Immunity and Vaccines Flashcards
(41 cards)
How is the normal microbiota part of our immune system
part of our innate immunity to pathogens - by colonizing niches of our bodies and releasing primary and secondary metabolites
Functions of immune system
- Recognize and protect us from invading microorganisms and cancers.
- Differentiate between pathogens, self, and harmless antigens.
- Regulate itself so that it is not responding to self (auto-immune disease) or harmless environmental antigens (allergies).
Innate immunity vs. adaptive
Innate (non-specific) immunity:
* Provides resistance to any foreign molecule or pathogen
* Does not require previous exposure
* Strength of response does no increase upon repeat exposure
Adaptive (specific) immunity:
* Acquired ability to recognize and destroy a specifc pathogen
* Prior exposure strenghens and quickens response
Aspects of innate immunity
- Physical/chemical barriers: skin, mucus, stomach acids, good microbes
- Phagocytosis (innate and adaptive)
- Inflammation (innate and adaptive)
Function of phagocytosis & what cells do this
engulf and destroy microbes: microbe taken up into phagosome, phagosome fuses with lysosome (organelle containing lysozyme, proteases, nucleases, lipases), lysosome destroys microbe
* macrophages, neutrophils
How to pathogens avoid phagocytosis
- capsule (steptococcus sp.)
- Escape phagosome (mycobacterium tuberculosis taking over macrophages
- Resist lysosomal enzymes
Components of inflammtion
- vasodilation
- blood vessels become more permeable
- neutrophils move out of capillaries
goal of inflammation
localize and destroy the pathogen
What molecules does the innate immune system recognize as foreign
Molecules that are found on microbes but not our cells -** microbe associated moelcular patterns (MAMPs)**
* Bacterial: lipopolysaccharide (LPS), Flagellin, Teichoic Acids
* Fungal: B-glucans (part of cell wall), Mannans
* Viral: dsRNA
Characteristics of adaptive immunity
- specific
- takes time to generate
- creates memory
- Diverse: can recognize billions of pathogens
What must an a compound lead to for it to be considered an antigen
and adaptive immune response
* polysaccharides, proteins, glycoprotiens, flagella, pili, toxins, etc,
* lock and key fit
Where is the O antigen of gram - bacteria
Lipopolysaccharide in cell wall
Two major spike proteins on flu virus
- Hemagglutinin (HA)
- Neuraminidase (NA)
Spike proteins of viruses are good antigens
COVID vaccines are mostly aimed at the
spike glycoproteins
antibodies
glycoproteins made in response to an antigen that can recognize and bind to it
What creates different antibodies
gene rearrangment
Antibody functions
- stimulation of inflammation response
- Neutralization (covering up active site on toxin or pathogen)
- Opsonization (pathogen coated with antibodies to enhance phagocytosis)
What cells are the reason for memory
B cells
Artifically acquired adaptive immunity =
immunization
immunization
process. y which our immune system becomes artificially fortified against a pathogen
passive vs active immunization
passive: administration of preformed antibodies, immunity is artificially acquired (from mom) Antibodies are given not made
Active: protective immunity is induced - our bodies make antibodies (vaccination)
Whole organism vaccines
- inactivated (killed) - intake spike proteins to elicit immune response but cannot incude infection (polio, rabies, pertussis, flu)
- attenuated (live but avirulent) - no longer cause disease on human cells cuz it is grown on monkey cells and mutates; **still has antigens on surface (spike proteins) but can no longer infect us ** (measles, chicken pox, small pox, typhoid)
Purified macromolecules (including toxoids)
Pieces of pathogens (tetanus, pneumococaal vaccine)
Toxoid
chemical modification that removes toxin moiety from the toxin leaving it with only the antigenic determinants = the toxoid
