Human Antibodies - Volume 13, issue 3

Authors: Sidner, Richard A. | Book, Benita K. | Agarwal, Avinash | Bearden, Christopher M. | Vieira, Carlos A. | Pescovitz, Mark D.

Article Type: Research Article

Abstract: Rituximab, chimeric anti-human CD20 monoclonal antibody approved for B-cell lymphoma, depletes circulating B cells. Little data exist on its use for nonmalignant diseases or B-cell subset recovery after treatment. We hypothesized that rituximab may reduce panel reactive alloantibodies (PRA) in dialysis patients awaiting renal transplantation and performed a single-dose, dose-escalation phase 1 trial. Here we report changes in lymphocyte phenotypes in subjects treated with rituximab alone. Nine subjects, 44 ± 10 years(Yr); (5 F, 4 M) received one dose (n=3) at 50, 150, or 375 mg/m2 without other immunosuppression. Blood was collected before dosing and intervals thereafter. No significant …changes in leukocytes, total or CD3+ lymphocytes were noted. In all, there was CD19+ depletion by day 2(D2) (12.0 ± 5.6 cells/mm3 vs. 181 ± 137, D0; p<0.01) and CD20+ (11.0 ± 12.0 vs. 205 ± 116, D0; p<0.01). At 6 months (mo), CD19+ and CD20+ remained low (51.1 ± 42.2, p<0.05; 75.4 ± 38.7, p<0.05, respectively) compared to D0. CD19+ CD5+ cells recovered more rapidly, returning to baseline by 6mo while B memory cells (CD19+ CD27+ ) remained low (32.3 ± 29.0) at 1Yr (7.5 ± 4.5; p<0.001) and 2Yr (12.1 ± 7.9; p<0.001) after treatment. We conclude that single dose rituximab ablates B cells in high PRA dialysis patients awaiting transplantation. B-cell ablation, particularly memory B cells, was long-lasting, lagging repopulation by CD5+ B cells. Show more

Keywords: CD20+, CD19+CD5+, CD19+CD27+, CD19+CD27-, lymphocyte subsets, memory B cells, naïve B cells, rituximab, renal failure, T cells

DOI: 10.3233/HAB-2004-13301

Citation: Human Antibodies, vol. 13, no. 3, pp. 55-62, 2004

Authors: Bhat, Neelima M. | Bieber, Marcia M. | Yang, Yuh-Cheng | Leu, Yi-Shing | van Vollenhoven, Ronald F. | Teng, Nelson N.H.

Article Type: Research Article

Abstract: The VH4-34 represents an unusual Ig heavy chain variable region gene given that it is conserved and overexpressed despite its autoreactivity. Besides RBC ‘I/i’ recognition, a subset of VH4-34 encoded Igs bind and kill human B-lymphocytes via interaction with a cytoskeletally-associated ligand similar in structure to the cord RBC ‘i’ antigen. In vivo, secretion of VH4-34 gene encoded antibodies is minimal in healthy individuals. The turn on signal occurs in few clinical conditions such as, systemic lupus erythematosus, AIDS and infectious mononucleosis. Here we show that secretion of VH4-34 Abs is also switched on in hepatitis C and nasopharyngeal carcinoma; …but not in diseases such as HPV-associated cervical carcinoma, multiple sclerosis and sarcoidosis. All syndromes with increased VH4-34 Igs appear to be associated with B cell hyperproliferation and B cell lymphotropic viruses, particularly EBV. The significance of the tightly controlled secretion of an autoreactive, conserved Ig gene is discussed. Show more

Keywords: EBV, B cell hyperproliferation, autoantibodies, lymphotropic viruses, VH4-34 gene, B cell regulation

DOI: 10.3233/HAB-2004-13302

Citation: Human Antibodies, vol. 13, no. 3, pp. 63-68, 2004

Authors: Jacobin, Marie-Josée | Santarelli, Xavier | Laroche-Traineau, Jeanny | Clofent-Sanchez, Gisèle

