Modifications of cysteine residues in the transmembrane and cytoplasmic domains of a recombinant hemagglutinin protein prevent cross-linked multimer formation and potency loss.

Background: Recombinant hemagglutinin (rHA) is the active component in Flublok®; a trivalent influenza vaccine produced using the baculovirus expression vector system (BEVS). HA is a membrane bound homotrimer in the influenza virus envelope, and the purified rHA protein assembles into higher order rosette structures in the final formulation of the vaccine. During purification and storage of the rHA, disulfide mediated cross-linking of the trimers within the rosette occurs and results in reduced potency.

Epidermal growth factor receptor regulates pancreatic fibrosis.

The development of pancreatic fibrosis has been shown to be a major component in several diseases of the pancreas including pancreatic cancer, chronic pancreatitis, and type 2 diabetes mellitus, but its actual role in the progression of these disorders is still unknown. This fibrosis is characterized by stromal expansion and the excessive deposition of extracellular matrix (ECM) that replaces pancreatic tissue. This eventually leads to dysregulation of ECM turnover, production of cytokines, restriction of blood flow, and often exocrine and endocrine insufficiencies.

Establishment of conditionally immortalized epithelial cell lines from the intestinal tissue of adult normal and transgenic mice.

It has proved to be impossible to culture epithelial cells from the gastrointestinal tract of adult animals. Researchers have had to use either cell lines derived from newborn rat small intestine or colon carcinoma cell lines that have retained some of the properties of the gastrointestinal mucosa. We have described a method for establishing conditionally immortalized cell lines from the stomach, small intestine, colon, pancreas, and liver from tissue obtained from a transgenic mouse strain carrying a temperature-sensitive mutant of the SV40 large T gene (the "Immortomouse").

Conditionally immortalized colonic epithelial cell line from a Ptk6 null mouse that polarizes and differentiates in vitro.

Background And Aims: PTK6 is an intracellular src-related tyrosine kinase that regulates differentiation in the intestine, where knockout animals have increased proliferative activity and growth characteristics. To explore the phenotype further we attempted to establish epithelial cell lines from the intestinal mucosa.

Method: We mated Ptk6 null mice with a tsSV40 large T transgenic mouse (Immortomouse) to obtain null mice carrying the SV40 gene.