Cytoplasmic domain heterogeneity and functions of IgG Fc receptors in B lymphocytes

Science. 1992 Jun 26;256(5065):1808-12. doi: 10.1126/science.1535455.

Abstract

B lymphocytes and macrophages express closely related immunoglobulin G (IgG) Fc receptors (Fc gamma RII) that differ only in the structures of their cytoplasmic domains. Because of cell type-specific alternative messenger RNA splicing, B-cell Fc gamma RII contains an insertion of 47 amino acids that participates in determining receptor function in these cells. Transfection of an Fc gamma RII-negative B-cell line with complementary DNA's encoding the two splice products and various receptor mutants indicated that the insertion was responsible for preventing both Fc gamma RII-mediated endocytosis and Fc gamma RII-mediated antigen presentation. The insertion was not required for Fc gamma RII to modulate surface immunoglobulin-triggered B-cell activation. Instead, regulation of activation involved a region of the cytoplasmic domain common to both the lymphocyte and macrophage receptor isoforms. In contrast, the insertion did contribute to the formation of caps in response to receptor cross-linking, consistent with suggestions that the lymphocyte but not macrophage form of the receptor can associate with the detergent-insoluble cytoskeleton.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antigen-Antibody Complex / metabolism
  • Antigen-Antibody Reactions / genetics
  • Antigen-Antibody Reactions / immunology
  • Antigens, CD / genetics
  • Antigens, CD / immunology*
  • Antigens, Differentiation / genetics
  • Antigens, Differentiation / immunology*
  • B-Lymphocytes / immunology*
  • Calcium / metabolism
  • DNA-Binding Proteins*
  • Dose-Response Relationship, Immunologic
  • Endocytosis / genetics
  • Endocytosis / immunology
  • Humans
  • Immunohistochemistry
  • Lymphocyte Activation / immunology
  • Microscopy, Electron
  • Molecular Sequence Data
  • Receptors, Fc / genetics
  • Receptors, Fc / immunology*
  • Receptors, IgG
  • Repressor Proteins / pharmacology
  • Transcription Factors / pharmacology
  • Transfection
  • Viral Proteins
  • Viral Regulatory and Accessory Proteins

Substances

  • Antigen-Antibody Complex
  • Antigens, CD
  • Antigens, Differentiation
  • DNA-Binding Proteins
  • Receptors, Fc
  • Receptors, IgG
  • Repressor Proteins
  • Transcription Factors
  • Viral Proteins
  • Viral Regulatory and Accessory Proteins
  • phage repressor proteins
  • Calcium