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95 Cards in this Set

  • Front
  • Back
what are the functions of lymph nodes?
filtration by macrophages, storage/proliferation of B and T cells, antibody production
what is the site of B cell localization and proliferation?
which follicles are dense and dormant?
which follicles have pale central germinal centers and are active?
these communicate with efferent lymphatics and contain reticular cells and macrophages
what region of the lymph node houses T cells?
in an extreme cellullar immune response, what part of the lymph node becomes greatly enlarged?
this portion of the lymph node is not well developed in patients with DiGeorge syndrome
what drains the right arm and the right half of the head?
right lymphatic duct
what drains everything but the right arm and right half of head?
thoracic duct
where are T cells found in the spleen?
periarterial lymphatic sheath adn red pulp (T rex)
where are B cells found within the spleen?
white pulp
these are long, vascular channels in red pulp with fenestrated "barrel hoop" basement membrane
sinusoids of spleen
what is found in the marginal zone of the spleen?
where do T cells mature? what is this derived from embryologically?
thymus; epithelium of 3rd branchial pouches
what part of the thymus is dense with immature T cells?
what part of the thymus is pale with mature T cells and epithelial reticular cells?
medulla (M-mature/medulla)
what part of the thymus contains Hassall's corpuscles?
MHC restriction occurs in what type of selection?
nonreactive to self is associated with what type of selection?
where do positive and negative selection occur in the thymus?
corticomedullary junction
these cells producse IL-2 and gamma-interferon
Th1 cells
these cells activate macrophages and Tc cells
Th1 cells
what do macrophages produces to influence naive helper T cells to differentiate into Th1 cells?
what cells produce IL-4 and IL-5? what does this do?
Th2 cells - causes B cells to differentiate into plasma cells
what type of cells are responsible for host defense against infection with TB, virus-infected cells, and fungi?
T cells
what type of cells opsonize bacteria and neutralize toxins and viruses?
B cells
what type of cells are responsible for hay fever and Type I hypersensitivity reactions?
B cells
what type of cells are responsible for poison oak allergy and type IV hypersensitivity?
T cells
what type of cells are responsible for autoimmunity?
B cells
what type of cells are responsible for graft and tumor rejection and regulation of antibody response?
T cells
what MHC class consists of 1 polypeptide with beta2-microglobulin?
MHC class I
what MHC class consists of 2 polypeptides, and alpha and beta chain?
MHC class II
what cells have MHC I proteins?
all nucleated cells
what cells have MHC I and MHC II proteins?
what MHC class are the main determinants of organ rejection?
MHC class II
where does MHC I antigen loading occur?
in RER (viral antigens)
where does MHC II antigen loading occur?
in acidified endosome
helper T cells have ____, which binds to ____ on antigen-presenting cells
cytotoxic T cells have ____, which binds to ____ on virus-infected cells
this is a cluster of polypeptides associated with a T-cell receptor; it is important in signal transduction
CD3 complex
what does Th cell secrete that activates Tc cell to kill virus-infected cell?
what do APCs express that bind to CD28 on Th cells to create the costimulatory signal?
what part of an antibody recognizes antigens?
variable part of L and H chains
what part of antibody fixes complement?
constant part of H chain of IgM and IgG
what chain contributes to both Fc and Fab fractions?
heavy chain
what chain contributes only to Fab fraction?
light chain
how is antibody diversity generated?
1. random recombination of VJ (light chain) or VDJ (heavy chain) genes
2. random combination of heavy chains with light chains
3. somatic hypermutation
4. addition of nucleotides to DNA during genetic recombination by terminal deoxynucleotidyl transferase
what mediates isotype switching?
cytokines and CD40 ligand
what is the main antibody in the secondary response?
what is the most abundant antibody?
