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Ciclosporin A prevents P2 T cell line-mediated experimental autoimmune neuritis (AT-EAN) in rat
Neuroscience Letters, 83 (1987) 195-200 Elsevier ScientificPublishers Ireland Ltd.
195
NSL 04996
Ciclosporin A prevents P2 T cell line-mediated experimental autoimmune neuritis (AT-EAN) in rat Hans-Peter H a r t u n g 1, B/irbel Schfifer l, Walter Fierz 2, Kurt Heininger 1 and Klaus V. T o y k a 1 JDepartment of Neurology, University of Diisseldorf, Diisseldorf (F.R.G.) and :Division of Clinical Immunology, Department of Medicine, University of Ziirich, Ziirich (Switzerland) (Received 22 July 1987; Revised version received 24 August 1987; Accepted 26 August 1987)
Key words. Experimental autoimmune neuritis (EAN); P2-reactive T cell line; Ciclosporin A; Immunosuppression; Rat Adoptive transfer experimental autoimmune neuritis (AT-EAN) produced in Lewis rats by injection of P2-reactive T lymphocyte line cells offers the unique possibility to study the exclusivecontribution of cell-mediated immune responses to the pathogenesis of autoimmune disease of the peripheral nervous system (PNS). It further lends itself to the evaluation of novel therapeutic approaches that may bear relevance to the human acute Guillain-Barr6 syndrome. The effects of the immunosuppressive agent ciclosporin A on the clinical, electrophysiologicaland morphological expression of AT-EAN were examined. We found that ciclosporin A suppressed development of the disease. In view of the known actions of ciclosporin A on T cells, these results indicate the requirement of activation and clonal proliferation of T lymphocytes to produce myelin damage in autoimmune diseases of the PNS.
T lymphocytes obtained from lymph nodes of rats afflicted with experimental autoimmune neuritis (EAN) can be specifically selected for their exclusive reactivity with the neuritogenic P2 protein of peripheral nervous system (PNS) myelin. After repetitive cycles of stimulation with antigen and interleukin 2, these cell lines can be transferred to naive syngeneic Lewis rats and produce adoptive transfer (AT)-EAN, an animal model of the acute Guillain-Barr6 syndrome [7, 11, 15]. AT-EAN offers the unique possibility to discriminate cellular and humoral immune responses of this acute inflammatory demyelinating polyradiculoneuropathy. This new model of EAN lends itself to the elucidation o f purely cellular events leading to myelin damage, a n d to the e v a l u a t i o n of m o r e specific i m m u n o s u p p r e s s i v e t r e a t m e n t strategies. W e examined the effects o f ciclosporin A for b o t h purposes. This i m m u n o s u p p r e s s i v e drug has emerged as a v a l u a b l e tool to dissect complex m e c h a n i s m s o f i m m u n e cell activation [6, 16]. A P2-specific T cell line o f the W3/25 +, O X 8 - helper/inducer p h e n o t y p e was
Correspondence: H.-P. Hartung, Neurologische Universit~itsklinik,Moorenstr. 5, D-4000 Diisseldorf 1, F.R.G. 0304-3940/87/$ 03.50 O 1987 ElsevierScientificPublishers Ireland Ltd.
196
raised and used to induce AT-EAN in 8-10-week-old female Lewis rats (180-200 g body wt.) with one single injection of 5 × 10 6 freshly activated T cells [11]. Seven rats received sham-treatment with intraperitoneai (i.p.) injections of sterile isotonic saline whereas 7 rats were treated with 1.5 mg/kg body wt., ciclosporin A (Sandimmun, Sandoz) in one daily i.p. injection from day 0 until sacrifice. Disease activity was monitored clinically on a non-linear 10-grade scale (0, normal to 10, death) [8], electrophysiologically using the left sciatic nerve as described [4], and after sacrifice at the height of the disease (day 9 after cell transfer, p.t.) by morphological examination. Animals were perfused with dextran followed by 4% paraformaldehyde-0.5% C l C L O - A
S H A M
L______ I
80
60
r
NCV Italy]
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afferent
'r "-'--1.
