Defenses and Immunity - Adaptive Immunity and Pathogens Flashcards
(28 cards)
In contrast to treating diseases, some _____ _____ disease.
Antibodies cause
An antigen from the environment enters body, how does the body react?
The body produces antibodies against the antigen. These antibodies coat specialized cells called mast cells.
If you encounter the same antigen again, how does your body react?
The antigens attach to antibodies coating mast cells. When these mast cells detect the antigen, they release large quantities of a molecule called histamine.
What do histamines cause?
Inflation, runny nose, and congestion- symptoms of an allergic response
True or False:
Antibodies can cause autoimmune diseases.
True
What is an autoimmune disease?
“Rouge” immune cells attack “self” cells
What do B cells do within the immune system?
B cells help eliminate antigens or microorganisms that are outside of cells
What do T cells do?
T cells help eliminate microorganisms or viruses that are inside of a cell
How does a T cell “know” what is going on within a cells?
All cells present cytoplasmic antigens (usually short peptides) on their surface using carrier proteins called MHC molecules.
How does a T cell ‘deal with’ cells that are presenting a foreign antigen?
- A cytotoxic T cell binds to an infected cell
- Perforin makes holes in the infected cell’s membrane, and enzymes that promote cell death enter.
- The infected cell is destroyed (lysed)
Rather than killing cells, _____ __ cells help other cells fight invaders more effectively.
Helper T
How do dendritic cells activate helper T cells?
- Dendtritic cells swallow microbes and chop them up into antigens
- Antigens from the microbe are loaded onto MHC molecules
- These MHC molecules are displayed on the cell’s surface
- Helper T cells can now come along and use their antigen receptors to bind the MHC molecule
Once activated, what do helper T cells do?
- Activated helper T cells release signals that help them divide, generating many helper T call clones
- Some of these cells help activate B cells
- Other helper T cells stimulate cytotoxic T cells
Helper T cells play a critical role in ________ nearly all aspects of a/an _____ _______ response.
Coordinating; adaptive; immune
How do cytotoxic and helper T cells differ?
Cytotoxic T cells express a T-cell receptor that only recognizes class I MHC molecules displaying a foreign peptide; helper T cells express a T-cell receptor that only recognizes class II MHC molecules
Define MHC-I:
Large alpha chain paired with beta2-microglobulin, alpha chain forms the peptide- bonding groove
Define MHC-II:
Alpha chain paired with beta chain, Peptide-binding groove is formed by the interface between the two chains
MHC-I is in all ____ cells (makes sense: any _____ cells can be infected)
Nucleated; nucleated
MHC-II is in only ________ _______-______ cells (makes sense: these are the only cell types that communicate with helper T cells)
Professional antigen-presenting
By loading _____ from different compartments onto different ____ molecules, the immune system can detect there a _____ came from.
Peptides; MHC; peptide
True or False:
This is the correct order of events:
(cytoplasmic peptide->MHC-I ->cytotoxic T cell -> cell death
True
True or False:
This is the correct order of events:
(Extracellular peptide -> MHC-II -> helper T cell -> assistance to B cells and other fighting EXTRACELLULAR pathogens
True
The T cell ____ binds to the _____ plus the _____ molecule that is presenting it
Receptor; peptide; MHC
What are the properties of CD8?
Membrane protein expressed by cytotoxic T cells, Binds MHC-I and not MHC-II
