title: NK Cells and Other Innate Lymphoid Cells in Hematopoietic Stem Cell Transplantation.
abstract: Natural killer (NK) cells play a major role in the T-cell depleted haploidentical hematopoietic stem cell transplantation (haplo-HSCT) to cure high-risk leukemias. NK cells belong to the expanding family of innate lymphoid cells (ILCs). At variance with NK cells, the other ILC populations (ILC1/2/3) are non-cytolytic, while they secrete different patterns of cytokines. ILCs provide host defenses against viruses, bacteria, and parasites, drive lymphoid organogenesis, and contribute to tissue remodeling. In haplo-HSCT patients, the extensive T-cell depletion is required to prevent graft-versus-host disease (GvHD) but increases risks of developing a wide range of life-threatening infections. However, these patients may rely on innate defenses that are reconstituted more rapidly than the adaptive ones. In this context, ILCs may represent important players in the early phases following transplantation. They may contribute to tissue homeostasis/remodeling and lymphoid tissue reconstitution. While the reconstitution of NK cell repertoire and its role in haplo-HSCT have been largely investigated, little information is available on ILCs. Of note, CD34(+) cells isolated from different sources of HSC may differentiate in vitro toward various ILC subsets. Moreover, cytokines released from leukemia blasts (e.g., IL-1β) may alter the proportions of NK cells and ILC3, suggesting the possibility that leukemia may skew the ILC repertoire. Further studies are required to define the timing of ILC development and their potential protective role after HSCT.
authors.affiliation: Department of Experimental Medicine, University of Genova , Genova , Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Vacca
authors.affiliation: Division of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute , Milano , Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Montaldo
authors.affiliation: Department of Experimental Medicine, University of Genova , Genova , Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Croxatto
authors.affiliation: Department of Internal Medicine, University of Verona, Verona, Italy; Ospedale Sacro Cuore Negrar, Verona, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Moretta
authors.affiliation: Department of Pediatric Hematology and Oncology, IRCCS Bambino Gesù Children's Hospital , Rome , Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Bertaina
authors.affiliation: Department of Experimental Medicine, University of Genova, Genova, Italy; U.O. Immunology IRCCS AOU San Martino-IST, Genova, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Vitale
authors.affiliation: Department of Pediatric Hematology and Oncology, IRCCS Bambino Gesù Children's Hospital, Rome, Italy; Department of Pediatrics, University of Pavia, Pavia, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Locatelli
authors.affiliation: Department of Experimental Medicine, University of Genova, Genova, Italy; U.O. Immunology IRCCS AOU San Martino-IST, Genova, Italy; Centro di Eccellenza per la Ricerca Biomedica - CEBR, Genova, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Mingari
authors.affiliation: Department of Immunology, IRCCS Bambino Gesù Children's Hospital , Rome , Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Moretta
keywords: GVHD; NK cells; hematopoietic stem cell transplantation; innate lymphoid cells