Functional Analysis of CD28/B7 and CD40/CD40L Costimulation During the in vivo Type 2 Immune Response
Abstract
Cytokine production and other effector functions ofCD4+ T helper (Th) cells are crucial for the initiation of a primary immune response. The activation of naive CD4+ Thcells requires two signals delivered from antigen presenting cells (APCs). The engagement of the T cell surface receptor (TCR) by antigenic peptides presented in the context of major histocompatibility complex (MHC) class IT molecules on APCs provides the primary signal, but this Ag-specific signal alone is not sufficient to activate naiveCD4+ Th cells. A second or costimulatory signal from APCs, which is independent of Tcell receptor signaling, is required for optimal activation, proliferation, and cytokine production by naive CD4+ Th cells. Recent studies have shown that T cell surface molecule CD28, and its homologue CTLA-4, can provide costimulatory signals to 10cells when they interact with their ligands, B7-11B7-2 on APCs. Interactions between 10cell surface CD40 ligand (CD40L) and B cell CD40 molecules have also been shown to costimulate Th cell activation. In this investigation, the role of CD28/CTLA4-ligand costimulation in nave Th cell activation and T cell cytokine production was examined by blocking CTLA-4-Iigand interactions in two in vivo type 2 immune response models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 06, 1995
- Accession Number
- AD1011520
Entities
People
- Pin Lu
Organizations
- Uniformed Services University of the Health Sciences