efferent
H
F-wive
140
20 0
3
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H-reflex
Latency
[ms] ~ _ ~ r - ~ - ~
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SSEP S*reaponae
2 * p (0.0S 6
Cllnicel Score
S 0
'w LI
"¢ 8
r 0
~
r
DAYS AFTER TRANSFER
Fig, 1. Serial electrophysiological studies in sham- and ciclosporin A-treated rats. Displayed, from top to bottom: NCV, motor nerve conduction velocity of the sciatic nerve (afferent: stimulation at the metacarpophalangeal joints or at the malleolus, recording with near-nerve electrodes at the sciatic notch; efferent: stimulation at the sciatic notch or the malleolus, recording at small foot muscles. Latencies of F-wave response, H-reflex, and S-response of lumbar somatosensory evoked potential (SSEP) at DI:/LI spinal level. N u m b e r s indicate in how m a n y of the 7 animals these responses could be obtained in the course of the disease, the remaining ones lacking discernible potentials. Values represent means/S.D, of 7 animals per treatment group. Asterisks indicate statistical significance of differences between groups ( P < 0 . 0 5 ) (Mann Whitney test).
197
glutaraldehyde in phosphate-buffered saline (PBS). Spinal cord, roots and right sciatic nerves were dissected, fixed for a further 4 h and postfixed in 2% osmium tetroxide. One micrometer Epon sections were stained with Toluidine blue. About 250 intraneural perivascular areas per animal were blindly scored for the severity of pathological alterations on a 4-grade scale [5]: 0, normal; 1, mild perivascular cellular infiltrate; 2, infiltrate plus demyelinated fibers in immediate proximity to a vessel; 3, infiltration plus demyelination throughout sections. The total percentage of lesional sites assigned to any of these grades was estimated for control and treatment groups. Sham-treated animals developed first clinical signs on day 4 p.t. and reached peak disease activity (paraparesis) on day 8 p.t. Electrophysiologically, these rats exhibited nerve conduction slowing and failure, temporal dispersion of F waves with increased latencies or even F wave failure, delayed or absent H reflexes, and prolonged latencies and temporal dispersion of the S response of lumbar somatosensory evoked potentials at the D12/L1 spinal level (Fig. 1). In marked contrast, ciclosporin A-treated rats did not show clinical signs nor did they have significant impairment of nerve function (Figs. 1 and 2). The efficacy of ciclosporin A in preventing AT-EAN was also ascertained morphologically in that perivascular demyelination was only very mild (Figs. 3 and 4). Our results demonstrate that administration of ciclosporin A from the day of cell transfer throughout the course of the disease completely protected rats from developing the disease. Suppressive activity of ciclosporin A on classical myelininduced EAN has been reported before in a morphological study [8]. No measurements of functional nerve properties were presented and, in this model, it was not possible to differentiate between ciclosporin A effects on the T and B cell compartment of the immune response, both of which are profoundly influenced by this agent SHAM |
C I CLO-A
SHAM
C I CLO-A
,i
,i
,U"
DAY 0 M
F
DAY 8 ~
lo~v[ ,m
A
2our1 2ms
B
Fig. 2. Representative redrawn original recordings o f motor nerve conduction (A) and lumbar SSEP (B). Arrows indicate stimulation artifact. Numbers give latencies to S response (B). A: compound muscle action potentials (M) and F waves (F) obtained from small foot muscles upon stimulation of the sciatic nerve proximally at the sciatic notch (lower traces), or distally at the malleolus (upper traces). Note the marked fall in M response and F wave amplitudes and the delayed and dispersed F waves in sham-treated rats. B: S response of lumbar SSEP indicating dysfunction of afferent nerve conduction in sham-treated rats.
