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Biomedical subjects

P Emmerling

Publications and source records attributed to P Emmerling.

At least 37 records · Page 2Linked to original sources

[Influence of killed Bordetella pertussis cells on the resistance against infection with Listeria monocytogenes (author's transl)].

The influence of killed Bordetella pertussis cells (B.p.) on the cell-mediated resistance of mice against infection with virulent germs of Listeria monocytogenes has been studied. Resistance of mice was decreased, when 3 X 10(9) B.p. were injected 1 day before, simultaneously with or 1 day after infection, resulting in augmented amounts of viable Listeriae recovered from the spleens 3 days after infection (figure 1). The LD50 was strongly reduced (Table 1). Transfer of immune spleen cells to recipient mice, which had been treated 1 day previously with 3 X 10(9)B.p., did not support resistance definitely (Table 2). Therefore, it can be concluded that probably the macrophage system was impaired just after B.p. injection. When, however, B.p. were given several days before infection, resistance was increased. A maximum of resistance enhancement was seen 7-14 days after B.p. treatment. Thereafter, this beneficial effect gradually decreased but persisted for at least 67 days (figure 1). This resistance enhancing effect of B.p. was surely not due to adjuvant effect of B.p. on the T-lymphocyte-mediated immune reaction to Listeriae, since in B.p.-pretreated mice the development of immunity during the primary infection to a secondary listeric infection has even been lacking (Table 3). It is more likely that the macrophage system was stimulated at this time by B.p. In mice treated 7 days prior to infection the elimination of Listeriae from the spleens was supported from the very beginning of the infection (figure 2).

Adjuvants, Immunologic↗

[Resistance to infection with Listeria monocytogenes in normal and thymusless mice treated with ampicillin (author's transl)].

NMRI mice were infected intravenously with a sublethal dose of Listeria monocytogenes and divided into four groups. One group served as the control and the other three were treated with ampicillin beginning 4, 8 or 24 hours after infection. The animals were injected in the morning and in the evening each time with 4 mg ampicillin subcutaneously until a total dose of 48 mg was reached. As demonstrated by counting of the bacteria in the spleen, Listeria could multiply in the ampicillin treated mice in comparison to the control group at best delayed but the infection continued to persist for some days at a level of 10(3)-10(4) Listeriae per spleen independent from the starting point of the treatment. Eight days after the first infection all animals received a challenge dose of 10(4) Listeriae. Compared with the control animals the ampicillin treated mice had a clearly reduced immunity, even in the group in which ampicillin application had been started 24 hours after the primary infection. If the challenge infection was given at first after an intervall of six weeks between primary and secondary infection, only a reduced immunity was found. Furthermore, whereas spleen cells of mice 7 days after infection were able to transfer immunity to untreated recipients, spleen cells of ampicillin treated mice were unable to do so. Finally, an attempt was made to cure chronic listeric infection in thymusless nude mice by the application of high doses of ampicillin. The observation of a continuous infection in these animals showed that the T-cells played a primary importance in the elimination of the bacteria.

Ampicillin↗

Suppression of the secondary immune response by specific antibody, when given together with the secondary antigenic stimulus.

It is generally believed that antibody-mediated immunosuppression can be only produced in non-primed individuals, and that this applies both to experimental animals and Rh-negative women at risk. However, in this paper it is reported that the additional injection of 0.2 ml of an antiserum to sheep erythrocytes (SE) together with a secondary antigenic stimulus of 10(8) SE into mice, primarily immunized by a tiny dose of 5 x 10(5) SE 28 days before, was capable of producing effective suppression of the secondary immune response.

Animals↗

Cell-mediated resistance to infection with Listeria monocytogenes in nude mice.

Congenitally dysthymic nude (nu/nu) NMRI mice showed increased resistance to viable Listeria monocytogenes cells during the initial phase of infection as compared with euthymic control mice. The intravenous mean lethal dose (LD50), as determined for euthymic mice after an observation time of 7 and 14 days, amounted consistently to 6 X 10(4) Listeria. The corresponding values determined in nude mice were found to be increased by either 20-fold (1.2 X 10(6) Listeria after an observation time of 7 days) or 4-fold (2.4 X 10(5) Listeria after an observation time of 14 days). The transfer of spleen cells from immune euthymic donor mice into chronically infected nude mice caused almost complete elimination of Listeria within 1 week. The injection of dextran sulfate 24 h before a secondary infection with L. monocytogenes caused loss of antibacterial resistance in both chronically infected nude mice and Listeria-immune euthymic mice, this being expressed by a rapid increase in the numbers of bacteria in the spleens as well as the occurrence of serious signs of illness.

Animals↗

Antibody-forming potential of lymph nodes in aged mice, with special reference to the influence of adjuvant.

