Detection of Vibrio anguillarum by a sandwich enzyme-linked immunosorbent assay performed with monoclonal antibodies

Monoclonal antibodies (Mabs) against V. anguillarum were produced and characterized by Western blotting analysis, competitive binding assays and cross-reactivity tests. Their ability to detect V. anguillarum in a liquid culture was tested in a sandwich enzyme-linked immunosorbent assay (ELISA) performed with different combinations of these Mabs used as capture or tracer antibodies. One combination was selected as the most suitable for diagnostic applications, showing the highest sensitivity and specificity.     

Kinetic constants of alpha-methyl-D-glucoside transport in the chick small intestine during perinatal development

BACKGROUND: Experimental evidence suggests that neutralizing antibodies could constitute an important factor in the control of AIDS progression and that the V3 loop of gp120 constitutes the main target for such purposes. We have previously developed two neutralizing murine monoclonal antibodies (Mabs) against the V3 region of the HIV-1 MN strain. OBJECTIVES: To characterize those Mabs in terms of fine specificity and DNA sequence of their V regions and to study if Fab fragments retain their neutralizing potential in vitro. STUDY DESIGN: A set of 12-mer alanine substituted peptides were employed for epitope mapping using two ELISA procedures: (1) indirect, with each peptide bound to polystyrene plates, and (2) competitive, with co-incubation of peptides and Mabs in solution. The V regions of both Mabs were PCR amplified from cDNA and their nucleotide sequences were determined. Finally, Fab fragments of Mab 10F10 were generated and their neutralizing capacity against the MN isolated was assessed. RESULTS: We first restricted the minimal length of the epitopes recognized by 2C4 and 10F10 to the 12-mer peptide KRIHIGPGRAFY. The core of the epitopes recognized by Mabs 2C4 and 10F10 were IHIGP-R and IHIG-R, respectively. While substitution of proline in position 7 completely abolished the binding of 2C4, it only reduced that of 10F10 by 50%. Finally, Fab fragments of Mab 10F10 were still able to neutralize the HIV-1 MN strain in vitro. CONCLUSION: This subtle distinction in the fine mapping of the epitope recognized by Mabs 2C4 and 10F10 should correspond to three amino acid differences that we found in the heavy chain V-regions. The Fab fragments of Mab 10F10 retained the neutralizing capacity. This indicates that HIV neutralization by anti V3 Mabs is an Fc independent process.     

Xenobiotic metabolizing enzymes in fish: diversity, regulation and biomarkers for pollutant exposure

The specificity, detection limit, and stability of twelve anti-Salmonella monoclonal antibodies (Mabs) were evaluated by cloth-based enzyme immunoassay (CEIA) and polymyxin-cloth based enzyme immunoassay (p-CEIA). Using the p-CEIA, five Mabs were found to react with cholate extracted lipopolysaccharide (LPS) antigens of all 44 Salmonella strains representing 19 different serogroups examined, with the exception of the one strain of serogroup-O tested. These five Mabs did not react with cholate extracts of any of 16 Gram-positive or Gram-negative non-Salmonella bacteria tested. The detection limit of purified S. typhimurium LPS antigen in the p-CEIA was approximately 40 ng for four of the Mabs and approximately 20 ng for the other Mab. Four of the five Mabs were stable during storage at 22 degrees C-23 degrees C for 24 h. These four Mabs are potentially useful for the immunodetection of Salmonella in foods and other samples.     

