Interferon beta augments suppressor cell function in multiple sclerosis

Suppressor cell function has been previously reported to be decreased in patients with progressive multiple sclerosis (MS). The abnormality could not be corrected in vitro and was present even after patients were treated with immunosuppressive agents. We now report that interferon beta augments suppressor cell function in vitro in progressive MS. Nonspecific suppressor cell function as measured in a concanavalin A (Con A) suppressor assay was reduced in 24 MS patients (mean percent suppression, 19.6 +/- 2.2) when compared to 19 normal subjects (mean percent suppression, 35.0 +/- 3.3). The data are highly significant (p less than 0.001). When recombinant human interferon beta (10(3) units/ml) was added to lymphocyte cultures with Con A, suppressor activity improved significantly. The mean percent suppression improved from 19.6 +/- 2.2 to 37.8 +/- 2.6 in MS (p less than 0.001) and from 35.0 +/- 3.3 to 46.2 +/- 3.5 (p less than 0.025) in control subjects. This study shows that recombinant interferon beta improves suppressor function in humans, an effect that is particularly significant in progressive MS.     

HLA-DR beta, -DQ alpha, and -DQ beta restriction fragment length polymorphisms in multiple sclerosis

Restriction fragment length polymorphism (RFLP) studies were performed on DNA from unrelated Caucasian patients with multiple sclerosis (MS) using cDNA probes to the HLA class II genes DR beta, DQ alpha, and DQ beta. In a study of 34 patients and 34 controls who were not matched for DR type, we found that the DQ beta allele-specific RFLP or allogenotype, termed DQ beta lb, which corresponds at the molecular level to the DQwl serotype, is preferentially associated with MS. A significant disease association with DR2 was demonstrated by serology but this was not confirmed using DR2/Dw2-specific RFLPs. We suggest that DQ beta lb is largely responsible for HLA-associated susceptibility to MS and that the apparent MS-DR2 serological association is due to the strong linkage disequilibrium between DR2 and DQ beta lb. Homozygosity of one of the two allelic bands of the DX alpha gene, usually termed the DX alpha lower (DX alpha L) band (which cross-hybridizes with the DQ alpha probe), correlated with reduced susceptibility to MS. Similarly a 5.3 kb band identified by the DQ alpha probe in Mspl digests showed a negative correlation with MS. In an analysis of 27 DR2+ controls and 26 DR2+ patients it was found that these individuals all had DR2/Dw2-specific RFLPs and all had identical DR2/Dw2-associated DQ beta (DQ beta lb) and DQ alpha (DQ alpha lb) allogenotypes. We detected no polymorphisms of DR beta, DQ alpha, or DQ beta genes among the DR2+ MS patients which distinguished them from normals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lymphomononuclear cells from multiple sclerosis patients spontaneously produce high levels of oncostatin M,tumor necrosis factors alpha and beta,and interferon gamma

Proinflammatory cytokines are deemed to play a pivotal role in the pathogenesis of multiple sderosis (MS). They provide signals for T-cell activation and inflammatory cell recruitment in the brain and might directly alter neuroglial and neuronal cell survival and function. We found that peripheral blood mononuclear cells (PBMCs) from MS patents spontaneously produce high levels of TNFalpha, TNFbeta, IFNgamma, and oncostatin M (oncM), a proinflammatory cytokine actng on cells of neural, vascular, hematopoietic, and lymphoid origin. Spontaneous production of these cytokines was significantly higher (p < 0.01) in PBMC short-term culture supernatants from MS patients than in blood donors (HC). On average, lectin-induced production of these cytokines by PBMC was higher in MS patents than in HC significantly so only for TNFalpha (p = 0.013). Determination of TNFalpha, TNFbeta IFNgamma, and oncM in corresponding sera showed that on average, oncM levels were higher in MS patients than in HC, though the results were not statistically significant whereas levels of TNFalpha, TNFbeta and IFNgamma were below the assay threshold in most patients. The finding that MS PBMCs are primed in vivo to produce and release high levels of proinflammatory cytokines suggests the presence of a basal activation of the immune system which, in turn, may play a role in the complex circuitry of molecular and cellular interactions responsible for neurologic damage in MS.     

Activated suppressor cell function in severely disabled patients with multiple sclerosis

Defective suppressor cell function has previously been demonstrated in patients with multiple sclerosis (MS) with progressive disease and moderate degrees of disability. In the present study activated suppressor cell function was assessed in patients with documented progressive disease who, at the time of study, had experienced severe disability (Kurtzke score greater than or equal to 6.5) for at least 2 years. We found that mean suppressor levels were significantly increased in this patient group compared with the suppressor levels in the MS patient group with progressive disease but only moderate disability (Kurtzke score of less than or equal to 6.0 within 2 years of study) (59 +/- 8% vs 19 +/- 7%, respectively, p less than 0.01). The mean value in the latter group was significantly reduced compared with the mean value for normal control subjects (47 +/- 4%, p less than 0.01), a finding consistent with previous reports. The results of this study indicate that suppressor cell function, as measured by our assay system, need not be defective in MS patients who have become severely disabled from the progressive form of the disease. Whether the patients who are now severely disabled from progressive MS passed through a phase of disease associated with the same suppressor defects as found in the progressive patients currently with moderate disability will remain speculative until long-term longitudinal studies are performed.     

