IHL I - Overview of the Immune System Flashcards
adaptive immunity
antigen-specific lymphocytes to antigen (memory)
immune
state of being resistant
previous exposure (adaptive)
inherent trait (innate)
innate immunity
mechanisms prior to host exposure to antigen
4 main tasks of immune system
1 recognition
2 contain and eliminate (effector task) - clonal expansion
3 immune regulation - after response, need to return homeostasis
4 memory
principal components of innate immunity
barriers, defensins, cells, blood proteins, cytokines
innate immunity
aka natural, inheret, non-specific immunity
adaptive immunity
develop as a response to infection and adapts to the infection
secondary response is more rigorous
specific immunity
aka adaptive and acquired immunity
humoral immunity
extracellular microbes
B lymphocytes - antibody products
cell-mediated immunity
T lymphocytes
helper - activate macrophages to kill phagocytosed microbe
cytotoxic - kill infected cells
helper T cells
activate macrophages to kill phagocytosed microbes
cytotoxic T cells
kill infected cells
cardinal features of adaptive immunity
specificity, diversity, memory, clonal expansion, specialization, contraction and homeostasis, nonreactivity to self
specificity
highly specific to antigens
B cells
extracellular antigens (soluble)
proteins, polysaccharide, lipid
accessible, hydrophilic, mobile peptides
T cells
need antigen displayed (HLA)
mostly proteins, some lipids presented
internal linear peptides produced by processing of antigen
diversity
huge diversity of possible antibodies
between V, D, and J gene and segment
clonal selection
lymphocyte precursors in the bone marrow
-for both B and T cells
antigen-specific clones are selected by antigens
contraction and memory
need immune response to return to homeostasis
-also need to form memory
nonreactivity to self
T cells responsive to self are destroyed
active immunity
have to have been exposed to antigen previously
passive immunity
take antibodies from one individual and administer them to another
ex/ someone with infection who has never been vaccinated (or it is unknown) you can inject tetanus antibodies to protect patient
natural immunity
active and passive
ex/ passive - mother antibodies cross placenta to baby
artificial
active (ex/ vaccination)
passive (ex/ serotherapy - monoclonal antibodies)
primary response
takes about 2 weeks to respond
first exposure
secondary response
much faster and is much stronger of a reaction
IL-3
secreted by T cells
stimulates differentation of pluripotent stem cell to lymphoid and myeloid progenitor
descendents of lymphoid progenitor
NK cells, B lymphocytes, T lymphocytes
descendants of myeloid progenitor?
erythrocytes, platelets, basophils, eosinophils, neutrophils, and monocytes
IL-7
secreted by bone marrow stromal cells and fibroblasts
necessary for commitment to the lymphoid lineage
survival of T cells
neutrophils
ploys, PMN cells
within a few hours
highly phagocytic
macrophages
M (mew)
monocytes in blood, mature in tissue
later response, but survive longer
NK cells
recognized infected, stressed, malignant cells
kill them
dendritic cells
pick up antigen and process
bridge between innate and adaptive immunity
B lymphocytes
extracellular antigen recognition
helper T lymphocyte
activate macrophage with a phagocytosed microbe
cytotoxic T cells
kill infected cells
regulatory T lymphocyte
suppression of immune response
natural killer cell
kill infected cell indiscriminately
location of B lymphocytes
bone marrow
location of T lymphocytes
thymus
innocuous antigen
allergy
not pathogen, but body elicits immune response
hypersensitivity
immune response to an innocuous antigen
autoimmunity
body reacts to self
complement
part of innate immunity
cells of innate immunity
phagocytes and natural killer cells
phagocytes = neutrophils and macrophages
immunological tolerance
non-reactivity to self
