Innate to Adaptive Immunity Flashcards
What cell produces defensin and cathelicidin?
Epithelial and white cells
By what mechanism do defensin and cathelicidin neutralize bacteria?
They are positively charged so they bind to negatively-charged pathogen membranes, into which they insert themselves to form lethal pores.
True or false: Most of the bacterial organisms are beneficial.
True
What is the function of innate immune system?
To detect intruders that have ventured too deep into the body’s structures, and then arrange for their inactivation, destruction, and removal.
Name three structures that are recognized by the innate immune system.
- PAMPs- Foreign molecular structures called pathogen-associated molecular patterns
- DAMPs- Stress or damage indicator molecules expressed by body cells, called damage-associated molecular patterns
- The absence of certain normal cell surface molecules, which would certainly indicated a problem- this recognition is done by NK cells
What is PRR?
Pattern-recognition receptors.
Where are PRRs found?
One the surface or on the inner membranes of MOST CELLS IN THE BODY
What are “Toll-like receptors”?
They are a type of PRR that recognizes a foreign molecular structure humans DO NOT have.
What cells are Toll-like receptors found?
Most cells of the body
A pathogen binds to a TLR found on a endothelial blood vessel cell.. What happens next?
Signaling cascades are activated within the cell that lead to the expression of cytokines and chemokines that cause or increase inflammation.
What is it called when there is an increase in blood vessel diameter, stickiness, and leakiness with an efflux of fluid and phagocytic white blood cells into the tissues?
Inflammation.
Identify the final transcription factor that is most commonly activated in inflammation.
All TLR except TLR3 use the IRAK pathway. The net effect is to activate the mother of all inflammatory transcription factors, NF-kappa B
Can TLRs bind DAMPs?
Yeah. Took me a long time to get this but Yea!
What is one disadvantage and one advantage of innate immunity?
Advantage- Fast
Disadvantage- cannot adapt to totally new challenges- it only sees a few established patterns
What cell is responsible for the connection between the innate and the adaptive immune response?
Dendritic cells
What and where are dendritic cells activated?
Dendritic cells are activated at the wound site by cytokines and chemokines released by local cells
Are dendritic cells marcophages?
Yes
So a dendritic cell is activated, now what?
Dendritic cells are activated by chemokines and cytokines. Then they begin phagocytizing any and everything including foreign molecules derived from the invaders. It then travels to the nearest draining lymph node to show what it has eaten to the lymphocytes
What is the role of lymphocytes?
Recognition of foreignness
What is the role of phagocytes?
Eating and Digestion
True or False:Lymphocytes have a hundred thousand cell surface receptors that are all different so each cell can recognize a hundred thousand different antigens.
False. A lymphocyte may have a hundred thousand receptors on its surface, but all are identical; so each cell can recognize only one foreign shape
Define: Antigenic determinant or epitope
Only a small part of a large antigenic molecule. perhaps 10-20 amino acids that fits into the lymphocyte’s receptor
Does lymphocyte diversity exist before or after the antigen comes in?
Before
Generally what happens after the lymphocyte binds its antigen?
The naive lymphocyte is activated and begins to proliferate so that a clone of identical cells is produced. Some of its cells differentiate and begin to secrete proteins which get the immune response rolling.
What is immunologic memory?
Occurs when lymphocytes are long lived, so that the factory remains expanded and the next time we encounter that organism we can usually overwhelm the invader before it can establish an infection. Accomplished through memory cells
What is the role of B cells?
They protect the extracellular spaces of the body with by releasing antibodies into the fluids.
What is the role of T cells?
They themseles survey the surfaces of the body’s cells, looking for ones that have ingested antigens, have parasites within them, or are dangerously changed or mutated
What short-range mediators do activated T-cells release after restimulated by local antigen-presenting cells?
Lymphokines