Article Type: Research Article

Abstract: Purification of human IgM monoclonal antibodies (MAbs) has proved to be difficult. Since IgM Mabs tend to bind strongly to a variety of resin support surfaces, the number of chromatographic steps used in the purification of these biomolecules should be minimized. Here we describe procedures developed for the optimal production and purification of the human monoclonal IgM B7, which specifically binds to the myosin heavy chain of human ventricular myocardium. This property makes this antibody potentially useful for the diagnosis of myocardial necrosis. Several chromatographic techniques were evaluated (size exclusion, ion exchange, affinity chromatography). The best results were obtained …with anion exchange membrane chromatography using Sartobind Q15 (98% purity, 30% recovery). IgM production was improved by the hollow fiber technology which permitted the use of serum-reduced medium and an increase in antibody concentration to an average production of 300–400 μg/ml, compared to 20 μg/ml in flask culture. Several flow-rates were also evaluated, the optimal being 20 ml/minute for 30% of recovery. Importantly, the purified IgM molecule was able to bind to human myosin in ELISA and Western-blotting, thus allowing the IgM to be kept intact for further radiolabeling. Show more

Keywords: human monoclonal antibody, IgM Purification, membrane ion exchangers, myosin

DOI: 10.3233/HAB-2004-13303

Citation: Human Antibodies, vol. 13, no. 3, pp. 69-79, 2004

Authors: Ludwig, Dale L. | Witte, Larry | Hicklin, Daniel J. | Prewett, Marie | Bassi, Rajiv | Burtrum, Douglas | Pereira, Daniel S. | Jimenez, Xenia | Fox, Floyd | Saxena, Babita | Zhou, Qinwei | Ma, Yuemei | Kang, Xiaoqiang | Patel, Dipa | Barry, Michael | Kussie, Paul | Zhu, Zhenping | Russell, Douglas A. | Petersen, William L. | Jury, Thomas P. | Gaitan-Gaitan, Fernando | Moran, Daniel L. | Delannay, Xavier | Storrs, Bradley S. | Tou, Jacob | Zupec, Mark E. | Gustafson, Karen S. | McIntyre, John | Tarnowski, S. Joseph | Bohlen, Peter

Article Type: Research Article

Abstract: Recombinant protein production in plants such as corn is a promising means to generate high product yields at low comparable production cost. The anti-EGFR monoclonal antibody C225, cetuximab, is a well-characterized receptor antagonist antibody recently approved for the treatment of refractory colorectal cancer. We initiated a study to test and compare the functional activity of glycosylated and aglycosylated C225 produced in stable transgenic corn seed. Both corn antibodies were shown to be functionally indistinguishable from mammalian-derived C225 in demonstrating high-affinity binding to the EGF receptor, blocking of ligand-dependent signaling, and inhibiting cell proliferation. In addition, consistent with cetuximab, both corn …antibodies possessed strong anti-tumor activity in vivo. Acute dose primate pharmacokinetic studies, however, revealed a marked increase in clearance for the glycosylated corn antibody, while the aglycosylated antibody possessed in vivo kinetics similar to cetuximab. This experimentation established that corn-derived receptor blocking monoclonal antibodies possess comparable efficacy to mammalian cell culture-derived antibody, and offer a cost effective alternative to large-scale mammalian cell culture production. Erratum: 10.3233/HAB-2009-0208 . Show more

Keywords: antibodies, transgenic plants, epidermal growth factor receptor, cancer

DOI: 10.3233/HAB-2004-13304

Citation: Human Antibodies, vol. 13, no. 3, pp. 81-90, 2004

Authors: Chappel, Jonathan A. | Hollingdale, Michael R. | Kang, Angray S.

Article Type: Research Article

Abstract: Malaria is one of the world's most devastating diseases, and Plasmodium falciparum (Pf) causes significant mortalities particularly in Sub-Saharan Africa. The rise and spread of multi-drug resistant strains of the parasite has coincided with an era of increased travel to malaria endemic regions. In the absence of an effective vaccine against malaria it may be possible to utilize human monoclonal antibodies against the stage transmitted by mosquito bites (sporozoites) as a prophylactic to prevent infection. We report the characterization of an engineered human IgG4 monoclonal antibody against Pf sporozoite cloned from a protected individual recognized the sporozoite surface and …inhibited sporozoite invasion of human hepatocytes in vitro. The fully human monoclonal antibody PfNPNA-1 IgG4 against (NPNA)3 specifically labels Plasmodium falciparum in an IFA. This antibody also inhibits Plasmodium falciparum sporozoite invasion of human hepatocytes HepG2-A16 in a dose dependent manner in an in vitro assay. PfNPNA-1 IgG4 is a promising candidate for evaluation for the prevention of malaria. Show more

Keywords: Plasmodium falciparum, sporozoite, human monoclonal antibodies

DOI: 10.3233/HAB-2004-13305

Citation: Human Antibodies, vol. 13, no. 3, pp. 91-96, 2004