Immunology Concepts Flashcards
Fc region
part of the antibody molecule that fits into a receptor on the phagocytic cell
Lymphokines
soluble mediators produced by lymphocytes, primarily T cells
HLA complex is primarily located on this chromosome
Chrom 6,
A young woman shows increased susceptibility to pyogenic infections. Upon assay she shows a low level of C3, what is probably true?
she has a decreased production of C3, autoimmune disease susceptibility does not include pyogenic infections
What is Digeorge syndrome?
decreased T cells
example of immune injury caused by ag-ab complexes?
acute glomerulonephritis - acute inflammatory reactions happen after ag-ab complex is deposited on the glomerular membranes
IgE mediated anaphylatic reactions
Bee stings/penicillin
Contact dermatitis mediated by?
T cells, not antibody
Serologically detectable antibody produced in RA? … explain more
IgM due to agglutination activity. RF (rheumatoid factor) commonly used in diagnosis of rheumatoid arthritis
Direct immunoflourescence assay
conjugated reagent antibody reacts with antigen to form antigen-antibody complexes
in individuals allergic to pollen, hyposensitization protocols may be initiated, what type of injections may these pts recieve?
involves gradually increasing concentration of the allergen until the pt is tolerant and no longer has symptoms
Why can we transplant corneal tissue from one pt to another so successfully?
the cornea is nonvascularized and is sequestered. The immune system of the host does not “see” the cornea and recognize it as foreign
a transplant from one identical twin to another is an example of?
same genetic makeup, meaning they would be isografts or syngeneic grafts
Autographs
one transplant from a site to another in the same individual
Allograft
transplantation of two nonidentical individuals of the same species
Bruton’s disease
congenital agammaglobuliemia
mostly males
B cells not produced
IgA,IgD,IgE and IgM undetectable
IgG absent or very low
cell source of IL-2?
T cells
activated Helper T cells
passive immunization benefits
ab is available immediately
short lived ab
mostly IgG
active immunization
ab production takes a while
life long persistance
where are antibodies digested?
in the GI
compliment has been activated, what attracts leukocytes and macrophages to the site of compliment activation?
C5a - it is chemotactic
IgM can activate the compliment cascade but is not chemotactic
anamnestic response
secondary response to a stimuli, not innate
phagocytosis by polymorphonuclear cells is an example of?
innate immunity
Prozone phenomena
high titer of excess ab is present, not enough antigen is present for cross linking and lattice formation. Ab blocks all binding sites/no complement is able to start
Rapid plasma reagin assay for syphilis does nto need to be read microscopically because the ag is?
complexed with charcoal, when combined with pt sample and ag, this reaction can be read Macroscopically
VDRL test for syphilis is classified as a(n)
flocculation reaction, read on low power
one cause of false positive VDRL tests?
connective tissue disorders like SLE, or mono, pregnancy, malaria ..etc
ELISA, visible reaction is due to?
enzyme and substrate, will produce a colored reaction
alkaline phosphatase is used
light chains
kappa and lambda, two, but in any one molecule only one type is found
Fc fragment of an immunoglobulin molecule?
binds to specific fc receptors on the surface of white blood cells
monoclonal antibodies are produced by?
hybridomas/hybrid myeloma - prepared from mouse and human plasma cells fused with myeloma cells
antibodies that bind to the same epitope are of the same
idiotype - refers to the specificity of the molecule, variable region of the molecule
isotype
different classes and subclasses of antiboides (IgG vs IgM)
determined by which heavy chain is present
allotype
refers to different alleles of the same isotype
Skin testing is a useful diagnostic tool in a number of disorders, such as tuberculosis….how does this work?
it causes a delayed hypersensitivity reaction, if sensiitized T cells are transferred from one individual to another the recipient will also have a delayed rxn
Interaction between B and T helper cells involves
Foreign antigen on B cell binding to T cell receptor
cell mediated hypersensitivity
contact dermatitis, usually a hapten is the ag and combines with carrier molecule on the surface
incompatible blood transfusions are examples of?
Type II hypersensitivity reactions, ag binds to ab and lyses the rbcs
A soluble antigen and soluble antibody reacting to form an insoluble product describes
precipitation reactions
What is the indicator system used in the complement fixation test?
Sensitized sheep red blood cells
IgM antibody to OspC
marker for lyme disease, detected by western blot
Rheumatic fever sometimes occurs after group A streptococcal infections. In this condition, an autoimmune response attacks the tissue of the heart valves. This phenomenon is an example of…
molecular mimicry
moleculary mimicry definition
an immune response directed against one antigen may be extended to include activity against closely related antigens.
“Superantigens” are toxins produced by some strains of Staphylococcus aureus and group A streptococci and cause damage by
polyclonal T cell activation, resulting in things such as TSS
In a competitive radioimnumosorbent test (RIST), what does a high signal suggest?
a high signal indicates low unlabled IgE from the patient sample
what indicates a chronic HBV infection vs Acute?
chronic will have HbsAg, HbeAg and anti-Hbc
