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C C Bernard

Publications and source records attributed to C C Bernard.

117 records · Page 7Linked to original sources

Suppressor T cells prevent experimental autoimmune encephalomyelitis in mice.

Immune suppression (immunoprotection) in experimental autoimmune encephalomyelitis (EAE) was studied in (SJL X BALB/c)F1 mice using inocular of mouse spinal cord homogenate (MSCH), or mouse basic protein of myelin (M-BPM), in Freund's incomplete adjuvant (FIA). Such immunization specifically recruited lymphoid cells which markedly suppressed the capacity of effector lymph node cells from appropriately immunized syngeneic mice to transfer adoptively EAE. Suppression was demonstrable with transfer of bone marrow and spleen cells, but not with lymph nodes or thymus cells. Adoptively transferred suppression was maximal when cells were injected 9-30 days after the suppressive injection. Inhibition of EAE by suppressor cells was specific for the relavant antigen BPM, and required viable cells. Treatment of cells with anti-Thy-1 serum before transfer abolished their suppressor activity. After adoptive transfer of suppressor cells into syngeneic recipients subsequently immunized for EAE, there was inhibition of EAE and reduced cell-mediated immune response to BPM as judged by macrophage migration inhibition assays. Hence, in mice at least, immuno-protection against EAE is explicable by recruitment of suppressor T lymphocytes with the dual capacities of inhibiting development of effector T cells after antigenic stimulation, and of blocking their damaging effects on the antigen in the central nervous system.

Animals↗

T cell necessity in the pathogenesis of experimental autoimmune encephalomyelitis in mice.

Cellular transfer of experimental autoimmune encephalomyelitis (EAE) was effected in mice with lymph node and spleen cells from appropriately immunized donors. In contrast to lymphoid cells, immune serum did not transfer this autoimmune disease nor did serum have any facilitating or inhibitory effect on the capacity of lymphoid cells to transfer EAE. Transfer of EAE was effected in normal mice, lightly irradiated (350 rad) and lethally irradiated (850 rad) and bone marrow-protected mice, but not in mice which had been given 850 rad total-body irradiation. There was a striking augmentation of severity of transferred EAE in the lightly irradiated recipients, possibly attributable to selective radiosensitivity of suppressor T cells. Cell-mediated immunity but not circulating antibody to basic protein of myelin was demonstrated in recipients with transferred EAE. The immune lymphoid cells responsible for transfer of EAE were T lymphocytes. Thus transfer was successful after passage of sensitized cells through anti-immunoglobulin columns and was abrogated following treatment with anti-Thy-1 serum and complement. Neonatally thymectomized mice failed to develop either EAE, cell mediated immunity or humoral antibody against myelin basic protein (BPM). Inhibition of EAE and immune responsiveness was solely due to the removal of the source of thymus lymphocytes, because reconstitution of neonatally thymectomized mice with T lymphocytes completely restored these functions. It is concluded that T lymphocytes are required for the production and adoptive transfer of EAE, for the development of cell-mediated immunity to BPM and for the production of antibody to BPM.

Animals↗

Experimental autoimmune encephalomyelitis in mice: genetic control of susceptibility.

Experimental autoimmune encephalomyelitis (EAE) was induced in inbred and congenic strains of mice by injection of mouse spinal cord homogenate (MSCH) in Freund's complete adjuvant (FCA) with pertussis vaccine. Genetic analyses showed that susceptibility to EAE in mice was inherited as a dominant trait and was in part controlled by genes located in the centromeric half of the H-2 complex. Mice with EAE developed cell-mediated immune responsiveness to basic protein of myelin (BPM), as judged by the macrophage migration inhibition assay, using peritonealyexudate cells; this was not observed with mice of resistant strains. However, the migration of peritoneal exudate cells of both susceptible and resistant strains was significantly inhibited in the presence of purified protein derivative (PPD) of M. tuberculosis. Thus, the genes involved in the control of susceptibility to EAE also influence T cell responsiveness to BPM. Antibody to BPM, as judged by radioimmunoassay, was detected in susceptible and resistant strains but there was no correlation between the presence or levels of antibody and susceptibility or resistance to EAE. It is suggested that resistance to EAE is associated with failure of T cells to recognize and/or respond to the encephalitogenic determinant of the BPM molecule.

Alleles↗

Inhibition by serum of autoimmune aspermatogenic orchitis.

Inhibition by serum of experimental autoimmune orchitis (EAO) was studied in guinea-pigs. It was found that the capacity of an autoantigen, antigen P, purified from guinea-pigs' spermatozoa, to produce lesions of EAO could be inhibited by mixing antigen P with a small amount of normal human serum before injection into guinea-pigs. In protected animals, cell-mediated immunity and humoral antibodies to antigen P were also significantly suppressed.

Animals↗

Inhibition by serum of encephalitogenic activity of myelin basic protein.

Basic protein of myelin from bovine brain (B-BPM) in Freund's complete adjuvant (FCA) is highly encephalitogenic for the guinea pig. However, when B-BPM is mixed with serum from various species it loses its encephalitogenic effect but not its immunogenic properties. When the synthetic tryptophan peptide matching residue 115-126 of human BPM is mixed with normal human serum it loses both its encephalitogenic and immunogenic effects. The time of exposure to serum necessary for complete inhibition of encephalitogenic activity of B-BPM varied: rat, horse, sheep and human sera produced their inhibitory effect immediately after mixing, whereas guinea pig serum required 8h. The capacity of serum to abrogate the encephalitogenic effects of B-BPM was not due to complete degradation of the molecule by proteinases in serum, because all animals injected with the B-BPM serum mixture gave cutaneous delayed hypersensitivity reactions to B-BPM. The inhibitory effect could be attributed to a factor in serum which is non-dialysable, thermostable at 56 degrees C, for 1 h, and present in high concentration in fetal calf serum. It may be an alpha2 macroglobulin which can act selectively on the main encephalitogenic determinant, around or within residues 115-126 of the basic protein of myelin.

Animals↗

Experimental autoimmune encephalomyelitis in mice: immunologic response to mouse spinal cord and myelin basic proteins.

It was confirmed that experimental autoimmune encephalomyelitis EAE, could be induced in SJL/J mice with mouse spinal cord homogenate. It was shown that induction of EAE in mice was critically dependent on the concentration of pertussis vaccine. The encephalitogen present in mouse brain was the basic protein of myelin. The smaller form of the mouse and rat basic proteins induced EAE; thus the mouse like the rat responds to determinants other than the "tryptophan region," which induced EAE in guinea-pigs. Mice with EAE developed a cell-mediated immune response to myelin basic protein, as judged by inhibition of peritoneal cell migration. However, levels of antibody to mouse basic protein were low, as judged by radioimmunoassay. The establishment of this autoimmune disease model in the mouse will allow the application of well established techniques for the analysis of the immunologic mechanisms leading to disease manifestation.

Animals↗