Third Party Cytokine-Induced Killer Cells Protect from Murine Lethal Graft-Versus-Host Disease
Authors: Kuroda Rie , Mase Shintaro , Fujiki Toshihiro , Maeba Hideaki , Araki Raita , Ikawa Yasuhiro , Fukuda Masaki , Koizumi Shoichi , Yachie Akihiro , Nishimura Ryosei 
Published: October 2019

Abstract
Cell adoptive immunotherapy protect from lethal graft-versus-host disease (GVHD) while preserving graft-versus-tumor effects is ideal in allogeneic hematopoietic stem cell transplantation (HSCT) in patients with hematologic malignancies. Moreover, the use of third party cells would open a huge source of availability and feasibility across major histocompatibility barriers. In fact, some studies demonstrated that infusion of third party derived cells such as whole bone marrow cells or iNKT cells could ameliorate lethal GVHD in a murine model.
Cytokine-induced killer (CIK) cells are ex vivo-expanded T lymphocytes expressing both natural killer and T-cell markers. We have previously reported that donor-type CIK cells have potential to separate graft-versus-tumor effects from GVHD by eliminating host dendritic cells due to the enhanced killing activity by interferon-gamma. Actually, donor-typed CIKs infusion for refractory hematological malignancies after HSCT has been started in some clinical trails. In the present study, we examine the effect of third party cells against GVHD protection, in particular third party CIK cells for prevention from lethal GVHD in a murine model of allogeneic HSCT.
To test this, lethally irradiated host Balb/c (H-2d) mice were given C3H (H-2k) or B6 (H-2b) bone marrow cells and splenocytes to induce lethal GVHD with/without third-party cells (C57/BL6 or C3H) such as CIK cells, whole splenocytes, or bone marrow derived dendritic cells (BMDCs) on day 0, which were cultured from bone marrow cells with GM-CSF. Mice receiving third party CIK cells showed much less GVHD and significant survival benefit compared those with third party splenocytes, or BMDCs as shown in the figure below. Interestingly, when infusion of third party splenocytes was delayed until day 4 after bone marrow transplantation, host mice receiving splenocytes survived much better compared with mice receiving splenocytes on day 0, even though reduced number of third party splenocytes was used. This result indicated that timing of third party cell infusion was quite important, especially when third party splenocytes were used. As expected, the mice given reduced number of third CIK cells also showed excellent survival with much less GVHD. Taken together, our results clearly demonstrated that third party CIK cells have strong potential to prevent lethal GVHD without attention to timing of cell infusion.
Next, to further investigate the advantage of third party CIK cells rather than whole splenocytes, we compared the hematological reconstitution between the mice given third party CIK cells on day 4 after BMT and whole splenocytes. Both mice showed much less GVHD with the same level, however the recovery of white blood cell count on day 21 after BMT was significantly better in the mice receiving third party CIK cells.
In conclusion, infusion of third party CIK cells has strong potential to prevent lethal GVHD with faster hematological recovery after HSCT.

Disclosures
No relevant conflicts of interest to declare.