198
V
4
Fig. 3. Representativemicrographs of 1-pm Epon sections at S~ root levelsfrom sham-treated (A, B) and ciclosporin A-treated animals (C, D). Note extensivecellular infiltrationand demyelinationin (A, B) and the almost completeabsence of such findingsin (C, D). [10, 12]. Such a dissociation has only become possible with the advent of the ATEAN model in which B cell-mediated humoral responses contributing to tissue damage can be discounted because of the very short interval from transfer to manifestation of the disease, and the absence of detectable antibodies against myelin components in the sera of these animals [11, 15]. Ciclosporin A acts primarily on the T helper cell subset by interfering with early activation steps and thus prevents subsequent proliferation [l, 2, 6, 16]. This drug impairs the production of interleukin 2, at a pretranscriptional level [3, 9], by T helper cells not only in primary but also in secondary responses of sensitized lymphocytes upon specific re-challenge with antigen. Further, ciclosporin A diminishes interleukin 2-receptor gene expression [13]. Hence, it inhibits the clonal expansion of antigen-
199 100" 90 80 70 60 5o 4o 30 20 10 0
o
1
2
SHAM
3
O
1
CiCLO
2
A
Fig. 4. Semiquantitative assessment of histological alterations in sham-treated and ciclosporin A-treated rats. Approximately 250 intraneural perivascular areas from root sections of each animal were evaluated and the severity of morphological alterations graded on a 4-grade scale (0-3) (cf. methods). Bars represent cumulated total percentage of lesional sites assigned to any of these grades.
reactive cells required to amplify the o n g o i n g T cell-mediated response. A n o t h e r mechanism m a y be the blockade o f y-interferon release from T cells [14]. This lymphokine m a y be o f particular importance since it induces M H C class II antigen expression o f Schwann cells and apparently renders them capable o f acting as antigen-presenting cells, thereby m a r k i n g them as targets for the T cell-mediated autoimm u n e process [17]. By inference from the k n o w n spectrum o f ciclosporin A properties, our results emphasize the pathogenetic importance o f T cell activation and proliferation in the initiation and amplification phase o f E A N , the animal model o f the acute GuillainBarr6 syndrome. We t h a n k Ms. B. B l o m e n k a m p for expert technical assistance. This w o r k was supported by D F G SFB 200/B5; Ministerium fiir Wissenschaft und Forschung, N R W ; Gemeinn~tzige Hertie-Stiftung; and Schweiz. N a t i o n a l f o n d s zur F 6 r d e r u n g der wissenschaftlichen F o r s c h u n g (Projekt-Nr. 3.998-0.86 (W.F.)).
1 Bunjes, D., Hardt, C., R611inghoff,M. and Wagner, H., Cyclosporin A mediates immunosuppression of primary T-cell responses by impairing the release of interleukin 1 and interleukin 2, Eur. J. Immunol., 11 (1981) 657-661. 2 Dos Reis, G.A. and Shevach, E.M., Effect of cyclosporin A on T cell function in vitro, J. Immunol., 19 (1982) 2360-2367. 3 Elliott, J.F., Lin, Y., Mizel, S.S., Bleackley, R.C., Harnish, D.G. and Paekan, V., Induction of interleukin 2 messenger RNA inhibited by cyclosporin A, Science, 226 (1984) 1439-1441.
