Killer Immunoglobulin-like Receptors (KIR) haplogroups A and B track with Natural Killer Cells and Cytokine Profile in Aged Subjects: Observations from Octo/Nonagenarians in the Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST)

Immunity & Ageing

Owen A Ross⁶  Derek Middleton²  Martin D Curran⁵  H Denis Alexander⁴  Susan E McNerlan⁷  Lynn D Maxwell³  Irene Maeve Rea¹ 

[1] School of Medicine, Dentistry and Biomedical Science Queens University, Belfast, UK;Transplantation Centre, Liverpool, UK;Immunology and Microbiology Laboratory, Belfast Health and Social Care Trust, Belfast, UK;School of Biomedical Science, University of Ulster, Coleraine, UK;Molecular Diagnostic Microbiology Section, Health Protection Agency, Addenbrookes Hospital, Cambridge, UK;Mayo Clinic Jacksonville, Jacksonville, FL, USA;Cytogenetics Laboratory, Belfast Health and Social Care Trust, Belfast, UK

关键词: TNF-α;    sIL-2R;    Active TGF-β;    IL-10;    IL-12p40;    IL-12;    IL-6;    Cytokines;    KIR A and B haplotypes;    BELFAST octo/nonagenarians;    Ageing;   

Others  :  814243
DOI  :  10.1186/1742-4933-10-35

 received in 2013-03-15, accepted in 2013-08-10,  发布年份 2013

【 摘 要 】

Background

Natural Killer Cells (NK) play an important role in detection and elimination of virus-infected, damaged or cancer cells. NK cell function is guided by expression of Killer Immunoglobulin-like Receptors (KIRs) and contributed to by the cytokine milieu. KIR molecules are grouped on NK cells into stimulatory and inhibitory KIR haplotypes A and B, through which NKs sense and tolerate HLA self-antigens or up-regulate the NK-cytotoxic response to cells with altered HLA self-antigens, damaged by viruses or tumours. We have previously described increased numbers of NK and NK-related subsets in association with sIL-2R cytokine serum levels in BELFAST octo/nonagenarians. We hypothesised that changes in KIR A and B haplotype gene frequencies could explain the increased cytokine profiles and NK compartments previously described in Belfast Elderly Longitudinal Free-living Aging STudy (BELFAST) octo/nonagenarians, who show evidence of ageing well.

Results

In the BELFAST study, 24% of octo/nonagenarians carried the KIR A haplotype and 76% KIR B haplotype with no differences for KIR A haplogroup frequency between male or female subjects (23% v 24%; p=0.88) or for KIR B haplogroup (77% v 76%; p=0.99). Octo/nonagenarian KIR A haplotype carriers showed increased NK numbers and percentage compared to Group B KIR subjects (p=0.003; p=0.016 respectively). There were no KIR A/ B haplogroup-associated changes for related CD57+CD8 (^{high or low}) subsets. Using logistic regression, KIR B carriers were predicted to have higher IL-12 cytokine levels compared to KIR A carriers by about 3% (OR 1.03, confidence limits CI 0.99–1.09; p=0.027) and 14% higher levels for TGF-β (active), a cytokine with an anti-inflammatory role, (OR 1.14, confidence limits CI 0.99–1.09; p=0.002).

Conclusion

In this observational study, BELFAST octo/nonagenarians carrying KIR A haplotype showed higher NK cell numbers and percentage compared to KIR B carriers. Conversely, KIR B haplotype carriers, with genes encoding for activating KIRs, showed a tendency for higher serum pro-inflammatory cytokines compared to KIR A carriers. While the findings in this study should be considered exploratory they may serve to stimulate debate about the immune signatures of those who appear to age slowly and who represent a model for good quality survivor-hood.

