Localization of antigenic determinants on bovine encephalitogenic protein further studies with the macrophage migration inhibition assay in guinea-pigs

Suppression and reversal of allergic encephalomyelitis in rhesus monkeys with basic protein and peptides

We have extended earlier studies on the suppression of clinically evident experimental allergic encephalomyelitis (EAE) in monkeys, repeated injections of human basis protein. The results confirm that after suppressive treatment, recovered animals remain clinically normal and do not show spontaneous recurrence of symptoms. However, recovered animals are susceptible to EAE upon renewed challenge, and they develop the disease more rapidly and more severely than after the initial challenge; resuppression is also accomplished in these cases by the same methods used previously. The results indicate further that the basic protein or peptide T administered without mycobacteria is effective in suppressing the development of basic protein-induced EAE regardless of the species from which it was derived.

Peptides and autoimmune disease

The use of derived and synthetic peptides has contributed greatly to our understanding of encephalitogenic determinants in the basic protein molecule. Peptides derived from BP by use of trypsin, pepsin, cathepsin D (brain and liver) and BNPS-skatole have proven most useful. Synthetic peptides have served to define the disease-inducing determinants with precision. A remarkable feature of these studies is that different antigenic determinants serve as encephalitogenic sites in different species. The encephalitogenic sites comprise short peptide domains of the BP polypeptide chain, only 8 residues (rat), 9 residues (guinea pig), and 10 residues (rabbit) in length. In view of the requirement for both haptenic and carrier specificity of an immunogenic molecule, it is impressive that these peptides themselves elicit the autoimmune disease, EAE. While less active than BP on a molar basis, they are nonetheless potent encephalitogens, producing clinical signs in rats and guinea pigs at less than 1 microgram dose. The data indicate that for most animal species (guinea pig, rat, monkey) there appears to be only one major encephalitogenic determinant, an unusual finding in view of the number of antigenic determinants for cell-mediated immunity existing in the BP molecule. Possibly a combination of genetic and anatomical factors may account for this phenomenon. A relationship may exist between multiple sclerosis and EAE as shown by peptide studies; lymphocytes are found in MS patients during exacerbation sensitized to the same region of BP active in the monkey. The major encephalitogenic sites are: Guinea Pig (9) Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys(Arg); Rabbit (10) Thr-Thr-His-Tyr-Gly-Ser-Leu-Pro-Gln-Lys; Rat (8) Ser-Gln-Arg-Ser-Gln-Asp-Glu-Asn; Monkey (14) Phe-Lys-Leu-Gly-Gly-Arg-Asp-Ser-Arg-Ser-Gly-Ser-Pro-Hser.

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.

Cell-mediated immune response to guinea pig and bovine basic proteins of myelin in Lewis and PVG rats and their hybrids

The in vitro cell-mediated immune response of rat lymph node cells (LNC) to guinea pig and bovine encephalitogenic protein (EP) has been studied with a LNC transformation test. LNC were obtained from either Lewis, PVG, or F1 (Lewis x PVG) rats 28 days after challenge with guinea pig or bovine EP in Freund's complete adjuvant (FCA) of different mycobacterium content. No differences between the strains or their hybrids in LNC response could be shown if stimulated with sensitizing EP, despite the great differences in capacity for disease development in those animals. Nor did a fivefold lowering of the amount of mycobacterium content in FCA, when guinea pig EP was used at challenge, lessen the in vitro response, although this reduces the disease development. Sensitization with guinea pig EP causes an in vitro cross-reactivity to bovine EP and the reciprocal cross-reactivity probably also exists. In rabbits, this cross-reactivity in both directions was clear-cut. LNC from Lewis rats challenged with guinea pig EP in FAC, with the higher amount of mycobacterium, showed in vitro responses to tested peptides of this EP; the amino acid sequences of these were: 1-42, 43-88, 89-169, and HNB-89-169 (89-169 blocked at the tryptophan-residue by hydroxynitrobenzylation).