Barriers to infection

Phagocytic cells

Complement system

Native defense cytokines

NK cells

Skin

Mucus

Normal flora

Acid in stomach

Antimicrobial peptides -- defensins

Neutrophils

Macrophages

Types of cytokines

Macrophage derived in response to PAMPs

Pro-inflammatory

Chemokines

Interferones

Recognize and kill cells that do not express normal proteins

Kill some virus infected and tumor cells

Humoral

Cell Mediated

T helper cells

Cytotoxic T cells

Gamma delta T cells

Vasodilation and increased vascular permeability

10^9

(very specific)

Only peptides processed and presents on MHC molecules

Higher titer of Ab

Ab can bind more tightly

Ab class has switched

Ag present during lymphocyte maturation are tolerated

Ag not present during lymphocyte maturation are not tolerated

Hypersensitivity reactions

Allergy reactions

Autoimmune disease

Immunodeficiency

Basophils

Eosinophils

Monocytes

Neutrophils

Lymphocyte

What is the half life of eosinophils

What % in blood is basophils?

Hematopoietic stem cell

1. Common lymphoid progenitor

2. myeloid progenitor

3. Erythroid progenitor

Lymph nodes

Blood

Spleen

Intestine

Bone marrow

Other tissue

Domains are homology regions.

There are 4 heavy domains and 2 light domains

450 residues

(110 residues / domain)

Fab is where the antibody will bind.

Has antigen specificity

Fc is the same for each class of antibody.

"Fragment Crystallizable"

What is one difference between IgG and IgM

1. Electrostatic forces

2. Hydrogen bonds

3. Van der waals force

4. Hydrophobic forces

Reversible

Goes to equilibrium

Rapid (depending on temperature)

pH

Ionic strength

Covalently link antigen to bead

Add antibody

Wash unbound antibody

Change pH

Antibody will fall off

What are 5 important properties of strong antigens?

Foreigness

Size ( > 10000)

Molecular complexity

Rigidity

Degradability

40

(20 on each light and heavy chains)

What accounts for antibody affinity

Sum of attractive and repulsive forces

What are the two types of epitopes

Linear

Discontinuous

3D structures

1. Bacterial lysis

2. Phagocyte chemotaxis

3. Bacteria opsonization

1. C1-INH inhibits C1

2. Classical C3 convertase controlled by C4-binding protein

3. Alternative C3 convertase controlled by factors H and I

4. Terminal pathway is controlled byCD59

What are they soluble proteins that regulate complement activation?

C1 inhibitor

C4 binding protein

Factor H

Factor I

Anaphylatoxin inactivator

Others

What membrane proteins regulate complement activation

Decay accelerating factor

Membrane cofactor protein (CD46)

Membrane inhibitor of reactive lysis (CD59)

Heat to 56 C for 30 minutes

Chelate Ca++

EDTA

Acid citrate dextrose

Ab-Ag complex

C1 binds to Fc

Activates C1 and C1s

What does C1s do?

Cleaves C4b

Cleaves C4b2 -->C4b2b+C2a

C1 can't cleave just C2 (cleavesC4b2)

D can't cleave B (cleaves C3bB)

C4b2b can't cleave C5 (cleaves C3b5)

C1 must bind to at least 2 IgG

Pentameric IgM

Mannose binding lectin binds to mannose on bacteria surfaces which activates MASP2

1. Innate activations through TLCs

2. Immune activation (IFN gamma and microbial stimuli)

3. Alternative activation

what happens to C3b normally in the body?

(alternative pathway)

C3BbB

C4b2b

Anaphylatoxin

Mast cell degranulation

Immune regulation

Opsonization

What does C2a do?

What does C5a do?

Neutrophil chemotaxis

Anaphylatoxin

Lysosomal enzyme secretion

Neutrophil activation

Increased vascular permeabilty

Smooth muscle contraction

Virus covalently bound to bead

Add serum

Wash

Change pH

Take bead with rabbit anticanine IgG bound to bead

Add antibodies from the first round

Wash

Change pH

Pentamer with disulfide bonds and J chain

5 domains 

Has 10 antigen binding sites

Has kappa or lambda light chains

In mucus --> dimer

In the serum --> monomer

J chain (makes it a dimer)

Has a secretory component (when in mucus)

Makes IgA resistent to proteolytic digestion 

 Monomer

Heavy chain has 5 domains

Lots of carbohydrates

Long term immunity

Memory antibodies

Produced at first response to antigens

can serve as B-cell receptor

Secretory antibody

On mucous membranes

Intravascular

Complement activation

Agglutination

Intravascular

Transplacenta

Interstitial fluid

Complement activation

Neutralization

Opsonization

Immunity in neonate

Luminal secretions

Breast milk

Neutralization at body surfaces

Intestinal immunity in neonates

Subcutaneous

Submucosal

Mast cell sensitivity

Eosinophil activation

B cell surface

Non known

Agglutination

Toxin neutralization

Blocking attachment

Complement fixation

Opsonization for phagocytosis

Antibody-dependent cell-mediated cytotoxicity (ADCC)

Ag-Ab binding goes to equilibrium

Ab or Ag can be found to a solid surface (plastic)

Labeled will compete with labeled

Ab

Ag

Anti-immunoglobulin

Labels

How do you name an anti-globulin

Species it was made in

Anti-species

Isotype it recognizes

(Isotype)

Describe ELISA to detect Ag

Describe Competitive ELISA

 •Constant amount of Ab in test tube

Describe single radial diffusion

Do serial diluations

Add constant amount of Ag

Last tube to see precipitate is the titer

What are the 3 granulocytes?