【 授权许可】

   
2013 Rea et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

【 参考文献 】

• [1]Evert J, Lawler E, Bogan H, Perls T: Morbidity profiles of centenarians: survivors, delayers, and escapers. J Gerontol A Biol Sci Med Sci 2003, 58:232-237.
• [2]Farag SS, Fehniger TA, Ruggeri L, Velardi A, Caligiuri MA: Natural killer cell receptors: new biology and insights into the graft-versus-leukemia effect. Blood 2002, 100:1935-1947.
• [3]Be’ziat V, Duffy D, Nguyen Quoc S, Le Garff-Tavernier M, Decocq J, Combadie’re B, Debre P, Vieillard V: CD56brightCD16+ NK cells: a functional intermediate stage of NK cell differentiation. J Immunol 2011, 186:6753-61. Epub 2011 May 9
• [4]Jacobs R, Hintzen G, Kemper A, Beul K, Kempf S, Behrens G, Sykora KW, Schmidt RE: CD56bright cells differ in their KIR repertoire and cytotoxic features from CD56dim NK cells. Eur J Immunol 2001, 31:3121-3127.
• [5]Tamura H, Ogata K: Natural killer cells and human longevity, chapter 27. In Handbook on immunosenesence: basic understanding and clinical applications. Edited by Fulop T, Franceschi C, Hirokawa K, Pawelec G. Netherlands: Springer; 2009:545-561. http://dx.doi.org/10.1007/978-1-4020-9063-9 webcite. ISBN 978-1-4020-9062-2. e-ISBN: 978-1-4020-9063-9
• [6]Robertson MJ, Ritz J: Biology and clinical relevance of human natural killer cells. Blood 1990, 76:2421-2438.
• [7]Phillips JH, Lanier LL: A model for the differentiation of human natural killer cells: studies on the in vitro activation of Leu-11_ granular lymphocytes with a natural killer-sensitive tumor cell, K562. J Exp Med 1985, 161:1464-1482.
• [8]Chattopadhyay PK, Betts MR, Price DA, Gostick E, Horton H, Roederer M, De Rosa SC: The cytolytic enzymes granyzme a, granzyme B, and perforin: expression patterns, cell distribution, and their relationship to cell maturity and bright CD57 expression. J Leukoc Biol 2009, 85:88-97.
• [9]Lopez-Verges S, Milush JM, Pandey S, Norris P, Nixon D, Lanier LLL: CD57 Defines a functionally unique subset of NK cells in humans. J Immunol 2009, 182:134.1.
• [10]Lopez-Verge’s S, Milush JM, Pandey S, York VA, Arakawa-Hoyt J, Pircher H, Norris PJ, Nixon DF, Lanier LL: CD57 Defines a functionally distinct population of mature NK cells in the human CD56dimCD16_ NK-cell subset. Blood 2010, 116:3865-3873.
• [11]Björkström NK, Riese P, Heuts F, Andersson S, Fauriat C, Ivarsson MA, Björklund AT, Flodström-Tullberg M, Michaëlsson J, Rottenberg ME, Guzmán CA, Ljunggren HG, Karl-Johan Malmberg KJ: Expression patterns of NKG2A, KIR and CD57 define a process of CD56 dim NKcell differentiation uncoupled from NK-cell education. Blood 2010, 116:3853-3864.
• [12]Wang EC, Taylor-Wiedeman J, Perera P, Fisher J, Borysiewicz LK: Subsets of CD8+, CD57+ cells in normal, healthy individuals: correlations with human cytomegalovirus (HCMV) carrier status, phenotypic and functional analyses. Clin Exp Immunol 1993, 94:297-305. PMCID: PMC1534246
• [13]Harel-Bellan A, Quillet A, Marchiol C, DeMars R, Tursz T, Didier Fradelizi D: Natural killer susceptibility of human cells may be regulated by genes in the HLA region on chromosome 6. Proc Nat Acad Sci 1986, 83:5688-5692.
