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A subset of anti-dsDNA autoantibodies (autoAbs), cell-penetrating Abs, may play a pathogenic role in lupus nephritis. However, the pathogenic role(s) of the Abs has not been well explored. In this study the pathological effects of a positively charged CDR3-VH-containing and cell-penetrating anti-dsDNA monoclonal mouse autoAb 2C10 immunoglobulin G (IgG) and its recombinant VH domain were investigated in a mouse mesangial cell line with respect to activation of signaling molecules and transcription of pro-inflammatory cytokines. The IgG and VH reduced cell viability in cytotoxicity assays and delayed cell cycle progress in flow cytometric analysis. Western blotting experiments showed that they activated p38, MAPKAPK-2, RSK-1, Bcl-2 and ATF-2 in the associated pathway; RSK-1 activation was regulated by p38; p38 also activated MAPKAPK-2 and ATF-2; MAPKAPK-2 regulated RSK-1 activation, and Bcl-2 was up-regulated by RSK-1. The IgG and VH remarkably stimulated the transcription of pro-inflammatory cytokines, TNF-α, IL-6 and IL-1β And the transcription was regulated by p38 activation. These results indicate that the cell-penetrating autoAbs such as 2C10 may play a pathogenic role in mesangial cells mainly through activation of p38 signaling pathway in combination with the stimulation of pro-inflammatory cytokine production.

Application of antibodies in most therapeutic area is limited to extracellular or membranous targets because of their impermeability of membrane. For the purpose of biotechnological and therapeutic application, developing intracellular localizing antibody is the invaluable research field. A new recombinant single-chain variable fragment of an anti-dsDNA monoclonal antibody G2-6, IgG of which has been previously shown to have a cell-penetrating activity, was engineered and produced for the use as a delivery vehicle of biomolecule(s). The penetrating capacity of single-chain variable fragment in three mammalian cell lines, L929, NIH/3T3, and COS-7 was analyzed using flow cytometry and confocal microscopy. The results demonstrated that the single-chain variable fragment can effectively internalize all three cell lines, although the internalization level varied. It was also shown that the internalization was time- and concentration-dependent. Moreover, the single-chain variable fragment was located in...

Premature ovarian failure (POF) that could result from chemotherapy applied to young female cancer patients is a significant challenge in reproductive biology. It is widely believed that the hyperactivation of dormant primordial follicles following chemotherapy is a leading cause of POF, but it remains unclear how therapeutic cues are generated and transduced into follicular activation. Here, we provide evidence that supports that GV1001, an immunotherapeutic peptide targeting telomerase, plays a role in the deterrence of POF in mice. In vivo non-small cell lung carcinoma (NSCLC) tumor xenografts were produced by inoculating NSCLC cells into the flank of BALB/c female athymic mice and then subjected to cancer chemotherapy with GV1001 and bevacizumab, an anti-cancer antibody drug, humanized anti-VEGF monoclonal antibody. Bevacizumab when administered at the dosage of 5 mg/kg for three weeks was effective in inhibiting growth of NSCLC tumor xenografts, and its anti-cancer efficacy was not interfered by the presence of GV1001. As expected, bevacizumab induced follicular loss by accelerating primordial follicle growth into primary or secondary follicles concomitant with a decline of serum antimullerian hormone (AMH) level and deactivation of Foxo3 signaling as evidenced by immunohistochemical and immunofluorescent assessment. However, bevacizumab-induced follicle stimulating effects were mitigated by GV1001 co-administration as evidenced by the analysis of follicular count, serum AMH level, and Foxo3a expression. From this study, we propose that a combinatorial administration of GV1001 and bevacizumab could deter POF of young female cancer patients without hampering the anti-cancer effectiveness of bevacizumab.

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&ndash, TRAIL receptor 1 (DR4) monoclonal antibody Fab fragment, DR4-4, on various TRAIL-resistant and -sensitive cancer cell lines. The mechanisms of DR4-4 Fab&ndash, induced cell death in a human T cell leukemia cell line (Jurkat) were investigated using cell viability testing, immunoblotting, immunoassays, flow cytometry, and morphological observation. DR4-4 Fab&ndash, induced caspase-independent necrosis was observed to occur in Jurkat cells in association with p38 mitogen-activated protein kinase activation, cellular FLICE (FADD-like IL-1&beta, converting enzyme)-inhibitory protein degradation, decreased mitochondrial membrane potential, and increased mitochondrial reactive oxygen species production. Increased cytotoxic effects of DR4-4 Fab were observed in combination with TRAIL or &gamma, irradiation. Our results indicate that the novel DR4-4 Fab might overcome TRAIL-resistance and induce death in leukemia cells via cellular mechanisms different from those activated by TRAIL. DR4-4 Fab may have application as a potential therapeutic antibody fragment in single or combination therapy for cancer.

