Introduction To Immunology Flashcards
You are studying microbes and discover that a particular microbe replicates intracellulary and uses host-cell energy resources. What type of microbe have you discovered?
Intracellular microbe
What are some examples of infectious organisms?
Worms
Protozoans
Fungi
Bacteria
Viruses
What is immunity?
A set of cooperative defense mechanisms which provide protection from various infectious diseases.
What are antigens (noninfectious foreign substances) capable of doing?
Eliciting an immune response.
What are Ags?
Substances (microbial or nonmicrobial, proteins, carbohydrates, lipids and nuclei acids) that induce an immune response.
What is an antibody?
A protein produced by the immune system when it detects antigens.
What is an epitope?
A portion of an Ag molecule to which the antibody binds.
What are the smallest epitopes to which an antibody can be made?
3 - 6 amino acids
5 - 6 sugar residues.
True or false: all immunogens are Ags, but not all Ags are immunogens.
True
What are immunogens?
Ags which can stimulate an immune response
All large molecules have multiple ____
Epitopes
What do Abs bind to?
Conformational antigenic epitopes.
True or false: all large molecules have one epitope.
Fales; all large molecules have multiple epitopes.
You are exposed to a new antigen. What line of defense will initially be used in order to fight against infection?
Innate immunity
You have been exposed to an antigen for the second time. How will the response of innate immunity differ from its initial response?
It will not change.
What type of barriers are important to innate immunity?
Physical and chemical barriers.
What are the three principal components of innate immunity?
Physical and chemical barriers
Phagocytic cells
Blood proteins (complement system and other mediators).
You are studying the response of the body to a particular antigen. You note that the antigen is eventually engulfed by a particular molecule. What molecule is this?
Phagocytes.
This is innate immunity.
What are antimicrobial peptides?
Small peptides which target pathogenic microorganisms ranging from viruses to parasites.
What is complement?
A system of plasma proteins that enhances the ability of Abs and phagocytic cells to clear pathogens from an organism.
What are acute phase proteins?
A large group of blood proteins whose plasma concentrations change in response to tissue inury, acute infections, buns or inflammation.
What are cytokines?
Signaling molecules that aid cell to cell communication in immune responses.
What are chemokines?
A subfamily of cytokines secreted by immune cells to induce chemotaxis in nearby cells.
What are phagocytes?
Immune cells that have the ability to ingest and digest microbes.
What are two cells that are components of adaptive immunity?
B and T lymphocytes.
What is the specificity of innate immunity?
Innate immunity is specific for molecules shared by groups of related microbes and molecules produced by damaged host cells.
What is the specificity of adaptive immunity?
For microbrial and nonmicrobial antigens.
How does the diversity of innate and adaptive immunity compare?
Innate immunity has a limited diversity and adaptive immunity has a large immunity.
What type of immunity has memory?
Adaptive immunity
True or false: innate and adaptive immunity mechanisms are reactive to self.
False
Phagocytes, dendritic cells and NK cells are part of innate immunity. How long does it take for them to develop?
Hours
B lymphocytes, T lymphocytes, antibodies and effector T cells are part of adaptive immunity. How long does it take for these components to develop?
Days
True or false: many cells and molecules of the innate immune system are also used by the adaptive immune system and vice versa
True
In addition to inflammation, the innate immune system is responsible for what other function?
It evaluates the invader in the context of intracellular vs extracellular microbes and provides instructions to adaptive immunity.
How do cells communicate?
Through direct cell-to-cell contacts, as well as interactions involving cytokines and chemokines.
What are two main functions of cytokines?
Regulate growth and differentation of all immune cells
Activate the Effector functions of lymphocytes and phagocytes.
Each cytokine acts via a ____ expressed on target cells.
Specific signaling receptor
What are chemokines?
A large subset of structurally related cytokines that regulate cell migration and movement.