200 4 Heiniger, K., Stoll, G., Linington, C., Toyka, K.V. and Wekerle, H., Conduction failure and nerve conduction slowing in experimental allergic neuritis mediated by P2-specific T-cell lines, Ann. Neurol., 19 (I 986) 44 49. 5 Heininger, K., Sch/ifer, B., Hartung, H.P., Fierz, W., Linington, C. and Toyka, K.V., The role ofmacrophages in experimental autoimmune neuritis induced by a P2-specific T cell line, Ann. Neurol., in press. 6 Hess, A.D. and Colombain, P.M., Mechanism of action of ciclosporin: in vitro studies, Prog. Allergy, 38 (1986) 198-221. 7 lzumo, S., Linington, C., Wekerle, H. and Meyermann, R,, Morphologic study on experimental allergic neuritis mediated by T cell line specific for bovine P2 protein in Lewis rats, Lab. Invest., 53 (1985) 209 218. 8 King, R.H.M,, Craggs, R.I., Gross, L.P., Tomkins, C. and Thomas, P.K., Suppression of experimental allergic neuritis by cyclosporin A, Acta Neuropathol. (Berlin), 59 (1983) 262-268. 9 Kr6nke, M., Leonard, W.J., Depper, J.M., Arya, S.K., Wong-Staal, F., Gallo, R.C., Waldmann, T.A. and Greene, W.C., Cyclosporin A inhibits T-cell growth factor gene expression at the level of mRNA transcription, Proc. Natl. Acad. Sci. USA, 81 (1984) 5214-5218. 10 Kunkl. A.S. and Klaus, G.G.B., Selective effects of cyclosporin A on functional B cell subsets in the mouse, J. lmmunol., 125 (1980) 2526-2531. 11 Linington, C., Izumo, S., Suzuki, M., Uyemara, K., Meyermann, R. and Wekerle, H., A permanent rat T cell line that mediates experimental allergic neuritis in the Lewis rat in vivo, J. Immunol., 133 (1984) 1946-1950. 12 Muraguchi, A., Beutler, J.L., Kehrl, J.H., Falkoff, R.J.M. and Fauci, A.S,, Selective suppression of an early step in human B cell activation by cyclosporin A, J. Exp. Med., 158 (1983) 690-702. 13 Reed, J.C., Abidi, A.H., Alpers, J.D., Hoover, R.G., Robb, R.J. and Nowell, P.C., Effect of cyclosporin A and dexamethasone on interleukin 2 receptor gene expression, J. Immunol., 137 (1986) 150 154.
14 Reem, G.H., Cook, L.A. and Vilcek, J., Gamma interferon synthesis by human thymocytes and T lymphocytes inhibited by cyclosporin A, Science, 221 (1983) 63-65. 15 Rostami, A., Burns, J.B., Brown, M.J., Rosen J., Zweiman, B., Lisak, R.P. and Pleasure, D.E., Transfer of experimental allergic neuritis with P2-reactive T-cell lines, Cell. Immunol., 91 (1985) 354361. 16 Shevach, E.M., The effects of cyclosporin A on the immune system, Annu. Rev. Immunol., 3 (1985) 397~423. 17 Wekerle, H., Schwab, M., Linington, C. and Meyermann, R., Antigen presentation in the peripheral nervous system. Schwann cells present endogenous myelin autoantigens to lymphocytes, Eur. J. Immunol.,16(1986) 1551 1557.
195
NSL 04996
Ciclosporin A prevents P2 T cell line-mediated experimental autoimmune neuritis (AT-EAN) in rat Hans-Peter H a r t u n g 1, B/irbel Schfifer l, Walter Fierz 2, Kurt Heininger 1 and Klaus V. T o y k a 1 JDepartment of Neurology, University of Diisseldorf, Diisseldorf (F.R.G.) and :Division of Clinical Immunology, Department of Medicine, University of Ziirich, Ziirich (Switzerland) (Received 22 July 1987; Revised version received 24 August 1987; Accepted 26 August 1987)
Key words. Experimental autoimmune neuritis (EAN); P2-reactive T cell line; Ciclosporin A; Immunosuppression; Rat Adoptive transfer experimental autoimmune neuritis (AT-EAN) produced in Lewis rats by injection of P2-reactive T lymphocyte line cells offers the unique possibility to study the exclusivecontribution of cell-mediated immune responses to the pathogenesis of autoimmune disease of the peripheral nervous system (PNS). It further lends itself to the evaluation of novel therapeutic approaches that may bear relevance to the human acute Guillain-Barr6 syndrome. The effects of the immunosuppressive agent ciclosporin A on the clinical, electrophysiologicaland morphological expression of AT-EAN were examined. We found that ciclosporin A suppressed development of the disease. In view of the known actions of ciclosporin A on T cells, these results indicate the requirement of activation and clonal proliferation of T lymphocytes to produce myelin damage in autoimmune diseases of the PNS.
