Generation of HLA-deficient platelets from hematopoietic progenitor cells.
BACKGROUND
Exposure to allogeneic blood products often leads to the development of human leukocyte antigen (HLA) antibodies. Refractoriness to platelet (PLT) transfusion caused by alloimmunization against HLA Class I antigens constitutes a significant clinical problem.


METHODS
We developed an RNA interference (RNAi)-based approach to silence the expression of HLA Class I molecules on PLTs derived from CD34+ progenitor cells. A lentiviral-based system was used to express short-hairpin RNA (shRNA) targeting β2-microglobulin (β2m) transcripts in CD34+ progenitor cells. Differentiation to PLTs was performed by incubating progenitor cells in the presence of thrombopoietin and interleukin-3.


RESULTS
The transduction of RNAi cassettes containing the sequences for shRNAs targeting β2m caused up to 85% reduction of progenitor cells HLA Class I antigen expression, which was maintained in the culture-derived PLTs. The HLA-deficient PLTs derived from HLA-silenced CD34+ cells proved to be fully functional in in vitro tests when compared to peripheral blood-derived PLTs.


CONCLUSIONS
Our data show that in vitro generating HLA Class I-deficient PLTs from hematopoietic progenitor cells prove to be feasible. As malignancy risks associated with insertional mutagenesis are not to be expected in anucleated PLTs, provision of HLA-deficient PLTs from large-scale production units may become reality in the management of patients suffering from PLT transfusion refractoriness.
Figueiredo
Constança
C
Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany.
Goudeva
Lilia
L
Horn
Peter A
PA
Eiz-Vesper
Britta
B
Blasczyk
Rainer
R
Seltsam
Axel
A
D020868:Gene Silencing; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D006801:Humans; D008533:Megakaryocytes / Q000276:immunology*; D017713:Platelet Transfusion; D034622:RNA Interference; D001613:beta 2-Microglobulin / Q000037:antagonists & inhibitors
D015395:Histocompatibility Antigens Class I; D001613:beta 2-Microglobulin