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P J Neveu

Publications and source records attributed to P J Neveu.

13 recordsLinked to original sources
PubMed1979

Attempts to modulate the immune response to a hapten-carrier complex with various hapten-containing compounds.

The immune response to a hapten-carrier conjugate appears to be a complex phenomenon where reactions of the T-cell population are not restricted to the carrier and where the reactions of the B-cell population are not limited to the hapten determinant of the antigen molecule. To get a better understanding of the different cell interactions during the immune response to a hapten-carrier complex, the effects of immunogenic or tolerogenic injections of various hapten-containing compounds on the responses induced by immunization with the same hapten coupled to protein carriers were studied. The results indicate that T cells involved in delayed hypersensitivity and T cells involved in contact dermatitis could belong to distinct subclasses and confirm that hapten and carrier moieties of the antigen molecule could compete, probably at the macrophage level, for both delayed hypersensitivity to the carrier and antibody synthesis to the hapten.

Animals↗
PubMed1978

Modulation of antibody synthesis by an anti-tumour alga.

An unicellular alga, Chlorella pyrenoidosa, which had been reported to protect C3H mice against sarcoma BP8, is shown, when injected in Freund's incomplete adjuvant, to modulate the antibody synthesis induced by immunization with a hapten-carrier complex. C. pyrenoidosa appeared to be able to initiate an antigenic competition between hapten and carrier determinants of the antigen molecule during antibody synthesis, and thus it could be speculated that C. pyrenoidosa modulates the immune response at the macrophage level.

Anaphylaxis↗
PubMed1978

Suppression of delayed hypersensitivity to the hapten by induction of tolerance to the carrier.

Delayed hypersensitivity reactions (DHR) and anaphylactic reactions to carrier and hapten determinants were studied in guinea pigs immunized with DNP-mycobacterium and rendered partially tolerant to the carrier by a single intravenous injection of mycobacterium prior to immunization. The results clearly show that the induction of depressed DHR to mycobacterium leads to a suppression of DHR to the hapten while no depression of anaphylaxis to the hapten is observed. It is proposed that the tolerogenic treatment acts at the macrophage level rather than at the T cell level.

Animals↗
PubMed1978

The effects of thiol moiety of levamisole on both cellular and humoral immunity during the early response to a hapten-carrier complex.

Cell-mediated reactions to the carrier and antibody-mediated reactions to the hapten were studied in guinea-pigs treated with a single i.v. injection of the thiol moiety of levamisole (DTC), before or after immunization with a hapten-carrier complex. The results show that a heavy dose of DTC induced delayed hypersensitivity reactions to the carrier and decreased antibody synthesis to the hapten. On the other hand, with a small dose of DTC no delayed hypersensitivity could be induced, but antibody synthesis to the hapten was depressed or enhanced, depending upon whether the injection was done before or after immunization. The mechanisms whereby DTC modulated the immune response are discussed.

Animals↗
PubMed1978

Modulation of the immune response by passive antibodies. IV. Effects of IgG1 and IgG2 anti-hapten antibodies.

The effects of IgG1 and IgG2 anti-hapten antibodies waere studied on celluar and humoral reactions induced by immunization with a hapten-carrier complex. IgG2 was shown to depress delayed hypersensitivity reactions to the carrier and to enhance anaphylactic reactions to both the hapten and the carrier whereas IgG1 appeared to have no activity except a little enhancing effect on antibody synthesis to the carrier. The regulatory role of IgG2 antibodies, which were cytophilic for macrophages, in the immune response to a hapten-carrier conjugate is discussed.

Anaphylaxis↗
PubMed1977

Are cellular and humoral components of the immune response linked by a dispatcher cell?

Variations in opposite directions of cellular and humoral reactions observed during desensitization and immune deviation could reflect a balance controlled by a cell which dispatches information towards cells involved in delayed hypersensitivity and those involved in antibody synthesis. This dispatcher cell could be one of the targets of antigen-antibody complexes which modulate both cellular and humoral components of the immune response.

Animals↗
PubMed1977

Stimulation and inhibition of macrophages prior to immunization with a hapten-carrier conjugate.

Delayed hypersensitivity reactions and antibody-mediated reactions to the carrier and to the hapten have been studied in animals treated with BCG or/and trypan blue before immunization with a hapten-carrier complex. The results show that it is possible to induce, with BCG, at the beginning of the response, an antigenic competition between hapten and carrier moieties of the antigen molecule. Macrophages which modulate the response to the hapten-carrier complex by acting both on T cells involved in cellular immunity and those involved in antibody synthesis, appear to be the target of antigenic competition.