Etretinate augments interferon beta-1b effects on suppressor cells in multiple sclerosis

BACKGROUND: Interferon beta treatment is only partially effective in multiple sclerosis (MS) suggesting a potential role for adjunctive therapies. Retinoids can augment the clinical efficacy of type 1 interferons in patients with cancer. We reasoned that the same might hold in MS. Interferon beta-1b added to peripheral blood mononuclear cells in vitro partially reverses the CD8 suppressor cell defect of patients with MS. All-trans retinoic acid added to peripheral blood mononuclear cells from untreated patients with MS or from controls potentiates this ability of interferon beta-1b to augment CD8 suppressor cell function in vitro. OBJECTIVE: To determine whether retinoid administration to patients with MS who are being treated with interferon beta-1b augments their CD8 suppressor cell function. SETTING: A university hospital MS clinic. PARTICIPANTS: Patients with MS who were being treated with interferon beta-1b, 14 patients with secondary progressive MS and 3 patients with relapsing remitting MS. RESULTS: Seventeen patients with MS received etretinate treatment for up to 6 months. Planned dosing was 10 mg 3 times daily for the first month, 25 mg twice daily for the second and third months, and 10 mg twice daily thereafter. The 25-mg twice daily dose was not well tolerated and of the 14 patients who remained in the phase 1 clinical trial through month 3 dose reduction to 10 mg thrice daily was required in 1 patient and to 10 mg twice daily in 4 patients. Eleven patients completed the trial. Etretinate treatment significantly augmented suppressor function over baseline values at 1, 3, and 6 months. No meaningful change was noted in disability or quality of life over the course of the phase 1 clinical trial. Neuropsychological testing of completers suggested improvement on selected aspects of verbal memory at 6 months compared with baseline values. CONCLUSIONS: Etretinate treatment at a dose of 10 mg twice or three times daily augments suppressor cell function in patients with MS receiving interferon beta-1b. Higher dose etretinate treatment (25 mg twice daily) is poorly tolerated by patients with MS. Even at 10 mg twice daily adverse experiences involving the mucous membranes and the skin become troublesome for some, but not all, patients. Whether pulse therapy or administration of retinoid restricted to the day of interferon beta dosing will also augment suppressor function, while being better tolerated, remains to be determined.     

Activated suppressor cell function in multiple sclerosis — clinical correlations

Activated suppressor cell function mediated by either freshly isolated peripheral blood mononuclear cells (MNCs), freshly isolated CD8⁺ lymphocytes or by CD8⁺ cell lines, has previously been found to be reduced compared to controls in multiple sclerosis (MS) patients with progressive disease (MS-P). In this study, we found that suppressor activity mediated by CD8⁺ cell lines, derived from MS patients with stable disease (MS-S) patients and maintained in culture for 14 days, was significantly greater (45 ± 6%) compared to that mediated by MS-P patients' CD8⁺ cells (11 ± 4%, P < 0.005). The MS-S suppressor values were, however, suggestively reduced compared to controls (60 ± 6%, P < 0.05). MNC-mediated suppressor values for the MS-S group (61 ± 5%) did not differ from the control group (67 ± 6%). Values for the MS-P group (7 ± 6%) were significantly reduced compared to MS-S and control groups. Cytotoxic activity mediated by CD8⁺ cell lines showing defective suppressor function did not differ from control values. The cell lines in MS and control did not differ with respect to their rate of proliferation in the presence of IL-2 and OKT3. Suppressor function in this assay was ablated if exogenous IL-2 was removed from the culture media. These data suggest that defective activated suppressor function is characteristic of the progressive form of MS, although a suppressor defect is also partially expressed in stable MS patients when CD8⁺ cell lines are studied.     