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. To assess the contribution of antigen-binding sites, especially the VH, in cell- and nuclear-penetration, we evaluated the characteristics of recombinant single chain Fv(scFv), VH, and variable light domain (VL) of a penetrating mAb. The scFv and VH domain, containing arginine in CDR3-VH maintained the ability to penetrate cells and the cell nuclei, whereas the VL domain, having no arginine in CDR3, did not penetrate cells. The penetratingm Abs, scFv, and VH activated ERK and increased cellular protein levels of Bcl-2, whereas the non-penetrating Ab and VL did not. The cell survival was decreased by the penetrating mAbs, scFv and VH, not by the non-penetrating mAb and VL. The data indicate that an antigen-binding site is required for cell-penetration and that positively-charged arginine residues in CDR3-VH contribute to the cell- and nuclear-penetrating ability of a subset of anti-dsDNA autoAbs. Furthermore,the nuclear-penetrating anti-dsDNA autoAbs could possibly function as a pathogenic factor for lupus nephritis by up-regulating ERK activation and Bcl-2 production in mesangial cells. The cell- and nuclear-penetrating VH domain may be exploited as a vehicle for the intra cellular delivery of various useful molecules.

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. Analysis of the variable region sequences revealed that the antibodies used diverse members of V(H) gene families with different D(H) and J(H) segments. However, in V(L), KV3-20 gene family member along with KJ1 segment was used often. Similarities between the rearranged genes and the closest germline sequences were low. The sequences of V(H) were highly mutated and V(H)-CDR3 varied greatly in length and sequences. The ratios of R/S (replacement mutation to silent mutation) were remarkably high in CDRs in all V(H) regions except one clone. Furthermore, mutations to positively charged amino acids were frequent in all V(H) and most V(L). These results suggest that the occurrence of somatic hypermutation and antigenic selection is critical, not the usage of certain V(H) gene family members or segments, in producing affinity-matured anti-HSP60 autoantibodies in atherosclerosis. However, expression of the combined germline genes of KV3-20 with KJ1 might be important for the selection by HSP60 at the early stage of B cell development. Two of these anti-HSP60 Fabs inhibited the binding and uptake of human HSP60 by murine macrophage cells. One of them also reduced the release of the pro-inflammatory mediators and inhibited the activation of NF-κB in HSP60-stimulated macrophages. To elucidate the functional roles of anti-HSP60 autoantibodies in atherosclerosis and the potential use of these Fabs to treat atherosclerosis, further investigation is worthy to be performed.

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. Combination treatment with aspirin and TRAIL markedly enhanced apoptotic cell death, as assessed by lactate dehydrogenase (LDH) assay and analysis of cell cycle sub-G1 phase. The two agents together activated the several caspases and mitochondrial signaling pathway. Whereas Mcl-1 protein level was increased and extracellular signal-related kinase (ERK)1/2 was activated in cells treated with TRAIL alone, combination treatment dramatically inhibited ERK1/2 activation and down-regulated Mcl-1 protein level. An inhibitor of ERK1/2 activation, PD98059, also augmented TRAIL-induced apoptosis. Combination treatment with PD98059 and TRAIL showed the activation of caspases and mitochondrial pathway, and the down-regulation of Mcl-1 level. These results suggest that cancer cells can be sensitized to TRAIL-induced apoptosis by pre-treatment with aspirin via suppression of ERK1/2 activation. These findings provide a basis for further exploring the potential applications of this combination approach for the treatment of cancer, including cervical cancer.

This study was undertaken to produce a Fab fragment of a human monoclonal antibody reactive to oxidized and carbamylated low-density lipoprotein (oxLDL and cLDL) using phage display technology. An analysis of DNA sequences of this Fab, termed plaque 15,16-46 Fab, revealed that the rearranged VH was highly mutated. Complementarity-determining regions of the VH showed a very high R/S ratio and contained many positively charged amino acids. In direct binding and competitive ELISA, the Fab reacted strongly with both MDA-LDL and Cu-oxLDL forms of oxLDL, and also showed high affinity for cLDL. Immunofluorescence and immunohistochemical analyses showed that this Fab positively stained atherosclerotic aortic plaques in ApoE−/− mice as well as those in patients with atherosclerosis. The Fab also showed positive staining in placental decidua from patients with preeclampsia. It is suggested that the plaque 15,16-46 Fab against oxLDL and cLDL might possibly be applicable for developing a diagnostic reagent f...

