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Flashcards in Acquired Immunity Deck (24):

Differences between innate and acquired immunity? Similarities?


-rapid response (hours)

-fixed, broad

-limited number of specificities

-constant during response



-slow response (days to weeks)


-highly selective specificities

-improve during response


-more advanced

-resolves infection usually

Similar -common effector mechanisms for destruction of pathogens


Besides infectious processes, what is the immune system involved in?

-transplantation immunity

-autoimmune disorders

-hypersensitivity (allergies)



What is the immune system composed of?




-macrophages, monocytes, dendritic cells







What are the lymphoid cells? where are they produced? Function?

B lymphocytes:

-made in bone marrow

-key in adaptive immunity (humoral)


T lymphocytes:

-made in thymus

-key in adaptive immunity (humoral and cell mediated)


Describe the antigen receptors on B lymphocytes?

-have an antigen binding site-determines which cell responds, very specific

-heterodimer chain

-light chain with binding site

-heavy chain which anchors molecule, goes through transmembrane region

-more diverse


Describe antigen receptors on T lymphocytes?

-antigen binding site, very specific

-alpha and beta chain

-variable region on top

-constant region on bottom

-anchored in transmembrane region

-less diverse, recognize linear molecules


Explain why B and T lymphocytes are important to adaptive immunity?

T -centrally important in most adaptive antigen specific immune responses

-made in thymus


B -make antibodies which can attack viruses or bacteria


What are antibodies? Where are they produced? Function? What do they look like?

-protein that binds specifically to an antigen

-produced by plasma cells (differentiated B cell) in response to infection or immunization

-binds to and neutralizes pathogen or prepares for destruction by phagocytes or complement

-look like B lymphocytes, but chains are connected by disulfide bonds


What are the major subsets of T cells? What do they regulate? Functions?



-make cytokines

-regulate afferent (generation) and efferent (effecting the response) arms of many different types of response

-produce antibodies

-generate cell mediated and humoral responses

-Regulatory T cells



-cytolytic T cells

-cytotoxic or cytolytic for cells bearing relevant antigen

-regulates immune responses (suppression)


Functions of B lymphocyte, Helper T lymphocytes, Cytotoxic T lymphocytes, Regulatory T lymphocytes?

B -make antibodies

-neutralize microbes, phagocytosis, complement activation


Helper T -make cytokines

-activate macrophages


-activation of T and B lymph


Cytotoxic T -kill infected cells


Regulatory T -Suppress other lymphocytes


What are the types of specific immunity? Specificity? Memory?


-generate a response

-natural via infection

-artificial via vaccination


-has memory



-natural by transplacental or colostral transfer of antibody

-artificial by administration of immune globulins


-no memory


Adoptive -transfer of immune cells


What activates natural killer cells (NK)?

when a virus inhibits class 1 MHC expression


What are natural killer cells? Function?

-clear virally infected cells

-clear tumor cells

-effector in natural immunity

-act in same time frame as innate

-faster than B and T cells

-may enhance inflammation

-phagocytosis of extracellular microorganisms and viruses


What are the two subsets of NK cells? Function? Where found?

CD56 dim -make up 90% of NK cells in blood

-enhanced cell killing capacity


CD56 bright -make up 90% of NK cells in tissues

-enhanced growth factor and non inflammatory cytokines


What leukocytes have the biggest proportion in human blood?

-neutrophil (40-75%)

-lymphocyte (20-50%)


What are the cardinal features of adaptive immune response?





-self limitation

-discrimination of self and non self


Cardinal features: specificity?

-an immune response is specific for distinct antigens

-function of distinct antigen receptors on the lymphocyte surface

-antigen receptors present before exposure to antigen

-basis of clonal selection theory


Cardinal features: diversity?

-total number of antigenic specificities of lymphocytes in an individual is large

-individual can discriminate at least 1 billion different antigens

-result of incredible variability in the antigen receptors among lymphocytes


Cardinal features: adaptability?

ability to respond to antigens not previously encountered in nature


Cardinal features: memory?

-exposure of the immune system to foreign antigen enhances its ability to respond again

-secondary immune responses are more rapid, bigger, qualitatively different


Cardinal features: self limitation?

-immune response wanes with time because of the elimination of antigen, effector cells are short lived, regulatory feedback elements of immune response


Clonal selection theory?

-every individual contains numerous clonally derived lymphocytes

-each lymphocyte has an antigen receptor specific for a single antigen

-these are present prior to exposure to antigen

-antigen selects a pre existing clone and activates it


What is the architecture of a lymph node? where do T cells and B cells congregate?

T cells- in center

B cells- outer


What is the difference between the primary and secondary immune response to the same antigen?

see pic