BIOS 222 Lecture Notes - Lecture 3: Antigen-Presenting Cell, Mhc Class Ii, T Cell

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greywallaby484

23 Nov 2016

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Document Summary

Cell bio for human body: role of phagocytes in innate or nonspecific immunity. First line of defense: skin, mucous membranes, stomach acid. Second line of defense: inflammatory response and phagocytes (white blood cell or leukocyte) Phagosome: vesicle that contains the pathogen in the phagocyte. Major histocompatibility complex (mhc) ii: presents the antigen of the digested pathogen on the outside of the phagocyte. Neutrophils: it is a fast and abundant phagocyte. Dendritic cells: types of immune responses: innate and adaptive. Specific/adaptive immune system: makes lymphocytes and has 2 major parts a) B - lymphocytes- form in bone marrow. T - lymphocytes - form in bone marrow but mature in the thymus. Humoral response: b - lymphocytes in the fluid: professional antigen presenting cells (apc) and mhc ii complexes. Mhc ii - mhc protein go to the surface of the cell. Epitope is where the pathogen binds to the b cell.

Related Questions

Functional Magnetic Resonance Imaging is a tool that has been very useful in identifying what parts of the brain do what. Scientists can have a person perform some particular activity and then look for active areas in the brain. How does fMRI work?

	A.	It takes a picture of the inside of the brain according to electricity levels. The more electrical current in the area, the more active it is.
	B.	It takes a picture of the inside of the brain according to blood flow. More blood flow indicates more activity in that area.
	C.	It takes images of thin layers of the brain and the more electrical activity in a layer, the more magnetic it is and this shows up in fMRI.
	D.	Electrodes attached to the skull can trigger activity in particular brain areas which then trigger a person to perform certain behaviors.
	E.	It takes a picture of the brain according to oxygen levels. More oxygen in an area indicates more activity in that area.

The strategy of vaccination to fight diseases uses what type of immunity?

	A.	Non-specific immunity
	B.	Cell-mediated immunity
	C.	Natural immunity
	D.	Specific immunity
	E.	Passive immunity

If you came into contact with Vibrio, what defense do you have to keep it from even getting to your intestines?

	A.	Your skin is an effective barrier against bacteria you come in contact with.
	B.	Antimicrobial enzymes in saliva
	C.	Acid in the stomach
	D.	Mucous membranes in the digestive and respiratory tract
	E.	All of the above

What do B cells do when they identify a pathogen?

	A.	Engulf and eat it
	B.	Kill it
	C.	Produce antigens to bind to the pathogen and memory cells to guard against future infection.
	D.	Produce antibodies to bind to the pathogen and memory cells to guard against future infection.
	E.	Engage helper T cells to fight the infection

There are chemical signals that call on non-infected cells to help fight a virus. Which are they?

	A.	Complement proteins
	B.	Macrophages
	C.	B cells
	D.	Interferons
	E.	Natural killer cells

When someone gets a bone marrow transplant, they have to be quarantined and carefully protected from pathogens for a period of time afterward. Why?

	A.	Bone marrow produces the main cells involved in the specific immune response, so these patients are at special risk of infection until they build up enough marrow to produce sufficient cells.
	B.	Bone marrow produces blood cells, so they have insufficient circulation for a period of time so their immune system lacks the energy to fight off any infection.
	C.	Anytime a foreign substance, even someone else's bone marrow, is introduced to a body, there is an extra risk of infection.
	D.	A common complication of bone marrow transplants is infection, and doctor's don't want the infection to spread to others.
	E.	It's a traumatic procedure, and any extra stress on their body could kill them.

1. Select which of the following are mechanisms used by pathogens to avoid host defenses and to successfully colonize the host.

A. Producing siderphores to obtain iron from the host for growth

B. producing adhesins for damaging host cells

C. Avoiding IgA proteases for avoiding secretory IgA

D. Avoiding secretory IgA by rapid turnover of pili

E. Producing toxic substances to suppress host responses

2. People considered obese have a different normal flora in the gastrointestinal tract compared to people who are considered lean.

A. true

B. false

3. Which of the following is NOT a mechanism used by pathogens for avoiding or surviving phagocytosis?

A. Killing macrophages and neutrophils

B. Colonizing the phagocyte

C. inhibiting opsonization

D. Inhibiting phagocte chemotaxis

E. these are all methods of avoiding or surviving phagocytosis

4.Which of the following immune responses is best suited to prevent a virus from infecting a cell?

A. complement cascade

B. inflammation

C. Virus-specific antibodies

D. Fever

E. phagocytic cells

5. Which of the following is NOT a method used by pathogens for penetrating skin or mucous membranes?

A. Injection of effector proteins that induce endocytosis

B. Exploiting antigen-sampling processes

C. these are all mechanisms for penetrating skin or mucous membranes

D. Exploiting an injury

E. Production of endotoxin

6. Antibodies, which are produced as part of the adaptive immune response, can sometimes be damaging rather than beneficial. People suffering from an autoimmune disease called antiphospholipid antibody syndrome (APS) make antibodies that bind to phospholipids. Some of the signs and symptoms affected individuals experience are blood clots, stroke, heart attack, and kidney damage. What is the likely cause of these symptoms?

A. the anti-phospholipid antibodies cuse immune complexes that lodge in the affected organs

B. The person fails to make protective antibodies

C. The anti-phospholipid antibodies weaken certain organs that contain fat

D. the person makes antibodies that bind inappropriately to bacterial capsules, preventing phagocytosis of these cells

E. Cell damage caused by binding of these antibodies initates inappropriate coagulation events which inferfere with blood flow in affected organs.

7. Only Gram-positive bacteria produce exotoxins

A. true

B. False

8. Which of the following members of the normal microbiota inhibit the growth of Candida albicans?

A. Lactobacilus species

B. Staphylococci species

C. E. coli

D. Neisseria species

E. Propionibacterium species

9. Would an antibody response against the B subunit of an A-B toxin protect against the effects of the toxin?

A. yes. if antibodies bind to the B protion, the toxin can no longer bind to target cells and will thus not affect those cells

B. No, even if antibodies bindto the B portion of the toxin, it is the A portion that actually causes damage to the cell

C. This question cannot be answer. The immune system does not mount a strong response against proteins, so this situation is unlikely to occur.

D. Yes, if antibodies bind to the B protein, that portion of the toxin does not become activated, and thus does not damage the host cell

E. No, even if antiibodies bind to the B portion of the toxin, the toxin is still taken into the host cell by phagocytosis, damaging that cell

10. Please select the correct definition of balanced pathogenicity.

A. A host-parasite relationship in which the parasite persists in the host, causing maximal harm. The pathogen becomes more virulent while the host becomes increasingly susceptible.

B. A mechanism that allows bacteria to transfer gene products directly into host cells, inducing changes such as altering the cell's cytoskeleton structure

C. A generated balance in the microbiome that may be caused by taking antimicrobial medication. it generally helps the host maintain optimal health

D. A situation in which an abnormally high number of T-helper cells are stimulated, causing a massive release of cytokines.

E. A host-parasite relationship in which the parasite persists in the host while causing minimal harm. The pathogen becomes less virulent while the host becomes less susceptible

11. Bacteria may survive phagocytosis by

A. preventing encounters with phagocytes AND preventing fusion of two pathogosomes

B. avoiding recognition and attachment of lymphocytes AND lysinf the phagosomes

C. preventing fusion of the lysosome with the phagosome AND mimicking host molecules

D. lysing the phagosome AND mimicking host molecules

E. preventing fusion of the lysosome with the phagosome AND lysing the phagosome