Immunology specific host defense

Question 1

Immune system: two part

Answer 1

1. Humoral Immune system

2. Cellular immune system

Question 2

Humoral Immune System

Answer 2

Involves a specific antibodies in the blood and lymph (the body’s humors) Produced by B CELLS

Question 3

Cellular Immune system

Answer 3

Involves T CELLS. That do not produce antibodies but secretes cytokines.

Question 4

Specialized lymphocytes responses to

Answer 4

Extracellular ags

Question 5

T cells mature in the

Answer 5

Thymus

Question 6

After maturation, T cell migrate to

Answer 6

Lymphoid tissues

Question 7

7 types of immunity

Answer 7

1. Innate Immunity
2. acquired immunity
3. Natural acquired ACTIVE immunity
4. Artificially acquired ACTIVE immunity
5. Passive immunity
6. Natural acquired PASSIVE immunity
7. Artificially acquired PASSIVE immunity

Question 8

Innate Immunity

Answer 8

Born with it

Question 9

Acquired Immunity

Answer 9

Adaptive immunity
Resistance to infection due to ANTIBODIES
a. Active immunity (made by yourself)
b Passive immunity (performed by someone else)

Question 10

Natural acquired active immunity

Answer 10

Person making their own antibodies
1. stimulus: Contact with the live microbes by Natural Process - infection; illness
2. Responses: Symptoms of disease or subclinical RXN. Active production of antibodies to the pathogen
Duration: Long term (months-years) sometimes life long. ex: Influenza.

Question 11

Artificially acquired active immunity

Answer 11

Antigen is intentionally introduced to the body (vaccine.immunization)

1. Stimulus: Vaccines/ Immunization:
   a. Kill pathogens (or their proteins alone)
   b. Attenuated/weaken live pathogen
   c. Inactivated toxin (TOXOID) - old, resembling toxoid will cause immune response.
2. Response: Production of specific antibodies without developing symptoms of disease (or prodromal symptoms only)
3. Duration: Variable (months-years-life time)

Question 12

Passive Immunity

Answer 12

Immunity acquired through transfer of antibodies.

Question 13

Naturally acquired Passive immunity

Answer 13

1. Mother to fetus through the placenta (Placental transfer) or in colostrum/milk during nursing.
2. Response: No immune response. Acquisition of antibody only.
3. Duration: short term (a few weeks - months)

Question 14

Artificially acquired passive immunity

Answer 14

1. Antibodies formed in one individual transferred/injected into another individual. Immune serum/gamma globulin.
2. Response: No immune response, acquisition of antibody only.
3. Duration: Very short (2-3 weeks) e.g. Venomous snakes bites, tetanus, Hep. A, Diphtheria, Botulism.

Question 15

Specific immune response involves production of ______ antibodies (Ab) against specific antigen (Ag).

Answer 15

nljnl

Question 16

The Nature of Antigens/Immunogens Definition

Answer 16

??

Question 17

The Nature of antigen/Immunogen: Characteristics

Answer 17

FOREIGN/NON Self Matter eg. Microorgamism, toxins, Foreign tissues.
Chemically: Complex Molecules: Eg. Protein or Polysaccharide
The more complex the better

Question 18

Hapten/Partial Antigen

Answer 18

Has reactivity (combines with specific antibody) without immunogenicity (stimulating production of specific antibodies) unless bound to a carrier.

Question 19

Antigenic determinant epitope

Answer 19

Antibodied are not formed against a whole organism but specific regoins or chemical groups

Question 20

Nature of antibodied/immunoglobulins

Answer 20

Definition: A protein produced by B lymphocytes in response to an immunogen/antigen and is capable of combing with that antigen.

Question 21

Gamma Globulins:

Answer 21

From separation of blood proteins by electrophoresis

Concerts artificial acquired passive immunity

Question 22

Antibody Structure

Answer 22

Two heavy chains and two light chains. Heavy and light chains both have C or constant portion and the V or variable portion.

Question 23

V portion:

Answer 23

Is different for each kind of Ab and gives ab its specificity. Ag binding occurs at the V portion.

Question 24

C portion:

Answer 24

Constant for each class of ab.

