§  Requires no previous exposure to effectively respond to antigen

§  NK cells

§  Phagocytic cells

·         Neutrophils

·         macrophages

§  Respond more effectively to 2^nd exposure

§  Highly restricted in ability to recognize antigens

§  B and T lymphocyes

§  Contains large numbers of B cells, T cells, and macrophages

§  Lymph fluid flows through for immune cells to filter, detect, and react to foreign material 

§  Bone marrow: produce cells, location of B cell maturation

§  Thymus: location of T cell maturation

§  Tonsils

·         Located in mouth and pharynx

·         Most likely to encounter microorganisms because of strategic location

§  Spleen

·         Located under diaphragm on left side of body

·         Macrophages in red pulp

o   Filter our foreign substances and old red blood cells

·         Lymphocytes in white pulp

o   Contact blood-borne antigens, then may migrate to other lymphoid organs for increased defense

§  Lymph nodes and lymphatics

§  Peyer patches

·         Produce antibodies to microorganisms that invade mucosal tissue

·         Mucosa-associated lymphoid tissue (MALT)

·         Gut-associated lymphoid tissue (GALT)

§  Monocytes

§  Lymphocytes 

§  Basophils

§  Neutrophils

§  Eosinophils 

o   Monocytes (immature, become macrophages (dendritic cells) in tissues

o   Neutrophils

o   Eosinophils  

o   B and T cells, NK cells 

o   Antigen presentation

§  Detected by surface receptors:

·         Antibodies

·         Cytokines

·         Selectin/integrin

o   Adhesion molecules

·         Complement

·         Toll-like receptors detect foreign patterns 

o   Allergic reactions and intestinal parasite infections

§  Structurally similar to mast cells

§  Mature basophils circulate in vascular system (can migrate to connective tissue, but don’t reenter bloodstream)

§  Found in connective tissue

§  Live for weeks to months

§  Cells release granules (contains histamine, platelet-activating factor, and other vasoactive amines)

§  Begins inflammatory response associated with allergic reactions

§  Involved with wound healing and chronic inflammatory conditions

o   Associated with innate immunity, can respond without prior exposure

o   Interact with antigens presented on the surface of specialized antigen-presenting cells such as dendritic cells, macrophages, and B cells. Then they secrete cytokines to activate other T cells, macrophages, B cell proliferation and antibody production.

o   Administer a lethal hit to offenders by activating rapid DNA defragmentation and nuclear collapse→Apoptosis

§  Proteins manufactured in cytotoxic T cells

§  Create pores in target cell membrane, allows for granzymes to degrade DNA and induce apoptosis 

o   Epitope is the surface on an antigen that is recognized by immune system which stimulates the immune response.

o   Classical pathway: initiated by an adaptive response (Ag/Ab complex)

o   Alternative pathway: initiated by an innate response, starts at C3 

o   Membrane Attack Complex: combination of activated molecules that form a hole in target cell which causes an inflow of sodium and water, resulting in cell rupture

o   Neutralize and destroy invading and harmful agents

o   Limit spread of harmful agents to other tissue

o   Prepare damaged tissue for repair

o   Redness

o   Swelling

o   Heat

o   Pain

o   Loss of function

o   Increase vascular permeability to allow WBC to spread out

o   Fibroblasts: stimulated to make collagen, proteoglycans, fibronectin to enduce repair of damage

o   Endothelial cells

o   Myofibroblasts

• Serous exudate (serosanguineous drainage)
• Fibrinous exudate (sticky, thick)
• Purulent exudate (pus)
• Hemorrhagic exudate (RBCs mixed in with serous fluid; can be a sign of severe inflammation)

o   Proteins on the surface of membranes that display or “present” antigens

o   Allows the immune system to know what is “self”

o   Precipitation

o   Agglutination

o   Neutralization

o   Opsonization

o   Complement activation

o   Each arm of immunoglobulin Y structure can bind an antigenic epitope

o   Allows antibodies and antigens to bind together into large insoluble complexes that precipitate out of body fluids

o   Can function as antitoxins

§  Neutralize bacterial toxin

§  Most common type, 75-90%

§  Smallest

§  Easily escapes bloodstream to enter interstitial fluid

§  Neutralizes toxins, binds and facilitates destruction of bacteria

§  10%

§  Large pentamers

·         Mostly found in intravascular pool; cannot penetrate capillary wall

§  First to be produced on exposure to antigens or after immunization

§  Major antibody found on B-cell surfaces

§  Works best to activate complement

§  Produced by plasma cells located in tissue under skin/mucous membranes

§  Primarily found in saliva, tears, teacheobronchial SECRETIONS, colostrums, breast milk, and GI/GU secretions

§  Secretory IgA

·         Complex made by binding to secretory compeonent produced by epithelial cells; secretory component prevents proteolysis

·         Allows transport of IgA into secretions

Know it has something to do with B cells

§  Found in tiny amounts in serum

§  Located primarily on B cell membranes (with IgM)

§  Thought to be cellular antigen receptor that acts to stimulate B cell to:

·         Multiply

·         Differentiate

·         Secrete other specific immunoglobulins

o   Antimicrobial peptides produced by skin epithelium that can kill a wide variety of bacteria and fungi 

o   Increase in circulating neutrophils

o   A shift in amount of mature and immature neutrophils, shift to the left means going from normal (95% mature and 5% immature) to abnormal (85% mature and 15% immature) seen in acute bacterial infections

o   Adhesion molecules on macrophages, aid in sticking to capillary walls and entering/moving through tissue

o   In every cell membrane. when there is damage pathway is initiated and inflammation occurs

o   Epitope is the surface on an antigen that is recognized by immune system which stimulates the immune response.

§  Acute:

·         short in duration, lasting less than 2 weeks

·         involves a discrete set of events

§  Chronic:

·         More diffuse

·         Extends over longer period

·         May result in scar tissue formation or deformity 

• "Cleaning Up"
• Transport leukocytes and antibodies
• Dilute toxins and irritating substances
• Transport nutrients for tissue repair