• [14]Moretta A, Bottino C, Pende D, Tripodi G, Tambussi G, Viale O, Orengo A, Barbaresi M, Merli A, Ciccone E: Identification of four subsets of human CD3–CD16+ NK cells by the expression of clonally distributed functional surface molecules. Correlation between subset assignment of NK clones and ability to mediate specific alloantigen recognition. J Exp Med 1990, 172:1589-1598.
• [15]Moretta L, Moretta A: Killer immunoglobulin-like receptors. Curr Opin Immunol 2004, 16:626-633. PMID: 15342010
• [16]Hsu KC, Liu XR, Selvakumar A, Mickelson E, O’Reilly RJ, Dupont B: Killer Ig-like receptor haplotype analysis by gene content: evidence for genomic diversity with a minimum of six basic framework haplotypes, each with multiple subsets. J Immunol 2002, 169:5118-5129. PMID: 12391228
• [17]Carrington M, Martin MP: The impact of variation at the KIR gene cluster on human disease. Curr Top Microbiol Immunol 2006, 298:225-257.
• [18]Hicklin DJ, Marincola FM, Ferrone S: HLA class I antigen down-regulation in human cancers: T-cell immunotherapy revives an old story. Mol Med Today 1999, 5:178-186.
• [19]Purdy AK, Campbell KS: Natural killer cells and cancer: regulation by the killer cell Ig-like receptors (KIR). Cancer Biol Ther 2009, 8:2211-2220. Epub 2009 Dec 28
• [20]Hsu KC, Dupont B: Natural killer cell receptors: regulating innate immune responses to hematologic malignancy. Semin Hematol 2005, 42:91-103.
• [21]Hollenbach JA, Augusto DG, Alaez C, Bubnova L, Fae I, Fischer G, Gonzalez-Galarza FF, Gorodezky C, Karabon L, Kusnierczyk P, Noble J, Richards O, Roberts C, Schafffer M, Shi L, Tavoularis S, Trachtenberg E, Yao Y, Middleton D: 16th IHIW: population global distribution of killer immunoglobulin-like receptor (KIR) and ligands. I J immunogenetics 2012, 40:39-45.
• [22]Martin AM, Kulski JK, Gaudieri S, Witt CS, Freitas EM, Trowsdale J, Christiansen FT: Comparative genomic analysis, diversity and evolution of two KIR haplotypes a and B. Gene 2004, 333:121-131. PMID: 15194195 NKref0328
• [23]Middleton D, Gonzelez F: The extensive polymorphism of KIR genes. Immunol 2009, 129:8-19.
• [24]McNerlan SE, Rea IM, Alexander HD, Morris TCM: Changes in natural killer cells, the CD8+CD57+ subset and related cytokines in healthy aging. J Clin Immunol 1998, 18:31-38.
• [25]Rea IM, Stewart M, Campbell P, Alexander HD, Morris TCM: Changes in lymphocyte subsets, interleukin 2 and soluble interleukin 2 receptor in old and very old age. Gerontol 1996, 42:69-78.
• [26]Rea IM, Rea S: Super Vivere: Reflections on Long Life and Ageing Well. Belfast, UK: Blackstaff Press Ltd; 2011.
• [27]Rea IM: BELFAST nonagenarians: nature or nurture? Immunological, cardiovascular and genetic factors. Immunity & Ageing 2010, 7:6. BioMed Central Full Text
• [28]Solana R, Mariani E: NK and NK/T cells in human senescence. Vaccine 2000, 18:1613-1620.
• [29]Lutz CT, Quinn LBS: Sarcopenia, obesity, and natural killer cell immune senescence in aging: Altered cytokine levels as a common mechanism. Aging (Albany NY) 2012, 8:535-546. Published on line August 29. PMCID: PMC3461341
• [30]Crescent L, Combe CL, Tyler J, Curiel TJ, Magali M, Moretto MM, Imtiaz A, Khan IA: NK Cells Help To Induce CD8+-T-Cell Immunity against Toxoplasma gondii in the Absence of CD4+ T Cells. Infect Immun 2005, 73:4913-4921. PMCID: PMC1201207
