Change of the metabolomic profile during short-term mononuclear cell storage.
BACKGROUND AND OBJECTIVES
Short-term storage of leukapheresis products used for immunotherapeutic mononuclear cell (MNC) products is a frequent event. The analysis of time-related metabolic patterns enables the characterization of storage-related effects in MNCs and the hypothesis-based optimization of the MNC medium.


MATERIALS AND METHODS
The MNC products from seven leukapheresis procedures were stored within a closed bag system for 48 h. Concentrations of amino acids, biogenic amines, phospho- and sphingolipids and hexoses in the medium were measured by targeted metabolomics. The viability of MNC subpopulations was assayed by Annexin V (AnV) and JC-1 staining.


RESULTS
Glucose depletion and a significant change of the acylcarnitine profile are early events within the first 24 h of storage. In contrast, for most amino acids, the maximum increase was observed at 48 h of storage as mirrored by an increase in the amino acid levels by a mean factor of 1·2 (1·3, 2·0) after 6 h (24 h, 48 h, respectively). This was except for the concentrations of glutamine and lysine, which did not change significantly. The taurine concentration showed a twofold increase within the first 24 h and remained constant thereafter. The steepest increase in AnV+ and 7-AAD+ CD4+ T cells was found between 24 and 48 h.


CONCLUSION
The time-course of apoptosis and metabolic patterns in the MNC products demonstrate that 24 h of storage is a decisive time-point, as afterwards key metabolic pathways showed nonlinear detrimental changes. Optimization of storage by supplementation of specific substrates demands therefore an early intervention.
['Steininger|P A|PA|', 'Strasser|E F|EF|', 'Ziehe|B|B|', 'Eckstein|R|R|', 'Rauh|M|M|']
D000588:Amines D000596:Amino Acids D017209:Apoptosis D001793:Blood Preservation D015496:CD4-Positive T-Lymphocytes D002331:Carnitine D002851:Chromatography, High Pressure Liquid D005947:Glucose D006801:Humans D007937:Leukapheresis D007963:Leukocytes, Mononuclear D055432:Metabolomics D010743:Phospholipids D013107:Sphingolipids D053719:Tandem Mass Spectrometry D013997:Time Factors
metabolomics short-term storage apoptosis cellular therapy mononuclear cell apheresis