Involvement of p38 Activation and Mitochondria in Death of Human Leukemia Cells Induced by an Agonistic Human Monoclonal Antibody Fab Specific to TRAIL Receptor 1.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces cancer cell death with minimal damage to normal cells; however, some cancer cells are resistant to TRAIL. TRAIL resistance may be overcome by agonistic antibodies to TRAIL receptors. In this study, we report the toxic effects of a novel recombinant agonistic human anti-TRAIL receptor 1 (DR4) monoclonal antibody Fab fragment, DR4-4, on various TRAIL-resistant and -sensitive cancer cell lines.

Variable Heavy Chain Domain Derived from a Cell-Penetrating Anti-DNA Monoclonal Antibody for the Intracellular Delivery of Biomolecules.

Targeting and modification of important intracellular proteins using efficient vehicles are invaluable in diagnostic and therapeutic fields. Cell-penetrating antibodies and their fragments can be utilized as vehicles for the delivery of modifiers into cells. In this study, we explored the applicability of variable heavy chain (VH) domain as delivery vehicles for mammalian cells.

Cell- and nuclear-penetrating anti-dsDNA autoantibodies have multiple arginines in CDR3 of VH and increase cellular level of pERK and Bcl-2 in mesangial cells.

Investigation of characteristics of cell- and nuclear-penetrating anti-double stranded (ds)DNA autoantibodies (autoAbs) is important to understand pathogenesis of lupus nephritis, but has not been clearly explored. The present study reports that three anti-dsDNA monoclonal autoAbs, which contain more than two arginine residues in their CDR3s of variable heavy domain (VH), penetrated into living murine mesangial cells and the cell nuclei. However, an anti-dsDNA monoclonal Ab (mAb) having only one arginine in the CDR3-VH did not penetrate cells.

Characterization of human anti-heat shock protein 60 monoclonal autoantibody Fab fragments in atherosclerosis: genetic and functional analysis.

Heat shock protein 60 (HSP60) is an important autoantigen in atherosclerosis. The genetic structures and pathogenic roles of anti-HSP60 autoantibodies, however, have not been well elucidated. Here, we cloned nine monoclonal IgG Fabs against human HSP60 from peripheral blood lymphocytes of atherosclerosis patients.

Aspirin enhances TRAIL-induced apoptosis via regulation of ERK1/2 activation in human cervical cancer cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers tumor-specific apoptosis. However, some tumors and cancer cell lines are resistant to TRAIL. Here, the effect of the non-steroidal anti-inflammatory drug aspirin on sensitization of human cervical cancer cells to TRAIL and the underlying mechanism(s) of the effect were explored.

Mouse monoclonal autoantibodies penetrate mouse macrophage cells and stimulate NF-kappaB activation and TNF-alpha release.

Autoantibodies against double-stranded DNA (dsDNA) are found in the serum of systemic lupus erythematosus (SLE) patients. However, the mechanism by which anti-dsDNA antibodies (Abs) contribute to the pathogenesis of SLE is not yet fully understood. In this study, we investigated four anti-dsDNA mouse monoclonal autoantibodies that share positively charged amino acids (including arginines) in their complementarity determining regions for their ability to penetrate RAW264.

CD4+CD25+ regulatory T cells selectively diminish systemic autoreactivity in arthritic K/BxN mice.

Although the arthritis symptoms observed in the K/BxN model have been shown to be dependent on the functions of T and B cells specific to the self antigen glucose-6-phosphate isomerase, less is known about the in vivo roles of CD4(+)CD25(+) regulatory T (T(reg)) cells in the pathology of K/BxN mice. We determined the quantitative and functional characteristics of the T(reg) cells in K/BxN mice. These mice contained a higher percentage of Foxp3(+) T(reg) cells among the CD4(+) T cells than their BxN littermates.

Effect of a novel fully human monovalent antigen-binding fragment on the survival of cancer cell lines.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a cytokine having potent cytotoxic activity specifically to tumor cells. Agonistic antibodies against TRAIL receptors are currently being explored as anti-cancer therapeutics. Here, we report studies on JKTR-18, a monovalent human monoclonal antibody Fab selected against human recombinant TRAIL receptor 2 (DR5) by phage display technology.

Cell-penetrating autoantibody induces caspase-mediated apoptosis through catalytic hydrolysis of DNA.

In the present study, we investigated the substrate specificity of catalytic activity of a cytotoxic anti-DNA monoclonal autoantibody, G1-5, which was obtained from an MRL-lpr/lpr mouse by hybridoma technology. The antibody catalyzed hydrolysis of single- and double-stranded DNA with a higher substrate specificity for thymine than adenine by either beta-glycosidic or phosphodiester bond cleavage. The hydrolysis rate (kcat) showed maximum at acidic pH conditions, suggesting that the catalytic site of the antibody contains essential carboxylic group(s).