Neutrophils

Eosinophils

Basophils

What is another name for granulocytes

Contains glycogen

Don't need glucose

Can travel far from the blood stream

Complement receptors (mainly for 5a or 3b)

Ab receptors (IgM and IgG Fc portions-- such as Ab coated bacteria)

Cell adhesion molecule (lets them stick to other cells like endothial cells)

Describe neutrophil rolling

What is loose adhesion mediated by

What causes tight binding of neutrophils to the endothelium wall

More hydrophobic molecule

Membrane covered by Ab or Complement

Granules move toward membrane when phagocytosis is occuring

Granules fuse with bacteria membrane

Dump contents into the bacteria to kill it

Defensins

Myelo-peroxidase

Neutral and acid hydrolases

Lysozyme

lysozyme

lactoferrin

collagenase

In phagocytic cells

Respiratory epithelial cells

Intestinal epithelial cells

Hydophobic outside

Hydrophilic inside

oxygen radiacle form hydrogen peroxide

H2O2 can form OH radiacles and OCl (hydroclorus acid-- with the help of myeloperoxidase)

All of the above kills bacteria

Last step of a neutrophil to kill bacteria

Consists of DNA, histones, grandular proteins

Prolonged tissue damage

Macrophage accumulation

Fibrosis

Granuloma

What can activate macrophages

What are the central roles of macrophages within the immune system?

1. Initial defense (secrete cytokines)

2. Antigen presentation to T cells (T cells then secrete more cytokines)

3. Effector function -- activated macrophages secrete cytokines, has anti-tumor functions and anti-microbe functions

What do macrophages develop from?

Stem cell (monoblast)

Promonocyte

Monocyte

what do monocytes develop into in the:

1. Brain

2. Connective tissue

3. Liver

4. Lung

5. Bone

6. Kidney

1. Microglia

2. Histiocyte

3. Kupffer cell

4. Alveolar macrophage

5. Osteoclast

6. Intraglomerular mesangial cells

All the blood draining the gut goes to the liver

The gut is full of bacteria

The Kupffer cells capture bacteria in the portal system that escaped the gut wall

How can alveolar macrophages leave the lungs

Up the airways

Into the interstitial space

Lung (cats, calf, sheep)

Liver/spleen

What do cytokines do

Build up at local site of inflammation

Spill into blood

Circulate to areas such as hypothalamus

Induce:

Loss of appetite, fever, depression

Bone marrow production of neutrophilia

Liver production of acute phase protein response

Toll like receptors

DNA

Lipopolysaccharide

Lipoprotein

Flagellin

1. Inflammation (IL1, IL6, TFN)

2. Tissue injury, apoptosis or septic shock (NOS2)

3. Direction antimicrobial response (NOS2)

4. Stimulate T cells (IL12)

Gram-negative have lipopolysaccharide on their surface with two membranes

Gram-positive have one membrane with a thick peptidoglycan shell

What can stimulate macrophages

(6 things listed)

1. Cytokines

2. Organisms

3. Lectins

4. Immune complexes

5. Inflammatory agents

6. Cell adherence

What effects can IL 1 have?

(7 general things listed)

1. Proinflammatory effects

2. Metabolic effects

3. Effects on cell growth

4. Effects on vascular tissue

5. Effects on the nervous sytem

6. Effects on leukocytes

7. Cytotoxic effects on tumor cells

Monocyte/macrophage activation

endothelial cell activation

Complement activation

Fever

Acute phase reactions

Low cardiac output

Low peripheral resistance

disseminated intervascular coagulation

 acute respiratory distress syndrome

(Septic shock effects)

What are 7 examples of acute phase proteins

complement components

major proteins

protease inhibitors

metal binding proteins

clotting factors

mannose binding proteins

negative acute phase proteins

Pain

Swelling

Redness

Heat

What do type I macrophages do?

Produce NO

Proinflammatory

Antimicrobial

Early in response

Do not produce NO
Anti-inflammatory

Promote healing

Late in response

 Macrophage activitation active the nitric oxide synthase 2

Arginine is made directly into citrulline and NO is released which damages the bacteria

Both neutrophil and macrophage have CD31

They bind, signal is sent, and macrophage leaves.

If neutrophil isn't healthy, it won't have CD31, message won't be sent and the macrophage knows to kill it.