Effects Of Antifreeze Proteins on Red Blood Cell Survival During Cryopreservation

TLDR

The study evaluated antifreeze proteins (types I–III) and site‑directed type III mutants for their ability to prevent red‑blood‑cell lysis during cryopreservation by measuring hemolysis after warming. All three AFPs lowered hemolysis to 25 % of control at micromolar doses, but higher concentrations increased lysis; efficacy correlated with thermal hysteresis activity, and cryomicroscopy revealed that protection was due to inhibition of ice recrystallization.

Abstract

ABSTRACT Antifreeze protein (AFP) types I, II and III were tested for their ability to protect red blood cells from lysis during warming, after cryopreservation in hydroxyethyl starch. All three types reduced hemolysis to 25 % of control values at similar micromolar concentrations but enhanced lysis as the AFP concentration approached millimolar levels. Site-directed mutants of type III AFP with different thermal hysteresis activities were tested for their ability to protect the cryopreserved cells from lysis. Their relative efficacy in protecting the cells correlated closely with their thermal hysteresis activity. Cryomicroscopy indicated that the protection of red cells by type III AFP and the mutant forms was due to inhibition of ice recrystallization.