A personal letter to George Bruyn, the Editor.
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Biomedical subjects
Publications and source records attributed to C S Raine.
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Experimental allergic encephalomyelitis (EAE) is an autoimmune disease characterized by inflammation and demyelination in the central nervous system (CNS). Administration of transforming growth factor-beta (TGF-beta) has been shown to inhibit EAE. In this study, the possible role of endogenous TGF-beta in the regulation of relapsing EAE produced by the transfer of myelin basic protein-specific T cell lines was assessed. Although TGF-beta is not present in the normal CNS, this cytokine was detected by immunohistology in areas of central nervous system inflammation in both acute and chronic disease. The administration of anti-TGF-beta at the disease onset led to a worsening of the clinical course of EAE and more extensive pathological lesions. These findings provide direct evidence for a role of endogenous TGF-beta in the remissions seen in chronic relapsing EAE.
We studied immunoreactivity for heat shock proteins (HSPs) in multiple sclerosis (MS) brain tissue and detected HSP-65 in chronic MS plaques at the edge of thinly myelinated (or remyelinated) areas. Serial-section immunocytochemistry and double staining revealed that HSP-65+ cells represented reactive, immature oligodendrocytes with strong reactivity for myelin basic protein and weak reactivity for galactocerebroside. Mature oligodendrocytes outside MS plaques did not stain for HSP-65. Control brain sections showed no HSP-65 reactivity. Oligodendrocytes expressed HSP-65 in mixed glial cell cultures. In this system in vitro, oligodendrocytes, but not astrocytes, showed constitutive expression of HSP-65. There was immunoreactivity for HSP-72 in astrocytes in MS and non-MS brains to a similar extent but no association between HSP-72 reactivity and MS plaques. Interestingly, HSP-65+ oligodendrocytes colocalized with T lymphocytes expressing the gamma delta T-cell receptor (TcR). Since HSP-65 has been implicated as a major antigen recognized by TcR gamma delta lymphocytes, our findings might represent a new immunologic interaction within MS plaques that leads to the destruction of immature oligodendrocytes involved in remyelination.
A body of literature exists implicating the major histocompatibility complex class II E molecule in development of immune tolerance and/or immunosuppression. To define better the regulatory mechanisms underlying susceptibility to experimental autoimmune encephalomyelitis, an autoimmune condition displaying major histocompatibility complex-II dependence, disease was induced in transgenic mice expressing a major histocompatibility complex-II E alpha d-transgene. This was compared with experimental autoimmune encephalomyelitis induced in age-matched E-negative, non-transgenic mice of the same strain. The results showed that experimental autoimmune encephalomyelitis could be induced by adoptive transfer methodology in both transgenic and non-transgenic mice of the A.CA (H-2f) strain. Virtually no differences were observed between the two mouse types with regard to disease onset, course, and neuropathology. The main difference noted was within nonirradiated recipient subgroups where the nonirradiated transgenic A.CA mice demonstrated greater inflammation and demyelination than the nonirradiated, non-transgenic mice throughout the disease course. Thus, the results did not support the idea that the E molecule, per se, is involved in the induction of tolerance or immunosuppressive mechanisms protecting against autoimmunity. In addition, histologic changes in the central nervous system of the A.CA strain, both transgenic and non-transgenic, differed in several respects from the changes observed in other more commonly studied susceptible strains. In A.CA mice, polymorphonuclear cells were a more prominent component of the acute inflammatory infiltrate and in chronic disease, large aggregates of lipid-laden macrophages and cholesterol clefts were present within white matter lesions. The present approach, using genetic manipulation of the immune system, may have relevance to the study of disease mechanisms in other putative autoimmune demyelinating disorders such as multiple sclerosis.
