Replacing human peripheral blood leukocytes with LRS-separated leukocytes for scientific research
Objective 
To investigate the feasibility of using leukocytes that were filtered out by LeukoReduction System (LRS) to replace conventional human peripheral blood leukocytes in experimental researches and to comparatively analyze the differences between them in vitro biological functions and phenotypes of T cells. 
 
 
Methods 
Mononuclear cells were isolated from LRS-separated leukocytes and whole blood sample that collected from the same person by using Ficoll. Fluorescence-activated cell sorting (FACS) was performed to analyze the phenotypes of T cells. CD3+ T cells were sorted out by using magnetic beads. The T cells that were collected by using two different ways were incubated with anti-CD3 and anti-CD28 antibodies and IL-2 in vitro for 10 days. Several assays including cell counting, FACS and cytometric beads array (CBA) were performed to comparatively analyze the differences in biological functions and phenotypes of T cells that were isolated by different methods. 
 
 
Results 
The phenotypes of T cells isolated from LRS filter and whole blood sample were highly similar at the initial stage. The sorting rate of CD3+ T cells form LRS filter reached a high level and met the requirements for experimental researches. No statistically significant differences in cell count, phenotype, expression of costimulatory molecules and cytokine secretion were observed between T cells isolated from LRS filter and whole blood sample. 
 
 
Conclusion 
This study suggested that the T cells isolated from LRS filter could be used as an alternative to whole blood T cells for fundamental researches since they were similar in cell vitality, phenotype and biological functions. It provided a new way to solve the problem of blood shortage in clinic and scientific research. 
 
 
Key words: 
LRS; Peripheral blood; CD3+ T cell