Imminobiology

• Specific
• Non specific

• Fight off specific pathogens by protein to protein interactions
• Allows us to become to immune to future infections by memory cells
• B&T cells

• Defenses that are used to fight off infection in general 
• Ex: Skin and mucous
• Skin will not let bacteria or viruses through unless it is penetrated
• Sweat and oil give skin a pH of 3-5 and discourage bacteria and microbes
• Mucous traps foreign particles and that are either coughed up or swallowed and digested by the stomach

Enzyme in saliva tears and mucous that destroys bacteria cells walls causing them to lyse

Large while blood cells that circulate looking foreign material to engulf via phagocytosis

Macrophages name when they are circulating the blood and are able to transport themselves through capillaries into infected tissue

Once in tissues knowns are macrophages

• used to pull in foreign particles to destroy them with lysosomes
• use actin and mysosin to make (feet) and put in particles

• Ex: macrophages
• They have the ability to display antigens they engulfed on their cell surface so that they can be recognized by T cells

Foreign particle

White blood cells that use phagocytosis but are not APC's

• Responsible for dialating the walls of capillaries, allowing macrophages and neutrophils to enter more easily 
• Resleased by basophils, and mast cells
• Increases blood flow to area, and results in redness and heat of injury

• Chemicals the excite specific immune defenses to activate
• Released by basophils and mast cells

Major defense used by specific system, B&T cells

Are produced in bone marrow and mature here and in spleen

• Are produced in bone marrow and mature in thymus
• Cannot detect free antigens only those displayed on macrophages
• Direct killing and overall activation of the immune system
• Basis for cell mediated immunity

Essential for educating T cells to recognize self antigens (and therefore those that are not self)

• Helper T cells
• Cytoxic T cells
• Suppressor T cells

• Killer T Cells
• Essential against viruse

Involved in controlling the immune response so it doesn't run out of control by suppressing antibodies produced by B cells

• Secrete chemicals to help B cells proliferate
• Helper T cells can bind to molecules displayed by MCH II  like macrophages and this binding triggers immune system to make antibodies

• Make up 30% of lymphocytes are specific for foreign antibodies by Y shaped receptors
• Secrete antibodies
• Basis for humoral or fluid immunity

Antibodies that are produced solely by B cells, B cell can produce any class of immunoglobulins

• IgG
• IgD
• IgM
• IgE
• IgA
• All Immunoglobin (then letter)

• Antigen binding site
• Formed for one variable Heavy and one variable light chain
• Each antibody has two

• Similar in amino acids but Heavy is longer
• Involved in antibody diversity
• Heavy chain is 5'VDJC3'
• Light chain is 5'VJC3'
• There are hundreds of V's, dozens of D's and 4-5 J's and C is a constant group
• They get spiced together to form a unique antibody amino acid sequence

Found in phagocytic cells

Secreted into the blood as primary immune response

Found on B cells they bind antigens together

are in salvia milk and respiratory secretions

• Found on most cells and elsewhere
• Are precursors to allergic reactions by releasing histamine

Antibodies cross link adjacent antigen molecules so that invaders get stuck together by antibodies and are engulfed by macrophage

Similar to agglutination but for soluble antigen molecules like small bacterial toxins

antibodies bound to foreign cells activate the 20 complement proteins that are turned on in a cascade lie fashion

• Coating of a foreign cell with antibodies
• Stimulates Macrophages to engulf and digest these invaders

• Requires antibodies to bind to antigens
• Complement proteins bridge the cap between adjacent antibody molecules 
• Lyse the cell membrane of invader
• Also activated mast cells to release histamine

• Occurs independantly of antigen-antibody binding
• Cell surface molecules of antigen can cause cell membrane attack complex without the help of antibodies

• Antibodies that arise in natural course of fighting pathogens
• But from several clones of B ells and cover a wide range of specificity

Antibodies that arise from a single clone of a single B Cell

• The period after exposure to a pathogen but before enough B cels have been made 
• APC's like macrophages process and display antigens to ThCells 
• Th Cells activate B cells to form antibodies
• First exposure lag period is usually 7-10 days

Second time a person is exposed to an antigen lag period is much shorter (1-4 days) and anitbodies are typically greater in number than they were at first response

• Specific antibody cells that remain after infection
• Memory B&T cells live for decades
• Basis of immunity and form concept behind vaccinations

• Surface cell proteins used in tissue typing
• MCH 1 displays a small bit of cellular contents on surface of cells, allows for killer T cells to monitor cells contents
• Cannot distinguish between self and antigen so grabs a bit of both and displays both on surface

• MCH 1 displays a small bit of cellular contents on surface of cells
• allows for killer T cells to monitor cells contentsCannot distinguish between self and antigen so grabs a bit of both and displays both on surface
• Killer T cells recognizes antigen and kills it

• Only found in macrophages and B cells
• Allows cells to display a bit of whatever they ingested through phagocytosis 
• Helper T cells can bind to molecules displayed by MCH II and this binding triggers immune system to make antibodies