naturally acquired immunity

artificially acquired immunity

host produces antibodies & T cells 

- can last from years to life time

-when antibodies are passed from one host to another

ex. antibodies through placenta from mother to fetus.

-lasts few weeks to months

-result of vaccination

-host makes antibodies that can last for years.

1. toxoid

2. killed bacteria cell

3.inactivated virus

4. live cells

5. purified polysaccharide

Toxoid

ex.?

chemically modified exotoxin retains antigenicity but loses toxicity.

ex. Tetanus, Diphtheria

Killed bacteria cell

ex.?

formaldehyde, heat

ex. Cholera (dead Vibrio cells)

Inactivated virus

ex.

Formaldehyde

ex. Salk polio vaccine, influenza

live cells/ virus

ex.

attenuated: has lost its virulence

ex. Tuberculosis, chicken pox

most effective way

Purified polysaccharide

ex.

from the bacterial cell

ex. Meningitis

Host receives antibodies (antiserum) from another host that has formed antibodies against a specific antigen

-snakebite victim

-lasts only few weeks

Phagocytic leukocytes do what?

(neutrophils & macrophages + monocytes)

engulf and destroy pathogens

contains lysosomes (inclusions contain H2O2, lysozyme, proteases, phosphatases, nuclease, and lipase)

Neutrophils

aka

Macrophages and monocytes

when is it called a monocyte?

what does a macrophage do?

- called monocyte when circulating

-differentiates into macrophage when enters tissues

-Macrophage: antigen presenting cell > presents peptide antigens to T cells to activate a specific immune response.

Immune system reacts to specific antigens (foreign proteins, sugars, chemicals)

-retains "memory" of these antigens

production of antibody proteins

-each binds different antigens

T cells that bind different antigens

-kill pathogens, control antibody production

Proteins:

b/c they are fixed and nonrepetitive shape

Immune reaction is specific.

blood types: type A attacks type B blood cell antigen

AB blood has both antigens, won't make antibodies

Antibody (Immunoglobin)

what is it?

produced by what?

interacts with what?

Cell mediated immunity 

or

Antibody mediated / Humoral immunity

What are the major classes of T cells?

1. Helper T cells (h1,h2,h0)

2. Cytotoxic T cells

3. Memory T cells

4. T cell receptors

Destroy tumor cells and infected cells by releasing cytotoxin

- also recognizes grafted tissues & organs as foreign

2 peptides (alpha & beta)

each with constant and variable domain

tumor cells

transplanted organs

tissues

When antibodies bind to antigens, they _____them.

What do antibodies recognize if not the entire pathogen?

Antibody binding:

1. activates _____ system

2. Enhances __________

3. causes _________

4. neutralizes _______

1. complement

2. phagocytosis

3. agglutination (clumping together)

4. antigens

Complement can:

1. increase _______

2. Attract and activate _______

3. cause _______

1. inflammation

2. phagocytes

3. lysis

process of enhancing phagocytosis

by binding both to a microbe and phagocyte, bringing them closer in proximity.

IgG consists of how many polypeptide chains?

IgG

IgA

IgM

IgE

IgD

Most abundant- 80% of Ig in serum

Only antibody that can be transferred through placenta

Gamma heavy chains

Predominant antibody in secretions (saliva, tears, milk, mucus.)

Dimer

Alpha heavy chain

2nd most abundant 

1st class of antibody made in response to infection

Aggregate of 5 molecules attached by disulfide bonds & J chain protein

can bind up to 10 antigens

Mu heavy chains

Low concentrations, responsible for allergies

binding of antigen to IgE causes release of histamine (allergies)

Epsilon heavy chain

Found on the surface of B cells

Binding of antigen to these antibodies stimulates B cells to produce antibody IgG

Delta heavy chains.

B cells disperse through:

b cell must phagocytize foreign cell so that polypeptides from that cell are bound onto B cell surface.

B cells differentiate into:

Which antibody is made first, then what?

Immune response diseases

Hypersensitivities

super antigens

results from 2 or more exposures to same allergen

1st exposure - B cell produce IgE> IgE binds mast cells and basophils

2nd exposure - Mast cells and basophils release histamine

Histamine produces what? 

causes what?

produces prostaglandin, leukotrienes

causes allergy symptoms.

constriction of airways and drop in blood pressure

treatment for allergies:

________ to neutralize histamine

________ to reduce inflammation

___________ to counter effects of histamine

____________- allergy shots that shift antibody production from IgE to IgG

1. antihistamines

2.steroids

3. adrenalin

4. desensitization

Type II Hypersensitivity:

antibodies bind to foreign ________ antigen

-blood transfusion recipients

-Rh- mother has antibodies to Rh+ fetus

-can occur within hours

Type III hypersensitivity:

antibodies bind to ________antigen

-large amounts of antigen- antibody complex are formed

-triggers complement cascade

-stimulate mast cells

-in response to certain antibiotics

-can take weeks to occur

result of sensitivity to chemicals or microbes

Th1 cells release cytokines that activate macrophages, NK cells, and Tc cells

takes few days to occur

typical antigens: M. tuberculosis& chemicals that covalently bind to skin creating new antigens

symptoms: hardening swelling, reddening pain and localized heating

autoantibodies

Rheumatic fever

hemolytic anemia

Graves disease

Myasthenia gravis

Autoantibodies to cardiac cells, damages heart valves

caused by similarity between epitope in M protein of Streptococcus pyogenes and cardiac tissue --(antigenic mimicry)

autoantibodies to acetylcholine receptor; causes progressive muscle weakness

Type III diseases

: antibodies bind soluble proteins, creating insoluble complex leading to complement and inflammation

Rheumatoid arthritis

Systemic lupus erythematosis

type IV autoimmune diseases

: T cells respond to self antigens

Multiple sclerosis

Type 1 diabetes

T cells attack myelin protein, destroying covering of neurons

t cells attack insulin

producing cells in pancreas; preventing insulin production

super antigens:

proteins that can cause very strong immune response, activate more T cells than normal

-bypass normal route of antigen processing by binding TCR &MHC 

-results in cytokine production, systemic inflammation.

Toxic shock syndrome

Scarlet fever

Toxic shock syndrome