Tissue prisms prepared by choping whole mouse brain maintained respiratory capacity and ultrastructural integrity of 3 h in vitro. Normal rabbit serum (ca. 25%) caused no morphological change but inhibited the synthesis of galactolipids by the prisms. Heating the serum abolished the inhibition. Complement containing anti-white matter rabbit serum destroyed myelin and inhibited galactolipid synthesis to a greater degree than did normal serum. Structures other than myelin were unaffected by the antiserum. Incubation in the presence of heated anti-white matter serum eliminated the myelin destruction but resulted in specific morphological changes characterized by the doubling of the myelin lamellae at the intraperiod line. Immunoperoxidase studies suggest specific binding of immunoglobulin to components of myelin located at the intraperiod lone. These changes were similar to those found in organotypic cultures. Heated antiserum did not inhibit galactolipid synthesis but addition of complement (normal guinea pig serum) to the heated antiserum restored only that portion of the inhibition which exceeded that caused by normal serum. Heat labile factors in normal rabbit serum which inhibit myelin lipid synthesis in the prisms must be corrected for in studies in which the heating of serum is used to demonstrate that the effect is complement dependent. The prism system is simpler than that of organotypic cultures and may be useful in the study of myelinotoxic factors.
An unusual case of concurrent MS and anaplastic astrocytoma is presented. MS was diagnosed in a female patient at the age of 22 years. A left side thalamotomy was performed for relief of severe intention tremor at age 28 and at age 32 she received immunosuppressive therapy for 1 year. At the age of 36 after a severe exacerbation of her symptoms a left side fronto-temporal tumor was diagnosed and a subtotal neurosurgical extirpation was performed. Histopathologically, the tumor was an anaplastic astrocytoma, which was further substantiated by electron microscopy and establishment of a permanent cell line in vitro. The cultured tumor cells were negative for measles virus by immunofluorescence. The relationship between the reactive astrocytes in MS plaques and astrocytic neoplasia is discussed.
The immunofluorescent staining properties of 65 serum samples from 54 patients with multiple sclerosis (MS), 63 samples from 55 patients with other neurological diseases (OND), and sera from 14 healthy normal individuals were examined on frozen sections of bovine and human brain. When tested on bovine brain sections, positive oligodendrocyte staining was present in 63% of MS sera, 43% of OND sera, and 29% of normal sera. The percentages were lower with human brain tissue. Astrocyte and myelin staining was common. F(ab')2 fragments purified from selected positive and negative MS and control sera gave no staining, though IgG fractions from the same sera prior to pepsin digestion gave positive staining. When tested against antihuman IgM and IgA conjugates, the same positive sera and their IgG-depleted globulin fractions gave minimal or no staining. These results indicate that oligodendrocyte staining is not specific for MS, is not due to specific antibody, and is probably the result of nonspecific binding to Fc receptors.
Circulating lymphocyte populations were examined in 85 patients with multiple sclerosis (MS), 26 of whom showed exacerbations; 48 patients with other neurological diseases (OND); 14 patients suffering from psychiatric disorders; and 2 normal subjects. The study involved the assay of early (active, high-affinity rosetting) T-cells, myelin basic protein (MBP)-reactive early T-cells, late (total, 24-hour rosetting) T-cell levels were significantly lower in MS (p less than 0.01) than in OND subjects. Exacerbations in MS were usually accompanied by further decreases in early T-cells. The lower levels of early T-cells in MS and their fluctuations are believed to reflect disease activity. MBP-reactive early T-cells were more frequently increased in MS (75% of cases) than OND (50%), and while this might be indicative of increased sensitization against myelin antigens, it was found not to be an MS-specific phenomenon.
Previous studies have shown that Strain 13 guinea pigs sensitised for experimental allergic encephalomyelitis (EAE) as adults usually develop an acute, fatal form of disease while animals inoculated as juveniles usually display a chronic relapsing form. The present study reports that following repeated short-interval blood sampling by cardiac puncture for the estimation of lymphocyte populations, some adult Strain 13 guinea pigs sensitised for acute EAE unexpectedly survived and developed chronic EAE, while a group of juveniles sensitised for chronic EAE and bled under the same conditions, developed a more severe, acute form of EAE. It is suggested that this reversal of disease course was related to the depletion of circulating factors.
