Immunology Flashcards
Bone Marrow
Large reserves of neutrophils, release when needed to fight an infection
Thymus
a primarily lymphoid organ, in thoracic cavity, where t cell maturation takes place
Spleen
Secondary lymphoid organ, placce where old RBCs are destroyed, blood borne antigens are tapped and presented to lymphocytes
Lymph Node
Secondary lymphoid organ, contains lymphocytes, macrophages, and dendritic cells, serves as site for filtration of foreign antigen and activation/proliferation of lymphocytes.
Innate Immunity
Rapid Response (hours)
Fixed
Limited specification
Constant during response
Adaptive immunity
Slow response
Variable
Numerous highly selective specifities
improve during response
Components of Innate Immunity
Skin, mucous membranes (barriers), phagocytes
Components of Adaptive Immunity
Antibody, T cell recognition, cell mediated activation of the innate immune system
Complement
Group of serum protein that can recognize certain types of microorganisms or bind to and recognize Ab molecules
Inflammation
Clears many bacteria
Phagocytosis
Bacteria bind to phagocytic receptors, induces engulfment and degradation
Or bacterial components signal receptors induce synthesis of infammatory cytokines
Opsonization
Makes pphagocytosis work better by binding to the object
Neutrophils
Most abundant leukocyte
Phagocytosis and killing of microorganisms
Eosonophils
1-3% of crculating leukocytes
contain EBP (kill parasitic worms)
Killing of Ab coated parasites through release of granules
Basophils
Basic granules
Control immune responses to parasites
Dendritic Cells
basophilic cells
Antigen presenting cells
Activation of Tcells
Initiation of immune responses
Mast Cell
Basophilic cell
Expulsion of parasites
Release of histamine and other active agents
Monocyte
Mononuclear phagocyte
Circulating precursor cell to macrophage
macrophage
mononuclear phagocyte
Phagocytosis and killing of microorganisms
activation of T cells and initiation of immune response
Lymphocytes
Adaptive immunity: B cells, T cells, NK cells
B cells
Lymphocytes
Production of antibodies
Expresses immunoglobulin on surface
T lymphocyte
Helper or Cytotoxic T cells (CD8)
Killing cells that have self antigen and foreign antigen
Ways in which cells are identified
Morphological criteria
Antigenic criteria
Using stains (acid, bases) to stain proteins
Size and shape of cell
Size and shape of nucleus
Morphological way to identify cells
Use of monoclonal antibodies to recognize subsets of immune cells
using CD, cluster of differentiation for reactivity group
Antigenic way to identify cells
What end of the immunoglobulin does what?
Constant region- binds to immune cells
Variable region- highly specific for antigen binding
Describe the chains of an immunoglobulin
2 identical heavy chains
2 identical light chains
Name the 5 classes of immunoglobulin
IgG, IgM, IgD, IgA, IgE
MW 150,000 Most common Ig with widest range of function predominant class in serum toxin neutralizing Agglutinating Opsonizing
IgG
MW 900,000 Most primitive Ig Most potent at complement fixation Unable to mediate many functions Pentameric in circulation
IgM
MW 160,000 Found predominantly as dimer predominant class in secretions Resists acid hydrolysis (Secretory piece from epithelial cells) Agglutinating, opsonizing
IgA
MW 200,000
Barely existent in serum
Fixes to Mast cells
ALLERGIES!!!!
IgE
MW 180,000
Sensitization of basophils
located on surface of human immature B cells
associated with some tumor cells
IgD
Fab fragment
In the variable region of the Ig
includes framework proteins that do not vary
includes hypervariable regions that are far apart in sequence but close together in tertiary structure
Fc fragment
Crystallized region, many cells have receptors to Fc, they are homogenous in all antibodies
Primary response
lag phase- initial exposure
log phase- Ab production begins
decay phase- extended period of time when small amount of antibody can be detected
predominantly IgM
Secondary response
After intial exposure to antigen, the immune response remains primed to respond, predominantly IgG
7 differences of Secondary Response compared to Primary
Shorter lag time higher peak Ab synthesis higher peak antibody titer longer persistence of Ab predominance of IgG higher affinity og IgG requires less antigen
Clonal selection
As antigen drop, only B cells with the highest affinity for antigen will be selected for.
B memory cells
after clonal expansion, a few cells remain in spleen and lymph nodes for years
B plasma cells
secrete antibody to mark antigens for immune response by Killer T cells. Have short lifespans, die quickly.
Helper t cells
recognize a different set of antigens. Pick up degraded antigens with the help of APC. Proliferate to produce factors that stimulate B cells. Responsible for switch from IgM to IgG. Need to react with antigen on presenting cell and antigen with MHC to stimulate B cells.
Antigen presenting cells
Initiate the interaction with antigen by endocytosis or phagocytosis
Digest antigen so T cell can recogniz it
Antigen is presented by cells that bear MHC signals.