Radiologic diagnosis of abdominal trauma

We have characterized 10 monoclonal antibodies (Mabs) to recombinant murine thyrotropin receptor extracellular domain (mTSHR-ecd). Affinity purified mTSHR-ecd (amino acids 22-415), expressed in a baculovirus-insect cell system, was refolded in vitro and used to hyperimmunize female Balb/c mice. Spleens were removed 10 days after a final boost of 25 microg mTSHR-ecd intraperitoneally and intravenously, and the cells were fused to SP-2 cells and cloned. Hybridoma supernatants were screened by enzyme-linked immunosorbent assay (ELISA) with folded mTSHR-ecd antigen. Ten of 18 higher affinity hybridomas were selected at random and ascites fluids prepared. Nine of the monoclonals were of IgG 1 isotype, and one was IgM. Five Mabs (M3, M4, M5, M6, and M9) inhibited the binding of 125I-TSH to functional hTSHR expressed on Chinese hamster ovary (CHO) cells, and four (M1, M3, M5, and M9) blocked the TSH-stimulated generation of cyclic adenosine monophosphate (cAMP), using the same cells. The remaining Mabs appeared to be neutral in their interaction with native TSHR. The Mabs were also compared for their reactivity to mTSHR-ecd under folding (ELISA) and unfolding (reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]) conditions. Most Mabs demonstrated reactivity to both conformational (folded) and linear (unfolded) forms of mTSHR-ecd, suggesting that they were generated primarily against linear epitopes although one Mab (M4) showed affinity for only folded antigen indicating a preference for a conformational epitope. Mapping the Mab epitopes using 26 overlapping peptides spanning the human (h)TSHR-ecd showed that 6 bound peptide 397-415, 1 bound peptide 352-371, and 1 peptide 22-41. These epitope mapped Mabs to the mTSHR-ecd, both receptor blocking and receptor neutral, will provide further insight into the structure-function of the TSHR ectodomain.     

The reactivity of monoclonal antibodies against orf virus with other parapoxviruses and the identification of a 39 kDa immunodominant protein

A panel of 27 mouse monoclonal antibodies (Mabs) was raised against orf virus. Sixteen of these Mabs reacted with a protein with a molecular mass of 65 kDa, 8 reacted with a protein with a molecular mass of 39 kDa and three remain uncharacterised. Reactivity of the Mabs with a library of recombinant vaccinia viruses expressing various regions of the NZ-2 orf virus genome identified the approximate positions of the genes encoding these 2 immunodominant orf virus proteins. The gene encoding the 39 kDa protein was identified and sequenced. The protein was detected in an envelope fraction of orf virus and was shown to be homologous to the envelope protein encoded by the H3L gene of vaccinia virus. The 65 kDa protein has not been fully chracterised, but the gene encoding it has been localised to a 10 kbp region of the orf virus genome. The Mabs were used to discriminate 4 parapoxviruses derived from sheep, 2 from cattle and 1 each from a seal and squirrel. Eighteen Mabs reacted with all 4 sheep viruses, 19 Mabs reacted with both cattle viruses, 6 recognised seal parapoxvirus and 2 recognised the squirrel parapoxvirus. Only one of the 27 Mabs reacted with all 8 parapoxviruses suggesting it recognises a conserved epitope within the genus.     

Pathological gambling: a review of the literature

The aim of this study was to characterize human anti-Rhesus monoclonal antibodies cross-reacting with tissue antigens. Of the 155 monoclonal alloantibodies tested, 49 also reacted with intracellular antigens, as demonstrated by immunofluorescence assay on cryostat sections of animal and human tissues. This cross-reactivity was mainly a property of monoclonal alloantibodies belonging to the IgM isotype (among the 49 cross-reacting Mabs, 37 were IgM). The results confirm that during an immune response against a foreign antigen (alloantigen), B cells that produce polyreactive antibodies are not excluded from the pool of responding cells.     

Albumin-binding surfaces: in vitro activity

Immobilized monoclonal antibodies (Mabs) have been used to attract specific molecules to a solid surface from complex mixtures such as blood, plasma or serum, thereby directing the response to the modified substrate, a key goal in rational biomaterial design. The nature of the Mab dictated the nature of the response: anti-albumin antibodies were used to prevent cell and platelet adhesion in vitro, whilst anti-fibronectin Mabs promoted attachment. Patterned surfaces could be formed, bearing Mabs that generated adhesive and non-adhesive regions. Fibrinogen adsorption from plasma showed a Vroman peak on unmodified control polymer, which was reduced by 64% in the presence of surface-bound anti-albumin Mab. Immobilization of a control Mab reduced fibrinogen adsorption only slightly, implying an albumin-mediated effect. In static tests, platelet adhesion from human platelet rich plasma was significantly reduced by the immobilization of anti-HSA Mab when compared to the untreated FEP surface (p < 0.0001). This effect was also seen with citrated blood flowing through Mab-treated polyurethane tubing at a shear rate of 132 s(-1) (p=0.034). Since platelets and proteins (as blood, plasma or serum) were introduced to the surface simultaneously, the generation of a defined protein film must have been sufficiently rapid as to shape the platelet or cell response.     

