Together with the observation that similar levels of the Nef protein were detected in nef-transfected cells and upon infection of PBMC, these data suggest a selective immunosuppression induced by nef in human T cells by altering TcR signaling without detectable impact on CD28 co-receptor function.
CD28 memory cells accumulate during CKD and appear to confer protection against acute rejection under standard immunosuppression and possibly costimulation blockade.
Costimulation blockade, specifically CD28/B7 inhibition with belatacept, has emerged as a clinical replacement for CNI-based immunosuppression in kidney transplantation.
Owing to different requirements in CD28 costimulatory and CTLA-4 coinhibitory signals to control naive and memory T cells, selective antagonists of CD28-CD80/86 interactions have been developed on the rationale that preservation of CTLA-4-mediated regulatory mechanisms would result in a better control of alloreactivity and would represent a regulatory T-cell-compatible immunosuppression.
Although CD28 is associated with the expression of inflammatory mediators, apoptosis-related protein, immunosuppression, and tumorigenesis, the effects of CD28 deficiency on blast exposure-induced lung injury have not been investigated.
Since the approval of belatacept in 2011 for use in the setting of de novo kidney transplantation, this CD80/86 - CD28 co-stimulation blocker has been shown to be a valuable treatment option for maintenance immunosuppression.