The extent of HLA-DR expression on HLA-DR+Tregs allows the identification of patients with clinically relevant borderline rejection
Regulatory T cells (Tregs) were shown to be involved into the pathogenesis of acute rejection after transplantation. The suppressive activity of the total regulatory T cell pool depends on its percentage of highly suppressive HLA-DR(+) -Treg cells. Therefore, both the suppressive activity of the total Treg pool and the extent of HLA-DR expression of HLA-DR(+) -Tregs (MFI HLA-DR) were estimated in non transplanted volunteers, patients with end-stage renal failure (ESRF), healthy renal transplant patients with suspicion on rejection, due to sole histological Bord-R or sole acute renal failure (ARF), and patients with clinically relevant borderline rejection (Bord-R and ARF). Compared to patie…
A distinct subset of HLA-DR+-regulatory T cells is involved in the induction of preterm labor during pregnancy and in the induction of organ rejection after transplantation.
Regulatory T cells (Tregs) are known to suppress alloimmune responses during pregnancy and post organ transplantation. We demonstrate that a distinct subset of FoxP3(+)DR(+)-Tregs among the total CD4(+)CD127(low+/-)CD25(+)-Treg cell pool is critically involved in preterm labor induction and kidney transplant rejection as well. Compared to healthy pregnancies and non-rejecting kidney recipients, we found that the percentage of the FoxP3(+)DR(+)-Treg subset was not reduced, but that the level of HLA-DR expression of such Tregs was strongly diminished in preterm laboring women and in patients with acute renal allograft rejection. In addition, both patient collectives showed a significantly red…
The role of recent thymic emigrant-regulatory T-cell (RTE-Treg) differentiation during pregnancy.
During pregnancy, regulatory T cells (Tregs) have a key role in maternal immune tolerance to the semi-allogeneic fetus. Our previous results showed that the naive CD45RA(+)-Treg pool is functionally improved in pregnant women compared with non-pregnant women. Therefore, we examined the thymic output and differentiation of CD45RA(+)CD31(+) recent thymic emigrant (RTE)-Tregs during normal pregnancy and in the presence of preeclampsia. With the onset of pregnancy, the composition of the total CD4(+)CD127(low+/-)FoxP3(+)-Treg pool changed in the way that its percentage of RTE- and CD45RA(-)CD31(+)-memory Tregs decreased strongly, whereas that of the CD45RA(+)CD31(-)-mature naive (MN)-Tregs did …
Pregnancy-associated diseases are characterized by the composition of the systemic regulatory T cell (Treg) pool with distinct subsets of Tregs
Dysregulations concerning the composition and function of regulatory T cells (T(regs)) are assumed to be involved in the pathophysiology of complicated pregnancies. We used six-colour flow cytometric analysis to demonstrate that the total CD4(+) CD127(low+/-) CD25(+) forkhead box protein 3 (FoxP3)(+) T(reg) cell pool contains four distinct T(reg) subsets: DR(high+) CD45RA(-), DR(low+) CD45RA(-), DR(-) CD45RA(-) T(regs) and naive DR(-) CD45RA(+) T(regs). During the normal course of pregnancy, the most prominent changes in the composition of the total T(reg) cell pool were observed between the 10th and 20th weeks of gestation, with a clear decrease in the percentage of DR(high+) CD45RA(-) and…
DR(high+)CD45RA(-)-Tregs potentially affect the suppressive activity of the total Treg pool in renal transplant patients.
Recent studies show that regulatory T cells (Tregs) play an essential role in tolerance induction after organ transplantation. In order to examine whether there are differences in the composition of the total CD4(+)CD127(low+/-)FoxP3(+)- Treg cell pool between stable transplant patients and patients with biopsy proven rejection (BPR), we compared the percentages and the functional activity of the different Treg cell subsets (DR(high+)CD45RA(-)-Tregs, DR(low+)CD45RA(-)-Tregs, DR(-)CD45RA(-)-Tregs, DR(-)CD45RA(+)-Tregs). All parameters were determined during the three different periods of time after transplantation (0-30 days, 31-1,000 days, >1,000 days). Among 156 transplant patients, 37 pat…