BL Immunology Unit 1 Flashcards Preview

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Flashcards in BL Immunology Unit 1 Deck (224)
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innate immune system is necessary to activate what?

the adaptive immune system, T and B cells


how quicky is skin replaced?

every seven days


how quickly are the intestine cells replaced?

every 3 days


what can survive on skin and what is killed?

staphylococci can survive, but ecoli dies within minutes of landing on skin via toxic proteins


what proteins are made by epithelial cells to defend the skin?

defendins or cathelicidin families. Small proteins made by epithelial cells, or brought to them by white blood cells.


cathelicidin are ______ charged?

positive. (cathelicidin=CATatonic HELICal). Bind - charged pathogen membranes. Insert themselves into lethal pores


how many bacteria live on/in us?

10^4 bacteria in gut. 10^10 bacteria on skin.


innate immunity

one of our sense organs. Immune system is designed to detect intruders and arrange for inactivation, destruction, . Recognizes molecular motifs.


what are the 3 things innnate immunity recognizes:

1. foreign molecular structures called pathogen-associated molecular patterns (PAMP).
2. Stress or damage indicator molecules expressed by body cells, caused by damage associated mollecular patterns (DAMP).
3. Absence of certain normal cell surface molecules, which would indicate a prroblem done by NK cells.


most cells have some ________ on surface or inner membrane.

PRR. Pattern recognition receptors. On surface/inner membrane.


what are TLR's?

Toll like receptors. There are ten of them. Homologous to the toll gene of the fruit fly. Each one can recognize foreign molecular structures.


TLR4 binds what?

liposaccharides (part of cell wall of gram negative bacteria). TLR2 binds peptidoglycan (gram positive bacteria), TLR3 binds double stranded RNA.


what happens when TLR or a WBC passes by an infected wound?

bind the foreign pattern-->signal cascades activated--> expression factors cause/increase inflammation-->factors (cytokines/chemokines) are released


what is the point of inflammation?

inflammation is the increase in blood vessel diamater, stickiness, leakiness.
Increases efflux of fluid and phagocytic WBC into tissue to get defense and healing agents into damaged/invaded area


what is the net effect of TLR cascades?

activate the mother of all inflammatory transcripton factors: NF-kB.
All TLR except TLR3 use the IRaK pathwaywhich does this. Goes into the nucleus, permits transcription of pro-inflammatory genes. Designed to not be a linear cascade so that the body can tolerate things up to a threshold.


what happens when cells get damaged and stressed?

they release a certain amt. of their internal molecules (DAMPs) and then TLRs will bind them to increase local inflammation.


mediator cells such as chemokines are ________ for phagocytic WBCs that flow in from distant areas.



can the innate system adapt to new challnges?

no. it can only see established patterns


what happens if the innate system can't handle a problem?

it activates the adaptive immune system. This is a slower but stronger and more capable system.


what is the connection between the innate and adaptive immune system responses?

special phagocytic cells interface btw the body and the world (skin, lung, mucosa)-->dendritic cells


what are dendritic cells?

highly branched cells that are the best phagocytes. At wound sites immature DCs get activated by cyto/chemokines and take up what they can. Then they leave and head to the lymph system to show what they ate to lymphocytes. This then is eventually recognized to initiate an immune response


what is recognized in lymph systems by B and T cells when dendritic cells present things?

antigens. (things recognzed by adaptive immunity)


can adaptive immune response develop in the periphery?



what 2 cells divide the work of the immune system up?

lymphocytes and phagocytes



specialized for recongition of foreignness. Have surface receptors that bind antigenic molecule with the best shape. All receptors on surface are identical.



specialized fore eating/digestion


how many parts of an antigenic molecule fit into a lymphocytes receptors?

10 to 20 amino acids. Called the antigenic determinant or epitope.


what happens to a lymphocyte after an antigen binds?

it is activated, it proliferates (makes clones) by doubling every 6-12 hours. Some cells differentiate and secrete proteins to activate the immune system. Once the clone is big enough and there are enough to fight infection, recovery starts


are lymphocytes short or long lived?

many are long lived. Contributes to immunologic memory. We have memory cells that can active quickly and respond to small amounts of antigen.


what are the 2 kinds of lymphocytes?

T and B. recognize and remove foreign substances.