The immune response to hapten-azo bovine serum albumin as detected by hemolytic plaque technique

Induction of antibodies against Newcastle disease virus with syngeneic anti-idiotype antibodies in mice

Anti-idiotype antibodies were induced by injecting BALB/c mice with syngeneic antibody against the hemagglutinin of Newcastle disease virus (NDV). These anti-idiotype antibodies were purified and injected into syngeneic mice. Anti-anti-idiotype sera thus prepared contained antibodies against the hemagglutinin of NDV. This NDV-mouse experimental system might provide a good experimental model for investigation of basic problems of idiotype vaccine.

Induction of abundant antibody formation with a protein-cellulose complex in mice

A method is described for immunizing mice with a protein-cellulose complex obtained by covalent coupling of antigenic protein molecules to suspended cellulose particles. Primary immunization of the animals with the complex led to a pronounced immune response persisting for 20-30 days. Subsequent administration of the same antigen in a soluble form resulted in extremely active antibody formation equal to or better than that induced with Freund's complete adjuvant. In BALB/c mice the antibody response was about ten times greater than in the C57BL/6 strain.

Correlation between the capacity of bacterial lipopolysaccharide to supress experimental allergic encephalomyelitis and its mitogenic activity for lymph node cells in guinea pigs

Protection of guinea pigs from experimental allergic encephalomyelitis (EAE) was attempted using bacterial lipopolysaccharide (LPS) from 4 sources. The ability of these LPS to induce DNA synthesis in guinea pig lymph node (LN) cells in vitro was also investigated. It was found that there existed a good correlation between the capacity of LPS to suppress EAE and their degree of mitogenic activities for LN cells. LPS from Escherichia coli 0111:B4 (Ec-LPS), which was most effective in suppressing EAE and also best inducer of DNA synthesis in LN cells, enhanced the proliferation of cells forming antibody to myelin basic protein (BP) in the regional LN. These results, in addition to the previous report, suggested that at the inductive phase the proliferation of B lymphocytes or their products, antibodies to BP, could inhibit formation of T lymphocytes sensitized to BP, resulting in suppression of EAE. Lipid A but not PS fraction of Ec-LPS showed a protective activity against EAE and a mitogenic activity for LN cells although less so than whole LPS. In addition, Lipid A appeared to exert its mitogenic effect mainly on B rather than on T lymphocytes.

Detection of antibody-forming cells and humoral antibody to horseradish peroxidase

Two new simple methods for detecting antibody-forming cells by hemolytic plaque assay and hemagglutinating antibody to horseradish peroxidase have been developed in mice. Both techniques utilize as target, sheep erythrocytes coupled directly with horseradish peroxidase. These assays are sensitive, antigen-specific and are useful to quantitate both direct and indirect antibody-forming cells and humoral antibodies.

Transition in the character of immunological memory in mice after immunization. II. Memory in T and B cell populations

Teh immunological memory in antibody response of mice to bovine serum albumin (BSA) was investigated at the level of antibody-producing cells or their precursor B cells and thymus-dependent helper T cells. Spleen cells obtained from mice previously primed with alum-precipitated BSA at various times were transferred to irradiated syngeneic mice. Spleen cells from mice immunized 8 days or 64 days before presented a high degree of adoptive secondary response, whereas the adoptive response of cells from mice immunized 2 days previously was found to be inferior even to that of unprimed spleen cells. Primed spleen cells treated with anti-mouse thymocyte rabbit serum plus complement were supplemented with normal thymus cells and the restoration of the responsiveness was examined. It was suggested that the memory was carried mainly by T cells in the earlier phases of the immunological memory (2 days or 8 days after the primary immunization). On the other hand, the immunological memory in the B-cell population was shown to grow gradually toward the later phase (later than 40 days).

Ineffectiveness of lipopolysaccharide for preventing the tolerance induction in bone marrow-derived lymphoid cells with dinitrophenyl-poly-L-(glutamic acid, lysine)

The effect of endotoxin or lipopolysaccharide (LPS) on tolerance induction in bone marrow-derived lymphoid cells (B cells) was investigated. Dinitrophenylated amino acid copolymer-L-(glutamic acid, lysine) (DNP-GL) acts as a potent tolerogen on normal and DNP-primed B cells. LPS significantly enhanced the anti-sheep red blood cell plaque-forming cell (anti-SRBC PFC) response that occurred after the immunization with a low dose of SRBC. LPS did not induce the primary anti-DNP PFC response after the injection of DNP-GL, nor did it prevent the tolerance induction in normal and DNP-primed B cells that occured after the administration of DNP-GL.

Transition in the character of immunological memory in mice after immunization. I. Memory for IgM and IgG antibody responses

The immunological memory in antibody response of mice to bovine serum albumin was investigated at the level of IgM and IgG antibody-forming cells, The antigen at a dose much lower than required for eliciting a detectable level of the primary antibody response could latently activate the immune machinery to an extent adquate for specific recall, whereas higher doses of antigen were effective in evoking strong anamnestic response. The potentiality to develop the anamnestic response was found even in the latent phase of the primary antibody response and was maintained for more than 2 months. The immunological memory acquired in an early phase after the primary immunization mainly involved IgM antibody response and late memory concerned IgG response.

Detection of virus-specific antibody-forming cells of mice immunized with Newcastle disease virus

The hemolytic plaque assay was adapted to the detection of antibodies to Newcastle disease virus (NDV) in an in vivo, an in vitro system, and a combined in vivo-in vitro system. Several conditions were tested for coupling of sheep erythrocytes to NDV and for the kinetics of plaque formation in the in vivo and in vitro systems. The one set of conditions which provided the best responses is presented. The effect of multiple injections of NDV into mice on plaque formation was optimized.

A hemolytic plaque assay for the detection of direct and indirect antibody-forming cells to keyhole limpet hemocyanin

A procedure is described for the in vitro enumeration of individual lymphoid cells producing antibody against Keyhole Limpet Hemocyanin (KLH) by a modification of the hemolytic plaque technique. Optimal conditions for the coupling of KLH to sheep erythrocytes by chromic chloride are described. Plaque-forming cells are detected in a liquid monolayer slide chamber assay system. The kinetics of the in vivo primary and secondary PFC responses of both rabbit popliteal lymph node cells and mouse spleen cells are described. Both direct (IgM) and indirect (IgG) plaque-forming cells can be enumerated. The method can also be used to detect an in vitro anamnestic response in dispersed rabbit lymph node cell suspensions. The method is simple, extremely sensitive and the results correlate with those previously obtained in which newly synthesized antibody was detected in similar systems using the coprecipitation assay.

Plaque-forming cells in rabbits immunized with BCG bacilli

Plaque-forming cells (PFC) in the regional lymph node, its efferent lymph, and the spleen of rabbits immunized with BCG were enumerated by localized hemolysis in gel, using sheep red blood cells coated with tuberculin protein. In the primary response, the maximal level of PFC production was reached at 5 days in the regional lymph node, and at 7 days in the spleen, whereas efferent lymphatic cells showed only a small number of PFC. Sharp peaks of PFC levels at 3 days were seen in the regional lymph node, spleen, and the efferent lymphatic cells in the secondary response. Blast cell outflow from the regional lymph node was maximal at 3 days in the secondary response as well as in the primary response. The relation between blast cell outflow and PFC production was discussed.