Participation of nonclassical major histocompatibility complex class I molecules in the human renal allograft.

RACCA A; VEAUTE C; BAILAT A; GAITE L; ARRIOLA M; MALAN BOREL I

Praga - República Checa

Congreso; 13th Congress of the European Society for Organ Transplantation; 2007

European Society for Organ Transplantation

&amp;amp;amp;amp;lt;!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman"; mso-fareast-language:EN-US;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt; mso-ascii-font-family:Calibri; mso-fareast-font-family:Calibri; mso-hansi-font-family:Calibri;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&amp;amp;amp;amp;gt; Unlike the widely expressed classical HLA class I molecules, the nonclassical ones exhibit a restricted pattern of tissue expression and lower polymorphism. HLA-G inhibits the allogeneic proliferative T cell response and protects susceptible target cells from NK cytolysis. On the other hand, MICA, cell stress sensor molecule, is recognized by NKG2D cytotoxicity-activating receptor expressed by NK cells, γδ T lymphocytes and CD8 αβ T cells. Therefore, the aim of this work was to determine MICA and HLA-G mRNA levels, by semiquantitative RT-PCR, in peripheral blood mononuclear cells from transplanted patients. For this purpose blood samples were obtained from patients who had undergo kidney allograft. Renal allograft were carried out and clinically followed at the Clínica de Nefrología, Urología y Enfermedades Cardiovasculares of Santa Fe city. Samples were taken at the sign appearance time of acute rejection (AR) (n=9), chronic rejection (CR) (n=13) or stable evolution (SE) (n=15). Healthy volunteers nontransplanted were studied as control group (C) (n=15). Results show that HLA-G mRNA levels were significantly higher in SE patients (1.23±0.18) than in those with AR (0.75±0.12) or CR (0.70±0.11) or C group (0.71±0.07) (p<0.05). With regard to MICA mRNA levels, the results indicated that those in AR patients (0.75±0.11) were higher than SE (0.46±0.04) or CR (0.49±0.05) or C group (0.50±0.05) (p>0.05). Taking into account that HLA-G and MICA have important immunoregulatory properties, these results suggest their participation in the human renal allograft maintenance.