Management of renal trauma at a rural, level I trauma center

Eotaxin is a potent and selective CC chemokine for eosinophils and basophils. We established several monoclonal antibodies (Mabs) allowing the neutralization and measurement of human eotaxin. Using the Mabs as probes, we demonstrated that normal eosinophils contained intracellular granule-associated eotaxin. Quantification of cell-associated eotaxin in different leukocyte subsets revealed that it was principally expressed in eosinophils. Finally, we showed that normal eosinophils released eotaxin upon stimulation with either of two secretagogues, C5a or ionomycin. These findings raise the possibility that eosinophil-derived eotaxin contributes to the local accumulation of eosinophils at the site of inflammation.     

The allergic theory of radiocontrast agent toxicity: demonstration of antibody activity in sera of patients suffering major radiocontrast agent reactions

An allergic, immunologic mechanism for certain adverse reactions to radiocontrast agents has been postulated on the basis of clinical and theoretical considerations. One obstacle to the acceptance of this allergic theory has been the inability to demonstrate significant antibodies with specificity for these agents. In our studies, rabbits were immunized with 4 analogues of radiocontrast agents which induced IgG or IgE antibodies specific for the contrast media analogues. Then, to determine if antibodies to contrast agents were present in man a prospective, one-year surveillance of radiocontrast agent reactions was undertaken. Sera from 27 patients suffering severe reactions and 37 control subjects were analyzed by radioimmunoassay for antibodies reactive with radiocontrast media. Binding of radiolabeled contrast media was significantly elevated (p less than 0.01) by the serum globulin fraction of the patients suffering severe reactions. Demonstration of this antibody activity, although not proof of cause and effect between the presence of antibody activity and clinical symptoms, nonetheless adds support to the hypothesis that some adverse reactions to radiocontrast agents are due to antibodies.     

Sequence and characterisation of a ribosomal RNA operon from Agrobacterium vitis

Because certain antiganglioside monoclonal antibodies can facilitate antibody-dependent cellular cytotoxicity against GD2+ ganglioside-bearing human and canine tumor cells, we wished to determine if clinically relevant antiganglioside monoclonal antibodies (Mabs) could also fix canine complement to lyse tumor cells in vitro. Using flow cytometry, human tumor cell lines (M21 melanoma and OHS osteosarcoma) were shown to highly express ganglioside GD2 and, to a lesser degree, GD3. In 51Cr release assays, M21 cells were lysed with canine serum, as a source of complement, plus either Mab 14.G2a or its mouse-human chimera, ch 14.18, specific for GD2. Heating canine serum abrogated its lytic activity and addition of rabbit complement reconstituted M21 lysis. Similar results were obtained with M21 cells when Mab R24 (against GD3) and canine serum were used. OHS cells were also lysed with canine serum plus Mab 14.G2a and lytic activity was abolished by heating canine serum but reconstituted with rabbit complement. Alone, canine serum or Mabs were not lytic to M21 or OHS cells. Conversely, human neuroblastoma (LAN-5) and K562 erythroleukemia cells were lysed by canine serum alone which was shown by flow cytometry to contain naturally occurring canine IgM antibodies that bound LAN-5 and K562 cells. The lytic activity of canine serum for LAN-5 or K562 cells was abolished by heating and restored by addition of either human or rabbit complement. Thus, human tumor cell lines can be lysed with antiganglioside Mabs through fixation and activation of canine complement-dependent lytic pathways. Canine xenoantibodies also mediate complement-dependent cytotoxicity of some human tumor cell lines. Together, these results are significant because they demonstrate an antitumor effect of the canine immune system which is of potential importance for cancer immunotherapy in a promising animal model.     

