Directed delivery of CD40 ligand from helper T cells to antigen-presenting B cells

This dissertation presents my studies investigating the delivery of CD40 ligand (CD40L, CD154) from helper T lymphocytes to antigen-presenting B lymphocytes. CD40L is a type two transmembrane TNF superfamily cytokine made by T cells that engages CD40 on antigen-presenting cells, including B cells, initiating downstream signaling resulting in B cell proliferation, differentiation, and antibody formation. Helper T cells can produce CD40L de novo upon antigen-specific interactions, but they also have an intracellular secretory compartment containing a small amount of preformed CD40L that is brought to the T cell surface rapidly upon antigen recognition.