Red blood cell storage and development

Abstract

The population of red blood cells that are grown in culture (cRBCs) are mainly composed of immature reticulocytes which arise from erythropoiesis after the enucleation stage. To fully mature, these reticulocytes must lose residual organelles and approximately 20% of their surface area through alterations in the plasma membrane and cytoplasmic protein content in a process known as reticulocyte maturation (RM). The excess proteins that have not reached their final placement make these reticulocytes unstable and therefore more fragile during storage. Storage of cRBCs is critical for a clinical or diagnostic application of this cellular component. In this project numerous additives to the standard storage solution SAG-M have been trialled to improve the stability of cRBCs during storage. It was found that the addition of 10% Dextran-40 to SAG-M, with rejuvenation, significantly reduced haemolysis of cRBCs over the ten days of storage and has the potential to extend their shelf-life to 20 days.

An alternative method to stabilise cRBC is to mature these cells in vitro. During RM, the cells are known to expel large phosphatidyl-serine (PS) exposing vesicles containing residual organelles and redundant proteins. Various attempts were made to encourage the cRBCs to extrude PS+ autophagic-endocytic vesicles. In a novel approach to investigate RM, a staged RM mechanism was derived from protein work on the expression of RM markers in different RBC variants of distinct cell size.

A study to investigate the protein expression of ABCB6 in blood donors that present the SNP Arg723Gln, causative of Familial Pseudohyperkalaemia (FP) was carried out, and it was shown that there is no enhanced vesiculation on irradiated units from FP and control samples.

Finally, sequencing of FUT2 and FUT3 was carried out to resolve phenotypic and PCR result discrepancies as part of a COVID-19 project.

Date of Award	27 Sept 2022
Original language	English
Awarding Institution	University of Bristol
Supervisor	Jan Frayne (Supervisor) & Lesley Bruce (Supervisor)