T follicular helper (Tfh) cells are key players in the production of antibody-producing B cells
Paired blood and lymph node (LN) samples were obtained from 61 transplant recipients immediately prior to organ implantation. Living-donor recipients received a week of tacrolimus prior to kidney transplantation. Deceased-donor recipients served as controls, as tacrolimus was not administered until after the transplant operation. Flow cytometry was used to compare LN and circulating cell subsets.
The calcineurin inhibitor (CNIs) tacrolimus specifically suppresses both LN Tfh cells and circulating Tfh cells, but not their regulatory counterparts or other CD4 T cell subsets.
Our findings suggest that CNIs may have a more important role in the prevention of antibody formation than previously understood and, therefore, have potential for antibody-associated conditions in which aberrant Tfh function has been implicated in disease.