolution PCR-SSP method. Cell lines from the 10th International Workshop were used to validate this test prior to implementation. KIR haplotypes differ in the number and type of genes present. Genes KIR3DL3 and KIR3DL2 on the centromeric and telomeric ends respectively, and KIR 3DP1-KIR2DL4 in the central region are present on virtually all haplotypes and have therefore been termed framework genes. To date we have performed more than 100 KIR genotypes. Recently we discovered a KIR genotype from an HIV infected patient that was lacking of KIR 3DL1/KIR3DS1, and two of the frame work genes, KIR2DL4 and KIR3DP1. We hypothesize that this genotype is the result of truncated KIR haplotypes that were produced by a non-reciprocal recombination event. Recently a new allele KIR3DP1*004 that associates with gene duplications of KIR3DP1, KIR2DL4, and KIR3DL1/KIR3DS1 was described. Non-reciprocal recombination has been postulated as the event that generated the haplotype containing a region of three duplicated genes. Two haplotypes with very different gene content resulted from this event; one containing duplicated genes, and one lacking of otherwise conserved genes. Rare KIR haplotypes, where some conserved genes are absent, have also been described previously in three other healthy individuals when performing population studies. The frequency of KIR haplotypes lacking of KIR3DL1/KIR3DS1, KIR2DL4 and KIR3DP1 may be higher than described, since these events have been detected when performing genotype testing, where only homozygous haplotypes with deleted genes can be detected. Further characterization of truncated KIR haplotypes may help to elucidate any functional consequences associated with this event.
2 22-P
KIR GENE CONTENT AND HIV PROGRESSION M.R. Uribe,1 S. Adams,1 L. Shupert,2 D. Stroncek,1 M. Connors,2 F. Marincola1, 1DTM HLA Lab., NIH, Bethesda, MD, USA; 2NIAID, NIH Several clinical correlations reported point to the importance of the KIR receptors in viral infections. We performed SSP-PCR low resolution KIR genotyping in 48 HIV⫹ individuals; 26 long term nonprogressors, or slow progressors (LTNP/SP) and 22 progressors(P). Seventy five percent were predetermined to be HLA- B57 (17 LTNP/SP, and 19 P ).HLA typing was performed by low resolution SSP-PCR. Data obtained was analyzed for association with KIR gene content (group A /B haplotypes), and presence of individual activating KIR genes with the corresponding HLA-KIR ligands. We found that 69% of the LTNP/SP had KIR genotypes with two or more stimulatory KIR genes (group B haplotypes), while only 45% of the progressors were in this group (table 1). No significant association was observed with individual activating genes and disease progression (table 2). Since individual NK clones express different activating and inhibitory KIRs, we hypothesize that individuals with several activating KIR genes have a higher probability of expressing them on any given NK cell than individuals with fewer activating KIRs. It is important to perform KIR genotyping at the allele level, since variation in gene content and allelic diversity may affect NK cell function. HLA-B57 allele typing will be informative to elucidate any additional correlation. TABLE 1 Disease Progression LTNP/SP P Total TABLE 2
Group A Haplotypes 8 (31%) 12 (55%) 20
Group B Haplotypes 18 (69%) 10 (45%) 28
Total 26 22 48
Disease Progression
KIR2DS1
KIR2DS2
KIR2DS3
KIR2DS4
KIR2DS5
KIR3DS1
LTNP/SP (HLA ligand) P (HLA ligand)
50% 13/26 (11/13) 27% 6/22 (5/6)
46% 12/26 (11/12) 36% 8/22 (7/8)
23% 6/26 (?) 27% 6/22 (?)
88%23/26 (1/23) 91%20/22 (2/ 20)
42%11/26 (?) 27%6/22 (?)
42% 11/26 (11/11) 27% 6/22 (5/6)