Transfer of allergic encephalomyelitis in rats by means of lymph node cells

Genetic control of susceptibility to experimental allergic encephalomyelitis in rats

Rats of the inbred strains Lewis and DA are highly susceptible to the induction of experimental allergic encephalomyelitis (EAE) while Brown Norway rats are resistant to this disease. Evidence has been obtained which suggests that a single dominant gene is associated with susceptibility to EAE. The locus controlling EAE susceptibility is closely linked to the Ag-B histocompatibility locus but is not identical to it.

Brachial neuritis and seventh nerve palsy--a rare hazard of DPT vaccination

The field of delayed hypersensitivity continues to grow in complexity. One expects that increasing understanding of cell-mediated responses in clinical immunology will lead to greater advances in this field. This review explains and summarizes the pertinent newer concepts of clinical promise.

Experimental allergic encephalomyelitis in the rat: response to encephalitogenic proteins and peptides

Lewis rats were used to determine the encephalitogenic activity of myelin basic protein of different species and of 45-residue fragments of basic protein. Basic protein from guinea pigs was more active than that from rats, and the fragments from the two species showed the same order of activity. Bovine basic protein was the least active of the intact proteins, and the respective fragment was inactive. Studies of serum-binding capacity did not support the hypothesis that blocking antibody played a role in this biological variation, whereas consideration of the amino acid sequences of the three fragments suggested that differences in primary structure, operating either at the sensitization or the effector phase of the immune response, could account for the variation.

Experimental allergic encephalitis. Dissociation of cellular immunity to brain protein and disease production

The encephalitogenic determinant of brain protein, a nonapeptide having the amino acid sequence Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys, has been characterized and synthesized. In a previous study, analogues of this encephalitogenic peptide were synthesized and some were shown to be encephalitogenic while others were not. Guinea pigs were immunized with encephalitogenic peptides having amino acid sequences different from that in the native protein. These guinea pigs did not show cellular immunity in vivo (skin reactivity) or in vitro (lymphocyte stimulation or macrophage migration inhibition) to the encephalitogenic brain protein (EP) although they did show cellular immunity to the immunizing antigenic peptide. Guinea pigs immunized with an encephalitogenic peptide having the same amino acid sequence as the brain protein, or with a nonencephalitogenic peptide having the same amino acid sequence as the native protein but lacking the terminal lysine, did develop cellular immunity to the EP. Animals immunized with EP showed cellular immunity to this protein, but not to the encephalitogenic peptides. Animals immunized with nonencephalitogenic protein (NEP), prepared by altering the tryptophan residue of EP, did not develop disease but did show cellular immunity in vitro and in vivo to the EP. Animals protected from disease by immunization with NEP similarly showed cellular immunity to EP. Thus, the results suggest a dissociation between cellular immunity to EP and the production of experimental allergic encephalitis (EAE). Animals immunized with the encephalitogenic peptides develop EAE, but do not show cellular immunity to EP, and animals immunized with NEP show cellular immunity to EP but do not develop EAE. A fresh approach to the examination of the pathogenesis of EAE is now possible through the use of these well-characterized antigens.

Pernicous anaemia, hypogammaglobulinaemia, and altered lymphocyte reactivity. A family study

A mother and her identical twin daughters were found to have pernicious anaemia and achlorhydria. The twins lacked detectable serum IgA and had low to absent serum IgG. Both girls also demonstrated a marked impairment of antibody response to a variety of antigens. Evidence for lymphocyte sensitization to intrinsic factor was demonstrated in these patients by the increased incorporation of tritiated thymidine into DNA and by the production of migration inhibition factor.

Multiple sclerosis. Current etiological concepts

An animal model for acute multiple sclerosis (ms) is experimental allergic encephalomyelitis (eae). eae is produced by intradermal injection of a protein component of central nervous system (cns) myelin. Ultrastructural studies of eae and of a peripheral nerve analog, experimental allergic neuritis (ean), have revealed an orderly sequence of cellular events leading to the destruction and removal of myelin with sparing of axons (primary demyelination). Acute ms has not been studied electron microscopically, but the ultrastructural similarities between ean and a case of acute Landry-Guillain-Barré syndrome, a primary demyelinating disease of the peripheral nervous system, suggest that a similar sequence of events might be found in acute ms. While the pathological findings support a cellmediated or delayed hypersensitivity response, there is also evidence for the pathogenetic role of circulating antibodies. Among such evidence is included the finding that sera from animals with eae and humans with acute ms rapidly produce a reversible block of complex (polysynaptic) electrical activity when applied to cns tissue cultures, which suggests a possible mechanism for transient symptoms in ms. Epidemiological and other studies link ms with a viral cause, although no direct evidence that ms is caused by a virus exists. Viral and immunological mechanisms are not mutually exclusive in considering pathogenetic possibilities for ms, for it can be postulated that a viral infection of the central nervous system acts as a triggering agent for a series of immune responses, including production of a bioelectric blocking antibody and demyelination mediated by sensitized cells, the combination of which ultimately produces the total clinical picture of ms.

