- Matthew E Call, PhD
Matthew E Call, PhD
- Head of Laboratory, Structural Biology Division
- The Walter and Eliza Hall Institute of Medical Research
- Department of Medical Biology
- The University of Melbourne
The mechanism by which an antigen triggers an adaptive immune response involves several steps. Potentially antigenic particles must be captured, processed, and presented in recognizable form to T cells with the appropriate concomitant signals. The cells that perform these functions are antigen-presenting cells (APCs). Most nucleated cells express at least some of the major histocompatibility complex (MHC) proteins required to present antigens to T cells, a feature that endows all cells with the potential to become targets of the immune response when damaged or infected. However, only a select subset of hematopoietic lineage cells possesses the specialized machinery required to efficiently activate or "prime" naïve T cells and thereby initiate a new adaptive immune response. These cells are "professional" APCs.
The antigen processing and T cell priming functions of APCs as well as clinical implications and applications of these cells are presented in this topic review. The cellular interactions that form the basis of the cellular immune response and an overview of MHC structure and function are presented separately. (See "The adaptive cellular immune response" and "Major histocompatibility complex (MHC) structure and function".)
Professional APCs — There are three professional APCs:
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- Professional APCs
- MAJOR FUNCTIONS
- Monitoring the intracellular environment
- - Antigen acquisition
- - Loading of MHC I molecules
- - Regulation
- Monitoring of the extracellular environment
- - Antigen uptake
- - Antigen processing
- - Loading of MHC II molecules
- - Regulation
- CROSS-PRESENTATION PATHWAYS
- T CELL PRIMING BY APCs
- LIPID ANTIGENS AND CD1
- COOPERATION BETWEEN T AND B CELLS
- CLINICAL RELEVANCE
- Diseases of APCs
- APC-based therapies
- - Vaccination
- APC-based cancer immunotherapy
- - Agents that block APC function
- Antigen-presenting cell functions
- Antigen processing and presentation