Role of Natural Killer Cell Alloreactivity in HLA-Mismatched Hematopoietic Stem Cell Transplantation

Autor: Marusca Capanni, Isabella Volpi, Andrea Velardi, Myriam Casucci, Elena Urbani, Robert S. Negrin, Loredana Ruggeri, Massimo F. Martelli, Katia Perruccio, Antonella Tosti
Rok vydání: 1999
Předmět:
Zdroj: Blood. 94:333-339
ISSN: 1528-0020
0006-4971
DOI: 10.1182/blood.v94.1.333.413a31_333_339
Popis: Because of the expression of inhibitory receptors (KIR) for major histocompatibility complex (MHC) class I allotypes, a person’s natural killer (NK) cells will not recognize and will, therefore, kill cells from individuals lacking his/her KIR epitopes. This study investigated the role of NK cell alloreactivity in human HLA haplotype-mismatched hematopoietic stem cell transplantation and, specifically, the role of the three major NK specificities, ie, those for HLA-C group 1, HLA-C group 2, and HLA-Bw4 alleles. In 20 of 60 donor-recipient pairs, KIR epitope incompatibility and functional analyses of donor NK cell clones predicted donor NK cells could cause graft-versus-host (GVH)/graft-versus-leukemia (GVL) reactions. NK cell clones of donor origin were obtained from transplanted recipients and tested for lysis of recipient’s cryopreserved pretransplant lymphocytes. Despite the absence of GVH disease, we detected high frequencies of NK clones which killed recipient’s target cells. Lysis followed the rules of NK cell alloreactivity, being blocked only by the MHC class I KIR epitope which was missing in the recipient. The alloreactive NK clones also killed the allogeneic leukemia. Transplants from these KIR epitope incompatible donors had higher engraftment rates. Therefore, a GVL effector and engraftment facilitating mechanism, which is independent of T-cell–mediated GVH reactions, may be operational in HLA mismatched hematopoietic cell transplants.
Databáze: OpenAIRE