T lymphocytes obtained from lymph nodes of rats afflicted with experimental autoimmune neuritis (EAN) can be specifically selected for their exclusive reactivity with the neuritogenic P2 protein of peripheral nervous system (PNS) myelin. After repetitive cycles of stimulation with antigen and interleukin 2, these cell lines can be transferred to naive syngeneic Lewis rats and produce adoptive transfer (AT)-EAN, an animal model of the acute Guillain-Barr6 syndrome [7, 11, 15]. AT-EAN offers the unique possibility to discriminate cellular and humoral immune responses of this acute inflammatory demyelinating polyradiculoneuropathy. This new model of EAN lends itself to the elucidation o f purely cellular events leading to myelin damage, a n d to the e v a l u a t i o n of m o r e specific i m m u n o s u p p r e s s i v e t r e a t m e n t strategies. W e examined the effects o f ciclosporin A for b o t h purposes. This i m m u n o s u p p r e s s i v e drug has emerged as a v a l u a b l e tool to dissect complex m e c h a n i s m s o f i m m u n e cell activation [6, 16]. A P2-specific T cell line o f the W3/25 +, O X 8 - helper/inducer p h e n o t y p e was
Correspondence: H.-P. Hartung, Neurologische Universit~itsklinik,Moorenstr. 5, D-4000 Diisseldorf 1, F.R.G. 0304-3940/87/$ 03.50 O 1987 ElsevierScientificPublishers Ireland Ltd.
196
raised and used to induce AT-EAN in 8-10-week-old female Lewis rats (180-200 g body wt.) with one single injection of 5 × 10 6 freshly activated T cells [11]. Seven rats received sham-treatment with intraperitoneai (i.p.) injections of sterile isotonic saline whereas 7 rats were treated with 1.5 mg/kg body wt., ciclosporin A (Sandimmun, Sandoz) in one daily i.p. injection from day 0 until sacrifice. Disease activity was monitored clinically on a non-linear 10-grade scale (0, normal to 10, death) [8], electrophysiologically using the left sciatic nerve as described [4], and after sacrifice at the height of the disease (day 9 after cell transfer, p.t.) by morphological examination. Animals were perfused with dextran followed by 4% paraformaldehyde-0.5% C l C L O - A
S H A M
L______ I
80
60
r
NCV Italy]
J.
afferent
'r "-'--1.
efferent
H
F-wive
140
20 0
3
t.-------'--~1
6
J* ~*
H-reflex
Latency
[ms] ~ _ ~ r - ~ - ~
r~
*
SSEP S*reaponae
2 * p (0.0S 6
Cllnicel Score
S 0
'w LI
"¢ 8
r 0
~
r
DAYS AFTER TRANSFER
Fig, 1. Serial electrophysiological studies in sham- and ciclosporin A-treated rats. Displayed, from top to bottom: NCV, motor nerve conduction velocity of the sciatic nerve (afferent: stimulation at the metacarpophalangeal joints or at the malleolus, recording with near-nerve electrodes at the sciatic notch; efferent: stimulation at the sciatic notch or the malleolus, recording at small foot muscles. Latencies of F-wave response, H-reflex, and S-response of lumbar somatosensory evoked potential (SSEP) at DI:/LI spinal level. N u m b e r s indicate in how m a n y of the 7 animals these responses could be obtained in the course of the disease, the remaining ones lacking discernible potentials. Values represent means/S.D, of 7 animals per treatment group. Asterisks indicate statistical significance of differences between groups ( P < 0 . 0 5 ) (Mann Whitney test).
