Attempts to modify lung granulomatous responses to Schistosoma japonicum eggs in low and high responder mouse strains

Characterization of monoclonal antibodies reactive with Schistosoma haematobium-soluble egg and infected human urinary antigens

Six murine monoclonal antibodies (MAbs) [Sh1/71.7 (IgM), Sh2/15.F (IgG1), Sh3/15.28 (IgG1), Sh3/38.2 (IgM), Sh4/14.3 (IgG1), and Sh5/32.30 (IgM)] produced against S. haematobium were extensively characterized. All the MAbs stained the surface membranes of miracidia as determined by the indirect fluorescent antibody test, yet three of them (Sh1/71.7, Sh3/15.28, and Sh3/38.2) also stained internal cytoplasmic antigens. Proteinase-K digestion and periodate oxidation studies showed that these three MAbs bound glycoprotein antigenic determinants, while the rest detected protein epitopes. Only Sh2/15.F, Sh3/15.28, and Sh4/14.3 could bind antigens with the western immunoblot assay. Sh2/15.F bound a 29-kDa antigen and Sh3/15.28 bound three antigen bands (53, 57, and 66 kDa) all in the soluble egg extract of an Egyptian strain of S. haematobium (SEAEgy), while Sh4/14.3 reacted with a 29-kDa antigen present in SEAEgy, as well as in the adult worm antigen extracts of Ghanaian strain(s) of S. haematobium and S. japonicum. Sh4/14.3 also bound a 78-kDa antigen in the S. japonicum worm. Cross-reactivity studies with S. haematobium, S. mansoni, S. japonicum, and Necator americanus revealed that Sh2/15.F and Sh3/15.28 were S. haematobium species-specific. Each of the remaining MAbs detected the three major human schistosomes without cross-reacting with N. americanus egg antigens. Three MAbs, Sh2/15.F, Sh4/14.3 and Sh5/32.30, could detect S. haematobium antigens in infected human urine.

Monoclonal antibodies reacting with Schistosoma japonicum eggs and their target epitopes

Ten monoclonal antibodies (McAbs) raised to Schistosoma japonicum eggs could be assigned using several serological and immunochemical techniques to 3 groups. The McAbs, termed A, B and C-McAbs, apparently recognize carbohydrate epitopes that can be located on the same antigen molecule. The antibodies, generally of IgM isotype, are idiotypically related. They are distinct from another IgM McAb (Group D-McAb) the carbohydrate target epitope of which can also be associated with the epitopes of A, B and C-McAbs. The McAbs produce large vacuolated bleb reactions in the circumoval precipitin test (COPT) and target epitopes have different representations in various life cycle stages such as immature and mature eggs, male and female worms (including S. mansoni). Antigens affinity purified on columns containing A, B, C and D-McAbs stimulate proliferation of T cells from egg-sensitized mice and elicit DTH reactions in such mice. This raises the possibility that the target antigens of these carbohydrate-reactive monoclonal antibodies are immunopathologic and involved in egg-induced granuloma formation.

Monoclonal antibodies against microorganisms

The recent spread of hybridoma technology among laboratories has promoted the development of monoclonal antibodies against a wide variety of infectious disease agents. While monoclonal antibodies theoretically represent an excellent (perhaps superior) alternative to conventional antisera as diagnostic, therapeutic or laboratory reagents, traditional antisera may be preferable to monoclonal antibody in some circumstances because of the fixed affinity and specificity as well as the limited functional capacities of some antibodies. The acceptance of monoclonal antibodies by the clinical microbiologist and physician must await proof of their reliability, safety and efficacy.

Onchocerca gibsoni: Increase of circulating egg antigen with chemotherapy in bovines

Monoclonal antibodies directed to stage-specific surface antigens of Onchocerca gibsoni eggs were used in immunoradiometric assays to detect antigens in the sera of cattle infected with O. gibsoni. Two monoclonal antibodies detected antigens, presumably of egg origin, in sera. The target antigens appeared to be carbohydrate in nature and of variable molecular weights. Significant increases in levels of circulating egg antigens were found after treatment of infected cattle with benzimidazole compounds. These drugs cause disruption of embryogenesis and accelerated loss of worm uterine contents. In contrast, administration of either macrofilaricides or microfilaricides to infected cattle did not alter pretreatment levels of circulating egg antigens. Measurement of changes in levels of circulating antigens by immunoradiometric assays with stage-specific monoclonal antibodies provides a new means of assessing the efficacy of drugs and their site of action in onchocerciasis.

Effect of pertussigen on inflammation caused by Freund adjuvant

Pertussigen, one of the toxins from Bordetella pertussis, greatly increased the inflammatory response produced by complete Freund adjuvant in the footpads of mice. This effect was not produced by pertussigen when the emulsion was made with saline and incomplete Freund adjuvant, but if an antigen was included in incomplete Freund adjuvant, the strong potentiating effect was again demonstrated. As little as 100 ng of pertussigen given intravenously was effective, but 400 ng proved better, and this latter dose was used routinely. The most striking action occurred when pertussigen was injected on the same day or 3 days after complete Freund adjuvant, but an effect was demonstrated when given from 3 days before to 6 days after complete Freund adjuvant. The action of pertussigen was not apparent until about 6 to 8 days after complete Freund adjuvant. The footpad swelling reached its maximum by day 14 and remained undiminished until day 29. Forty days later, a significant effect was still present. Histologically, the cellular infiltrate in the feet of mice injected with complete Freund adjuvant was more intense in animal treated with pertussigen. Nude BALB/c mice receiving an emulsion of complete Freund adjuvant in the footpads did not respond with an increased inflammation after receiving pertussigen, suggesting the possible involvement of T cells in this phenomenon. The intense and prolonged inflammatory response produced in pertussigen-treated mice by Freund adjuvant containing antigenic substances may serve as a useful model to study chronic inflammation.