Frontiers in Immunology (May 2016)

NK cells and other innate lymphoid cells in haematopoietic stem cell transplantation

  • Paola eVacca,
  • Elisa eMontaldo,
  • Daniele eCroxatto,
  • Francesca eMoretta,
  • Francesca eMoretta,
  • Alice eBertaina,
  • Chiara eVitale,
  • Chiara eVitale,
  • Franco eLocatelli,
  • Franco eLocatelli,
  • Maria Cristina eMingari,
  • Maria Cristina eMingari,
  • Lorenzo eMoretta

DOI
https://doi.org/10.3389/fimmu.2016.00188
Journal volume & issue
Vol. 7

Abstract

Read online

Natural Killer (NK) cells play a major role in the T-cell depleted haploidentical haematopoietic stem cell transplantation (haplo-HSCT) to cure high-risk leukemias. NK cells belong to the expanding family of innate lymphoid cells (ILC). At variance with NK cells, the other ILC populations (ILC1/2/3) are non-cytolytic, while they secrete different patterns of cytokines. ILC provide host defences against viruses, bacteria and parasites, drive lymphoid organogenesis, and contribute to tissue remodelling. 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 defences that are reconstituted more rapidly than the adaptive ones. In this context, ILC may represent important players in the early phases following transplantation. They may contribute to tissue homeostasis/remodelling 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 ILC. Of note, CD34+ cells isolated from different sources of HSC, may differentiate in vitro towards 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.

Keywords