197
glutaraldehyde in phosphate-buffered saline (PBS). Spinal cord, roots and right sciatic nerves were dissected, fixed for a further 4 h and postfixed in 2% osmium tetroxide. One micrometer Epon sections were stained with Toluidine blue. About 250 intraneural perivascular areas per animal were blindly scored for the severity of pathological alterations on a 4-grade scale [5]: 0, normal; 1, mild perivascular cellular infiltrate; 2, infiltrate plus demyelinated fibers in immediate proximity to a vessel; 3, infiltration plus demyelination throughout sections. The total percentage of lesional sites assigned to any of these grades was estimated for control and treatment groups. Sham-treated animals developed first clinical signs on day 4 p.t. and reached peak disease activity (paraparesis) on day 8 p.t. Electrophysiologically, these rats exhibited nerve conduction slowing and failure, temporal dispersion of F waves with increased latencies or even F wave failure, delayed or absent H reflexes, and prolonged latencies and temporal dispersion of the S response of lumbar somatosensory evoked potentials at the D12/L1 spinal level (Fig. 1). In marked contrast, ciclosporin A-treated rats did not show clinical signs nor did they have significant impairment of nerve function (Figs. 1 and 2). The efficacy of ciclosporin A in preventing AT-EAN was also ascertained morphologically in that perivascular demyelination was only very mild (Figs. 3 and 4). Our results demonstrate that administration of ciclosporin A from the day of cell transfer throughout the course of the disease completely protected rats from developing the disease. Suppressive activity of ciclosporin A on classical myelininduced EAN has been reported before in a morphological study [8]. No measurements of functional nerve properties were presented and, in this model, it was not possible to differentiate between ciclosporin A effects on the T and B cell compartment of the immune response, both of which are profoundly influenced by this agent SHAM |
C I CLO-A
SHAM
C I CLO-A
,i
,i
,U"
DAY 0 M
F
DAY 8 ~
lo~v[ ,m
A
2our1 2ms
B
Fig. 2. Representative redrawn original recordings o f motor nerve conduction (A) and lumbar SSEP (B). Arrows indicate stimulation artifact. Numbers give latencies to S response (B). A: compound muscle action potentials (M) and F waves (F) obtained from small foot muscles upon stimulation of the sciatic nerve proximally at the sciatic notch (lower traces), or distally at the malleolus (upper traces). Note the marked fall in M response and F wave amplitudes and the delayed and dispersed F waves in sham-treated rats. B: S response of lumbar SSEP indicating dysfunction of afferent nerve conduction in sham-treated rats.
198
V
4
Fig. 3. Representativemicrographs of 1-pm Epon sections at S~ root levelsfrom sham-treated (A, B) and ciclosporin A-treated animals (C, D). Note extensivecellular infiltrationand demyelinationin (A, B) and the almost completeabsence of such findingsin (C, D). [10, 12]. Such a dissociation has only become possible with the advent of the ATEAN model in which B cell-mediated humoral responses contributing to tissue damage can be discounted because of the very short interval from transfer to manifestation of the disease, and the absence of detectable antibodies against myelin components in the sera of these animals [11, 15]. Ciclosporin A acts primarily on the T helper cell subset by interfering with early activation steps and thus prevents subsequent proliferation [l, 2, 6, 16]. This drug impairs the production of interleukin 2, at a pretranscriptional level [3, 9], by T helper cells not only in primary but also in secondary responses of sensitized lymphocytes upon specific re-challenge with antigen. Further, ciclosporin A diminishes interleukin 2-receptor gene expression [13]. Hence, it inhibits the clonal expansion of antigen-
199 100" 90 80 70 60 5o 4o 30 20 10 0
o
1
2
SHAM
3
O
1
CiCLO
2
A
Fig. 4. Semiquantitative assessment of histological alterations in sham-treated and ciclosporin A-treated rats. Approximately 250 intraneural perivascular areas from root sections of each animal were evaluated and the severity of morphological alterations graded on a 4-grade scale (0-3) (cf. methods). Bars represent cumulated total percentage of lesional sites assigned to any of these grades.
reactive cells required to amplify the o n g o i n g T cell-mediated response. A n o t h e r mechanism m a y be the blockade o f y-interferon release from T cells [14]. This lymphokine m a y be o f particular importance since it induces M H C class II antigen expression o f Schwann cells and apparently renders them capable o f acting as antigen-presenting cells, thereby m a r k i n g them as targets for the T cell-mediated autoimm u n e process [17]. By inference from the k n o w n spectrum o f ciclosporin A properties, our results emphasize the pathogenetic importance o f T cell activation and proliferation in the initiation and amplification phase o f E A N , the animal model o f the acute GuillainBarr6 syndrome. We t h a n k Ms. B. B l o m e n k a m p for expert technical assistance. This w o r k was supported by D F G SFB 200/B5; Ministerium fiir Wissenschaft und Forschung, N R W ; Gemeinn~tzige Hertie-Stiftung; and Schweiz. N a t i o n a l f o n d s zur F 6 r d e r u n g der wissenschaftlichen F o r s c h u n g (Projekt-Nr. 3.998-0.86 (W.F.)).
