ABSTRACT
【Objective】 To understand the memory phenotype and function of SARS-CoV-2 reactive CD4+ T cells in healthy individuals. 【Methods】 In this study, SARS-CoV-2-derived peptides were used to stimulate PBMC from participants.SARS-CoV-2 reactive memory T cells were detected by intracellular staining and flow cytometry, and memory phenotype analysis was performed.CBA was used to detect cytokine secretion after SARS-CoV-2-derived peptides stimulation to evaluate the function of SARS-CoV-2 reactive memory T cells. 【Results】 We found that SARS-CoV-2 reactive CD4+ memory T cells could be detected in 40% (6/15) healthy donors.Phenotypic analysis of memory showed that these T cells were mainly composed of central memory T cells(82.2%), and other memory cells accounted for 17.8%.Compared with negative control, IL-10 was significantly decreased after stimulation of SARS-CoV-2-derived peptides (P<0.05), while the secretion of IFNγ, TNFα, IL-2 and IL-4 showed no significant difference. 【Conclusions】 SARS-CoV-2 reactive CD4+ memory T cells are present in healthy individuals from China.
ABSTRACT
Platelet transfusion is one of the important therapeutic methods for clinical prevention of bleeding and hemostasis. At present, agitated storage at (22±2)℃used for platelets leads to risk of bacterial growth, which limits platelet shelf life and safety in transfusion. Cold storage at 4 ℃ can significantly promote the abovementioned drawbacks and present a better hemostatic effect. Platelets storage lesion(PSL) due to the cold storage, however, may lead to platelet activation following transfusion, thus reducing the effective survival rate in vivo. This paper reviews the research advances in PSL and the application of platelets stored at 4 ℃.