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 V H genes from three different V H gene families (V H 3, V H 4, and V H 5) and distant members of the Vκ 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. Most of the utilized V H and Vκ sequences were highly mutated and the complementarity-determining regions (CDRs) varied greatly in length. The V H region of the antibody SLEhis18 had an isoelectric point of 6.1, and 29% of the mutations were changes to acidic amino acid residues. The second CDR (CDR2) of SLEhis18 V H contained one basic and three acidic residues. Acidic residues were observed in the CDR3 regions of V H , but not V L , in all isolated clones; this is unusual, as most autoantibodies are comprised predominantly of non-acidic residues. This is the first report of a systematic sequence analysis of human anti-histone monoclonal antibodies. Our results suggest that certain V genes are not important for autoreactive specificity to histones in SLE; instead, other mechanisms such as an existence of acidic residues and somatic mutations in CDRs are required for specific binding to histones, which might play a role as a stimulatory autoantigen for the activation of autoantibody-producing B-cells and the selection of high affinity antibody.

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. It is estimated that at least half of the patients with WD remain undiagnosed and die of untreated disease. Early detection of patients presymptomatically has been hampered by the lack of effective methods for mass screening. Recently, a sandwich ELISA method for ceruloplasmin measurement in blood spots was developed. We have used this method to analyze blood specimens collected on filter paper from 3667 children aged 3 months–15 years. The mean value of ceruloplasmin was 30.5±9.5 mg/dL. Among these children, we identified one WD case, a 32-month-old boy with markedly reduced ceruloplasmin concentration (2.3 mg/dL). Measurement of CP level in dried blood spot sample is proposed as a reliable method for population screening of WD.

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. Here we describe the production and in vitro characterization of the O2F3 scFv, and compare it with its parent monoclonal antibody, O2F3 IgM. To characterize O2F3 scFv and O2F3 IgM, we generated recombinant 3D8 fragments, including 3D8 scFv, 3D8 VH, and 3D8 VL, that were used as antigens in several assays. ELISA and Western blot analysis showed that both O2F3 scFv and O2F3 IgM recognized a conformational determinant formed by the association of the variable region heavy and light chains of the 3D8 antibody, suggesting that O2F3 scFv retained a similar binding pattern to its parent O2F3 antibody. The idiotope recognized by O2F3 was shown by competitive ELISA to be outside of the DNA binding site of the 3D8 antibody. This characterized O2F3 scFv could be applied for the regulation of anti-DNA antibody production and the manipulation of recombinant antibody-based proteins to which toxins, enzymes, and chemical agents can be connected.

We show that the tumor-specific primary cytotoxic T lymphocytes (CTL) induced in vitro with the MCA205 fibrosarcoma cells transduced with the B7.1 (CD80) gene are highly effective in adoptive-transfer therapy of the parental tumors. The MCA205 fibrosarcoma cell line was transduced with the retroviral vectors encoding the B7.1 gene and tested for their efficiency as stimulators in short-term (5 days) mixed lymphocyte/tumor cell cultures with highly purified syngenic, unprimed T cells as responders. The induction of the CTL required the presence of a low dose of interleukin-2 (25 U/ml). The injection of the CTL prevented colony formation by the intravenously injected tumor cells in a lung colonization assay in which the CTL were injected after inoculation of tumor cells. We also showed that the adoptive transfer of the same T cells was effective in delaying the growth of the subcutaneously injected tumor cells. These results imply that the short-term mixed lymphocyte/tumor cell culture with the tumor cells transduced with the gene for the B7.1 costimulatory molecule is potentially a good source of CTL for adoptive-transfer therapy of tumors.

We have used single and multiple site-directed mutagenesis, and molecular modeling, to identify critical residues in the DNA binding site of MAb 2C10, an IgG anti-dsDNA autoantibody from an MRL/lpr lupus mouse. Simultaneous replacement of four Arg residues in the CDR3H abolished binding activity. With one exception, replacement of any one of these Arg residues reduced the activity to 20-50% of the unmutated scFv activity. Arg to Asp replacements had a slightly greater effect than Arg to Ala replacements. In the one exceptional case, replacement of Arg99 with Ala actually increased DNA binding five-fold and replacement by Asp had little effect. Mutation of Phe32 and Asn35 to A1a in CDRIH decreased DNA binding, whereas replacement of Arg31 with A1a had negligible effect. Ala substitution of any one of a cluster of Asp residues in CDR1L increased DNA binding three to six-fold, confirming previous findings that the L-chain of MAb 2C10 is not favorable for DNA binding. The L-chain does participate in shaping the selectivity of antigen binding, and mutation of CDR3L residue Asp92 or Asn93 caused a decrease in DNA binding activity. Directed mutagenesis, consistent with a molecular model, indicates that: several CDR amino acids contribute to DNA binding, without one residue dominating; both VH and VL CDR3 domains contribute to specificity of binding whereas the CDR1L hinders DNA binding. The results suggest a significant role for electrostatics in the interaction of DNA with MAb 2C10.

