Phosphoinositide signaling pathway in T-cell proliferation (null)

The "T-cell proliferation via phosphoinositide signal transduction pathway" does not refer to a single molecular target but rather to a complex signaling cascade essential for T-cell function. Activation of the T-cell receptor (TCR) along with costimulatory molecules (e.g., CD28) triggers phosphoinositide 3-kinase (PI3K) to convert PI(4,5)P2 to PI(3,4,5)P3 (PIP3) at the membrane, recruiting key kinases such as PDK1 and AKT. Phosphorylated AKT then propagates downstream signaling, leading to T-cell growth, proliferation, survival, and differentiation. Negative feedback is provided by phosphatases such as PTEN and SHIP. This signaling network is a therapeutic target in oncology (immunotherapy, lymphoma, leukemia) and transplant medicine (immunosuppression), with multiple drugs targeting PI3K or mTOR components. However, it is not a "target" in the sense of a single molecule, receptor, or enzyme, but rather a pathway comprising numerous enzymes, lipid mediators, and kinases acting in concert[3][5][7].

Other names

Phosphoinositide signal transduction in T cellsPI3K/Akt pathway in T cellsT-cell PI pathway

Inhibition of PI3K reduces T-cell activation and survival by blocking PIP3 formation and downstream AKT activation\nmTOR inhibition decreases T-cell proliferation and immune responses