MICA polymorphism identified by whole genome array associated with NKG2D-mediated cytotoxicity in T-cell large granular lymphocyte leukemia.
BACKGROUND
Large granular lymphocyte leukemia is a semi-autonomous clonal proliferation of cytotoxic T cells accompanied by immune cytopenias and various autoimmune conditions. Due to the rarity of this disease and its association with autoimmune diseases, a theoretical germline or somatic mutation might have significant penetrance, thus enabling detection, even from samples of suboptimal size, through genome-wide association studies.


METHODS
To investigate a non-mendelian genetic predisposition to large granular lymphocyte leukemia, we used a step-wise method for gene discovery. First, a modified 'random forests' technique was used for candidate gene identification: this was followed by traditional allele-specific polymerase chain reaction, sequencing modalities, and mechanistic assays.


RESULTS
Our analysis found an association with MICA, a non-peptide-presenting, tightly regulated, stress-induced MHC-like molecule and cognate receptor for NKG2D, found abundantly on large granular lymphocyte leukemia cells. Sequencing of germline DNA revealed a higher frequency of MICA*00801/A5.1 in patients with large granular lymphocyte leukemia than in matched controls (64% versus 41%, P<0.001, homozygous 40% versus 15%, P<0.001). Flow cytometry was employed to determine the expression of MICA within hematologic compartments, showing that the signal intensity of MICA was increased in granulocytes from neutropenic patients with large granular lymphocyte leukemia in comparison with that in controls (P=0.033). Furthermore, neutrophil counts were inversely correlated with MICA expression (R(2)=0.50, P=0.035). Finally, large granular lymphocyte leukemia cells were able to selectively kill MICA(+) Ba/F3 lymphocytes transfected with human MICA*019 in a dose-dependent manner compared to naïve cells (P<0.001), an effect mitigated by administration of an anti-NKG2D antibody (P=0.033).


CONCLUSIONS
Our results illustrate that MICA-NKG2D played a role in disease pathogenesis in the majority of patients in our cohort of cases of large granular lymphocyte leukemia and further investigation into this signaling axis may provide potent therapeutic targets.
Viny
Aaron D
AD
Department of Translational Hematologic and Oncologic Research, Taussig Cancer Center R/40, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio, USA.
Clemente
Michael J
MJ
Jasek
Monika
M
Askar
Medhat
M
Ishwaran
Hemant
H
Nowacki
Amy
A
Zhang
Aiwen
A
Maciejewski
Jaroslaw P
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003602:Cytotoxicity, Immunologic; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D054066:Leukemia, Large Granular Lymphocytic / Q000209:etiology* / Q000235:genetics / Q000276:immunology; D008297:Male; D008875:Middle Aged; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000235:genetics*; D011110:Polymorphism, Genetic
D015395:Histocompatibility Antigens Class I; C527085:KLRK1 protein, human; C099187:MHC class I-related chain A; D055655:NK Cell Lectin-Like Receptor Subfamily K
Allergy. 1979 Oct;34(5):275-81
121045
Blood Rev. 1999 Dec;13(4):230-40
10741898
Hematology. 2003 Jun;8(3):173-81
12745651
J Clin Pathol. 1998 Sep;51(9):672-5
9930071
Immunogenetics. 2002 Feb;53(10-11):989-91
11862400
Hum Immunol. 2001 Jun;62(6):632-8
11390038
Arthritis Rheum. 1997 Apr;40(4):624-6
9125243
Scand J Immunol. 2007 Aug-Sep;66(2-3):320-8
17635809
Blood. 2005 Oct 15;106(8):2769-80
15914562
J Virol. 2008 May;82(9):4585-94
18287244
Blood. 2001 Jul 15;98(2):483-5
11435321
Blood. 2009 Apr 2;113(14):3226-34
19075187
Nature. 2002 Oct 17;419(6908):734-8
12384702
J Immunol. 2004 Feb 1;172(3):1960-9
14734782
Eur J Immunol. 2007 Jul;37(7):1938-53
17557375
J Immunol. 2004 Aug 15;173(4):2470-8
15294961
Leuk Lymphoma. 2008 May;49(5):932-8
18452068
Cell Cycle. 2006 Nov;5(22):2571-4
17172839
Hum Immunol. 2001 Jun;62(6):620-31
11390037
J Immunol. 2006 Sep 1;177(5):3143-9
16920952
J Biol Chem. 2007 Oct 19;282(42):30658-66
17690100
Curr Top Microbiol Immunol. 2006;298:121-38
16329186
Genes Immun. 2004 Aug;5(5):371-4
15164101
J Immunol. 2007 Jan 15;178(2):961-9
17202358
J Rheumatol. 2002 May;29(5):973-8
12022360
Ann Intern Med. 1985 Feb;102(2):169-75
3966754
Ann N Y Acad Sci. 2003 Nov;1005:314-8
14679082
Immunogenetics. 1999 Jul;49(7-8):605-12
10369917
J Gen Virol. 2007 Jan;88(Pt 1):242-250
17170457
Science. 1999 Jul 30;285(5428):727-9
10426993
Immunity. 2001 Jul;15(1):83-93
11485740
Blood. 2006 Jun 15;107(12):4834-40
16484592
Br J Haematol. 2007 Jan;136(2):237-48
17156396
Blood. 1997 Jan 1;89(1):256-60
8978299
Br J Haematol. 2003 Nov;123(3):449-53
14617004
Am J Med. 2000 Jun 15;108(9):744-5
10924655
Biotechniques. 2003 Oct;35(4):758-60, 762-5
14579741
Blood. 2008 Feb 1;111(3):1610-6
17993614
J Immunol. 2002 Aug 1;169(3):1236-40
12133944
Transpl Immunol. 2005 Aug;14(3-4):175-82
15982560
Oral Oncol. 2007 Mar;43(3):232-40
16857416
Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2971-6
11854468
Cancer Res. 2005 Aug 15;65(16):7502-8
16103105
Crit Rev Immunol. 1990;10(4):307-28
2285459
Nat Immunol. 2001 Mar;2(3):255-60
11224526
Blood. 1988 Mar;71(3):822-4
3345349
J Clin Invest. 2001 Feb;107(3):351-62
11160159