TY  - CHAP
M1  - Book, Section
TI  - Structure, Receptors, and Functions of Monocytes and Macrophages
A1  - Douglas, Steven D.
A1  - Douglas, Anne G.
A2  - Kaushansky, Kenneth
A2  - Lichtman, Marshall A.
A2  - Prchal, Josef T.
A2  - Levi, Marcel M.
A2  - Press, Oliver W.
A2  - Burns, Linda J.
A2  - Caligiuri, Michael
PY  - 2015
T2  - Williams Hematology, 9e
AB  - SUMMARYThe  monocyte  is  a  spherical  cell  with  prominent  surface  ruffles  and  blebs  when  examined  by  scanning  electron  microscopy.  As  the  monocyte  enters  the  tissue  and  differentiates  into  a  macrophage,  the  cell  volume  and  number  of  cytoplasmic  granules  increase.  Cell  shape  varies,  depending  on  the  tissue  in  which  the  macrophage  resides  (e.g.,  lung,  liver,  spleen,  brain).  A  characteristic  feature  of  macrophages  is  their  prominent  electron-dense  membrane-bound  lysosomes,  which  can  be  seen  fusing  with  phagosomes  to  form  secondary  lysosomes.  The  latter  contain  ingested  cellular  and  noncellular  material  in  different  stages  of  degradation.  A  broad  range  of  surface  receptors  for  many  ligands,  including  the  Fc  portion  of  immunoglobulin,  complement  proteins,  cytokines,  chemokines,  lipoproteins,  and  others,  are  on  the  cell  surface.  Macrophages  differ  in  appearance,  biochemistry,  and  function  based  on  the  environment  in  which  they  mature  from  monocytes.  These  differences  are  exemplified  by  the  diversity  among  dendritic  cells  of  lymph  nodes,  histiocytes  of  connective  tissue,  osteoclasts  of  bone,  Kupffer  cells  of  liver,  microglia  of  the  central  nervous  system,  and  macrophages  of  the  serosal  surfaces,  each  fashioned  to  meet  the  local  needs  of  the  mononuclear  phagocyte  system,  which  plays  a  role  in  inflammation  and  host  defense  against  microbes.  Modern  cell  biologic  methods  refined  our  knowledge  of  surface  receptors,  endocytosis,  and  lysosomal  degradation,  with  emphasis  on  membrane  flow  and  secretion.  These  pioneering  studies  culminated  in  the  discovery  of  dendritic  cells  as  potent,  specialized  antigen-presenting  cells.  Subsequent  development  of  monoclonal  antibodies  and  molecular  cloning  of  surface  proteins  and  cytokines,  followed  by  microarray  analysis  and  genomics,  provided  the  sensitive  and  specific  tools  to  analyze  macrophage  functions  in  vitro  and  in  vivo.  These  studies  have  brought  insights  into  macrophage  cytotoxic  and  antimicrobial  activities  and,  to  a  lesser  extent,  their  trophic,  homeostatic  functions  in  the  body.  Macrophages  play  a  major  role  in  innate  as  well  as  adaptive  immunity.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/16
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1121096305
ER  -