The gene encoding the rat glycosylation enzyme beta1-4-N-acetylglucosaminyltransferase III (GnTIII) was cloned and coexpressed in a recombinant production Chinese hamster ovary (CHO) cell line expressing a chimeric mouse/human anti-CD20 IgG1 antibody. The new cell lines expressed high levels of antibody and have growth kinetics similar to that of the parent. Relative QPCR showed the cell lines to express varying levels of mRNA. High-performance liquid chromatography (HPLC) analysis showed the enzyme to have added bisecting N-acetylglucosamine (GlcNAc) residues in most (48% to 71%) of the N-linked oligosaccharides isolated from antibody preparations purified from the cell lines. In an ADCC assay the new antibody preparations promoted killing of CD20-positive target cells at approximately 10- to 20-fold lower concentrations than the parent. This activity was blocked using an anti-Fc gamma RIII antibody, supporting the role of Fc gamma RIII binding in this increase. In addition, cell binding assays showed the modified antibody bound better to Fc gamma RIII-expressing cells. The increase in ADCC activity is therefore likely due to an increased affinity of the modified antibody for the Fc gamma RIII receptor.

We investigated the relation of oral hairy leukoplakia (HL) to human immunodeficiency virus (HIV) infection and to the presence or development of AIDS. All 155 patients with HL seen in our clinic were immunosuppressed homosexual men. Of 101 serum samples obtained from patients in this group who did not have AIDS, 100 showed antibodies to HIV. HIV was recovered from peripheral blood mononuclear cells of 22 of 28 patients tested. Most serum samples examined by immunoblot assay reacted with the viral envelope and gag gene precursors gp160 and p55. Of the 155 patients, 12 had AIDS at the time of diagnosis, and the syndrome developed in an additional 43 patients in one to 31 months. Survival analysis showed that the probability of AIDS developing in patients with HL was 48% by 16 months and 83% by 31 months. We conclude that oral HL is highly predictive of the development of AIDS.

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