1 Bunjes, D., Hardt, C., R611inghoff,M. and Wagner, H., Cyclosporin A mediates immunosuppression of primary T-cell responses by impairing the release of interleukin 1 and interleukin 2, Eur. J. Immunol., 11 (1981) 657-661. 2 Dos Reis, G.A. and Shevach, E.M., Effect of cyclosporin A on T cell function in vitro, J. Immunol., 19 (1982) 2360-2367. 3 Elliott, J.F., Lin, Y., Mizel, S.S., Bleackley, R.C., Harnish, D.G. and Paekan, V., Induction of interleukin 2 messenger RNA inhibited by cyclosporin A, Science, 226 (1984) 1439-1441.
200 4 Heiniger, K., Stoll, G., Linington, C., Toyka, K.V. and Wekerle, H., Conduction failure and nerve conduction slowing in experimental allergic neuritis mediated by P2-specific T-cell lines, Ann. Neurol., 19 (I 986) 44 49. 5 Heininger, K., Sch/ifer, B., Hartung, H.P., Fierz, W., Linington, C. and Toyka, K.V., The role ofmacrophages in experimental autoimmune neuritis induced by a P2-specific T cell line, Ann. Neurol., in press. 6 Hess, A.D. and Colombain, P.M., Mechanism of action of ciclosporin: in vitro studies, Prog. Allergy, 38 (1986) 198-221. 7 lzumo, S., Linington, C., Wekerle, H. and Meyermann, R,, Morphologic study on experimental allergic neuritis mediated by T cell line specific for bovine P2 protein in Lewis rats, Lab. Invest., 53 (1985) 209 218. 8 King, R.H.M,, Craggs, R.I., Gross, L.P., Tomkins, C. and Thomas, P.K., Suppression of experimental allergic neuritis by cyclosporin A, Acta Neuropathol. (Berlin), 59 (1983) 262-268. 9 Kr6nke, M., Leonard, W.J., Depper, J.M., Arya, S.K., Wong-Staal, F., Gallo, R.C., Waldmann, T.A. and Greene, W.C., Cyclosporin A inhibits T-cell growth factor gene expression at the level of mRNA transcription, Proc. Natl. Acad. Sci. USA, 81 (1984) 5214-5218. 10 Kunkl. A.S. and Klaus, G.G.B., Selective effects of cyclosporin A on functional B cell subsets in the mouse, J. lmmunol., 125 (1980) 2526-2531. 11 Linington, C., Izumo, S., Suzuki, M., Uyemara, K., Meyermann, R. and Wekerle, H., A permanent rat T cell line that mediates experimental allergic neuritis in the Lewis rat in vivo, J. Immunol., 133 (1984) 1946-1950. 12 Muraguchi, A., Beutler, J.L., Kehrl, J.H., Falkoff, R.J.M. and Fauci, A.S,, Selective suppression of an early step in human B cell activation by cyclosporin A, J. Exp. Med., 158 (1983) 690-702. 13 Reed, J.C., Abidi, A.H., Alpers, J.D., Hoover, R.G., Robb, R.J. and Nowell, P.C., Effect of cyclosporin A and dexamethasone on interleukin 2 receptor gene expression, J. Immunol., 137 (1986) 150 154.
14 Reem, G.H., Cook, L.A. and Vilcek, J., Gamma interferon synthesis by human thymocytes and T lymphocytes inhibited by cyclosporin A, Science, 221 (1983) 63-65. 15 Rostami, A., Burns, J.B., Brown, M.J., Rosen J., Zweiman, B., Lisak, R.P. and Pleasure, D.E., Transfer of experimental allergic neuritis with P2-reactive T-cell lines, Cell. Immunol., 91 (1985) 354361. 16 Shevach, E.M., The effects of cyclosporin A on the immune system, Annu. Rev. Immunol., 3 (1985) 397~423. 17 Wekerle, H., Schwab, M., Linington, C. and Meyermann, R., Antigen presentation in the peripheral nervous system. Schwann cells present endogenous myelin autoantigens to lymphocytes, Eur. J. Immunol.,16(1986) 1551 1557.