• [31]Imai K, Matsuyama S, Miyake S, Suga K, Nakachi K: Natural cytotoxic activity of peripheral-blood lymphocytes and cancer incidence: an 11-year follow-up study of a general population. Lancet 2000, 356:1795-1799.
• [32]Anderson SK: Biology of natural killer cells: what is the relationship between natural killer cells and cancer? will an increased number and/or function of natural killer cells result in lower cancer incidence? J Nutr 2005, 135:12-18.
• [33]Asai O, Longo DL, Tian ZG, Hornung RL, Taub DD, Ruscetti FW, Murphy WJ: Suppression of graft-versus host disease and amplification of graft-versus-tumor effects by activated natural killer cells after allogeneic bone marrow transplantation. J Clin Invest 1998, 101:1835-1842.
• [34]Cho D, Shook DR, Shimasaki N, Chang Y-H, Fujisaki H, Campana D: Cytotoxicity of activated natural killer cells against pediatric solid tumors. Clin Cancer Res 2010, 16:3901-3909.
• [35]Geller MA, Cooley S, Judson PL, Ghebre R, Carson LF, Argenta PA, Jonson AL, Panoskaltsis-Mortari A, Curtsinger J, McKenna D, Dusenbery K, Bliss R, Downs LS, Miller JS: A phase II study of allogeneic natural killer cell therapy to treat patients with recurrent ovarian and breast cancer. Cytotherapy 2011, 13:98-107.
• [36]Orange JS: Human natural killer cell deficiencies and susceptibility to infection. Microbes Infect 2002, 4(15):1545-1558.
• [37]Biron CA, Byron KS, Sullivan JL: Severe herpes virus infections in an adolescent without natural killer cells. NEJMed 1989, 320:1731-1735.
• [38]Wikby A, Johansson B, Olsson J, Lo¨fgren S, Nilsson BO, Ferguson F: Expansions of peripheral blood CD8 T-lymphocyte subpopulations and an association with cytomegalovirus seropositivity in the elderly: the Swedish NONA immune study. Exp Gerontol 2002, 37:445-453.
• [39]Strindhall J, Nilsson BO, Lo¨fgren S, Ernerudh J, Pawelec G, Johansson B, Wikby A: No immune risk profile among individuals who reach 100 years of age: findings from the Swedish NONA immune longitudinal study. Exp Gerontol 2007, 42:563-570. 42:563–570
• [40]Hadrup SR, Strindhall J, Køllgaard T, Seremet T, Johansson B, Pawelec G, Thor Straten P, Wikby A: Longitudinal studies of clonally expanded CD8 T cells reveal a repertoire shrinkage predicting mortality and an increased number of dysfunctional cytomegalovirus specific T cells in the very elderly. J Immunol 2006, 176:2645-2653.
• [41]Tarazona R, Gayoso I, Alonso C, Pita ML, Peralbo E, Casado JG, Sanchez-Correa B, Morgado S, Solana R, Fulop T, Tarazona R, Gayoso I, Alonso C, Pita ML, Peralbo E, Casado JG, Sanchez-Correa B, Morgado S, Solana R, et al.: NK cells in human ageing. In Handbook on immunosenesence 545–561. Edited by Fulop T, Fulop T. Netherlands: Springer; 2009:545-561.
• [42]Wang GC, Kao WHL, Murakami P, Xue Q-L, Chiou RB, Detrick B, McDyer JF, Semba RD, Casolaro V, Walston JD, Fried LP: Cytomegalovirus infection and the risk of mortality and frailty in older women: a prospective observational cohort study. Am J Epidemiol 2010, 171:1144-1152.
