Transplant tolerance through costimulation blockade--are we there yet?

Area of Science:

• Transplant immunology
• Immunosuppression
• T cell alloimmunity

Background:

• Current immunosuppression effectively manages acute rejection but not chronic rejection.
• Chronic rejection is driven by ongoing T cell-mediated alloimmune responses.
• Targeting T cell costimulation pathways is a key strategy for graft-specific tolerance.

Purpose of the Study:

• To review the role of positive and negative costimulatory pathways in alloimmune responses.
• To discuss the complex interplay between these costimulatory pathways.
• To summarize progress in targeting costimulatory pathways for improved transplant outcomes.

Main Methods:

• Review of current scientific literature on T cell costimulation in transplantation.
• Analysis of the roles of individual and interacting costimulatory pathways.
• Examination of immunosuppressive agents targeting these pathways in various organ transplant models.

Main Results:

• Alloimmune responses are determined by the intricate balance of positive and negative costimulatory signals.
• Targeting specific costimulatory pathways shows promise in modulating destructive alloresponses.
• Understanding pathway interactions is crucial for developing effective, non-specific immunosuppression.

Conclusions:

• T cell costimulation blockade is a viable strategy to achieve graft-specific tolerance.
• Further research into costimulatory pathway interactions can lead to novel immunosuppressive therapies.
• Successful modulation of alloimmune responses can mitigate chronic rejection and enhance allograft survival.