TY  - CHAP
M1  - Book, Section
TI  - Immunosuppressants, Tolerogens, and Immunostimulants
A1  - Krensky, Alan M.
A1  - Bennett, William M.
A1  - Vincenti, Flavio
A2  - Brunton, Laurence L.
A2  - Chabner, Bruce A.
A2  - Knollmann, Björn C.
PY  - 2015
T2  - Goodman & Gilman's: The Pharmacological Basis of Therapeutics, 12e
AB  - The  immune  system  evolved  to  discriminate  self  from  nonself.  Multicellular  organisms  were  faced  with  the  problem  of  destroying  infectious  invaders  (microbes)  or  dysregulated  self  (tumors)  while  leaving  normal  cells  intact.  These  organisms  responded  by  developing  a  robust  array  of  receptor-mediated  sensing  and  effector  mechanisms  broadly  described  as  innate  and  adaptive.  Innate,  or  natural,  immunity  is  primitive,  does  not  require  priming,  and  is  of  relatively  low  affinity,  but  is  broadly  reactive.  Adaptive,  or  learned,  immunity  is  antigen  specific,  depends  on  antigen  exposure  or  priming,  and  can  be  of  very  high  affinity.  The  two  arms  of  immunity  work  closely  together,  with  the  innate  immune  system  being  most  active  early  in  an  immune  response  and  adaptive  immunity  becoming  progressively  dominant  over  time.  The  major  effectors  of  innate  immunity  are  complement,  granulocytes,  monocytes/macrophages,  natural  killer  cells,  mast  cells,  and  basophils.  The  major  effectors  of  adaptive  immunity  are  B  and  T  lymphocytes.  B  lymphocytes  make  antibodies;  T  lymphocytes  function  as  helper,  cytolytic,  and  regulatory  (suppressor)  cells.  These  cells  are  important  in  the  normal  immune  response  to  infection  and  tumors  but  also  mediate  transplant  rejection  and  auto-immunity.  Immunoglobulins  (antibodies)  on  the  B-lymphocyte  surface  are  receptors  for  a  large  variety  of  specific  structural  conformations.  In  contrast,  T  lymphocytes  recognize  antigens  as  peptide  fragments  in  the  context  of  self  major  histocompatibility  complex  (MHC)  antigens  (called  human  leukocyte  antigens  [HLAs]  in  humans)  on  the  surface  of  antigen-presenting  cells,  such  as  dendritic  cells,  macrophages,  and  other  cell  types  expressing  MHC  class  I  (HLA-A,  -B,  and  -C)  and  class  II  antigens  (HLA-DR,  -DP,  and  -DQ)  in  humans.  Once  activated  by  specific  antigen  recognition  via  their  respective  clonally  restricted  cell-surface  receptors,  both  B  and  T  lymphocytes  are  triggered  to  differentiate  and  divide,  leading  to  release  of  soluble  mediators  (cytokines,  lymphokines)  that  perform  as  effectors  and  regulators  of  the  immune  response.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2022/07/03
UR  - accesspharmacy.mhmedical.com/content.aspx?aid=1127868751
ER  -