Microenvironment regulates antibody secretion by IgA+ plasma cells.

Studies of the mechanism of tunicamycin in hibition of IgA and IgE secretion by plasma cells.

Tunicamycin, an antibiotic which blocks the formation of N-acetylglucosamine-lipid intermediates, thereby preventing glycosylation of glycoproteins, inhibits the secretion of IgA and IgE by MOPC 315 mouse plasma cells and IR162 rat plasma cells, respectively. At 0.5 microng of tunicamycin per ml, D-[14C]glucosamine incorporation into newly synthesized immunoglobulin was inhibited greater than 9...

In vitro regulation of IgA subclass synthesis. I. Discordance between plasma cell production and antibody secretion

To investigate the in vitro regulation of IgA subclass synthesis, peripheral blood lymphocytes from healthy adults were cultured with the polyclonal B cell activator, pokeweed mitogen. Although 50% of the IgA plasma cells from a 7-d culture were positive for cytoplasmic IgA1 and 50% were positive for IgA2, less than 10% of the IgA released into the culture supernatant was IgA2. This discrepancy...

Intestinal Extravasation of IgA Antibody-Secreting Cells

What regulates secretion of non-stored proteins by eukaryotic cells?

Protein secretion is conventionally viewed as taking place by either of two cellular routes, a regulated pathway, involving external stimuli and secretory granules, unda presumptive ‘constitutive’ pathway, which doesnot involve hormonal or neuronal stimuli or the production of secretory granules. The evidence reviewed here strongly suggests that there are post-synthesis rate-limiting steps for ...

Mzb1 protein regulates calcium homeostasis, antibody secretion, and integrin activation in innate-like B cells.

Marginal zone (MZ) B cells of the spleen and B1 cells, termed innate-like B cells, differ from follicular B cells by their attenuated Ca(2+) mobilization, fast antibody secretion, and increased cell adhesion. We identified and characterized Mzb1 as an endoplasmic reticulum-localized and B cell-specific protein that was most abundantly expressed in MZ B and B1 cells. Knockdown of Mzb1 in MZ B ce...