Immune Response to Infection Flashcards
What are the key mediators of immunity?
Phagocytes and lymphocytes are key mediators of immunity
What is the role of phagocytes?
internalize pathogens and degrade them
What do B cells do?
Make antibodies - that are also effective against extracellular pathogens
What do T helper cells do?
Coordinate the immune response by direct cell-cell interactions and the release of cytokines
What are the two essential features of the adaptive immune syste?
Specificity and memory
Which immune response is able to mount a more effective response on second and subsequent encounter with a particular antigen?
The adaptive immune response
Which immune response does not alter on repeated exposure to an infectious agent?
Innate immune response
What are antigens?
Molecules that are recognised by receptors on lymphocytes
How do B and T cells differ in their interactions with antigen molecules?
B cells usually recognise intact antigen molecules, whereas T cells generally recognise antigen fragments that are displayed on the surface of the bodys own cells - in MHC
what are the two phases of the immune response?
Antigen recognition & antigen eradication
Which T Helper cells release IFN-Gamma?
Th1
Which interleukins are released by Th2?
IL-4/IL-5/IL-13
Which interleukins are released by Th17?
IL-17/IL-22
What is the principal function of the immune system?
To distinguish self from non-self
What are some examples of extracellular pathogens?
Staphylococcus, Streptococcus, Candida, microbiota, worms
What are some examples of surface adherant pathogens?
Enteropathogenic and enterohaemorrhagic E.Coli
What two areas can intracellular pathogens occupy?
Vacuole or cytoplasm
What are some examples of cytosolic intracellular pathogens?
Listeria, Burkholderia and Mycobacterium
What are some examples of intracellular vacuolar pathogens?
Salmonella, Chlamydia, Legionella Coxiella, Plasmodium
How does an immune response to infection start?
Tissue damage
Detection of microbes
What enables intercellular communication once tissue damage or microbes have been detected by the cells?
Interleukins and Chemokines - help prime the adaptive immune response
How does an immune response end?
- Clears pathogen
- Stops inflammatory cytokine production
- Repair tissue damage
What type of receptors does the innate immune system involve?
Germ line encoded receptors
What are the physical barriers that are included in the innate immune system?
Skin, mucous, epithelial cells
What does the humoral innate immune system comprise of?
Complement, Lectins, Pentraxins and antimicrobial peptides
What are the components of the cellular innate immune response?
Neutrophils, Macrophages, DC’s and NK cells
What are the components of the humoral adaptive immune system?
Antibodies and complement
What are the components of the cellular adaptive immune response?
T Killer Cells, T Helper Cells, T reg Cells, B cells and Plasma Cells
Which receptors does the adaptive immunity use?
Variable receptors that mature over time due to DNA recombination
What are PAMPs?
Pathogen Associated Molecular Patterns - These are features shared by classes of microbes that are recognised by identical toll like receptors