Intro Flashcards
What are the different types of pathogens? (4)
Extracellular bacteria, parasites, fungi
Intracellular bacteria, parasites, fungi
Viruses (extracellular)
Parasites worms (intracellular)
Describe innate immunity (6)
Born with it
Recognise pathogens
Pass onto offsprings as germ line coded
Recognise self from non-self Immediate maximal response
Exposure results in no immunological memory
What are the cell types involved in innate immunity (4)
Macrophages
Granulocytes
Natural killer cells
Tissue resident cells
Describe adaptive immunity (5)
Response is antigen-dependent
Lag time between exposure and maximal response
Antigen-specific
Exposure results in immunological memory
Second response better than the first
What are the cell types involved in adaptive immunity (2)
T lymphocytes
B lymphocytes
Where are leukocytes derived from? (1)
Haematopoietic stem cells
Describe neutrophils (5)
Can destroy bacteria intracellularly by phagocytosis and
extracellularly via the reactive antimicrobial species and
granule release, and “neutrophil extracellular traps (NETs)”
they release on their death
First defenders on the scene of bacterial invasion
Are controlled by cells of the innate and adaptive immune
system
Recruited very quickly
Short-lived, found normally in blood
What is inflammation (2)
Accumulation of fluid, plasma
proteins and leukocytes that is initiated by physical trauma, infection or a local immune response
(< 6 weeks acute, > 6 weeks chronic)
What are the clinical signs of inflammation (5)
Swelling
Pain
Redness
Heat
Loss of function
What are the 3 stages of inflammation? (3)
Initiation
Recruitment of effector cells
Resolution (switching off and removal of cells)
Give an example of an inflammatory disease (1)
Glandular fever (Infectious mononucleosis)
What are the two different T lymphocytes and their roles ? (4)
Cytotoxic T cells (CD8 T cells) – can destroy virus infected or cancer cells
T helper cells (CD4 T cells) – provide “help” to B cells and CD8 T cell mediated immunity (determine direction of immune response)
What are B cells? (2)
Mature to plasma cells which produce antibodies
Responsible for antibody-mediated or humoral immunity
What are natural killer cells? (4)
Lymphoid, targeted secretory cell
Found in blood and tissues
Cells are crucial for recognising changes in tumour cells and virally infected cells
Target and kill these cells
How do effector CD8+ T cells kill target cells? (4) (DOUBLE CHECK THIS)
Granules contain pore forming
proteins and toxins (granzyme)
Pores are formed in target cell membrane
Toxin enters cell and induces cell death
What are the different CD4 T helper cells and describe their role (4)
Regulatory cells - switch off immune response
TH1 - co-ordinate the immune response through secretion of cytokines
TH2 - B cells and antibodies
TH17 - trigger neutrophils
What is tetanus and how can it be prevented? (2)
Clostridium tetani produces a neurotoxin which causes muscular spasms
Tetanus can be prevented by vaccination with tetanus toxoid
What are eosinophils? (4)
Found in blood and also in gut, lungs, urogenital tract
Important in helminth infection
Involved in allergy and asthma and parasitic infection
Contains toxic granules and inflammatory mediators
What are mast cells/basophils? (6)
Play a role in inflammation and allergic responses
Granules contain: histamine and heparin
Activated by IgE receptors
Stays in transit in the blood for less than a day (survives another 3-4 days in the tissue)
Release of histamine by mast cells requires the production of
antibodies (IgE) by B-cells and that process is regulated, in part,
by cytokines produced by basophils.
What is tuberculosis? (2) (DOUBLE CHECK THIS)
CHECK
What are monocytes? (2)
Circulating form (precursor) of tissue macrophages
Recruited to sites of inflammation
What are macrophages? (5)
Bacterial killing (also intracellular bacteria such as Mycobacterium tuberculosis)
Found in most, if not all tissues
Highly phagocytic and antimicrobial
Directs both innate and adaptive through secretion of cytokines and antigen presentation
Important for non-inflammatory clearance of apoptotic cells
What is mucosal immunity? (1)
First entry route for many diseases
What are the three different unwanted outcomes of the immune response and describe them (6)
Cancer - too much tolerance
Allergy - not enough tolerance
Autoimmunity - break down of tolerance
