title: Expression of HLA-G and MICA mRNA in renal allograft.
abstract: HLA-G is a nonclassical MHC class I antigen that displays tolerogenic functions; MICA is a stress-regulated molecule recognized by NKG2D cytotoxicity-activating receptor expressed by NK and T cells subsets. We evaluated HLA-G isoforms and MICA mRNA levels in peripheral blood mononuclear cells (PBMCs) and in biopsies from kidney allograft recipients with acute rejection (AR), chronic rejection (CR), and stable graft evolution (SE). HLA-G1 was the only transcript resulted from amplification, both in PBMCs as in biopsy samples. HLA-G1 mRNA levels in PBMCs from 9/10 patients with CR, 7/9 with AR and 8/10 healthy volunteers were below the median value of SE patients. The analysis of biopsies revealed that patients with AR (n=6), who overcame rejection had a tendency towards higher HLA-G1 levels than those with nephrotoxic acute tubular necrosis (ATN) (n=3). Similar levels of MICA expression were observed in PBMCs from AR, CR, SE and C groups; MICA expression levels were similar also in biopsy specimens from AR and nephrotoxic ATN patients. No correlation was found between MICA expression and the graft state. These preliminary results suggest that HLA-G1 isoforms, but not MICA mRNA levels, may provide a marker for measuring the state of kidney allograft, and be the basis for further studies that may establish the influence of these molecules in renal allograft rejection or acceptance.
authors.affiliation: Laboratorio de Inmunología Básica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Pje El Pozo, Santa Fe, Argentina.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Racca
authors.forename: Carolina M
authors.initials: CM
authors.lastname: Veaute
authors.forename: Alejandra S
authors.initials: AS
authors.lastname: Bailat
authors.forename: Luis
authors.initials: L
authors.lastname: Gaite
authors.forename: Mariano
authors.initials: M
authors.lastname: Arriola
authors.forename: Silvia E
authors.initials: SE
authors.lastname: Hajos
authors.forename: Ileana S
authors.initials: IS
authors.lastname: Malan Borel
mesh_terms: D000328:Adult; D005260:Female; D006084:Graft Rejection / Q000235:genetics* / Q000378:metabolism; D006680:HLA Antigens / Q000235:genetics* / Q000378:metabolism; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000032:analysis; D014184:Transplantation, Homologous
chemical_list: D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A; D020033:Protein Isoforms; D012333:RNA, Messenger