this Ig type fixes complement, crosses the placenta, opsonizes bacteria, and neutralizes bacterial toxins and viruses
IgG (Goes across placenta)
this Ig type prevents attachment of bacteria and viruses to mucous membranes, does not fix complement
this Ig type is a monomer or dimer that is found in secretions and picks up secretory cmoponent from epithelial cells before secretion
this Ig type is produced in the primary response to an antigen
IgM (priMary)
this momomer or pentamer fixes complement but does not cross the placenta; antigen receptor found on the surface of B cells
this Ig type does not have a clear function; it is found on the surface of many B cells in serum
this Ig mediates immediate (type I) hypersensitivity by inducing the release of mediators from mast cells and basophils when exposed to allergen
this Ig has the lowest concentration in serum
this Ig mediates immunity to worms
this type of Ig epitope differs among members among members of same species; can be on light chain or heavy chain
allotype (polymorphism)
this is an Ig epitope common to a single class of Ig (5 classes, determined by heavy chainn)
isotpe (IgG, IgA, etc.)
this Ig epitope is determined by antigen-binding site; specific for a given antigen
patients are given preformed antibodies after exposure to what four diseases?
tetanus, botulinum, HBV, rabies (to be healed rapidly)
this type of immunity is based on receiving preformed antibodies from another host
this type of immunity is induced after exposure to foreign antigen - slow onset but long-lasting production
how does salmonella show antigen variation?
two flagellar variants
how does nenisseria gonorrhoeae show antigen variation?
pilus protein
what is anergy?
self=reactive T cells become nonreactive without costimulatory molecule
what types of hypersensitivity are antibody-mediated?
in this type of hypersensitivity, antigen cross=links IgE on presensitized mast cells and basophils, triggering release of vasoactive amines (e.g. histamine)
type I (anaphylactic and atopic)
anaphylaxis, asthma, hives, local wheal and flare are examples of what type of hypersensitivity?
type I
in this type of hypersensitivity, IgM, IgG bind to antigen on "enemy" cell, leading to lysis (by complement) or phagocytosis
type II (cyotoxic)
autoimmune hemolytic anemia, Rh disease, Goodpasture's, rheumatic fever, Grave's disease, bullous pemphigoid, MG, and ITP are all examples of what type of hypersensitivity?
type II
in this type of hypersensitivity, antigen-antibody complexes activate complement, which attracts neutrophils; neutrophils release lysosomal enzymes
type III
polyarteritis nodosa, immune complex glomerulonephritis, SLE, RA, serum sickness, and Arthus reaction are examples of what type of hypersensitivity?
type III
this is an imuune complex disease in which antibodies to foreign proteins are produced (takes 5 days); immune complexes are formed and deposit in membranes where they fix complement
serum sickness (type III)
this is a local subacute antibody-mediated hypersensitivity (type III) reaction in which intradermal injection of antigen induces antibodies which form Ag-Ab complexes in skin
Arthus reaction
this type III hypersensitivity reaction is characterized by edema, necrosis, and activation of complement
Arthus reaction
hypersensitivity pneumonitis (farmer's lung) and thermophilic actinomycetes are examples of what?
Arthus reaction
in this type of hypersensitivity, sensitized T lymphocytes encounter antigen and then release lymphokines, which leads to macrophage activation
type IV (delayed/T-cell mediated)
transplant rejections, TB skin tests, and contact dermatitis are examples of what type of hypersensitivity?
type IV
fever, urticaria, arthralgias, proteinuria, lymphadenopathy 5-10 days after drug exposure
serum sickness
what defends agains gram-negative bacteria?
the classic pathway is activated by what?
IgG or IgM (GM makes classic cars)
what activates the alternate pathway?
molecules on the surface of microbes (especially endotoxin)
interferons induce the production of a 2nd protein that inhibits viral protein synthesis by doing what?
degrading viral mRNA
these are proteins that place uninfected cells in an antiviral state
interferons (alpha, beta, gamma)
which interferons inhibit viral protein synthesis?
alpha and beta interferons
what does gamma-interferon do?
increases MHC I and II expression and antigen presentation in all cells
this type of rejection is due to the presence of preformed antidonor antibodies in the transplant recipient
hyperacute rejection
this type of transplant rejection is cell-mediated due to cytotoxic T lymphocytes reacting against foreign MHCs
acute rejection
what type of transplant rejection is reverisble with immunosuppressants such as cyclosporin and OKT3?
acute rejection
this type of transplant rejection is characterized by antibody-mediated vascular damage (fibrinoid necrosis) and is irreversible
chronic rejection
what are major symptoms of graft-versus-host disease?
maculopapular rash, jaundice, hepatosplenomegaly, and diarrhea