Antigen-presenting cell interactions

Reported by Hoffmann, et al. (1994) who used site-ditected mutagenesis and synthetic peptides to localize molecular regions involved in T cell and antigen presenting cell interactions. Zinc binding was determined by the 1.9A SEC3 crystal structure (Chi, et al., submitted). 

Inhibit the interaction between antigen or antigen-presenting cells (AJPCs) and T-lymphocytes... 

Inhibitors of Interaction between Antigen or Antigen-Presenting Cells and T-Lymphocytes... 

The development of effector T cells following activation by antigen-presenting cells also requires the interaction of another receptor-ligand pair. CD40 molecules on antigen-presenting cells are required to bind... 

Farrer, D. F., Hueber, S. and McCabe, Jr., M.J., Lead enhances CD4+ T cell proliferation indirectly by targeting antigen presenting cells and modulating antigen-specific interactions, Toxicol. Appl. Pharmacol. In Press, 2005. 

Interaction of Regulatory T Cells with Antigen-Presenting Cells in Health and Disease... 

Although closely related, monocytes/macrophages (MO) possess features that are distinct from DCs. Due to their limited expression of T-cell costimulatory molecules, MO are not able to prime T cells de novo, but rather stimulate effector/memory T cells by the secretion of cytokines, which support T-cell proliferation. As DCs, MO differentiate from myeloid precursors and form a heterogeneous population of antigen-presenting cells (APCs) that link the innate and adaptive immune systems. However, their ability to interact with T cells via MHC class II TCR interaction(s) as well as engagement of T-cell costimulatory receptors on their surface, makes close contact between MO and Tregs likely to occur in vivo. 

The class II proteins are produced mainly within specific cells, known as antigen-presenting cells (APC). Their role is to prepare antigens derived from the pathogens in such a way that they can interact with the T-helper cell receptor. Since this is their only role, they are sometimes called professional antigen-presenting cells , i.e. other immune cells can also present peptides to T-helper cells (e.g. macrophages, B-lymphocytes) but this is not their prime role. The professional APCs are also known as dendritic cells. 

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