• [43]Sun JC, Lanier LL: The natural selection of herpes viruses and virus-specific NK cell receptors. Viruses 2009, 1:362.
• [44]Simanek AM, Dowd JB, Pawelec G, Melzer D, Dutta A, Aiello AE: Seropositivity to cytomegalovirus, inflammation, all-cause and cardiovascular disease related mortality in the United States. PLoS One 2011, 6:e16103.
• [45]Rea IM, Stewart M, Campbell P, Alexander HD, Morris TCM: CD4/CD8 Ratio in human ageing. Br J Haematol 1996, 93(Suppl 1):190-191.
• [46]Loenen WAM, Bruggeman CA, Wiertz EJHJ: Immune evasion by human cytomegalovirus: lessons in immunology and cell biology. Sem in Immunol 2001, 13:41-49.
• [47]Reyburn HT, Mandelboim O, Vales-Gomez M, Davis DM, Pazman L, Strominger JL: The class I MHC homologue of human cytomegalovirus inhibits attack by natural killer cells. Nature 1997, 386:514-517.
• [48]Bubenik J: MHC class I down- regulation: tumor escape from immune surveillance? Int J Oncol 2004, 25:487-549.
• [49]Van den Broek MF, Kägi D, Ossendorp F, Toes R, Vamvakas S, Lutz WK, Melief CJM, Zinkernagel RM, Hengartner G: Decreased tumor surveillance in perforin-deficient mice. J Exp Med 1996, 184(5):1781-1790.
• [50]Moss P: The emerging role of cytomegalovirus in driving immune senescence: a novel therapeutic opportunity for improving health in the elderly. Curr Opin Immunol 2010, 22:529-534.
• [51]Maxwell LD, Ross OA, Curran MD, Rea IM, Middleton D: Investigation of KIR diversity in immunosenescence and longevity within the Irish population. Exp Gerontol 2004, 39:1223-1232.
• [52]Middleton D, Meenagh A, Gourraud PA: KIR haplotype content at the allele level in 77 northern Irish families. Immunogenetics 2007, 59:145-158. Epub 2007 (Jan 3)
• [53]Uhrberg M, Parham P, Wernet P: Definition of the gene content for nine common group B haplotypes of the causasoid population:KIR haplotypes contain between seven and eleven KIR genes. Immunogenetics 2002, 54:221-229.
• [54]Yawata M, Yawata N, McQueen KL, Cheng NW, Guethlein LA, Rajalingam R, Shilling HG, Parham P: Predominance of group a KIR haplotypes in Japanese associated with diverse NK cell repertoires of KIR expression. Immunogenetics 2002, 54:54-560. Epub 2002 Oct 24. PMID 12439616
• [55]Jiang K, Zhu FM, Lv QF, Yan LX: Distribution of killer cell immunoglobulin-like receptor genes in the Chinese Han population. Tissue Antigens 2005, 65:556-563.
• [56]Uhrberg M, Valiante NM, Shum BP: Human diversity in killer cell inhibitory receptor genes. Hum Immunol 1997, 7:753-763.
• [57]Middleton D, Williams F, Halfpenny IA: KIR genes. Transpl Immunol 2005, 14:135-142. [PubMed]
• [58]Parham P, Moffett A: Variable NK receptors and their MHC class I ligands in immunity, reproduction and human evolution. Nat Rev 2013, 13:133-144.
• [59]Ku’snierczyk P: Killer cell immunoglobulin-like receptor gene associations with autoimmune and allergic diseases, recurrent spontaneous abortion, and neoplasms. Front Immunol 2013., 4REVIEW ARTICLE published: 29January2013
• [60]Parham P: MHC class I molecules and KIRs in human history, health and survival. Nat Rev Immunol 2005, 5:201-214.
• [61]Khakoo SI, Carrington M: KIR and disease: a model system or system of models? Immunol Rev 2006, 214:186-201.
