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Early activation and cell cycle entry of resting B cells after Fab-anti-Ig treatment: role of receptor crosslinking.

Publication ,  Journal Article
Lagoo, A; Sell, S
Published in: Cell Immunol
January 1989

Comparison of the effect of goat anti-rabbit Ig (GARIg) and its monovalent fragment (Fab-GARIg) demonstrates that surface Ig (sIg) crosslinking is not necessary to effect G0 to G1 transition in rabbit peripheral blood B cells but is required for induction of DNA synthesis. Five micrograms per milliliter or more of GARIg is sufficient to induce DNA synthesis but up to 50 micrograms/ml of Fab-GARIg is not. However, the monovalent reagent induces microscopically observable cytoplasmic and nuclear changes (blast transformation) in a dose-dependent manner. These differ qualitatively and quantitatively from the morphological changes seen with comparable doses of GARIg; Fab anti-Ig produces "small blasts" whereas complete GARIg induces large blasts. The monovalent reagent, in a wide range of concentrations, is as effective as the complete antibody in modulating sIg from rabbit B cells. Fab-GARIg treatment modulates sIg in a biphasic manner. It clears the high-density sIg within 5 min, whereas the remaining low-density receptors disappear after 4 hr. Cytosolic protein kinase C levels decline equally after treatment with either Fab-GARIg or whole anti-Ig. RNA synthesis, as measured by [3H]uridine incorporation, increases for the first 12 hr in cells activated with either reagent. It declines to basal levels in Fab-GARIg stimulated cells, but a continuous increase occurs in cells stimulated with 5 and 50 micrograms/ml of complete antibody. Simultaneous addition of 50 micrograms/ml Fab-GARIg with 5 microgram/ml of GARIg causes greater RNA synthesis for 12 hr after stimulation than is caused by GARIg alone. After 12 hr the monovalent reagent has an inhibitory effect on RNA synthesis. Fluorescence-activated cell sorter analysis of acridine orange-stained cells shows that Fab anti-Ig-stimulated cells have higher RNA content than resting cells, but lower than GARIg-activated cells. These findings suggest that rabbit B cells can be activated from the G0 stage of cell cycle to G1 by monovalent anti-Ig reagents but further cell cycle progression requires maintenance signals provided by receptor crosslinking. The implications of these results for B cell activation signalling are discussed in the context of the floating receptor model.

Duke Scholars

Published In

Cell Immunol

DOI

ISSN

0008-8749

Publication Date

January 1989

Volume

118

Issue

1

Start / End Page

53 / 67

Location

Netherlands

Related Subject Headings

  • Signal Transduction
  • Receptors, Fc
  • Receptors, Antigen, B-Cell
  • Rabbits
  • RNA
  • Protein Kinase C
  • Protein Binding
  • Male
  • Lymphocyte Activation
  • Immunology
 

Citation

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Chicago
ICMJE
MLA
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Lagoo, A., & Sell, S. (1989). Early activation and cell cycle entry of resting B cells after Fab-anti-Ig treatment: role of receptor crosslinking. Cell Immunol, 118(1), 53–67. https://doi.org/10.1016/0008-8749(89)90357-2
Lagoo, A., and S. Sell. “Early activation and cell cycle entry of resting B cells after Fab-anti-Ig treatment: role of receptor crosslinking.Cell Immunol 118, no. 1 (January 1989): 53–67. https://doi.org/10.1016/0008-8749(89)90357-2.
Lagoo, A., and S. Sell. “Early activation and cell cycle entry of resting B cells after Fab-anti-Ig treatment: role of receptor crosslinking.Cell Immunol, vol. 118, no. 1, Jan. 1989, pp. 53–67. Pubmed, doi:10.1016/0008-8749(89)90357-2.
Journal cover image

Published In

Cell Immunol

DOI

ISSN

0008-8749

Publication Date

January 1989

Volume

118

Issue

1

Start / End Page

53 / 67

Location

Netherlands

Related Subject Headings

  • Signal Transduction
  • Receptors, Fc
  • Receptors, Antigen, B-Cell
  • Rabbits
  • RNA
  • Protein Kinase C
  • Protein Binding
  • Male
  • Lymphocyte Activation
  • Immunology