Interferon beta,birth weight and pregnancy in multiple sclerosis

Journal of Neurology -     

Localization of GABAA receptor subunits alpha 1, alpha 3, beta 1, beta 2/3, gamma 1, and gamma 2 in the salamander retina

Electrophysiological studies have demonstrated that gamma-aminobutyric acid receptors type A (GABA(A)) mediate important information processing in the retinas of salamander and other vertebrates. The pharmacology and physiology of GABA(A) receptors depend on their subunit composition. We studied the localization of GABA(A) receptor subunit isoforms alpha(1), alpha(3), beta(1), beta(2/3) (antibody BD-17 and 62-3G1), gamma(1), and gamma(2) in salamander retina with immunocytochemical methods. All three beta-subunit antibodies labeled similarly in the outer retina, especially the inner segments and synaptic terminals of rod photoreceptors (identified with protein kinase C). Somatic labeling was observed in cell bodies of some horizontal cells, bipolar cells, amacrine cells, and cells in the ganglion cell layer (GCL). Puncta were present throughout the inner plexiform layer (IPL) for beta(1) and 62-3G1, but not for BD-17. alpha(1)-immunoreactivity (IR) stained a population of presumed OFF rod-dominated bipolar cells, including dendrites, soma, and axon terminals in the distal IPL. A subtype of GABAergic amacrine cell also expressed alpha(1)-IR, with puncta sparsely distributed at the distal and proximal margins of the IPL. Both the OPL and IPL were labeled throughout for alpha(3)-IR, as opposed to the narrow distribution of alpha(1)-IR in the IPL, suggesting that the two alpha-subunits are localized at different synaptic sites. Punctate gamma(1)-IR was observed in the OPL and IPL, whereas gamma(2) was most prominent in cone photoreceptors (identified with calbindin), including the terminal telodendria, in cell bodies of some horizontal cells, amacrine cells, cells in the GCL, and less intensely in the IPL. In addition, several subunits were present in Müller cells. The differential labeling suggests the existence of GABA(A) receptor subtypes with different subunit compositions that mediate multiple GABAergic functions in salamander retina.     

Novel effects of estradiol and estrogen receptor alpha and beta on cognitive function

Estrogen influences the development of memory function in humans and rodents and can modulate memory in adults. In these studies we examined the role of the estrogen receptors alpha (ERalpha) and beta (ERbeta) in mediating performance on a hippocampal-dependent, hormone-sensitive task, inhibitory avoidance (IA). Ovariectomized (OVX) estrogen receptor-alpha-knockout (ERalphaKO) mice displayed impaired performance on the IA task and OVX heterozygotic (HET) mice exhibited performance that was intermediate between ERalphaKO and wild-type (WT) mice. Impaired performance by ERalphaKO mice was rescued by E(2) treatment. The ER antagonist, tamoxifen, did not block enhancement of retention by E(2) suggesting that E(2) mediated modulation of memory is not caused by known genomic receptor mechanisms. In contrast to ERalphaKO mice, IA performance by OVX estrogen receptor-beta-knockout (ERbetaKO) mice was not compromised. The results indicate an important role for ERalpha, relative to ERbeta, in the establishment of cognitive function and suggest that E(2) modulates memory function via a novel estrogenic mechanism.     

Interhemispheric disconnection effects in multiple sclerosis.

Patients with multiple sclerosis reported less left ear numbers but more right ear numbers than controls in a dichotic listening test. The multiple sclerosis patients were also relatively impaired on three learning tasks; one of these, a test for paired-associate learning of names and faces, correlated with left ear findings; the results are interpreted as supporting a hypothesised disconnection mechanism.     

Paradoxical effects of temperature in multiple sclerosis.

Six cases of multiple sclerosis are reported in which cold produced a temporary exacerbation of symptoms and signs of the disease. Also, in one case investigated in detail by psychophysical methods, heating produced a paradoxical deterioration in vision and simultaneous improvement in sensory and motor function. The effect of temperature in multiple sclerosis is discussed and a physiological explanation for the paradoxical response to heating is suggested.     

Clinical trials of interferons in multiple sclerosis what have we learned?

Although multiple sclerosis (MS) is generally believed to be an immune-mediated disease, conventional therapy with ACTH, corticosteroids, or immunosuppressive drugs is unsatisfactory. Aside from their unpredictable therapeutic effects, these agents are potentially hazardous and can only be given for short periods of time. There is an urgent need for less toxic yet effective immunotherapy, that that can be administered early in the disease and continued indefinitely. Clinical trials of the interferons (IFNs) have not only led to a promising new approach to treatment, but have also stimulated basic research in the immunological mechanisms of underlying disease activity. Administration of IFN-γ promotes exacerbations of MS, whereas recombinant IFN-β has been shown, in controlled clinical trials, to suppress them. Other ongoing studies are likely to provide further information about its long-term therapeutic value. More importantly, laboratory studies performed in conjunction with these clinical trials have provided fresh insights into the pathogenesis of MS by revealing immunoregulatory mechanisms in which endogenous IFN-γ, TNF-α, and other cytokines appear to play central roles. The ‘Decade of the Brain’ may therefore see answers both to the therapeutic dilemma of MS, and to more basic questions about the function of IFNs and other cytokines in activation and regulation of the disease process.