Inflammatory Response Flashcards
What is an inflammatory response?
Non-specific defence that is innate from birth and occurs when tissues are injured, causing blood vessels to leak fluid into the tissue (swelling).
A localised process
What are the phagocytic cells associated with non-specific responses?
Neutrophils (neutrocyte)
Eosinophils
Monocytes (leukocyte)
Macrophages
What are the non-phagocytic cells associated with non-specific immune response?
NK Cells (Natural Killer cell)
Mast Cells
Basophils
Name the two types of inflammatory responses
Acute- mins/hours
Chronic- weeks/years
Describe the characteristics of acute inflammatory response.
Redness Heat Swelling Pain Loss of function Increase permeability Oedema Cell recruitment & migration
Describe the characteristics of chronic inflammatory response
Macrophages
Lymphocytes
Granuloma formation (mass of granulation tissue/ new connective tissue)
Name the mediators of a non-specific response.
Vasoactive amines (histamine, serotonin)
Arachidonic acid metabolites
Cytokines
Complements system
What is the complement system?
Series of proteins in plasma activated by immune system or infection.
What are the products of the complement system?
Opsonins
Anaphylatoxins
Chemotactic factors
What are cytokines?
Hormone like molecule produced by many cell types.
E.g. Interleukins (IL-1), colony stimulation factors (CSF), tumour necrosis factors (TNF).
What’s the function of cytokines?
Chemotaxis (movement of Cells due to inc or Dec of substance)
Cellular proliferation, differentiation, activation, apoptosis.
How does cell recruitment and migration occur in non- specific response?
Selective process... Margination (capture) Adhesion- to endothelium (pavementing), involves expression of adhesion molecules on leucocytes and receptors on endothelial cells. Migration Chemotaxis Proliferation
Describe the acute phase response.
Whole body (systemic) response to infection.
Caused by monocytes/macrophages releasing cytokines =
Inc. number of neutrophils
Inc. production of acute phase proteins.
What are the symptoms of acute phase response?
Fever
Drowsiness
Loss of appetite
Muscle break down
How is the SPECIFIC immune response characterised?
Specific to pathogen
Diversity (many different pathogens)
Immunological memory
Self-non-self discrimination
Name the types of lymphocytes.
B lymphocytes
T lymphocytes:
1) cytotoxic T lymphocytes (CD8+)
2) helper T lymphocytes (CD4+)
Where do lymphocytes mature?
B- bone marrow
T- thymus
Describe the cell surface receptors of lymphocytes
B- membrane bound antibodies on surface
T- T cell receptors on surface
Define immunogen
Stimulates a specific immune response
Define Antigen
Combines with the products of an immune response
Define Epitope
The part of the immunogen recognised by a small lymphocyte (T or B) to which an antibody binds.
Describe the process of clonal selection and expansion (selective inflammatory response)
All small lymphocytes have receptors for epitope
They bind = proliferation and differentiation (clonal expansion, requires cytokines)
Most Cells differentiate into effector Cells
Some remain as memory cells
What are antibodies?
Immunoglobulins (glycoproteins in plasma fluids and secretions)
Specific to epitopes
Bind to epitope and stimulate removal of immunogen (phagocytes & activation complement)
Name the classes of antibodies
1) IgG
2) IgM
3) IgA
4) IgE
5) IgD
How does immunological memory work?
Response activated earlier
More cells released to fight
Much more sustained/ for longer
What are the two types of specific immune response?
Humoral Immunity- antibody production by B cells (extracellular pathogens)
Cell mediated immunity- production of cytotoxic T cells (intracellular pathogens)
How are helper T cells stimulated in specific immune response?
Interact with antigen presenting Cells (e.g. Macrophages)
Don’t directly kill infected cells
Then activate, proliferate, differentiate (activate cytokines secretor)
What are the two types of T helper Cells?
Th1- secretes IL-2 cytokines, TNF & IFN. Supports cell mediated immunity against intracellular parasites.
Th2- secretes IL-4, 5, 6, 10 cytokines. Support humoral immunity against extracellular parasites.
Describe the process of humoral immunity.
Immunogen presented on APC.
B cell has antibodies for epitope
Activated to plasma cell (fully differentiated B cell) that produces lots of antibodies specific to epitope
Cytokines produced by t helper used to activate.
Some B cells also activated to memory cells.
Describe the process of cell mediated immunity (specific immune response)
Normally for a viral infection
Any cell can be infected
T cell responds to viral epitope on cell.
MHC1 molecule (all cells have this marker) so know its own cell.
Once activated needs IL-2 from Helper T
Turns into cytotoxic T cell
Can either kill directly or indirectly (NK cells)
How are infected cells killed in cell mediated immunity?
Granules in cytotoxic cells contain perforin which degranulates and released onto target cell to form channels, degradation enzymes released and go through perforin channels and kill cell