• [62]Ploski R, Luszczek W, Kusnierczyk P, Nockowski P, Cislo M, Krajewski P, Malejczyk J: A role for KIR gene variants other than KIR2DS1 in conferring susceptibility to psoriasis. Hum Immunol 2006, 67:521-526. PMID: 16829306
• [63]Ramos-Lopez E, Scholten F, Aminkeng F, Wild C, Kalhes H, Seidl C, Tonn T, Van der Auwera B, Badenhoop K: Association of KIR2DL2 polymorphism rs2756923 with type 1 diabetes and preliminary evidence for lack of inhibition through HLA-C1 ligand binding. Tissue Antigens 2009. Epub, PMID: 19392800
• [64]Ramírez-De Los Santos S, Sánchez-Hernández PE, Muñoz-Valle JF, Palafox-Sánchez CA, Rosales-Rivera LY, García-Iglesias T, Daneri-Navarro A, Ramírez-Dueñas MG: Associations of killer cell immunoglobulin-like receptor genes with rheumatoid arthritis. Dis Markers 2012. Epub, PMID: 22960345
• [65]Majorczyk E, Pawlik A, Luszczek W, Nowak I, Wisniewski A, Jasek M, et al.: Associations of killer cell immunoglobulin-like receptor genes with complications of rheumatoid arthritis. Genes Immunn 2007, 2007(8):678-683.
• [66]Middleton D, Meenagh A, Wright GD: No association in frequency of KIR receptors in patients with rheumatoid arthritis from northern Ireland. Tissue Antigens 2007, 69:577-582.
• [67]Rea I, Middleton D: Is the phenotypic combination A1B8Cw7DR3 a marker for male longevity? J Am Geriatr Soc 1994, 42:978-923. PMID: 8064108
• [68]Husain Z, Levitan E, Larson CE, Mirza NM, Younes S, Yunis EJ, Alper CA, Dubey DP: HLA-Cw7 zygosity affects the size of a subset of CD158b natural killer cells. J Clini Immunol 2002, 22:28-36.
• [69]Nowak I, Majorczyk E, Wisniewski A, Pawlik A, Magott-Procelewska M, Passowicz-Muszynska E, Malejczyk J, Płoski R, Giebel S, Barcz E, Zoń-Giebel A, Malinowski A, Tchórzewski H, Chlebicki A, Łuszczek W, Kurpisz M, Gryboś M, Wilczyński J, Wiland P, Senitzer D, Sun JY, Jankowska R, Klinger M, Kuśnierczyk P: Does the KIR2DS5 gene protect from some human diseases? PLoS One 2010, 5(8):e12381.
• [70]Henney CS, Kuribayashi K, Kern DE, Gillis S: Interleukin-2 augments natural killer activity. Nature 1981, 291:335-338.
• [71]Rea IM, McNerlan SE, Alexander HD: Total serum IL-12 and IL-12p40, but not IL-12p70, are increased in the serum of older subjects; relationship to CD3(+)and NK subsets. Cytokine 2000, 12(2):156-159. PMID: 10671301
• [72]Kobayashi M, Fitz L, Ryan M, Hewick RM, Clark SC, Chan S, Loudon R, Sherman F, Perussia B, Trinchieri G: Identification and purification of natural killer cell stimulatory factor (NKSF), a cytokine with multiple biologic effects on human lymphocytes. J Exp Med 1989, 170:827-845.
• [73]Wang KS, Frank DA, Ritz J: Interleukin-2 enhances the response of natural killer cells to interleukin-12 through up-regulation of the interleukin-12 receptor and STAT4. Blood 2000, 95:3183-3190. PMID 10807786
• [74]Aste-Amezaga M, DqAndrea A, Kubin M, Trinchieri G: Cooperation of natural killer cell stimulatory factor/interleukin-12 with other stimuli in the induction of cytokines and cytotoxic cell-associated molecules in human T and NK cells. Cell Immunol 1994, 156:480-492.
• [75]Rossi AR, Pericle F, Rashleigh S, Janiec J, Djeu JY: Lysis of Neuroblastoma cell lines by human natural killer cells activated by interleukin-2 and interleukin-12. Blood 1994, 83:1323-1328.