Question 25

Fab

Answer 25

Antigen binding fragament: the two arms

Question 26

Fc:

Answer 26

Crystallizable fragement: the "trunk" of the antibodies. Contains the complement binding site.

Question 27

5 Classes of antibodies

Answer 27

``` IgG IgM IgA IgD IgE ```

Question 28

IgG

Answer 28

Monomer 80% of serum antibodies (most abunant ab in Serum) can cross the placenta **Pretects fetus and newborn Fix complemen. Enhance phagocytosisl neutralize toxins and virus,

Question 29

IgM

Answer 29

Pentamer 5-10% of serum antibodies Fixes complement in blood, lymph, on B cells Agglutinate microbes; also Ab produced in response to infection

Question 30

IgA

Answer 30

Dimer 10-15% of serum antibodies main ab in mucus secretion, and breast milk. mucosal protection

Question 31

igD

Answer 31

Monomer 0.2% of serum antibodies in blood and lymph. Receptor on B cells

Question 32

IgE

Answer 32

Monomer 0.002% of serum antibodies. on mast cells and basophils, in blood. Allergic reaction; lysis of parasitic worm

Question 33

Antibody responses (B cells)

Answer 33

1st response: contact with the Ag for the first time. -plasma cells -> antibodies - Memory cells are formed - has specific receptors 2nd response/anamnestic(memory) response - Memory cells activated -> plasma cells -> antibodies formed quickly and in large number

Question 34

Cell mediated immunity

Answer 34

Involves interaction of macrophages and specific T lymphocytes (T-cells) Pathogens enter the gastrointestinal or respiratory tracts pass through peyer's patches, which contain APCs (antigen-presenting cells)

Question 35

Dendritic cells

Answer 35

M (Microfold) cells over Peyer's patches facilitate contact of antigens with the immune system.

Question 36

T-cells differentiate into _____ T cells when stimulated by an antigen.

Answer 36

effector Some effector T-cells become memory cells

Question 37

T cell types

Answer 37

``` Helper T cell (CD4, Th) Th1 Th2 Cytotoxin T cell Delayed hypersensitivity T cell Suppressor T cell ```

Question 38

Th1

Answer 38

Activate cells related to cell-mediated immunity

Question 39

Th2

Answer 39

Activate B cells to produce IgM and igE

Question 40

Cytotoxic T cells (CD8,Tc)

Answer 40

Destroy target cells with perforin

Question 41

Delayed hypersensitivity t cell

Answer 41

Td: Associated with allergic reaction, transplant rejection, and tuberculin skin test

Question 42

Suppressor Tcells

Answer 42

ts: turns off immune response when antigen is no longer present. Also called regulator t cells

Question 43

Nonspecific cells

Answer 43

``` Activated macrophages Natural killer cells T-dependent Antigens T-Independent Antigen Antibody-dependent Cell-mediated Cytotoxicity Self Tolerate Clonal deletion Major Histocompatibility complex Human leukocyte Antigen complex ```

Question 44

Activated Macrophages

Answer 44

Macrophages stimulated by injection of antigen or by cytokines

Question 45

Natural killer cells

Answer 45

lymphocytes that destroy virus-infected cells, and tumors Same function of cytotoxic Tcells but nonspecfic - clumsy. A lot of collateral damage.

Question 46

T-dependent antigen

Answer 46

Sequence of event t cell comes before b cells (plasma memory)

Question 47

T-independent antigen

Answer 47

limitation: has to be a large molecule but B cell can replicate without Tcell

Question 48

Antibody dependent cell mediated cytotoxicity

Answer 48

Read page 485

Question 49

Self tolerant

Answer 49

The immune system does not normally attack self tissues or compounds.

Question 50

Clonal deletion

Answer 50

During embryonic development lymphocytes with antigen receptors for molecules present in the body are destroyed (theory)

Question 51

Major Histocompatibility complex

Answer 51

(MHC) or other wise known as Human Lekocyte Antigen complex (HEA) Glycoproteins in plasma membrane the enable the immune system to distinguish self from nonself. Class I MHC: On all nucleated cells (almost all your cells) Class II MHC: On macrophages and B cell.