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Article: Immune Synapse
- Article from:
- World of Microbiology and Immunology
CopyrightCOPYRIGHT 2003 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Immune synapse
Before they can help other immune cells respond to a foreign protein or pathogenic organism, helper
T cells
must first become activated. This process occurs when an antigen-presenting cell submits a fragment of a foreign protein, bound to a Class II
MHC
molecule (virus-derived fragments are bound to Class I MHC molecules) to the helper T cell. Antigen-presenting cells are derived from bone marrow, and include both dendritic cells and Langerhans cells, as well as other specialized cells. Because T cell responses depend upon direct contact
with their target cells, their
antigen
receptors, unlike antibodies made by
B cells
, exist bound to the membrane only. In ...