Immunomodulation via targeted inhibition of antigen receptor signal transduction

Andrew E Schade1, Gonzalo Gonzalez-Stawinski

  • 1Department of Clinical Pathology, Cleveland Clinic, Cleveland, OH 44195, USA. schadea@ccf.org

Coronary artery vasculopathy (CAV), characterized by diffuse concentric coronary artery intimal thickening with fibrosis, remains a significant complication impeding long term engraftment in heart transplantation. The pathophysiologic processes driving CAV are not well understood, however T cell mediated cellular immunity and cytokines have been implicated. The inability to prevent CAV may be related in part to a limited spectrum of inhibition that that current immunosuppressive therapies exhibit against second messenger pathways elicited by T cell receptor (TCR) activation and dose limiting toxicities. Therefore, considering that antigen specific T cell activation is initiated at the TCR, including alloresponses involving direct and indirect antigen presentation, targeting the proximal kinases involved in this process may provide novel therapeutic options for controlling rejection. Src family kinases (SFK), particularly p56(lck) (Lck) and p59(fyn) (Fyn), are intimately associated with the earliest signaling events through the TCR and could provide targets for immunomodulatory agents. Such targeted inhibition of TCR signaling may institute a novel approach for diminishing the T cell mediated response associated with CAV. In this review we discuss therapeutic agents that have been shown to inhibit SFK and the rationale for investigating the potential application of these agents in heart transplantation.

Related Concept Videos

Tumor Immunotherapy01:27

Tumor Immunotherapy

Immunotherapy is a treatment that boosts or manipulates the immune system to fight diseases, including cancer. For instance, by stimulating an immune response through vaccinations against viruses that cause cancers, like hepatitis B virus and human papillomavirus, these diseases can be prevented. Nonetheless, some cancer cells can avoid the immune system due to their rapid mutation and division. The immune response to many cancers involves three phases: elimination, equilibrium, and escape.
Targeted Cancer Therapies02:57

Targeted Cancer Therapies

The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
There are several types of targeted therapies against specific...
Cell-mediated Immune Responses01:40

Cell-mediated Immune Responses

Overview
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...