Logo Annals of Transplantation Logo Annals of Transplantation Logo Annals of Transplantation

29 October 2004

Costimulatory Pathways as A Basic Mechanisms of Activing A Tolerances Signal in T Cells

M Magott - Procelewska

Ann Transplant 2004; 9(3): 13-18 :: ID: 10210


Immune tolerance is an active response leading to the T cell unresponsiveness in the presence of the graft, which may develop through acouple of mechanisms including costimulation blockade. The CD28/B7 and CD40L/CD40 costimulatory pathways have been described as the critical for T cell activation. When activated T cell upregulate CTLA4, which importance as a negative regulatory costimulatory molecule is highlighted by the recent evidence suggesting that CTLA4 may function as a master switch for peripheral T cell tolerance. The effects of CTLA4 engagement are directed at the inhibition of CD28 signaling. Modulation of proximal TCR signals and down-stream effector pathways of T cell activation result in altered T cell differentiation and downregulation of immune responses. CTLA4 may regulate signal transduction in a rare subset of CD4+CD25+ T cells which leads to differentiation into regulatory cells. CD40L/CD40 interaction provides a bi-directional signal for T and B cell activation. A possible mechanisms of tolerance induction by CD40L/CD40 blockade involve reduction in expression of B7 molecules, effects on bcl-xL gene and APC function modification. The role of the new discovered pathways: ICOS/B7RP-1 and PD-1/PD-L1 in regulation of T cell response in transplantation is becoming apparent.

Keywords: Costimulatory Molecules;, CD28;, Cytotoxic T Lymphocyte Antigen (CTLA4);, CD40 Ligand;, CD40;, B7;, Allograft Rejection;


In Press

20 Jan 2022 : Original article  

Impact on Waitlist Outcomes from Changes in the Medical Eligibility of Candidates for Simultaneous Liver-Ki...

Ann Transplant In Press; DOI: 10.12659/AOT.934850  

19 Jan 2022 : Original article  

Carbohydrate Metabolism Disorders in Relation to Cardiac Allograft Vasculopathy (CAV) Intensification in He...

Ann Transplant In Press; DOI: 10.12659/AOT.933420  

18 Jan 2022 : Original article  

PLGA+Fe₃O₄+PFP Nanoparticles Drug-Delivery Demonstrates Potential Anti-Tumor Effects on Tumor Cells

Ann Transplant In Press; DOI: 10.12659/AOT.933246  

17 Jan 2022 : Original article  

Impact of Thyroid Incidentaloma on Liver Transplant: A Study of 1010 Recipients at a Single Center

Ann Transplant In Press; DOI: 10.12659/AOT.934988  

Most Viewed Current Articles

29 Dec 2021 : Original article  

Efficacy and Safety of Tacrolimus-Based Maintenance Regimens in De Novo Kidney Transplant Recipients: A Sys...

DOI :10.12659/AOT.933588

Ann Transplant 2021; 26:e933588

22 Dec 2021 : Original article  

Comparison of Coronary Artery Calcium Scoring with Dobutamine Stress Echo for Detection of Coronary Artery ...

DOI :10.12659/AOT.934163

Ann Transplant 2021; 26:e934163

12 Jan 2022 : Original article  

Risk Factors for Developing BK Virus-Associated Nephropathy: A Single-Center Retrospective Cohort Study of ...

DOI :10.12659/AOT.934738

Ann Transplant 2022; 27:e934738

01 Dec 2021 : Original article  

Solid-Phase C1q/C3d Fixing Readouts Correlate with High Median Fluorescence Intensity (MFI) De Novo Donor-S...

DOI :10.12659/AOT.934175

Ann Transplant 2021; 26:e934175

Your Privacy

We use cookies to ensure the functionality of our website, to personalize content and advertising, to provide social media features, and to analyze our traffic. If you allow us to do so, we also inform our social media, advertising and analysis partners about your use of our website, You can decise for yourself which categories you you want to deny or allow. Please note that based on your settings not all functionalities of the site are available. View our privacy policy.

Annals of Transplantation eISSN: 2329-0358
Annals of Transplantation eISSN: 2329-0358