• [76]Robertson MJ, Cameron C, Atkins MB, Gordon MS, Lotze MT, Sherman ML, Ritz J: Immunological effects of interleukin 12 administered by bolus intravenous injection to patients with cancer. Clin Cancer Res 1999, 5:9-16. PMID: 9918197
• [77]Allan DS, Rybalov B, Awong G, Zuniga-Pflucker JC, Kopcow HD, Carlyle JC, Strominger JL: TGF-b affects development and differentiation of human natural killer cell subsets. Eur J Immunol 2010, 40:2289-2295.
• [78]Marcoe JP, Lim JR, Schaubert KL, Nassima F-C, Marsel M, McCubbrey AL, Farr AR, Vidal SM, Yasmina L: TGF-β is responsible for NK cell immaturity during ontogeny and increased susceptibility to infection during mouse infancy. Nat Immunol 2012. Published online 05 August 2012
• [79]Bellone G, Aste-Amezaga M, Trinchieri G, Rodeck U: Regulation of NK cell functions by TGF-beta 1. J Immunol 1995, 155:1066-73.
• [80]Wilson EB, El-Jawhari JJ, Neilson AL, Hall GD, Melcher AA, Meade JL, Cook GP: Human tumour immune evasion via TGF-β blocks NK cell activation but Not survival allowing therapeutic restoration of anti-tumour activity. PLoS ONE 2011, 6(9):e22842.
• [81]Schönberg K, Fischer JC, Kögler G, Uhrberg M: Neonatal NK-cell repertoires are functionally, but not structurally, biased toward recognition of self HLA class I. Blood 2011, 117:5152-5156. Published online before print March 17, 2011
• [82]Rea IM, McNerlan SE, Alexander HD: CD69, CD25, And HLA-DR activation antigen expression on CD3+ lymphocytes and relationship to serum TNF_, IFN_ and sIL-2R levels in aging. Exp Gerontol 1999, 34:79-93.
• [83]Samuelson EJ, Kelsey JL, Kiel DP, Roman AM, Cupples LA, Freeman MB, Jones RN, Hannan MT, Leveille SG, Gagnon MM, Lipsitz LA: Issues in conducting epidemiological research among elders. Lessons from the MOBILIZE Boston study. Am J Epidemiol 2008, 168:1444-1451.
• [84]Dellett M, Colyer HAA, Pettigrew KA, McMullin M-F, Rea IM, Mills KI: Altered methylation levels in elderly acute myeloid leukaemia patients compared to elderly well individuals. Brit J Haematol 2013, 161:294-296. Epub 2013 Jan 24
• [85]Uhrberg M: Shaping the human NK cell repertoire: an epigenetic glance at KIR gene regulation. Mol Immunol 2005, 42:471-5. [PubMed]
• [86]Folstein MF, Folstein SE, McHugh PR: Mini mental state. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975, 12:189-198.
• [87]Lightart GJ, Corberand JX, Fornier C, Galanaud P, Hijmans W, Kennes B, Muller-Hermelink HK, Steinman GG: Admission criteria for immunogerontological studies in man: the SENIEUR protocol. Mech Ageing Dev 1984, 28:47-55.
• [88]Rea IM, Myint PK, Mueller H, Murphy A, Archbold GP, McNulty H, Patterson CC: Nature or nurture; BMI and blood pressure at 90. Findings from the Belfast elderly longitudinal free-living aging study (BELFAST). Age (Dordr) 2009, 31:261-267. Published online 2009 June 4
• [89]Rea IM, Gillen S, Clarke E: Anthropometric measurements from a cross-sectional survey of community-living subjects >90 years of age. Eur J Clin Nutr 1997, 51:102-106.
• [90]Miller SA, Dykes DD, Polesky HF: A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res 1988, 16:1215-1219.