Animals↗
PubMed1976

The effects of BCG on both cellular and humoral immunity during the early response to a hapten carrier complex.

Cell-mediated reactions to the carrier and antibody-mediated reactions to hapten and carrier were studied in guinea-pigs treated with a single i.v. injection of BCG at different intervals of time before immunization with two different doses of a hapten-carrier complex. The results clearly show that BCG-induced delayed hypersensitivity reactions to the carrier and decreased antibody synthesis to the hapten. It is proposed that BCG acts on a dispatcher cell which controls both cellular and humoral immunity.

Anaphylaxis↗
PubMed1975

Modulation of the immune response by passive antibodies. I. Anti-hapten antibodies enhanced delayed hypersensitivity to the carrier and depressed antibody synthesis to the hapten.

The modulating effects of passive antibodies on both delayed hypersensitivity to the carrier and antibody synthesis to carrier and hapten determinants were studied in guinea pigs. Animals were injected with antibodies directed against either the carrier or the hapten prior to immunization with the hapten-carrier conjugate in Freund's complete adjuvant. Anti-hapten antibodies have been shown to have an enhancing effect on delayed hypersensitivity to the carrier and a suppressive effect on antibody synthesis to the hapten. In this experiment, anti-carrier anti-bodies seemed to have had no effect on delayed hypersensitivity to the carrier and on antibody synthesis to the hapten.

Animals↗
PubMed1975

Carrier and hapten functions in immune deviation. I. Contrary effects of hapten and carrier on cellular and helper functions of T cells.

Carrier and hapten functions have been studied in the immune deviation phenomenon. Delayed hypersensitivity to the carrier and anaphylaxis and Arthus hypersensitivities to the hapten and to the carrier were studied in guinea-pigs injected intravenously with large doses of carrier, homologous and heterologous hapten-carrier conjugates and subsequently immunized with the hapten-carrier conjugate in Freund's complete adjuvant. Pretreatment with DNP-BSA or with HGG were found to modify, in opposite directions, the hypersensitivity reactions induced by DNP-HGG in adjuvant. It is suggested that the hapten and carrier moieties of the antigen molecule might have antagonistic effects on the T cells responsible for cellular immunity as well as on T cells involved in helper functions for B cells.

Anaphylaxis↗
PubMed1975

Carrier and hapten functions in immune deviation. II. Role of hapten and carrier on the helper functions of the T cells.

The kinetics of haemagglutinating and haemolytic antibody synthesis to the hapten and to the carrier determinants were studied in guinea-pigs injected intravenously with large doses of the carrier, or of the hapten conjugated to an homogous or heterologous protein carrier and subsquently immunized with the hapten-carrier conjugate in Freund's complete adjuvant. The animals treated with the heterologous conjugates exhibited enhanced reactions to the hapten and supressed reactions to the carrier, whereas the animals injected with the homologous conjugate showed depressed reactions to the hapten but unaffected reactions to the carrier. Pretreatment with the carrier alone-seemed to have no effect. These experiments confirm that the hapten determinant must act at the T-cell level but do not exclude the possibility that it could also act at the B-cell level. On the other hand, they allow the dissociation of the different components of the immune response directed against the hapten and carrier determinants of the antigen molecule in immune deviation.

Animals↗
PubMed1975

Hapten and carrier specificities of cellular and humoral responses to highly substituted dinitrophenyl-human gamma-globulins in guinea-pigs.

Delayed hypersensitivity (DH) and antibody reactions to the carrier and to the hapten have been studied in guinea-pigs immunized with different doses of highly substituted dinitrophenyl-human gamma-globulins (DNP56-HGG) in Freund's complete adjuvant (FCA). The results confirm that DH reactions are specific for the carrier while antibody-mediated reactions are specific for the hapten in the early stages of the immune response. Later in the response, however, DH reactions to the hapten as well as a transient humoral reaction to the carrier could be observed. T cells specific for the hapten and B cells specific for the carrier are therefore triggered after a single infection of a highly substituted hapten-carrier conjugate in FCA. Their regulatory functions in the immune response to hapten-carrier conjugates are discussed.

Anaphylaxis↗