Cells APCs

Antigen-presenting cells (APCs) are cells of the immune system that are able to process and present foreign antigens to effector cells. The antigen is presented in the context of an MHC-I or MHC-II molecule on APCs in the presence of so-called costimulatory molecules to activate the effector cells. 

Dendritic cells (DCs) are functionally classified into myeloid (MDCs) and plasma-cytoid DCs (PDCs), both of which are potent professional antigen presenting cells (APC) but vary in the expression of a number of surface molecules. They also exhibit differences in their susceptibility to various strains of HIV-1 (Lore et al. 2005 Smed-Sorensen et al. 2005). Their role in the dissemination of HIV-1 is of... 

Class 2 MHC molecules are expressed on the surface of B cells, macrophages, monocytes, various antigen-presenting cells (APCs) and certain cells of the T-cell famify. 

Class II. These molecules are expressed solely on the surfaces of antigen-presenting cells (APCs). The APCs serve to... 

Dendritic cells (DCs) are bone marrow-derived professional antigen-presenting cells (APCs) (1). The function of DCs depends on their maturation stages progenitors in the bone marrow, precursors in the blood, immature DCs in peripheral tissues, antigen-transporting DCs in the afferent lymphatics, and... 

The production of an antibody response requires an antigen to be taken up by antigen-presenting cells (APCs) in order to be recognized by lymphocytes... 

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. 

We also addressed IRIV effects on antigen-presenting cells (APC). We investigated IRIV effects on DC, some of the most effective professional APC. 

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. 

An antigenic protein enters either the blood or the interstitial fluid, where it is taken up by an antigen-presenting cell (APC), digested and the peptide fragments are presented, along with MHC-11 molecules, on the surface of the APC. 

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