Lecture 3

Question 1

Neutrophils recreuited due to…

Answer 1

Vasolidation

Question 2

Margination

Answer 2

Sticky cell wall

Question 3

Dendritic cells

Answer 3

MHC class II molecules
Puts peptide(antigen) onto it’s surface, travels to regional lymph node, puts it in contact with lymphocyte which has matching receptors

Question 4

Specific adaptive immunity

Answer 4

Defends against specific microbes and foreign substances
Invloves memory for previously encountered antigents

Question 5

B and T lymphocytes

Answer 5

Must recognize the specific antigen to be activated

Question 6

Helper T cells

Answer 6

Activate B and cytotoxic T cells

Question 7

B cells

Answer 7

Transform into plasma cells to produce and secrete antibodies
Humoral response: With Antibodies and Complement

Question 8

Cytotoxic T cells

Answer 8

Attack infected body cells, cancer cells, foreign cells
Cell-mediated response

Question 9

Macrophage presents antigen to Helper T cell

Answer 9

Puts MHC class 2 molecules to find helper T-cells that have appropriate receptor/connector
Activates helper T-cell

Question 10

B-cell needs…

Answer 10

Assistance from Helper T cell via release of cytokines for full activation of B-cells so they produce plasma cells which release antibodies and also memory cells

Question 11

Activation of Helper T Cells

Answer 11

Specific Recognition
- MHC-II + Peptide - T cell receptor
Co-reception
-CD28 - B7
Cytokine Release from APC
-Stimulates

Question 12

3 stages of adaptive immune response

Answer 12

1) recognition of an antigen by lymphocytes
2)Lymphocyte activation
3) Attack launched by the activated lymphocytes and their secretions

Question 13

Humoral

Answer 13

B cells:
- transform into plasma cells and produce and secrete antibodies
- Use antibodies and Complement to kill

Question 14

Helper T-cells are necessary for….

Answer 14

Activation of of B-cells to plasma cells
Activation of Cytotoxic T cells

Question 15

APC presents antigen and finds B-cell and T-cell with right receptor on it’s surface to start the process… how does it recognize the antigen???

Answer 15

MHC-II molecule bears an antigen which has to be recognized by specific T-cell receptor on helper T cell
B7 - surface of dendtritic cell
CD28 on surface of T helper cell - makes sure we are activating the right cells

Question 16

Checkpoint Inhibition - why 2 key mechanism is so important

Answer 16

All biological systems need a way to shut off their actions
Need displacement of CD28 from B7
Uses CTL4A or PD1 on T cell surface (It’ll outcompete binding of B7 and replace the binding)
That tells the cell that the threat is over (stop killing)

Question 17

Anti-CTLA4

Answer 17

Used when someone has cancer, so cytotoxic T-cells keep killing

Question 18

Activation of B cells in Secondary Lymphoid Organs

Answer 18

Helper T-cell divides
Gets receptors for particular antigen
These activate the B-cells

Question 19

B cell needs…

Answer 19

Cytokines from helper T-cell AND its own recognition of the antigen to start multiplying and making plasma cells and antibodies

Question 20

B cells can process and Present Antigen to a Helper T-cells

Answer 20

Will present a Class II MHC protein to a helper 2 cell

Question 21

Serum Protein Electrophoresis

Answer 21

Lot of albumin
alpha 1 and 2
Beta and gamma

Question 22

Increased amount of gamma-globulin (antibodies) means…

Answer 22

Body is fighting infection

Question 23

Plasma Cell

Answer 23

Produce Antibodies
1 week lifespan
They jus make antibodies for a living

Question 24

Antibodies (Immunoglobulins)

Answer 24

Y shape
4 polypeptide chains
2 identical heavy chains
2 identical light chains

Question 25

Variable region (upper part of antibody) - both a piece of heavy and light chain

Answer 25

Antigen binding site - hypervariable FAB region

Question 26

Constant region - bottom part

Answer 26

Mostly heavy chain piece, some bit of light chain Conserved by all antibodies of a class

Question 27

5 classes of antibodies

Answer 27

Determined by constant region: IgG - most abundant, cross placenta, mother to fetus IgA - dimer, mucous areas, also present in breast mil IgM - pentimer, produced first in an immune response, later replaced with IgG, activate the Complement cascade IgD - found prenatally IgE - allergic responses

Question 28

Antibody-Mediated Immunity

Answer 28

Carried out by B cells Undergo clonal selection to produce plasma cells secreting specific antibodies and memory cells that allow for a faster response if the antigen is seen again

Question 29

Antibody - Actively or Passively Acquired

Answer 29

Active: person's own immune system reponds to microbe Long - lasting protection - Memory cells are involved Natural: Exposed to antigen by chance (e.g flu virus) Artificial: Purposefully exposed to antigen e.g flu VACCINE Passive: Person receives antibodies from another person or animal, temporary protection - No memory cells involved Natural : IgG from mother to fetus across placenta, IgA in breast milk Artificial: Receive serum containing antibodies from person or animal that has been vaccinated

Question 30

Active Immunity

Answer 30

Resistance due to the body's contact with microorganisms, their toxins or other antigenic components

Question 31

General Principle of Active Immunity

Answer 31

Exposure to the antigenic substance results in an active immune response that induces formation of memory cells required for rapid effective response to future infections of that organism

Question 32

Passive Immunity

Answer 32

Direct transfer of antibodies from one person to another E.g fetus receives maternal IgG antibodies that cross the placenta Breast fed children receive IgA antibodies in the mother's milk V important for infant bc their antibody-synthesis ability is low

Question 33

Antibody Functions

Question 34

Neutralizing Antigen

Answer 34

Neutralize an antigen, change the 3d shape of the bacteria by binding to the toxin, can prevent toxic from infection you Bacterial toxin

Question 35

Agglutinating Antigen

Answer 35

Glue the antigens together, antibody holds them together by 2 diff ends LOL makes it easier for them to be phagocytosed

Question 36

Precipitating Antigen

Answer 36

Precipitate antigen, bring things out of solution of fluids of body and hold them together, keep the antigen from performing it's function

Question 37

Activating complement

Answer 37

Complement in non-specific immunity can activate compliment c3B to bind to surface of a pathogen to help it be phagocytosed C1 - first complement protein (inactive) Bacteria finds matching antigen so C1 complement is activated This sets of a cascade of activity that leads to the activation of other complements leading to the MEMBRANE ATTACK COMPLEX - loss of content from that cell and death of that cell

Question 38

Opsonization

Answer 38

If antibody is specific to microbe it will bind to it and make it more visible to phagocytes Phagocyte has receptors to Fc part of the anitbody molecule, Fc is the handle, variable region has binding event with antigen, non-specific effect of antigen

Question 39

Antibody dependent Cellular Cytotoxicity via cytotoxic t cells

Question 40

Rate of Antibody Production following initial exposure to an antigen and subsequent exposure to the same antigen

Answer 40

Increase rate and number of antibodies quickly after 1st antigen injection 2nd antigen injection causes crazy spike in antibody concentration much longer lasting (that's immunization)