Effects of immunopharmacological compounds in the Lyme arthritis model using normal and SCID mice

The murine Lyme borreliosis causes a special type of arthritis whose development appears to be controlled by a functioning immune system. Immunocompetent C3H and severe combined immunodeficient (SCID) mice were infected with Borrelia burgdorferi (strain SH-2-82) to induce experimental Lyme disease. Expression of clinical symptoms was mild to very moderate in the C3H but more rapidly developing and severe in the SCID mouse. Various pharmacological compounds, such as anti-inflammatory and immunosuppressive drugs, monoclonal antibodies and other miscellaneous agents, were investigated for profiling their effects in this model in both mouse strains. Several disease parameters were assessed, in particular paw swelling. The use of these various compounds provided further evidence that experimental borreliosis in mice represents a special type of arthritis which has no autoimmune basis and which requires productive infection with Borrelia burgdorferi. In addition, when comparing these results with those obtained in other mainly immune driven arthritis models commonly used in inflammation research, it is concluded that this arthritis model is not suitable for the therapeutic assessment of antiinflammatory agents.     

Expression and cellular distribution of baculovirus-expressed bovine herpesvirus 1 (BHV-1) glycoprotein D (gD) sequences

Glycoprotein D (gD) of bovine herpesvirus 1 (BHV-1), a homolog of herpes simplex virus gD, represents a major component of the viral envelope and is a dominant immunogen. To study the antigenic properties of the different regions of gD, we have expressed the full-length gD encoding gene and overlapping fragments spanning various regions of the gD open reading frame in a baculovirus (Autographa californica nuclear polyhedrosis virus)--insect cell (Spodoptera frugiperda, SF-9) system. Maximum levels of expression for all proteins were obtained 48 to 72 h post infection of SF-9 cells by recombinant viruses. Full-length and truncated recombinant gD proteins reacted specifically with anti-gD monospecific serum as determined by immunoprecipitation and immunoblotting, indicating that the proteins retained their antigenicity. However, based on the reactivity with a panel of gD-specific monoclonal antibodies (Mabs), the full-length recombinant gD lacked proper expression for two highly neutralizing linear epitopes identified by Mabs R54 and 9D6. The rest of the epitopes appeared to be preserved and antigenically unaltered. Immunofluorescence studies of recombinant baculovirus infected SF-9 cells using gD monospecific serum, revealed no direct correlation between cellular localization of the expressed proteins and their amino acid sequences.     

Early increases in ischaemic heart disease mortality dissociated from and later changes associated with respiratory mortality after cold weather in south east England

Monoclonal antibodies against spores of Glugea atherinae were obtained after lymphocytic hybridization made from immunized mouse splenocytes. Screening using an indirect enzyme linked immunosorbent assay (ELISA), revealed seven monoclonal antibodies with an intense but variable reaction with the spores of fish microsporidia, and a moderate reaction with those of an insect microsporidium (Nosema sp.). The reaction was weaker with spores of Encephalitozoon intestinalis found in HIV+ patients. FITC and Dot Blot confirmed the majority of these results. After biotinylation of the seven antibodies, inhibition tests allowed the localization of two different recognition domains on the spores of Glugea atherinae. The multiple antigenic determinants and their probable polysaccharide nature seem to be in accord with the class IgM of the antibodies produced. This work confirms the potential of these antibodies for microsporidian taxonomy and diagnosis, especially the use of Mabs 12F9 and 12H5 for detection of spores in stools of HIV+ patients.     

Establishing a link between oncogenes and tumor angiogenesis

We have tried to stress that mutant oncogenes or overexpressed, nonmutated proto-oncogenes, in addition to their direct affect on promoting aberrant tumor cell proliferation (and survival), may possess a crucial indirect means of stimulating tumor cell growth through regulation of angiogenesis. This effect would never be observed in tissue culture studies of oncogene function using pure cultures of tumor cells, which probably helps explain why the pro-angiogenic function of oncogenes has not been appreciated until only relatively recently. Indeed, the very first indication of a possible contributory role of oncogenes, such as ras and myc, to tumor angiogenesis was first reported by Thompson et al. in 1989, who used reconstituted organ cultures of the mouse prostate gland for their studies (69). This potentially important contribution of oncogenes to tumor growth and development may prove to have an impact on how various signal transduction inhibitors that are now in early phase clinical trials, e.g., monoclonal neutralizing antibodies to the human EGF receptor (70), function in vivo as anti-tumor agents.     

