A GPI-linked isoform of the IgD receptor regulates resting B cell activation.
The induction of a humoral response depends upon efficient cross-linking by antigen of surface immunoglobulin on primary B lymphocytes. We demonstrate here the presence of a glycosylphosphatidylinositol-linked isoform of membrane IgD (mIgD) receptors on murine resting B cells. This subset was constitutively localized to cell membrane raft microdomains. Its stimulation resulted in the activation of cAMP-dependent signaling pathways, which integrated with signals derived from the transmembrane mIgD receptors. This, in turn, provided a mechanism by which the activation status of the target cells could be variably regulated. Thus, by partitioning receptor activity, preimmune B cells can moderate the extent to which they are activated, depending upon the strength of the antigenic stimulus.
Chaturvedi
Akanksha
A
Immunology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
Siddiqui
Zaved
Z
Bayiroglu
Fahri
F
Rao
Kanury V S
KV
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D000242:Cyclic AMP / Q000276:immunology; D018858:Germinal Center / Q000276:immunology; D017261:Glycosylphosphatidylinositols / Q000096:biosynthesis / Q000276:immunology*; D007072:Immunoglobulin D / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D021962:Membrane Microdomains / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010641:Phenotype; D020033:Protein Isoforms; D011961:Receptors, Fc / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology
D017261:Glycosylphosphatidylinositols; D007072:Immunoglobulin D; D020033:Protein Isoforms; D011961:Receptors, Fc; C050855:immunoglobulin D receptor; D000242:Cyclic AMP