Modification of the state of bone marrow hematopoietic cells after cryopreservation

The structural and functional characteristics of bone marrow (BM) hematopoietic stem cells (HSCs) prior to and after cryopreservation were studied using different methodical approaches. The HSCs colony-forming ability and the cell capability to homing and proliferation were analyzed. We observed a temporary decrease in capability of the cells in detecting hematopoietic microenvironment and to be settled in spleen and BM (homing) of the mouse after cryopreservation and following transplantation. The part of cryopreserved cells settled after transplantation lost the capability of proliferating. To check possible transformations in cell receptor repertoire, we have estimated the Thy-1,2-antigen presence on HSCs and the dynamics of its synthesis after immune modulation. The decreased accumulation of the antigen in HSCs was contributed, at least partially, to shedding this structure off the cell membranes after cryopreservation. The damaging effect of low temperature was detected at all levels of cell metabolism regulation: from signal perception by all HSCs receptors, its transduction, and realization at transcription and translation levels.