Section of Cell Biology, Laboratory of Cellular Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland.
Transfusion. 2014 Jun;54(6):1604-9. doi: 10.1111/trf.12534. Epub 2014 Jan 12.
Bacterial sepsis is still a complication in patients transfused with stored platelets (PLTs). We have recently demonstrated that selected antimicrobial peptides (AMPs) have bactericidal activity in bacteria-spiked PLTs. In a subsequent preclinical study, we have also shown that these AMPs do not elicit antibody response in rabbits and treatment of PLTs before transfusion does not affect their in vivo recovery and survival in severe combined immunodeficient mice. Here we have selected two such AMPs, Arg-Trp (RW) repeats of tri- and tetra-peptides (RW3 and RW4) in combination (i.e., cocktail), and evaluated their effect on the in vitro properties of PLTs.
Leukoreduced ABO- and D-identical whole blood-derived PLT concentrates were pooled and divided into two 60-mL aliquots in CLX storage bags. On Day 0, one bag received a peptide cocktail of RW3 plus RW4 at 0.01 mmol/L final concentration (test) and the other bag received only phosphate-buffered saline (PBS), the AMP solvent (control). The treated PLTs were stored for 7 days at 20 to 24°C. Samples were collected on Days 1, 5, and 7 to evaluate the in vitro properties of PLTs with standard assays.
In vitro properties of the RW3 plus RW4 cocktail-treated PLTs were similar to those incubated with PBS only. There were no significant differences between the control and test PLTs during the 7-day storage.
Leukoreduced whole blood-derived PLTs treated with a mixture of RW3 and RW4 peptides maintain their in vitro properties during 7 days of storage.
储存的血小板（PLT）输注仍会导致细菌感染。我们最近发现，某些抗菌肽（AMP）在含有细菌的 PLT 中具有杀菌活性。在随后的临床前研究中，我们还发现这些 AMP 不会在兔子体内引发抗体反应，并且在输注前对 PLT 进行处理不会影响其在严重联合免疫缺陷小鼠体内的恢复和存活。在此，我们选择了两种此类 AMP，即三肽和四肽的 Arg-Trp（RW）重复序列（RW3 和 RW4）的组合（即鸡尾酒），并评估了它们对 PLT 体外特性的影响。
从白细胞减少的 ABO 和 D 型相同的全血衍生的 PLT 浓缩物中收集并分装到两个 60 毫升的 CLX 储存袋中。在第 0 天，一个袋子接受终浓度为 0.01mmol/L 的 RW3 加 RW4 肽鸡尾酒（测试），另一个袋子仅接受磷酸盐缓冲盐水（PBS），即 AMP 溶剂（对照）。处理后的 PLT 在 20 至 24°C 下储存 7 天。在第 1、5 和 7 天收集样品，用标准测定评估 PLT 的体外特性。
RW3 加 RW4 鸡尾酒处理的 PLT 的体外特性与仅用 PBS 孵育的 PLT 相似。在 7 天的储存过程中，对照组和测试组的 PLT 之间没有显着差异。
用 RW3 和 RW4 肽混合物处理的白细胞减少的全血衍生 PLT 在 7 天的储存期间保持其体外特性。
