lecture 33 - linking innate and adaptive immunity Flashcards
What are 3 key components of immune cell communication?
Soluble chemical messengers, surface bound ligands, antigens
What are soluble chemical messengers and how do they lead to cell communication?
Soluble molecules (chemokines and cytokines) bind to chemokine and cytokine cell membrane receptors which triggers a cellular response.
How are surface bound ligands involved in immune cell communication?
Cell surface-bound receptors bind to cell surface ligands which can relay between T and B cells, altering the function of one or both cells, by up or down regulating gene expression
What are ligands, in terms of immunity?
Molecules that are relayed between cell surface receptors on different cells for communication.
What are antigens, in terms of a pathogen?
A part of a pathogen that can be recognised by the immune system .
How are antigens involved in immune cell communication, particularly in linking innate and adaptive immunity?
Dendritic and other cells can present antigens to T-cells by binding them to cell surface receptors, which triggers an adaptive response.
What are the types of antigens?
Foreign and self antigens
What are foreign antigens?
Antigens that come from outside the body - pathogens, chemicals, etc.
What are self antigens?
Antigens produced by the body that the immune system is usually tolerant of and recognises as self.
What is activated dendritic cell communication?
Process in which PAMP activated dendritic cells make cytokines and chemokines, utilise surface bound ligands and present antigens to active T-cells.
What does MHC stand for in immunology?
Major histocompatability complex
What is MHC, and what is its function?
A group of genes that code for cell surface receptors that are essential for the adaptive immune system
What are the 2 types of MHCs?
MHC-I and MHC-II
What is MHC-I?
MHC that is expressed on all nucleated cells, and is used to present endogenous/intracellular antigens to T cells.
What is MHC-II?
MHC that is expressed only on antigen presenting cells (e.g. dendritic cells) and presents exogenous (extracellular) antigens
What are endogenous antigens?
Intracellular antigens
What are exogenous antigens?
Extracellular antigens
What are cytokines?
Molecules that control immune cell growth and activity
What are 2 key examples of cytokines?
Interleukins, interferons
What are chemokines?
Molecules that stimulate leukocyte (white blood cell) migration.
What immune system/s produce cytokine and chemokines?
Both innate and adaptive
What are helper T cells?
T cells that have been activated in such a way that they can help B cells to make antibodies
How do helper T cells activate B cells?
Making cytokines that bind to receptors on B cell membranes, and using their surface receptors to bind to B cell surface bound ligands.
How can B cells be activated, aside from by helper T cells?
When complement fragments bound to antigens are recognised by B cell receptors.
