Co-stimulation pathway (null)

The **co-stimulation pathway** refers to a collection of molecular interactions and signaling events necessary for full activation of immune cells, most notably T lymphocytes[1][3]. T cell activation requires two signals: the first is antigen recognition via the T cell receptor (TCR); the second is co-stimulation, provided by co-stimulatory molecules (e.g., CD28 on T cells engaging CD80/CD86 on antigen-presenting cells)[1][2][3]. Co-stimulatory receptors belong mainly to the immunoglobulin superfamily (with well-known examples such as CD28, ICOS) and the tumor necrosis factor receptor superfamily (e.g., CD40, OX40)[2][6]. Therapies that modulate co-stimulatory pathways—including antagonists that dampen autoimmunity and agonists that boost anti-cancer immunity—are in clinical and preclinical use[2][3]. Because "Co-stimulation pathway" itself is not a discrete molecule, it is not appropriate to treat it as a single therapeutic target; instead, individual co-stimulatory and co-inhibitory molecules within the pathway (such as CD28, CD80, CD86, ICOS, CTLA-4) are the therapeutic targets[2][3][6].

Other names

Co-stimulatory moleculeCo-stimulatory pathwaySecondary signal in immune activation

Inhibition or activation of T cell co-stimulation (blocking ligand binding, agonism of co-stimulatory receptors)