The nature and the specificity of mononuclear cells in experimental autoimmune inflammations and the mechanisms leading to their accumulation

The nature and specificity of the mononuclear cells in passively transferred autoimmune encephalomyelitis and adrenalitis were studied. The recipients were prepared by production of a small heat lesion in the target tissue 5 days before transfer. Within 24 hr after transfer of lymph node cells from donors sensitized with the corresponding tissue antigen, a dense mononuclear cell infiltrate developed around the lesion. When lymph node cells labeled in vitro with (3)H-thymidine or (3)H-adenosine were transferred, a significant number of labeled lymphocytes was found in the infiltrate at 24 or 48 hr. Lymphocytes labeled with (3)H-thymidine showed a greater tendency to accumulate than cells labeled with (3)H-adenosine, indicating that newly formed lymphocytes were more prone to enter the reaction than older cells. Labeled lymphocytes and macrophages of recipient origin and labeled lymphocytes from donors stimulated with B. pertussis were also shown to accumulate around the heat lesion provided the reaction had been initiated by transfer of unlabeled lymphocytes from donors sensitized to the appropriate tissue-specific antigen. In recipients which were given lymph node cells from two groups of donors, sensitized either to spinal cord or to adrenal antigens, with cells from only one group of donors labeled, equal percentages of labeled cells were found around each lesion. Thus, no evidence of preferential accumulation of specifically sensitized lymphocytes was obtained. In recipients which received whole body irradiation on the day of production of the heat lesions, 5 days before transfer of lymph node cells from appropriately sensitized donors, neither monocytes nor lymphocytes accumulated around the lesion. However, if the tibial bone marrow was shielded or if bone marrow cells were given to the recipients shortly after irradiation, inflammation developed as in normal recipients. In recipients which were irradiated 24 hr after the transfer of unlabeled lymph node cells from donors sensitized to the appropriate tissue antigen and then given labeled lymph node cells from B. pertussis-stimulated donors, labeled lymphocytes were found in the reaction 24 hr later. This accumulation occurred although virtually all the lymphocytes present in the lesion at 24 hr after the first transfer were destroyed by the irradiation. The results are interpreted as follows. The autoimmune reaction is initiated by the arrival at the site of a few specifically sensitized lymphocytes, probably on a random basis. After contact with antigen, factors are produced and released which cause the influx of monocytes and of lymphocytes, in particular newly formed ones, of various specificities. There is no preferential accumulation of specifically sensitized cells. The influx of lymphocytes appears to require the presence of monocytes or macrophages in the reaction.

Autosensitization in vitro

Autosensitization of rat or mouse lymphoid cells against syngeneic fibroblast antigens was induced in cell culture. Rat lymphoid cells autosensitized by this method were able to produce immunospecific lysis of syngeneic target fibroblasts in vitro or GvH reactions in newborn rats. Autosensitized mouse spleen cells mediated similar GvH reactions when injected into newborn mice. The nature of the system used to induce immunity in vitro appears to argue against the possibility that lymphocytes capable of reacting against self-antigens could arise by mutation in cell culture. Hence, it is likely that cells potentially reactive against self-antigens preexisted in the lymphoid cell donors. The ability of autosensitized cells to mediate immune reactions in vivo suggests that the immunogenic self-antigens present on sensitizing fibroblasts also were accessible in the intact animals. Loss of natural self-tolerance in vitro, therefore, can be explained most simply by the existence of lymphocytes which are reversibly tolerant to self. Hence, ontogenic elimination of potentially self-reactive cells may not be the only basis for natural tolerance. Regulatory mechanisms, such as antigen excess, may have to function in vivo to prevent differentiation of self-tolerant lymphocytes. These regulatory mechanisms appear to be annulled in the cell-culture system. The present system thus may offer a new approach to studies of tolerance and regulation of cellular immunity.

The effect of antisera against rat immunoglobulins on cellular transfer of experimental allergic encephalomyelitiin Lewis rats

Lymph node cell (LNC) transfers of experimental allergic encephalomyelitis (EAE) in Lewis rats were performed in which suspensions of sensitized LNC, prior to injection into recipients, were incubated in vitro with antisera against rat whole serum or rat γ-globulin. No interference with the transfer of EAE was observed. Fluorescent antibody studies revealed essentially no binding of anti-rat globulin to suspensions of intact LNC. Definite binding of anti-rat globulin was demonstrable, however, after alcohol-fixation of LNC. These observations provide additional evidence that immune responses of the delayed-type intimately associated with sensitized lymph node cell suspensions are more important than conventional immunoglobulin responses in development of EAE.

Passive transfer of experimental allergic thyriditis, delayed hypersensitivity to thyroglobulin and anti-thyroglobulin antibody formation in inbred Lewis rats

Inbred Lewis rats regularly develop experimental allergic thyroiditis, delayed skin hypersensitivity and Arthus reactivity, and produce anti-thyroglobulin antibodies 14–21 days after immunization with bovine thyroglobulin in adjuvant.

Attempts have been made to transfer thyroiditis to normal rats by means of thymus, spleen or lymph node cells, as well as by serum containing anti-thyroid antibodies. The following types of lymphoid cells were used: viable or non-viable cells from donors immunized with bovine thyroglobulin in adjuvant, cells from donors sensitized only with adjuvant, cells from donors immunized with adjuvant alone and mixed with thyroglobulin prior to the injection into recipients, and cells from donors injected with egg albumin in adjuvant.

Thyroglobulin-sensitive lymph node cells were most effective in transferring thyroiditis, delayed skin hypersensitivity and anti-thyroglobulin antibody production; spleen cells exhibited slight activity, whereas thymus cells were incapable of inducing immune responses. Passively produced thyroiditis was characterized by mild inflammatory lesions. The incidence of delayed skin hypersensitivity in positive recipients was much higher than the occurrence of thyroiditis. Prolonged treatment of intact animals with immune or normal rat serum did not induce lesions typical of allergic thyroiditis.

It was concluded that passive induction of experimental allergic thyroiditis can be accomplished in inbred Lewis rats by immunologically active lymphoid cells. The role of anti-thyroid antibodies in the pathogenesis of thyroiditis was discussed.