CMB1003/L18 Intro to Immunity Flashcards
Define immunity.
The ability of an organism to resist a particular infection or toxin by the action of specialised cells or molecules
Give an example of active natural infection.
Catching a virus
Give an example of active artificial infection.
Immunisation
Give an example of passive natural infection.
Placental transfer of maternal IgG
Give an example of passive artificial infection.
Human IgG (normal or immune)
Briefly describe innate immunity. (3)
Present from birth
Simple recognition systems
Rapid response with no memory
Briefly describe adaptive/acquired immunity. (3)
Not present from birth
Sophisticated, highly specific
Slower response with memory
What is the goal of the immune system?
To clear potential pathogens in a controlled and efficient process
Give 3 factors that affect immunity.
General health
Infection
Nutrition
Adverse environmental conditions
State of microbiome
Pregnancy
Genetic disorders
Stress
Describe herd immunity.
Disease in a population declines declines is majority of population is immune
What percentage of the population needs to be vaccinated for herd immunity to be effective?
> 95%
When was the MMR vaccine introduced?
1988
What are the 4 main types of vaccine?
Live/attenuated
Killed/inactivated
Subunit
Nucleic acid
Define serology.
Looking at antibodies in the blood to determine infection
Where are antibodies synthesised?
Plasma cells (mature B/lymphocyte cells)
Where are myocytes NOT found?
In tissues
Describe clonal selection. (4)
Single progenitor cell gives rise to large number of lymphocytes with different specificities
Removal of potentially self-reactive immature lymphocytes by clonal deletion
Pool of mature naive lymphocytes
Proliferation and differentiation of activated specific lymphocytes to form a clone of effector cells
Give 2 primary lymphoid tissues.
Bone marrow
Thymus
What is the role of bone marrow in the immune response? (3)
B cells mature here; T cells leave to thymus
Clonally diverse
Cells specific to antigen
What is the role of the thymus in the immune response?
T cells educated here (2-4% survival)
Give 2 secondary/peripheral lymphoid tissues.
Lymph nodes
Spleen
Tonsils
Mucosal associated lymphoid tissues (MALTS)
What occurs in secondary lymphoid tissues?
Developed B and T lymphocytes recirculate and undergo clonal expansion in these tissues
Describe mucosa-associated lymphoid tissue.
A diffuse system of non-encapsulated, submucosal lymphoid tissue in intestinal and respiratory tracts
What are different effector mechanisms dependent on?
Type of pathogen
Localisation
Stage of infection
Challenge
