[PDF][PDF] iPSC-derived platelets depleted of HLA class I are inert to anti-HLA class I and natural killer cell immunity

D Suzuki, C Flahou, N Yoshikawa, I Stirblyte… - Stem cell reports, 2020 - cell.com
D Suzuki, C Flahou, N Yoshikawa, I Stirblyte, Y Hayashi, A Sawaguchi, M Akasaka…
Stem cell reports, 2020cell.com
The ex vivo production of platelets depleted of human leukocyte antigen class I (HLA-I)
could serve as a universal measure to overcome platelet transfusion refractoriness caused
by HLA-I incompatibility. Here, we developed human induced pluripotent cell-derived HLA-I-
deficient platelets (HLA-KO iPLATs) in a clinically applicable imMKCL system by genetic
manipulation and assessed their immunogenic properties including natural killer (NK) cells,
which reject HLA-I downregulated cells. HLA-KO iPLATs were deficient for all HLA-I but did …
Summary
The ex vivo production of platelets depleted of human leukocyte antigen class I (HLA-I) could serve as a universal measure to overcome platelet transfusion refractoriness caused by HLA-I incompatibility. Here, we developed human induced pluripotent cell-derived HLA-I-deficient platelets (HLA-KO iPLATs) in a clinically applicable imMKCL system by genetic manipulation and assessed their immunogenic properties including natural killer (NK) cells, which reject HLA-I downregulated cells. HLA-KO iPLATs were deficient for all HLA-I but did not elicit a cytotoxic response by NK cells in vitro and showed circulation equal to wild-type iPLATs upon transfusion in our newly established Hu-NK-MSTRG mice reconstituted with human NK cells. Additionally, HLA-KO iPLATs successfully circulated in an alloimmune platelet transfusion refractoriness model of Hu-NK-MISTRG mice. Mechanistically, the lack of NK cell-activating ligands on platelets may be responsible for evading the NK cell response. This study revealed the unique non-immunogenic property of platelets and provides a proof of concept for the clinical application of HLA-KO iPLATs.
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