Introduction:
While T cell inhibition is a prerequisite for organ transplantation, no reliable method to measure T cell function has been established. We have performed in vitro assessments of T cell response in lung transplant (LTx) recipients, comparing different modes of immunosuppression and the relationship to clinical outcomes to improve immunosurveillance.
Methods:
Blood samples were drawn at 1, 3, 6 and 9 months after LTx, and compared to healthy controls. PBMC were isolated and T cells stimulated in vitro with beads (CD2, CD3 & CD28) for 4 days and PMA/Ionomycine the final 2 hrs. Proliferation was measured using CFSE; surface markers and intracellular cytokines using appropriate antibodies after fixation, using a BD LSR Fortessa flow cytometer and FlowJo v.10.8.2.
Results:
Patients CD4+ T cells showed stronger proliferation than CD4+ T cells from healthy controls after in vitrostimulation. The expression IFN-y from CD8+ cells show a higher production in LTx patients, but a higher response from baseline activation in healthy controls. (Figure 1.)
Conclusion:
Preliminary results show clear differences between LTx patients and healthy controls in CD4+ T cell proliferation. LTx patients had a stronger unstimulated production of IFNy but a reduced ability to increase upon stimulation than healthy controls. We believe the observations can be a used to develop tools for personalized immunosuppression.