Suppression and enhancement of humoral immune response toToxoplasma gondii by passive antibody

Summary Anti-toxoplasma antibodies administered passively to mice may lead to suppression or enhancement (reported for the first time with Protozoan parasites) of subsequent antibody response when these animals are later infected withToxoplasma gondii. The outcome is dependent on infecting strain of Toxoplasma and the antigen-antibody ratio.     

Suppression of humoral immune response in mice by administration of high molecular levan

Summary High molecular levan, a polyfructoside, has a dose-dependent inhibitory effect on the primary immune response to sheep red cells (SE) in Balb/c mice, when given as from 1–2 days prior to the antigen injection. A slight stimulation of the immune response was observed when levan was given shortly before or 1 day after the antigen.     

The humoral immune response to heat shock proteins

Humoral immune reactions to heat shock proteins (hsp) from microorganisms are one aspect of microbial infections in humans. The production of antibodies which are specific to epitopes present on procaryotic hsp leads also to the appearance of cross-reactive serum antibodies in the host organism that react with human hsp. This article discusses the consequences of such autoreactive antibodies for the host in context with the development of immune tolerance and autoimmune diseases, especially rheumatoid arthritis (RA), and in experimental animal models for arthritis such as adjuvant arthritis in rats. On the basis of epitope cross-reactivity between hsp and other host proteins, a hypothesis is presented for the development of autoimmune disease following the production of hsp-specific antibodies.     

The humoral immune response to heat shock proteins.

Humoral immune reactions to heat shock proteins (hsp) from microorganisms are one aspect of microbial infections in humans. The production of antibodies which are specific to epitopes present on procaryotic hsp leads also to the appearance of cross-reactive serum antibodies in the host organism that react with human hsp. This article discusses the consequences of such autoreactive antibodies for the host in context with the development of immune tolerance and autoimmune diseases, especially rheumatoid arthritis (RA), and in experimental animal models for arthritis such as adjuvant arthritis in rats. On the basis of epitope cross-reactivity between hsp and other host proteins, a hypothesis is presented for the development of autoimmune disease following the production of hsp-specific antibodies.     

Suppression of the primary immune response by antilymphocyte serum

Zusammenfassung Die immunosuppressive Wirkung des Antilymphozytenserums wird beschrieben.     

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

Summary 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 10⁸ SE into mice, primarily immunized by a tiny dose of 5×10⁵ SE 28 days before, was capable of producing effective suppression of the secondary immune response.This work was supported by grants from the Deutsche Forschungsgemeinschaft.     

Stimulation of humoral immune response by pentosan sulfate (SP 54)

Zusammenfassung Pentosan Sulfat (SP 54) erhöht sowohl die primäre als auch die sekundäre Immunantwort bei Mäusen, wenn diese mit einer suboptimalen Antigendosis geimpft werden.     

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.     

Host cell manipulation by the human pathogen Toxoplasma gondii

Toxoplasma gondii is an obligate intracellular parasite that can infect virtually any nucleated cell. During invasion Toxoplasma creates the parasitophorous vacuole, a subcellular compartment that acts as an interface between the parasite and host, and serves as a platform for modulation of host cell functions that support parasite replication and infection. Spatial reorganization of host organelles and cytoskeleton around the parasitophorous vacuole are observed following entry, and recent evidence suggests this interior redecorating promotes parasite nutrient acquisition. New findings also reveal that Toxoplasma manipulates host signaling pathways by deploying parasite kinases and a phosphatase, including at least two that infiltrate the host nucleus. Toxoplasma infection additionally controls several cellular pathways to establish an anti-apoptotic environment, and subverts immune cells as a conduit for dissemination. In this review we discuss these recent developments in understanding how Toxoplasma achieves widespread success as a human and animal parasite by manipulating its host.     

Enhancement of humoral immune response against human lung elastin peptides

Summary When guinea pigs instead of rabbits were used as the host animals, 8–16 times higher antibody titers against human lung elastin peptides were produced with only 1/20 the amount of antigen per unit body weight. This corresponds to a 200-fold enhancement of the immune response.Presented at the 6th Colloquium of the Federation of European Connective Tissue Clubs, Paris, August 28–30, 1978. The data form part of the Ph.D. thesis submitted by T.V. Darnule to the Department of Biology, New York University. Supported in part by NIH Program Project Grant HL15832 and by a Parker B. Francis Fellowship to T.V. Darnule.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Suppression of the immune response by drugs interfering with the metabolism of serotonin

Summary The work was based on the assumption that neurohumoral control of the immune response, particularly in stressed animals, involves central serotoninergic mechanisms. Rats immunized with sheep erythrocytes were stressed by repeated restraints and/or treated with a precursor of serotonin (5-hydroxytryptophan, 5-HTP) or with an inhibitor of serotonin synthesis (parachlorophenylalanine, PCPA). As expected, repeated stresses reduced the plaque-forming cell (PFC) response. Treatment with 5-HTP also reduced the PFC response, and potentiated the immunosuppressive effect of stress. This was accompanied by increased metabolism of serotonin in the brain, as indicated by increased concentration of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in cerebral tissue. Treatment with PCPA also suppressed the PFC response, but this suppression was accompanied by decreased levels of brain serotonin and of 5-HIAA. Plasma corticosterone levels were elevated in rats treated with PCPA. It seems that putative central effects of PCPA on serotoninergic regulation of the immune response were outweighed by its effects on corticosterone secretion and/or on lymphoid cells.     

Effect of actinomycin D on white blood count and humoral antibody response in hamsters

Zusammenfassung Actinomycin D fÜhrt bei erwachsenen männlichen Hamstern in einer Dosis, die fÜr 15% der Tiere letal ist, zu einem vorÜbergehenden Abfall der Lymphozyten und zu einem kontinuierlichen Anstieg der neutrophilen Granulozyten. Die Bildung agglutinierender Antikörper gegen Schaferythrozyten wird dagegen, unabhängig von der Antigendosis und vom Zeitpunkt der Antigenapplikation, durch Actinomycin D nicht beeinflusst.     

Effect of splenectomy on the humoral immune response in the lizard,Scincus scincus

Summary Adult splenectomy in the lizard,Scincus scincus, did not affect humoral immune response to rat erythrocytes until 30 days post-immunization, but severely depressed subsequent antibody production.This work was supported by United States Public Health Research, grant No. 03-015-N.     

Depression of humoral and cell-mediated immune responses by coxsackieviruses in mice.

Adult mice infected with coxsackieviruses A-15, B-1, B-2, B-4 and B-6 showed depressed antibody responses to unrelated antigens; mice infected with coxsackievirus B-3 developed reduced humoral and cell-mediated immune responses. These findings might have clinical and epidemiological implications.     

Induction of antibody response in lymphoid cells in vivo and in vitro by RNA-immuno-carrier from immune serum

Riassunto Nel siero di animali immunizzati è presente un RNA depositario del modello anticorpale che è capace di indurre la formazione di anticorpi in cellule linfoidi normali in vivo ed in vitro, sia di origine timica che splenica.     

Effect of splenectomy on the humoral immune response in the lizard, Scincus scincus.

Adult splenectomy in the lizard, Scincus scincus, did not affect humoral immune response to rat erythrocytes until 30 days post-immunization, but severely depressed subsequent antibody production.