HC were co-cultured with irradiated PBMC or SPL as stimulators in the presence of belatacept-mediated CSB.
(A) Percent inhibition of proliferation (measured by 3H-thymidine incorporation) on day 6 of primary CSB-MLR was comparable using PBMCs or SPL as stimulators. (HC=35, post-LTx=11)
(B) Frequencies of CD25highFoxp3+ Treg expressed as percentage of CD3+CD4+ cells prior to (baseline) and after primary CSB-MLR (denoted CSB) indicated similar Treg expansion using PBMC or SPL as stimulators. (HC=28, post-LTx=12)
Horizontal lines are medians, boxes are 25th and 75th percentiles, and whiskers are maximum and minimum values. P-values were calculated using unpaired t-test with Welsh’s correction (A) and paired-t test (B) with significant p-values highlighted in bold. HC: healthy controls; MLR: mixed lymphocyte reaction; CSB: costimulatory blockade; SPL: splenocytes; Treg: regulatory T cell; MFI: mean fluorescence intensity