The secondary antibody-forming potential of non-splenic lymphatic tissues during senescence was investigated in NMRI/Han mice, both at the cellular and humoral levels. The mean life span of conventionally reared NMRI/Han mice amounts to 19.86 months. After primary immunization of aged (20-month-old) NMRI mice with 4 X 10(8) sheep erythrocytes (SE) by the intraperitoneal (i.p.) route, the primary antibody-forming potential of both spleen and lymph nodes was significantly reduced, as compared to young adult (3-month-old) controls. In contrast, the anamnestic response elicited by an i.p. booster injection of 4 X 10(8) SE at the 44th day after primary immunization was not significantly diminished in comparison to the controls. When killed cells of Bordetella pertussis were found to be significantly increased in young adult as well as in aged mice. These data obtained at the cellular level were in accordance with corresponding serological findings. The impressive restitution of the antibody-forming potential evident after secondary antigenic stimulation was associated with a remarkable restitution of the lymph node morphology. This was particularly pronounced in the pronounced in the parathymic lymph nodes which represent the draining nodes for the peritoneal cavity. These findings indicate that the lymph nodes of the senescent individual also possess remarkable reserves in immunocompetence.

Adjuvants, Immunologic↗

[Influence of latent vitamin A deficiency of the mouse on the production of humoral antibodies against sheep erythrocytes and on the resistance against infection with Listeria monocytogenes (author's transl)].

Mice fed with a vitamin A free diet for several months did not develop signs of vitamin A deficiency. However, chemical analysis revealed a reduced content of vitamin A in the liver of such mice. The ability of these animals were latent vitamin A deficiency to produce antibodies against parenterally applicated sheep erythrocytes was not hampered. Similar numbers of antibody producing cells could be detected in the spleen of these mice compared with control animals. Resistance against intravenous infection with L. monocytogenes of these mice with latent vitamin A deficiency was not altered. The numbers of viable germs recovered from spleen and liver 2 days after infection were similar in both vitamin A deprived and normal mice.

Animals↗

Morphology and time course of experimental listeriosis in nude mice.

Experimental listeriosis in phenotypically normal (nu/+) euthymic NMRI mice has a characteristic morphology and short-term course. In contrast, listeric infection in congenitally dysthymic nude (nu/nu) mice does not proceed in clear-cut phases, develops more slowly, displays a chronic tendency from the beginning, and shows a considerably different morphology. The inability of nude mice to effectively control and terminate infection by Listeria monocytogenes obviously results from the lack of T lymphocytes.

Animals↗

[Studies on the mechanism and duration of antibody-mediated immunosuppression (author's transl)].

The simultaneous injection of either 10(8) or 5 X 10(5) sheep erythrocytes (SE) and an allogeneic anti-SE serum into mice produced not only a suppression of the primary immune response, but, moreover, the secondary immune reaction elicited, either 4, 8, 12, 16 or 30 weeks after the primary antigenic stimulation, was found to be impaired. This was mainly demonstrated by the significantly reduced numbers of 7 S antibody-synthesizing spleen cells. The suppression of the secondary immune responses is hardly compatible with the conception that the antibody-mediated immunosuppression is solely due to an inactivation of the antigenic determinants by the passively administered specific antibody in the periphery of the immune system. This objection against the so-called "peripheric theory" is supported by a further finding. When mice primarily immunized by a simultaneous injection of 10(8) SE and anti-SE-serum were treated with 2 X 10(7) SE 24 hours before boostering with 10(8) SE, in order to eliminate a possibly existing residual activity of the passively administered specific antibodies given together with the primary antigenic stimulus, the secondary 7 S response was likewise found to be significantly suppressed. On the basis of these findings it is suggested that besides the "peripheric mechanism" a "central" effect plays a significant role in the phenomenon of antibody-mediated immunosuppression, this being due to the reversible or irreversible inactivation of immunocompetent precursor cells by the attachment of antigen-antibody-complexes which results in an inhibition of their differentiation into antibody-producing cells.

Animals↗

Listeria monocytogenes infection in nude mice.

As compared to phenotypically normal (nu/+)NMRI mice showing the typical course of an experimental listeric infection, that of congenitally hypothymic (nude, nu/nu)NMRI mice was found to be characterized from the outset bya chronic trend. During the early phase of the infection, significantly reduced numbers of Listeria monocytogenes were observed in the spleens of nude mice.

Animals↗

[Immunosuppression mediated by antibodies (author's transl)].

Until quite recently, it was generally believed that antibody-mediated immunosuppression is purely effected by virtue of covering up antigenic determinants in the periphery of the immune system, thus preventing any contact of the antigen with immunologically competent cells within the central parts of the immune system. But this conception was not able to give a plausible explanation of experimental data obtained during the last years. It was therefore repeatedly postulated that the passively administered 7S antibody may have a "central" effect, whereby both B- and T-cells were considered as target cells. The experimental data available are discussed in connection with the possible consequences for the administration of antibodies in man.

Adjuvants, Immunologic↗