Abstract

Analyses of apoptosis receptors on CD34 stem cells obtained by apheresis

Author(s): Vladimir Jurisic

Investigation of hematopoietic stem cell (HSC) obtained from bone marrow or from peripheral blood from healthy donors is very important for transplantation or for application to cancer patients after intensive chemotherapy. Quality obtained CD34 stem cells after aphaeresis are most important characteristics for further cell manipulation and for transplantation. Until now, several protocols are mainly focused on techniques describing how to obtained cells from bone marrow or from peripheral blood. In addition, focus on viability cells is also very important. Many of techniques in every day practice are based only to analyses viable cells by enumeration using a light microscopy or by morphology analyses. Several investigation clearly indicated possibility to measured death cells using LDH release in the supernates of cultured cells. Principe of assay is based on fact that death cells released much more LDH released trough altered cell membrane. With introduction of Flow cytometry in research as well as in daily practice during hematopoietic stem cell manipulation, he is described as CD34+ cells. In addition, understanding apoptosis, necrosis and cell proliferation process simultaneously with death receptors describing, a new direction in assessment of CD34 are open. Between many molecules on cell surface, TNF receptors it seems to be useful for quality controls monitoring. Based on this consideration, expression of TNF1(CD120a) and TNFR2 (CD120b) on gated CD34 cells and all peripheral blood cells subsets from healthy donors are analyzed by Flow cytometry (BD, San Jose, USA) in this research. Data indicated that TNFR1 is more associated with apoptosis induction, while TNFR2 are more associated with cell proliferation in different tissues and cell subsets. In this study after aphaeresis, results showing that mean values of increased TNFR2 can indicated that CD34+ cells are more viable in comparison to those CD34+ subpopulation express more TNFR1. A little increase in TNFR2 expression after apheresis indicated successful process cell accumulation and especially cell accumulation with better quality. The cells with high level of TNFR1 can be associated with death cells and consequently with purer transplantation effects. Further study need to confirmed patients survival score based on these donors cell characteristics.