Twenty‐one monoclonal anti‐DNA autoantibodies were produced by fusing spleen cells from an autoimmune MRL//pr mouse with SP2/0 myeloma cells. Hybridomas generated by the fusions were chosen for cloning on the basis of DNA binding by supernatant antibody. Each monoclonal antibody was purified to homogeneity and analyzed for the heavy and light chain isotypes and the binding specificity for single‐stranded DNA, double‐stranded DNA, and RNA. Sequence specificities and isoelectric points of the antibodies were also examined. All of the antibodies were IgG and tended to bind to both single‐stranded and double‐stranded DNA with a preference for the double‐stranded form. Some of them also bound to RNA. Isoelectric points of the antibodies were shown to be high. The antibodies described in this report have characteristics of pathogenic anti‐DNA antibodies

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. It induced cell death in Jurkat and HL60 leukemia cell lines without the need for secondary crosslinkers in vitro. It did not compete with soluble TRAIL (sTRAIL) for binding to DR5, and its combination with sTRAIL resulted in greater cell death than either agent alone. The cell death induced by JKTR-18 included a caspase-independent mechanism. This is the first report of a monovalent antibody fragment against TRAIL receptor that can induce tumor cell death in the absence of a crosslinker.

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. Enhanced apoptosis in response to the combination treatment was associated with caspase-8 activation-mediated Bax and Bak activation and mitochondrial dysfunction. The combination treatment also resulted in synergistic up-regulation of TRAIL receptor R1 (DR4) and R2 (DR5). siRNA targeting of DR5 significantly attenuated the combination treatment-induced caspase-8 activation, mitochondrial dysfunction, and apoptotic cell death. Upon stimulation of cells with the combination treatment, NF-kappaB was activated. Moreover, siRNA targeting of NF-kappaB significantly attenuated the combination treatment-induced DR4 and DR5 expression and receptor-mediated caspase-8 activation. These results indicate that phytosphingosine sensitizes cancer cells to TRAIL through the synergistic up-regulation of DR4 and DR5 in an NF-kappaB-dependent fashion resulting in caspase-8 activation and subsequent mitochondrial dysfunction. These findings support the potential application of combination treatment with TRAIL and phytosphingosine in the treatment of cancers that are less sensitive to TRAIL.

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. Anaphylactic reactions, antigen-specific antibodies, splenocytes proliferation assays and cytokine productions were evaluated. Oral buckwheat challenges of sensitized mice provoked anaphylactic reactions such as severe scratch, perioral/periorbital swellings, or decreased activity. Reactions were associated with elevated levels of buckwheatspecific IgE antibodies. Splenocytes from buckwheat allergic mice exhibited significantly greater proliferative responses to buckwheat than non-allergic mice. Buckwheat-stimulated IL-4, IL-5, and INF-gamma productions were associated with elevated levels of buckwheat-specific IgE in sensitized mice. In this model, 1 mg and 5 mg dose of sensitization produced almost the same degree of Th2-directed immune response, however, a 25 mg dose showed blunted antibody responses. In conclusion, we developed IgE-mediated buckwheat allergy by intragastric sensitization and challenge, and this model could provide a good tool for future studies.

Background: Anti-cardiolipin antibody (Anti-CL Ab) is one of the various antiphospholipid antibodies (Anti-PL Abs) and found in the plasma of patients with systemic lupus erythematosus (SLE), atherosclerosis, and other infectious diseases. While anti-PL Abs found in the sera of patients with infectious diseases bind directly to CL, binding of anti-PL Abs to CL circulating in the sera of patients with autoimmune diseases is mediated by glycoprotein 1 (). The purpose of this study is to investigate the effect of on the antigen binding assay of anti-CL Abs present in the sera of patients with atherosclerosis, which has been known as one of autoimmune diseases. Methods: ELISA was performed with sera containing anti-CL Abs from three patients with atherosclerosis in the presence or absence of or FBS. Results: Reactivity of anti-CL Abs to CL was increased in the presence of or FBS in a dose dependent manner. Conclusion: or FBS could be used as co-factor in CL ELISA with anti-CL Abs present in the sera of patients with atherosclerosis. It is suggested that anti-CL Abs found in atherosclerosis patients are similar in terms of antigen binding property to those circulating in the patients with autoimmune diseases, not to infectious diseases.