NEW HLA-G ISOFORMS IN UMBILICAL CORD MESENCHYMAL STEM CELLS

IRIBARNE, AILEN; TRONIK-LE ROUX, DIANA; PORAS, ISABELLE; DAOUYA, MARINA; PALMA MARÍA BELÉN; ANDRINI LAURA; PELINSKI PABLO; CAROSELLA, EDGARDO D.; MIRIUKA, SANTIAGO G.; GARCÍA MARCELA N.

Mar del Plata

Congreso; Reunión Conjunta SAIC SAB AAFE AACYTAL 2023; 2023

Chronic venous ulcer (CVU) is the loss of substance that does not heal with conventional treatment after correcting the factor that produced it, leading to the appearance of infections and complications in the patient. Treatments based on the use of autologous mesenchymal stem cells (MSC) have been successful; however, their implementation entails complications. Umbilical cords (UC) offer an extensive source of MSC from Wharton?s jelly tissue with the same features for clinical applicability and avoiding difficulties. The umbilical cord mesenchymal stem cells (ucMSC) express the Human Leukocyte Antigen G (HLA-G), an immuno-checkpoint (IC), which produces a local inhibition of the system that would allow allogeneic transplantation playing a significant role in regenerative medicine. The present work aims to identify which HLA-G isoforms are present in ucMSC. First, immunohistochemistry (IHC) was used to detect the HLA-G presence directly in UC and surface labeling for specific antigens using flow cytometry (FC) was carried out in ucMSC. To detect different HLA-G isoforms, RT-PCR was performed using specific primers. In the results by IHC and FC the HLA-G expression was low. Then, RT-PCR analysis showed that 77.8% of UC were HLA-G positive. Until now, all HLA-G isoforms described have the α1 domain. However, within the positive UC, only 12% of them amplified α1 domain by PCR. The other 88% of UC have isoforms that lack this domain, which would correspond to the detection of new HLA-G isoforms. These data explain the low detection with IHC and FC, since the employed antibodies target α1 domain. The presence of this IC would modulate the activity of the immune system and could play a key role in the activation of angiogenesis depending on the isoform present. These different functions of HLA-G allow allogeneic transplantation of ucMSCs and a favorable environment for tissue regeneration, so these ucMSCs could be a new therapeutic alternative for the treatment of UVC.