J Cancer 2013; 4(1):25-35. doi:10.7150/jca.5049

Review

Clinical Relevance of Natural Killer Cells Following Hematopoietic Stem Cell Transplantation

Jeanne M Palmer1,2✉, Kamalakannan Rajasekaran1, Monica S Thakar1,3, Subramaniam Malarkannan1,2✉

1. Laboratory of Molecular Immunology, Blood Research Institute, 8727 Watertown Plank Road, Milwaukee, WI 53226, USA;
2. Departments of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
3. Departments of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.

Abstract

Natural killer (NK) cells are one of the first cells to recover following allogeneic hematopoietic stem cell transplantation (HSCT), and are believed to play an important role in facilitating engraftment or preventing post-transplant infection and tumor recurrence. Recent studies have provided novel insights into the mechanisms by which NK cells mediate these highly clinically relevant immunological functions. In particular, the ability of NK cells to reduce the risk of graft versus host disease (GVHD) and increase the graft versus leukemia effect (GVL) in the setting of human leukocyte antigen (HLA)-haploidentical HSCT highlights their clinical potentials. NK cells also mediate anti-viral protection, in particular against cytomegalovirus (CMV), an infection that causes significant morbidity and mortality following transplant. Another crucial function of NK cells is providing protection against bacterial infections at the mucosal barriers. NK cells achieve this by promoting anti-microbial defenses and regeneration of epithelial cells. These recent exciting findings provide a strong basis for the formulation of novel NK cell-based immunotherapies. In this review, we summarize the recent advances related to the mechanisms, functions, and future clinical prospects of NK cells that can impact post-transplant outcomes.

Keywords: Natural killer cells, immunological functions, stem cell, post-transplant

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How to cite this article:
Palmer JM, Rajasekaran K, Thakar MS, Malarkannan S. Clinical Relevance of Natural Killer Cells Following Hematopoietic Stem Cell Transplantation. J Cancer 2013; 4(1):25-35. doi:10.7150/jca.5049. Available from http://www.jcancer.org/v04p0025.htm