Aim: To investigate the role of the extracellular domain of human 4-1BBL (ex4-1BBL) in regulating the in vitro activities of peripheral blood lymphocytes (PBL).
Methods: Viable cells were quantified with Trypan-blue exclusion assay. CytoTox 96 Nonradioactive Cytotoxicity Assay Kit was used for measuring LDH levels of supernatant. ELISA kit was used for measuring IL-2 level. In vitro cytotoxity of PBL combined with anti-CD3/anti-Pgp bispecific diabody plus ex4-1BBL was analyzed with CytoTox 96 nonradioactive method.
Results: Ex4-1BBL can increase the proliferation of PBL, reduce cell death, promote IL-2 secretion, and the experimental group with ex4-1BBL showed obviously enhanced cytotoxic effect toward K562/A02 cells.
Conclusion: Ex4-1BBL may be an important adjuvant for improving activities of PBL.