Antisera to the secretory component recognize the murine Fc receptor for IgA.
Studies were undertaken to determine a possible structural relationship between the secretory component (SC) and the receptor for IgA (Fc alpha R). An IgA-mediated rosetting technique was used to assess the presence of Fc alpha R+ cells in various lymphoid tissues from normal BALB/c mice and mice bearing an IgA plasmacytoma (MOPC 315). Tissues from the MOPC 315-bearing BALB/c mice were found to have a significantly higher percentage of Fc alpha R+ cells; thus, nonadherent spleen cells from MOPC 315-bearing mice were used as a source of Fc alpha R+ cells in these studies. The cells were preincubated with anti-SC and then assayed for the ability of IgA to bind to the Fc alpha R. Antisera to SC from various species inhibited the formation of IgA-mediated rosettes, although preincubation of the Fc alpha R+ cells with antisera directed against other cell surface molecules (e.g., Thy1.2, Lyt1, Lyt2, Fc gamma R, MHC class I and II) or preimmune sera had no significant effect on IgA-mediated rosette formation. Preabsorption of the anti-SC with secretory IgA or with free SC removed the inhibitory effect; preabsorption with myeloma IgA had no effect. These data suggest that SC and Fc alpha R are related serologically and may be structurally related, possible in the IgA-binding region.
Crago
S S
SS
Department of Cell Biology, University of New Mexico, Albuquerque 87131.
Word
C J
CJ
Tomasi
T B
TB
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D007106:Immune Sera / Q000494:pharmacology; D007070:Immunoglobulin A / Q000378:metabolism* / Q000502:physiology; D007128:Immunoglobulin Fragments / Q000276:immunology*; D008221:Lymphoid Tissue / Q000032:analysis; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011961:Receptors, Fc; D011971:Receptors, Immunologic / Q000276:immunology* / Q000502:physiology; D012635:Secretory Component / Q000276:immunology*; D014018:Tissue Distribution
D000888:Antibodies, Anti-Idiotypic; C045281:IgA receptor; D007106:Immune Sera; D007070:Immunoglobulin A; D007128:Immunoglobulin Fragments; D008565:Membrane Proteins; D011961:Receptors, Fc; D011971:Receptors, Immunologic; D012635:Secretory Component