Phytosphingosine in combination with TRAIL sensitizes cancer cells to TRAIL through synergistic up-regulation of DR4 and DR5.

Sensitization of cancer cells to TRAIL could improve the effectiveness of TRAIL as an anticancer agent. We explored whether TRAIL in combination with phytosphingosine could sensitize cancer cells to TRAIL. The combined treatment enhanced synergistic apoptotic cell death of Jurkat T cells, compared to TRAIL or phytosphingosine alone.

Characterization of human monoclonal autoantibody Fab fragments against oxidized LDL.

Oxidized low-density lipoprotein (oxLDL) is a key autoantigen in atherosclerosis. The genetic structures and pathogenic roles of autoantibodies against this protein remain to be established. In this study, we cloned several monoclonal IgG autoantibody Fab fragments specific for oxLDL from peripheral blood lymphocytes of atherosclerosis patients, using phage display technology.

Murine model of buckwheat allergy by intragastric sensitization with fresh buckwheat flour extract.

Food allergies affect about 4% of the Korean population, and buckwheat allergy is one of the most severe food allergies in Korea. The purpose of the present study was to develop a murine model of IgE-mediated buckwheat hypersensitivity induced by intragastric sensitization. Young female C3H/HeJ mice were sensitized and challenged intragastricly with fresh buckwheat flour (1, 5, 25 mg/dose of proteins) mixed in cholera toxin, followed by intragastric challenge.

Variable region genes of human monoclonal autoantibodies to histones H2A and H2B from a systemic lupus erythematosus patient.

An antibody phage library obtained from peripheral blood lymphocytes of a systemic lupus erythematosus (SLE) patient was used to isolate four monoclonal autoantibodies against histones H2A and H2B. Analysis of the variable region sequences revealed that the anti-histone monoclonal antibodies were not clonally related; they used VH genes from three different VH gene families (VH3, VH4, and VH5) and distant members of the Vkappa group (L25, L6, A27, and O8) in conjunction with different D and J gene segments. These observations suggest that certain gene families or segments are not critical in producing anti-histone autoantibodies in SLE.

DNA-specific autoantibody cleaves DNA by hydrolysis of phosphodiester and glycosidic bond.

The DNA-recognizing autoantibodies were prepared in milligram scale and their catalytic activities were investigated using various standard substrates for hydrolysis of natural biomolecules such as DNA, carbohydrates, and proteins. Only phosphatase and glycosidase activity was found and no peptidase, sulfatase, or esterase activity was detected in most of anti-DNA monoclonal autoantibodies we tested. Antibody G1-2 showed the highest catalytic activities and its enzymatic characteristics were further investigated.

Analysis of the phenotypes of Jurkat clones with different TRAIL-sensitivities.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been shown to exert potent cytotoxic activity against many tumor cells but not normal cells. However, some tumor cells are resistant to TRAIL, and it has not been determined how this occurs. In the present study, we obtained three subgroups of Jurkat clones with TRAIL-sensitive, -partial resistant and -resistant phenotypes.

Specific modulation of the anti-DNA autoantibody-nucleic acids interaction by the high affinity RNA aptamer.

Anti-DNA autoantibodies are one of the frequently found autoantibodies in systemic lupus erythematosus patient sera. RNA aptamers for the monoclonal G6-9 anti-DNA autoantibody were selected from a random pool of RNA library. Binding affinity of the best aptamer is around 2nM, which is at least 100-fold higher than that of cognate DNA antigen to the autoantibody.

Production and characterization of an anti-idiotypic single chain Fv that recognizes an anti-DNA antibody.

A well-characterized recombinant anti-idiotype to an anti-DNA antibody can be useful for studies of the regulation of anti-DNA-producing B cells. Using a hybridoma technique, a monoclonal anti-idiotypic antibody, designated O2F3, was obtained, and its scFv gene was constructed. O2F3 single chain Fv (scFv) was produced against an idiotope of a monoclonal anti-DNA antibody, 3D8, that was obtained from an autoimmune-prone mouse, MRL-lpr/lpr.

Pilot study of mass screening for Wilson's disease in Korea.

Wilson's disease (WD) is an autosomal recessive disorder of copper metabolism with copper accumulation in the liver as well as in the central nervous system. Treatment of WD includes oral chelating agents and diet and it is effective. However, once irreversible damage has occurred, the effect of treatment is diminished and the patient's quality of life is compromised.

Simultaneous expression of allogenic class II MHC and B7.1 (CD80) molecules in A20 B-lymphoma cell line enhances tumor immunogenicity.

We expressed the allogenic class II MHC antigen and B7.1 (CD80) co-stimulatory molecule in A20 beta-lymphoma cells in order to test their efficacy as immuno-stimulating adjuvant agents in inducing tumor-specific immunity. The transduction of the allogenic I-Ab alpha and beta chain genes into A20 cell resulted in a surface expression of the allogenic class II MHC molecules.