basophils
release histamine, promote t cells
- innate and adaptive immune system
- in blood
eosinophils
kill antibody coated parasites
-adaptive immune system
neutrophils
stimulate inflammation, engulf and digest organisms
-innate immune system
mast cells
release histamine when damaged
- innate immune system
- mucosa
monocytes
develop into macrophages and dendritic cells
-innate and adaptive immune system
macrophages
engulf and digest microorganisms, activate t cells
-innate and adaptive
dendritic cells
present antigens to t cells
-adaptive immune system
natural killer cells
attack and lyse virus infected or cancerous body cells
-innate immune system
b lymphocytes
differentiate to form antibody producing cells and memory cells
-adaptive immune system
t lymphocytes
kill virus infected cells or cancer cells; regulate activity of other WBC
-adaptive immune system
IgG class
- monomer
- free in blood plasma, most antibodies
- most abundant antibody in primary and secondary immune responses, crosses placenta and provides passive immunization to fetus
IgM class
- pentamer
- on surface of B cell, free in blood plasma
- functions as antigen receptor on B cell membrane, first class of antibodies released by B cells during primary response
IgD
- monomer
- on surface of B cell
- functions cell surface receptor of mature B cell, important in b cell activation
IgA
- dimer
- in saliva, tears, milk, other secretions
- functions to protect mucosal surfaces, prevents attachment of pathogens to epithelial cells
IgE
- monomer
- secreted by plasma cells in skin and tissues lining GI tract and respiratory tract
- functions to bind to mast cells and basophils to sensitize them to binding of antigen, this trigers release of histamine that contributes to inflammation and some allergic responses
