Human Antibodies - Volume 8, issue 3

Authors: Penichet, Manuel L. | Harvill, Eric T. | Morrison, Sherie L.

Article Type: Research Article

Abstract: Advances in genetic engineering and expression systems have led to rapid progress in the development of immunoglobulins fused to other proteins. These ‘antibody fusion proteins’ have novel properties and include antibodies fused to the cytokine interleukin-2. In the present review we describe strategies for construction of these antibody-interleukin-2 fusion proteins and discuss their in vitro and in vivo properties. Antibody-interleukin-2 fusion proteins retain both antibody associated functions such as antigen binding, complement activation and Fc gamma receptor binding as well as interleukin-2 associated functions such as the stimulation of proliferation of CTLL2 cells. In vivo, they produce strong potentiation of …the host immune response against any associated antigen. In addition these novel molecules are able to target tumor cells and produce a specific and effective T cell response capable of eliminating the tumor. These properties suggest that antibody-interleukin-2 fusion proteins will be useful in the diagnosis and/or treatment of human cancer as well as in the potentiation of human immune response against any associated antigen. Show more

Keywords: Interleukin-2, antibody fusion protein, human IgG3, interleukin-2 receptor, cancer, treatment

DOI: 10.3233/HAB-1997-8301

Citation: Human Antibodies, vol. 8, no. 3, pp. 106-118, 1997

Authors: Ben-Hur, Herzl | Gurevich, Pavel | Huszart, Monika | Ziv-Sokolovskyt, Nadja | Zion, Hagay | Isaegson, Dya | Berman, Valentina | Zusman, Igor

Article Type: Research Article

Abstract: The level of different immunoglobulins (IgA, IgG, IgM) in the tissues of 38 late fetuses and newborns was studied with peroxidase-labeled monoclonal antibodies. IgA+ and IgM+ lymphocytes were found in the spleen, lymph nodes and sometimes in the liver. IgG+ lymphocytes were not found. A high level of IgA+ material was found in the epithelium of the trachea, the epithelium and submucosal glands of the bronchi, but not the bronchioles, and in the epithelium of hepatic bile ducts and in their lumina. Such IgA is considered to be secretory-sIgA. Secretory IgA-containing epithelial cells appeared at 20 to 21 weeks of …gestation; their number increasedfrom 2.5 cells/10,000 μm2 in 23- to 26-week-old fetuses, to 8 cells/10,000 μm2 in 36- to 40-week-old fetuses. Secretory IgG and IgM were not detected. Infetuses with pneumonia or sepsis, the number of IgM+ and IgA+ lymphocytes increased significantly. IgM+ lymphocytes appeared not only in the spleen and lymph nodes, but also in the lungs. In such cases, the number of sIgA-containing epithelial cells in the trachea, bronchi and intrahepatic bile ducts decreased, sometimes completely disappearing. The amount of IgA+ material in the lumina of these organs increased, reflecting an intensification of sIgA secretion during infections. The presence of a marked amount of sIgA in fetuses from week 20 of gestation is considered to reflect the high importance of this immunoglobulin against normal contamination by microbes after birth, and to evidence the early maturation of the immune system. Show more

Keywords: Fetuses, full-term, low birth weight, newborns, secretory IgA, sepsis

DOI: 10.3233/HAB-1997-8302

Citation: Human Antibodies, vol. 8, no. 3, pp. 119-123, 1997

Authors: Chapman, Caroline J. | Mockridge, C. Ian | Spellerberg, Myfanwy B. | Zhu, Delin | Stevenson, Freda K.

Article Type: Research Article

Abstract: Human autoantibodies can mediate the pathology of autoimmune disease. To plan therapeutic intervention based on inhibition of binding to Clutoantigen, it is desirable to map the amino acid residues involved in recognition. Bacterial expression provides a simple and rapid system for production and mutagenesis of recombinant antibody fragments, but there are problems with reproducible folding and dispersity of soluble products. Expression at the surface of phage particles avoids both these problems, and allows variable region gene sequences to be expressed as functional monomers. To apply this technology, we have expressed a human anti-DNA monoclonal antibody, derived from a hybridoma, at …the surface of the phage. The presence of the phage particle allowed highly sensitive detection of antibody activity by ELISA, so that minimal levels of expression were required. By measuring the amount of expressed antibody protein, it was possible to analyze the antibody activity/μg. We expressed the antibody as Fab or single chain (sc) Fv, andfound binding activities to be closely similar. The parental anti-DNA antibody utilizes the human V4−34 gene and displays the associated conformation-dependent 9G4 idiotope. Both the Fab and scFv expressed the idiotope, confirming similar molecular folding. This technology can be applied rapidly and efficiently to investigations of human autoantibody structure, with the option for expression as either Fab or scFv, and the only requirement being knowledge of VH and VL sequences. Show more

