Immunoglobulin (Ig)A provides the initial immune barrier to viruses at mucosal surfaces. Specific IgA interrupts viral replication in polarized epithelium during receptor-mediated transport, probably by binding to newly synthesized viral proteins. Here, we demonstrate by immunoelectron microscopy that specific IgA monoclonal antibodies (mAbs) accumulate within Sendai virus-infected polarized cell monolayers and colocalize with the hemagglutinin- neuraminidase (HN) viral protein in a novel intracellular structure. Neither IgG specific for HN nor irrelevant IgA mAbs colocalize with viral protein. Treatment of cultures with viral-specific IgA but not with viral-specific IgG or irrelevant IgA decreases viral titers. These observations provide definitive ultrastructural evidence of a subcellular compartment in which specific IgA and viral envelope proteins interact, further strengthening our hypothesis of intracellular neutralization of virus by specific IgA antibodies. Our results have important implications for intracellular protein trafficking, viral replication, and viral vaccine development.
Pubmed ID: 9763601 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
ZEISS SIGMA VP field emission scanning electron microscope (FE-SEM) for imaging of non-conducting samples. It images of bacteria, cells, plants and organisms. Uses ATLAS software and can be combined with 3View technology from Gatan Inc.
View all literature mentionsCell line MDCK is a Spontaneously immortalized cell line with a species of origin Canis lupus familiaris
View all literature mentionslaboratory mouse with name BALB/cAnNCrl from MGI.
View all literature mentionsCell line Sp2/0-Ag14 is a Cancer cell line with a species of origin Mus musculus
View all literature mentions