Continuous and common epitopes present in fimbriae of enterotoxigenic Escherichia coli (ETEC)

Colonization factor antigens (CFAs and PCFs) are important virulence factors of Escherichia coli (ETEC) diarrhea. Antibodies to CFAs produced after ETEC infection are protective; however, the CFA epitopes which induce protective antibodies have not yet been characterized. This study is the characterization of the immune response to CFAs at molecular level and identification of the epitopes associated with inhibition of cell-adherence and protection that will lead to the development of methods to prevent ETEC infection and disease. The aim of this study was the characterization of the linear epitopes of CFA/I that react with sera from acute and convalescent phase of ETEC-in-fected children, with adult sera from endemic and non-endemic areas, with monoclonal antibodies (Mabs) and with hyperimmune antiserum to CFAs and PCFs different from CFA/I. Three linear and common epitopes were recognized among the CFA/I in child sera and adult sera from endemic areas and with hyperimmune sera against other known CFAs and putative ETEC colonization factors.     

The isolation and characteristics of monoclonal antibodies to recombinant proteins of HIV-1 and HIV-2--the env and gag gene products

Ten hybridomas secreting monoclonal antibodies (Mab) against recombinant HIV-1 and HIV-2 antigens were produced (3 Mab anti-gag protein, 2 anti-env1, and 5 anti-env2). In the immunoblotting assay all the anti-gag Mabs reacted with HIV capsid protein p24, whereas one of them reacted also with p55 protein and with 7 other polypeptides. Another anti-gag Mab cross-reacted with the antigen of subpopulation of human peripheral blood lymphocytes. The third one interacted with the antigen of both HIV-1 and HIV-2. All the 10 Mabs interacted with natural HIV antigens and can be used for identification and differentiation of HIV-1 and HIV-2.     

Adhesion molecules in the nickel allergic reaction

Nickel is the major cause of allergic contact dermatitis, and to increase our understanding of this immune reaction we studied changes in the expression of adhesion molecules on mononuclear cells during nickel stimulation in vivo and in vitro. Nickel-induced lymphocyte cultures were used in vitro, the cells being examined with monoclonal antibodies (Mabs) and by flow cytometry. Mononuclear cells from skin biopsies of in vivo cutaneous nickel reactions were studied with Mabs and immunohistochemistry. The expression of adhesion molecules in vitro was differential: the number of cells carrying CD11c, CD29, CDw49b, CDw49d, CDw49e, CDw49f, CD54, CD56 and ELAM-1 being significantly overrepresented among the nickel-induced lymphoblasts whereas the number of blasts carrying CD44 was underrepresented and those of CD11a, CD18, CD58 and LAM-1 remained unchanged. CD4+ cells gained adhesion molecules during nickel-induced blast transformation whereas CD8+ cells lost most of their adhesion molecules. The in vivo results were in agreement with the in vitro ones except that CDw49b, CDw49f, CD56 and ELAM-1 could not be detected in a 96-hour nickel reaction in vivo. In conclusion, the nickel allergic reaction favors the expression of certain adhesion molecules, and this expression is induced on CD4+ cells while CD8+ cells tend to lose such molecules. The changes were more sensitively detected with the in vitro method.     

Monoclonal antibodies in the treatment of human B-cell malignancies

Monoclonal antibody technology emerged in the 1970's and was greeted by a wave of optimism. Many believed this new form of therapy would be effective in the treatment of human cancers. Early clinical trials in B-cell lymphomas demonstrated both the potential and limitations of unlabeled murine monoclonal antibody therapy, and taught us valuable lessons regarding the importance of the antibody structure, and nature of the targeted antigen. Since that time modifications in antibody structure and careful selection of target antigen have improved the clinical efficacy of these agents. Clinical trials using humanized antibodies have demonstrated that human/mouse chimeric antibodies and humanized antibodies have enhanced anti-tumor activity, decreased immunogenicity, and a very favorable toxicity profile. Radiolabeled monoclonal antibodies can induce durable remissions in lymphoma with toxicity limited largely to bone marrow suppression. Clinical trials with immunotoxins have demonstrated anti-tumor activity but also have been associated with significant toxicity. Standard treatment options for B-cell lymphoma will soon include antibody-based therapies. Further basic and clinical research is needed so we can understand more thoroughly the mechanisms responsible for the observed anti-tumor effects, and explore more extensively the best approach to their clinical use.