Allergic encephalomyelitis: characterization of the determinants for delayed type hypersensitivity

Sequence determinants of modified cobra venom neurotoxin which induce immune resistance to experimental allergic encephalomyelitis: molecular mechanisms for immunologic action

A nontoxic, iodoacetamide-modified cobratoxin derivative (CAM-NTX) induced resistance to experimental allergic encephalomyelitis (EAE) in guinea pigs. Resistance was retained after trypsin digestion and shown to reside in N-terminal and central peptides of CAM-NTX. A similarly modified protein cardiotoxin (CAM-CTX), representative of proteins homologous with cobratoxin, was not immunosuppressive. Depressed clinical symptoms in EAE-resistant animals correlated with reduced lymphocytic infiltration of the brain. Antibody to myelin basic protein (MBP) was reduced in immunosuppressed animals. The immunoinhibitory determinants in CAM-NTX may mimic immune response suppressor proteins (SIRS-alpha 7) and the EAE-resistance region of MBP.

Delayed-type hypersensitivity to myelin basic proteins in mice susceptible to allergic encephalomyelitis

The delayed-type hypersensitivity (DTH) response in mice immunized with autologous spinal cord homogenate or purified myelin basic protein (MBP) was measured by the 125I-UdR uptake ear assay. Mice were tested for DTH responses with MBP preparations from different species and with synthetic peptides. The 114-122 and 68-84 peptide regions appear to be major determinants for inducing and eliciting DTH in the mice which are susceptible to allergic encephalomyelitis.

Has myelin basic protein received a fair trial in the treatment of multiple sclerosis?

Autosensitization to some central nervous system antigen still remains one of the best hypotheses for the continuing pathogenesis of multiple sclerosis (MS). Enough is now known about the cause, pathogenesis, and treatment of experimental allergic encephalomyelitis (EAE) to test this hypothesis. Reports of therapeutic failure of the encephalitogen myelin basic protein (BP) in the treatment of MS have their counterparts in similar therapeutic failures in EAE. Only highly inbred strain 13 guinea pigs respond consistently to BP therapy, and this only when BP is administered in relatively high doses. Noninbred guinea pigs respond much less well to simple BP therapy, and monkeys hardly at all. In both strains of monkeys so far studied, a nonspecific adjunctive factor--an antibiotic in Macaca mulatta and a steroid in Macaca fascicularis--is also required. Accordingly, human trials of the therapeutic efficacy of BP in MS should include its administration in large concentrations together with an adjunctive agent.

Bovine myelin basic protein: immunochemical specificity examined by the macrophage migration inhibition test

Guinea pigs were injected with saline or with one of the following antigens incorporated into Freund's complete adjuvant: Bovine myelin basic protein (MBP), lysozyme, carboxymethylated lysozyme, or a crude commercial calf thymus histone preparation. Examination of the migration of peritoneal cells from these animals in the presence (50 microgram/ml) or the absence of the antigens revealed, at most, a slight one-way form of cross-reactivity between MBP on the one hand and the histone preparation--and possibly also lysozyme--on the other. This was observed only with cells from animals injected with the two last-mentioned antigens. Cells from animals sensitized with either histone or lysozyme mixed with poly AU instead of Freund's complete adjuvant were also slightly inhibited in their migration by the bovine MBP. Cells from animals injected with complete Freund's adjuvant alone or with the purified protein derivative of tuberculin (PPD) in poly AU did not react to MBP. Thus, in contrast to the high degree of internal cross-reactivity shown previously MBP shows a low degree of cross-reactivity with either ordered or unordered forms of some unrelated basic proteins.

Autoimmune disease antigens

The first step towards understanding the cellular interaction which results in autoimmune disease is to determine what triggers the recognition between a specific autoimmune antigen determinant and the cellular receptor. In this review, we have focused on the antigen inducing experimental allergic encephalitis (EAE) because the antigen has been characterized and a relatively large body of information on its biological activities has been accumulated. Clearly, a specific allergic encephalitis-producing determinant is present and is represented on a relatively small portion of the molecule. The determinant induces a wide variety of biological reactivities, some of which are classed as cellular mediated. An attempt is made to dissect activities such as blast transformation (BT), migration inhibitory factor (MIF), in vivo delayed type hypersensitivity reaction (DTH) and EAE and to relate them to the structural requirements which the determinants possess. The complexities which arise indicate that subpopulations of cells with different receptor activities may respond selectively and that recognition of the receptor is produced by an EAE determinant consisting of three amino acids in a specific linear sequence. Furthermore, under experimental circumstances the EAE activity can be dissociated from the other activities (BT, MIF, DTH), indicating that while these tests are used generally to follow various human autoimmune disease activities, they may represent the reaction of a broad spectrum of cells.