Nontypeable Haemophilus influenzae (NTHI) is an important respiratory pathogen. NTHI initiates infection by adhering to the airway epithelium. Here, we report that NTHI interacts with intracellular adhesion molecule 1 (ICAM-1) expressed by respiratory epithelial cells. A fourfold-higher number of NTHI bacteria adhered to Chinese hamster ovary (CHO) cells transfected with human ICAM-1 (CHO-ICAM-...

Poly-N-acetyllactosamine (PL) sequences (repeating (3Gal beta 1-4GlcNAc beta 1)n) in complex-type N-linked oligosaccharides often occur in branched tri- and tetraantennary chains containing alpha-linked mannosyl residues disubstituted by N-acetyllactosaminyl units at C-2 and C-6 (2,6-branched mannose). We report here our studies on the factors affecting PL biosynthesis and the branching of N-li...

Glycosylation greatly influences the safety and efficacy of many of the highest-selling recombinant therapeutic proteins (rTPs). In order to define optimal cell culture feeding strategies that control rTP glycosylation, it is necessary to know how nucleotide sugars (NSs) are consumed towards host cell and rTP glycosylation. Here, we present a theoretical framework that integrates the reported g...

During endocytosis in Chinese hamster ovary (CHO) cells, Semliki Forest virus (SFV) passes through two distinct subpopulations of endosomes before reaching lysosomes. One subpopulation, defined by cell fractionation using free flow electrophoresis as "early endosomes," constitutes the major site of membrane and receptor recycling; while "late endosomes," an electrophoretically distinct endosome...

The ability of O-benzylguanine (BG) to inactivate alkyltransferase (AGT) to potentiate the antitumor efficacy of 1,3-bis(2-chloroethyl)-1nitrosourea (BCNU) is being tested in clinical trials. As of now, there are no examples of acquired resistance to BG BCNU in the clinical setting. However, we hypothesized that genetically unstable tumors might develop resistance to the combination after repea...

Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin,...

The DNA repair protein O6-alkylguanine-DNA alkyltransferase (AGT) has been shown to protect cells from the toxic and mutagenic effect of alkylating agents by removing lesions from the O6 position of guanine. O6-Benzylguanine (BG) is a potent inactivator of AGT, resulting in an increase in the sensitivity of cells to the toxic effects of chemotherapeutic alkylating agents. Chinese hamster ovary ...

Positive selection-negative selection gene targeting was used to disrupt the nucleotide excision repair gene ERCC1 in a Chinese hamster ovary cell line, CHO-K1. Southern and Northern analysis showed that a cell clone isolated by this targeting approach, CHO-7-27, had an ERCC1 gene structure consistent with targeted disruption of ERCC1 exon V, and did not express ERCC1 mRNA. CHO-7-27 was further...