Abstract
Polymeric immunoglobulin receptor (secretory component, SC) is an intergral membrane protein synthesized by secretory epithelial cells and by hepatocytes of certain mammals. However, the synthesis, display and function of SC in human liver is not well characterized. We therefore sought evidence for SC synthesis by human liver using specific antibodies to SC to screen a library of phage expression vectors (λgtll) containing cDNA copies of human liver messenger RNA.
In initial screening, 3×105 phage were plated on E. coli (Y1090) and cultured for 3 hours before transfer to nitrocellulose filters containing the inducer IPTG. After 1.5 hr, the filters were probed using polyclonal antibody to SC and I125 labeled protein-A. Clones positive by autoradiography were replated until all visible plaques gave positive signals for SC.
Primary screening of the library produced 6–8 discrete signals each time. Secondary and tertiary screens yielded progressive enrichment of SC-positive plaques. A mixture of 5 monoclonal antibodies to SC confirmed that tertiary clones produced an SC-like protein. While further studies will be necessary to confirm the specificity of the gene, our studies provide the first evidence that mRNA for SC is present in human liver. Although the cell of origin is undefined, the availability of cloned genes should allow us to further define the role of SC in this and other tissues.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Goldblum, R., Kunapuli, S., Penney, R. et al. 976 EVIDENCE FOR SECRETORY COMPONENT GENE EXPRESSION IN HUMAN LIVER. Pediatr Res 19, 273 (1985). https://doi.org/10.1203/00006450-198504000-01006
Issue Date:
DOI: https://doi.org/10.1203/00006450-198504000-01006