Keywords: ScFv, autoantibodies, phage expression

DOI: 10.3233/HAB-1997-8303

Citation: Human Antibodies, vol. 8, no. 3, pp. 124-128, 1997

Authors: Zhao, Xiao-Xia | Hua, Ji | Smith, Teresa | Ferencz-Biro, Katalin | Liao, Mei-June | Rashidbaigi, Abbas

Article Type: Research Article

Abstract: Human leukocyte-derived IFN-αn3 (Alferon® N Injection) was administered subcutaneously to treat 20 patients with asymptomatic human immunodeficiency virus type 1 (HIV-1) and 141 patients with chronic hepatitis C virus (HCV) infections. The treatment of HIV-1 and HCV patients, previously untreated with any IFN preparations, did not result in development of neutralizing antibodies to IFN-αn3. Among 69 HCV refractory patients who were unresponsive to previous treatment with rIFN-α2b, 2 had neutralizing antibodies to rIFN-α2b prior to IFN-αn3 therapy, with no or limited cross-reactivity to IFN-αn3. After retreatment with IFN-αn3, both patients had detectable neutralizing titers to IFN-αn3. Additionally, 2 other patients …developed low and transient neutralizing titers to IFN-αn3. Interferon subtype specificity of these antibodies was tested against RP-HPLC purified fractions of IFN-αn3, as well as rIFN-α2b and rIFN-α8b. Sera from patients previously treated with rIFN-α2b with high antibody titers to rIFN-α2b strongly reacted with the natural IFN-α2b, and to a limited extent with other IFN-α subtypes. Neutralizing activity against IFN-α2b was significantly competed out by the presence of a small amount of other interferon subtypes present in IFN-αn3. One patient with prior presence of antibodies ta IFN-α2b developed a high antibody titer to IFN-α8b with limited reactivity to IFN-αn3. Two of the HCV refractory patients with prior neutralizing antibodies to rIFN-α2b responded to IFN-αn3 therapy. These data suggest that the presence of neutralizing antibodies to individual IFN-α species will not significantly diminish the biological activity and the clinical efficacy of multi-species IFN-αn3. Show more

Keywords: Leukocyte, interferon, human, neutralizing, antibody, HIV, HCV

DOI: 10.3233/HAB-1997-8304

Citation: Human Antibodies, vol. 8, no. 3, pp. 129-136, 1997

Authors: Haruta, Hirotaka | Tachibana, Hirofumi | Mochizuki, Katsumi | Hashizume, Shuichi | Kusakabe, Kiyoko | Shirahata, Sanetaka | Murakami, Hiroki

Article Type: Research Article

Abstract: The heavy and light chain genes (μ and λ) of the human anti-adenocarcinoma monoclonal antibody HB4C5 (MAb-C5) were cloned from the human-human hybridoma cell line HB4C5 and co-expressed in Chinese hamster ovary (CHO) and COS-7 cells. ELISA assay and the RI imaging of the cancer tissue xenografted into nude mice showed that the recombinant MAb-C5 retained the original antigen binding activity. We then replaced the IgM constant region of this MAb-C5 heavy chain gene with the human IgG1 constant region gene and co-expressed it with the light chain gene. This recombination was confirmed by a complete DNA sequencing and Western-blot …analysis. Despite thefact that the DNA sequence, the expressed protein size, and the assembly of heavy and light chains were indicated to be normal, the IgG1 type MAb-C5 could not bind to the original antigen. This result suggests that this antibody alters its antigen binding property upon class-switching. Show more

Keywords: Human monoclonal antibody, HB4C5, recombinant, class switch

DOI: 10.3233/HAB-1997-8305

Citation: Human Antibodies, vol. 8, no. 3, pp. 137-145, 1997

Authors: Bhat, Neelima M. | Bieber, Marcia M. | Teng, Nelson N. H.

Article Type: Research Article

Abstract: To evaluate the role of B-1 cells and polyreactive autoantibodies in the development of adult immune repertoire, it is necessary to assess their immunoglobulin heavy chain variable-gene usage. We thus screened 28 independently derived human polyreactive MAbs from fetal and adult splenic B lymphocytes for their VH -region usage. We demonstrate that the polyreactivity of the IgM antibodies secreted by B-1 cells is not the result of the expression of particular variable region gene families. All six VH families are represented roughly in proportion to their estimated family size. Furthermore, the representation of the six families appears similar in …polyreactive MAbs derived from fetal or adult lymphocytes. Show more

Keywords: CD5 + B cells, V H genes, autoantibodies

DOI: 10.3233/HAB-1997-8306

Citation: Human Antibodies, vol. 8, no. 3, pp. 146-150, 1997