Groups of juvenile Strain 13 guinea pigs sensitized for chronic relapsing experimental allergic encephalomyelitis (EAE) with isogeneic central nervous system (CNS) tissue in complete Freund's adjuvant (CFA) were either left to develop late-onset chronic EAE (unsuppressed), or given a series of injections of bovine myelin basic protein (MBP) in incomplete Freund's adjuvant (IFA) to suppress the disease. All unsuppressed animals developed disease and all suppressed animals remained healthy over a 27-month period of study. some unsuppressed and suppressed animals were rechallenged with CNS tissue in CFA 12 or 26 months post-inoculation (PI). Unsuppressed animals all became sick 2-4 weeks after rechallenge, while rechallenged, suppressed animals were protected, indicating that the suppression was permanent. Pathologic findings in the CNS complemented the clinical changes. Circulating lymphocyte studies were performed on animals from all groups. Early (active, high-affinity rosetting) T cell levels in unsuppressed animals showed significant decreases during exacerbations (P less than 0.01) and normal values during remissions. After rechallenge, circulating early T cells decreased in unsuppressed animals with the development of signs. In suppressed animals, early T cells showed significant elevations during, and for a short time after, the period of suppressive injections, and normal values afterwards. These levels did not change significantly after rechallenge. Late (total, 24 hour rosetting) T cell and B cell values showed minor fluctuations only which did not correlate with disease activity. These results indicate that chronic relapsing EAE can be successfully suppressed with MBP in IFA, that this suppression is permanent and that the immunologic findings presented correlate well with the clinical and pathologic facets of the disease. the findings are presented in terms of their relevance to multiple sclerosis.
MBP-reactive early T cells were determined simultaneously in the circulation and in inflammatory cells from the meninges of guinea pigs with acute EAE. In addition, early and late T cells as well as B cells were estimated in both compartments. Within the circulation, early T cells were found to decrease at the onset of clinical signs, and MBP-reactive early T cells were significantly higher than in normals. Different changes were found in inflammatory cells from the meninges. In this cell population, early T cells were increased but did not show significant, further elevation after incubation with MBP. This may indicate that the majority of early T cells in meningeal infiltrates had been previously activated by MBP in vivo.
A heterogeneous population of virions is generated by measles virus-infected cells. These particles are partially separable by sucrose density centrifugation into three peaks. Each population is stable and contains infectious particles. The particles of all three populations contain at least six polypeptide species that differ between particle populations only in quantity. All three populations contain a 50S RNA species, and the heaviest density peak also contains an additional species of 43S RNA. The difference between these results and previous studies with measles virions will be discussed.
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Mature myelinated cultures of mouse dorsal root ganglia (sometimes grown in combination with spinal cord tissue) have been exposed to unheated and heated (complement-inactivated) serum from rabbits with experimental allergic neuritis (EAN). Experimental cultures were examined for periods ranging from several hours to approximately 2 weeks of exposure. Some cultures were exposed to EAN serum for approximately 1 week then returned to normal medium for examination of the reversibility of the lesions. Unheated EAN serum induced demyelination of peripheral nervous system fibers within 96 hours of exposure. Following removal of the EAN serum, affected fibers remyelinated. Heated EAN serum produced a type of myelin swelling identical with that described previously in spinal cord explants exposed to serum from rabbits with experimental allergic encephalomyelitis. The lamellar spacing of the peripheral nervous system meylin was increased to approximately 23 nm. and the normal bifilar intraperiod line was increased to four leaflets. Some hypermyelination was seen. The swelling was incompletely reversible following removal of the heated serum. These findings are discussed in terms of their relevance to immunemediated demyelination and peripheral neuropathy associated with the hypergammaglobulinemic states.
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Within the retinal nerve fiber layer of a 6-week-old Sprague-Dawley rat, scattered aggregates of PNS myelinated axons have been found and described. We believe this is likely to represent a normal but rare phenomenon in the rat.
The presence of decomplemented anti-CNS antiserum profoundly affects myelinogenesis in cultured mouse embryo spinal cord. Light and electron microscope study has shown that oligodendroglia differentiate and produce an abundance of cell processes which surround the oligodendrocytes in a chaotic, disorganized array. Where the cell processes chance to meet, they form a kind of aberrant swollen myelin. Rarely, the oligodendroglial processes ensheath axons. For the most part, the available axons remain unmyelinated. On removal of the decomplemented antiserum, oligodendroglia differentiate and form normal myelin around the available axons. Myelination of peripheral nervous system (dorsal root ganglion) axons in the same preparations is unaffected by the presence of the antiserum. Thus, under these circumstances, the message from the neuron to the oligodendrocyte to make myelin is apparently intact, yet there is interference with the ability of the oligodendroglial cell process to find, attach to and encircle CNS axons with a normal myelin sheath.
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