Search PubMed⌕ Search

Biomedical subjects

J C Monier

Publications and source records attributed to J C Monier.

At least 109 records · Page 6Linked to original sources
PubMed1976

[Intermolecular antigenic competition. Influence of the site of antigen injection (author's transl)].

We have studied the intermolecular antigenic competition in mice, after simultaneous injections of two antigens by different ways and in various places. When the two antigens are administered by I.P. route, and when TNP-SHRBC (Test-Ag) and BSA (inhibitory Ag) are used, only an inhibition of the anti-hapten (TNP) response is observed but not of the anti-carrier response (SRBC). When these antigens are replaced by SRBC (Test Ag) and HRBC (inhibitory Ag), there is no antigenic competition. When the inhibitory Ag is the BSA and the test Ag a strong dose of LPS (10 mug) there is no competition but it occurs when a weak dose of LPS is used. When the two antigens are injected by subcutaneous route in the same leg and the PFC enumerated in the corresponding inguinal lymph-node there is no inhibition but an increased response against the test Ag. On the contrary, competition is obtained when the test Ag (TNP-SHRBC or SRBC) is injected in the right leg and the inhibitory-Ag (BSA or HRBC) in the left one. These facts lead to conclude that an inhibitory humoral factor is responsible for this phenomenon, and that this factor is probably thymodependent because this competition disappears when Nude mice are used.

Animals↗
PubMed1976

[Survival and humoral response of mice infected with Treponema pallidum (author's transl)].

To judge the pathogenicity of Treponema palllidum in mice, we inoculated two groups of animals. 1) One with a normal immune system : adult Swiss mice. 2) The other with an immune system presenting a defect in T cells : athymic Nude mice. No lesions appeared at the points of inoculation and the survival of these animals was not modified compared with control animals. We have also carried out a study of antitreponema antibodies in adult and new-born Swiss mice, using, for the adults, various concentrations of treponema pallidum and various routes of inoculation. In adult mice, the search for antibodies by fluorescence, showed, firstly, that the intradermal route permits a more rapid humoral response than the intraperitoneal route, with higher antibody titers. Furthermore, an inoculum of 8,6 X 10(6) per mice, gives earlier results and higher titers than those obtained with an inoculum twice lower. The earliness of the positive Nelson test is independent of the route of inoculation but related to the injected dose. On the other hand, the Kline reaction remained negative for all groups of mice throughout the whole period of our study. In new-born mice, 76% only became positive on fluorescence and Nelson test.

Animals↗
PubMed1976

Laboratoire d'Hygi'ene de la Facult'e de M'edecine de Lyon Universit'e Claude-Bernard, Domaine Rockefeller, 8, avenue Rockefeller, 69373 Lyon Cedex 2 France.

The objective of this study was to investigate the false-positive reactions in the Kline, FTA200 and FTA-ABS tests in acute disseminated lupus erythematosus, polyarthritis and controls. Though the false-positive Kline tests are frequent in autoimmune diseases, false-positive FTA200 when made on non lyophilised treponema are uncommon. On the other hand, when lyophilised treponema are used as substrate for the immunofluorescence, false-positive FTA200 and FTA-ABS are more common in the patients with autoimmune diseases than in controls. The false-positives had two patterns of fluorescence "beaded" or "homogeneous". The present investigation suggests that the false-positive reactions of the beaded type are due to the presence of anti-DNA antibodies in the sera.

Antibodies, Antinuclear↗
PubMed1975

[The inhibitory mechanism responsible for antigenic competition in the mouse, upon successive injections of 2 different antigens: the immunosuppressive function of T cells].

Antigenic competition cannot be obtained in congenital athymic Nude mice, whatever the dose of inhibitor Ag used and the free interval between inhibitory Ag injections and the Ag test. On the other hand, competition is normal and even increased, in thymectomised, adult Swiss mice, used 10 to 30 days after thymectomy. In normal mice, the inhibitory mechanism induced by a first thymodependent antigen, may also occur with regard to certain thymo-independent antigens and thus act on the B cells. The antigens may also serve as inhibitory antigens for thymodependent antigens if the free interval between the two injections is small. Injection of hydrocortisone (25 mg/kg) or ALS a short time before the inhibitory antigens, suppresses competition. On the other hand, methotrexate is without effect. Thus the inhibitory TD mechanism does not require mitoses (methotrexate) and depends on corticosensitive T cells which are, no doubt, recirculated (Anti-lymphocyte serum) with a life span greater than 30 days (adult thymectomy). The previous results were obtained when two antigens were administered by intraperitoneal route and the PF cells sought in the spleen. The same experiment was carried out, injecting two antigens subcutaneously, in the same limb, and counting the PF cells in the appropriate lymph node; it shows the adjuvant effect exerted by the first antigen on the response with regard to the second antigen. On the other hand, inhibition is produced if the first antigen is injected intraperitoneally or into another limb. One may thus distinguish an inhibitory effect or an adjuvant effect depending on the experimental conditions. The inhibitory effect seems to be related to the T cells with an immunosuppressive function.

Animals↗
PubMed1975

Antigenic competition between two sequentially acting antigens. Immunosuppressive effect of T cells in spleen and lymph nodes of mouse.

This study concerns the antigenic competition among heterologous red cells, a T suppressor-dependent phenomenon, in three cases, when the two antigens are administered by various routes, in (a) splenectomized mice or in Nude mice reconstituted with (b) lymph node cells, or spleen cells. Competition occurs whatever the routes of antigenic introduction, except when the two antigens are injected subcutaneously in the same leg and the anti-SRC plaque-forming cells are counted in the draining lymph nodes. In that case, the first antigen plays the role of adjuvant to the second. An adjuvant effect is also observed in splenectomized mice when the antigens are introduced intraperitoneally. However, competition does not occur in Nude mice but is present when those animals have been reconstituted either with lymphnode cells or with spleen cells. Those results play in favor of the presence of T suppressors, both in lymph nodes and in spleen; however, in lymph nodes, the immunosuppressive action induced by the first antigen is exceeded by an concomitant adjuvant effect.

Animals↗
PubMed1975

Spontaneous antinuclear autoimmunisation in Swan and nude mice: comparative study.

Spontaneous antinuclear autoimmunisation in both Swan and Nude mice seems due to a disparition of the T cell immunosuppressive function. Swan mice show a progressive diminution of thymic function, and thus T cell activity, with age; wherease Nude mice are congenitally lacking in a thymus and thus in T cells. Both strains of mice develop deposits of immunoglobulin in the glomerular membrane and the Swan mice have such deposits at the dermoepidermal junction. The antinuclear autoimmunity of the two strains of mice differs in that the number of Swan mice with detectable titres increases with age until, at 40 weeks, all the mice are positive, whereas the number of Nude mice positive at a young age rarely increase until the time of death. The antibodies produced by the Swan mice may be of any of the major immunoglobulin classes, whereas those produced by Nude mice are nearly always IgM.

Age Factors↗