Fig. 7: Human leukocyte antigen-specific T cells capture by monoallelic HLA-A*02:01-expressing pAPCs.

A Schematic illustrating the preparation of monoallelic HLA-A*02:01-expressing pAPCs for subsequent capture of virus-specific T lymphocytes from human PBMCs. An immunodominant antigen of cytomegalovirus (CMV), pp65, was used for to capture virus-specific lymphocyte from 3 CMV⁺ donors. B Representative flow cytometric plots and C quantification of HLA-A*02:01-pp65 tetramer-positive T cells following different lymphocyte isolation protocols. Non-cognate T cell dislodgement was performed by suspending captured pAPCs in solution for 15 min. T cells capture with control pHEK293T without pp65 peptide loading was incorporated as a negative control. PBMCs from three individual CMV seropositive donors were conducted independently. P values, ***p = 0002, **p0.0013, NS p = 0.2089. The error bars represent mean ± standard deviation (n = 3). D Schematic illustration of MART-1-specific T cell capture and cytolysis evaluation against a human melanoma cell line. MART-1-specific T cells were induced via MART-1 peptide vaccination in HLA-A*02:01 transgenic mice. E Flow cytometric analysis and F quantification of HLA-A*02:01-MART-1 tetramer-positive T cells before and after capture with MART-1 loaded pHEK293T. P = 0.0363 (Independent biological replicates n = 3). G Cytolysis assessment of MART-1-loaded pAPC-captured T cells against C32 human melanoma cell line. 10⁴ C32 human melanoma cells were incubated with designated effector to target cell ratios (E:T) ranging from 0 to 10. Following 48 h of incubation, cytolysis was assessed using a LDH cytotoxicity assay. P value from left to right, *p = 0.0113, * = 0.0257, * = 0.0252 (Independent biological replicates n = 3). The error bars represent mean ± standard deviation. Statistical analyses were performed by two-sided Student’s t tests.