B- lymphocytes: surface receptor and functions




B- lymphocytes: surface receptor and functions

  • The name B-cell is derived from its site of maturation and differentiation in Bursa of fabricius in Birds. In adult human B- cell originates and mature in Bone marrow.
  • Morphologically B- cells are indistinguishable from T-cells. B-cells are identified by their surface protein ie. Immunoglobulin or antibody which serves as receptor for antigen.
source;sinobiological

Other surface receptor molecules on B-cells are;

  • B220 (CD45): marker for B-cells and their precursor
  • MHC-II: permits B-cells to function as APC.
  • CR1 (CD35) and CR2 (CD21): complement receptor
  • FcγRII (CD32): receptor for IgG antibody
  • CD40: interacts with CD40 ligands on surface of TH cells.
  • B7-1 (CD80) and B7-2 (CD86): interacts with CD28 and CTLA-4 on TH cells.

Immunological functions of B-cells:

  • Antibody production against specific target antigen
  • Acts as APC and Present antigen to t-lymphocytes
  • Provides signal for T – cell activation

B- lymphocytes: surface receptor and functions