Patient PBMC were thawed and resuspend at 3×10
6/ml in AIM-V
® AlbuMAX
® serum-free media supplemented with 1mM L-glutamine. The KTR responders were run in triplicate in media, test wells and
Phytohemagglutinin (Sigma-Aldrich, St Louis, MO, USA) as a positive control. The MLR consisted of 3×10
5 thawed KTR PBMCs plated on an anti IFN-γ antibody (2G1, Thermo-Scientific, Woburn, MA, USA) coated
ELISPOT plate (Millipore, Bellerica, MA, USA) co-incubated with 4 or 5 B cells lines at 5×10
4/per B cell line, 2 B cell lines per well (total of 1×10
5 B cells/well), or with the 5
th B cell line at 1×10
5 B cells/well, for 24h. These B cell lines had either 17 or 21 disparate antigens, with the most similar cell lines paired. After which, the plates were handled as per previously published protocol
23 (link), with half the plates washed utilising an
ELx50 Microplate strip washer (BioTek, Winooski, VT, USA).
The images captured with Cellular Technology, Ltd (CTL)-ImmunoSpot
® S6 Micro Analyzer (Cellular Technology, Ltd, Shaker Heights, OH, USA) with
ImmunoCapture 6.4 software (Cellular Technology, Ltd). The spots counted using CTL ImmunoSpot 5.0 (Cellular Technology, Ltd) and quality controlled by inspecting every well and adjusting sensitivity. The IFN-γ
ELISPOT plates were analysed at the Clinical Trials of Organ Transplantation (CTOT) center in Mount Sinai School of Medicine, New York.
Hope C.M., Fuss A., Hanf W., Jesudason S., Coates P.T., Heeger P.S, & Carroll R.P. (2015). Peripheral natural killer cell and allo-stimulated T-cell function in kidney transplant recipients associate with cancer risk and immunosuppression related complications. Kidney international, 88(6), 1374-1382.