INDUCTION OF PERIPHERAL T CELL TOLERANCE TO MBP IN PUJ ...

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INDUCTION OF PERIPHERAL T CELL TOLERANCE. TO MBP IN PUJ MICE BY A NON DEPLETING. ANTI-CD4 mAb TREATMENT. Biasi G., Facchinetti.

INDUCTION OF PERIPHERAL T CELL TOLERANCE TO MBP IN PUJ MICE BY A NON DEPLETING ANTI-CD4 mAb TREATMENT.

INCREASE

Biasi G., Facchinetti B.‘, Monastra G.‘, Mexxaiira S.‘, Sivieti S:, Tavolato O.b, Gallo P.’ Inst. of Experimental Pathology University of Ancona, * Inst. of Oncology and l Inst. of Neurology-Second Newvlogic Clinic University of Padova, lfaly.

M. P. de Castro, M.. Otano, M.L. Subirk. J. Iriarte’. University Clime of Navarm, Pamplona, Spain. ‘Rush Presbyterian St. Lukes Medical Center, Chicago, IL. USA.

Following pre-treatment with a non dspleting antlCD4 mAb (Hl29.18), which induces long-lasting receptor saturation, PUJ mice were fully proGcad from experimental autoimmune encephalomyelitir (EAE) induced by injection of myelin basic protein (MBP). Lymph node cells from antiCM+ YBP-treated mice were specffically unreqonsive to YBP stimulation in vitro and these mice did not develop EAE following MBP re-challange 5 weeks later when the CD4+ cells were no longer coated by the mAb. Moreover, superantigen staphylococcal enterotoxin 6 (SEB) inoculation which rolnduces EAE in MBP kmtunixed mice, failed to activate encephalitogenic T ceils in antiCD4+ MBPtreated mice indkzatlng that 1 IymphocyW tolerance was established. However, MBP m-challenge 16 waeks later, but not SEB treatment, could produce acute EAE in these mice. This obse~~atlon indicates that no memory of the first priming existed at this time, and that new MBP-specific peripheralizad T cell preclNsors had roached the threshold to produce disease after MBP recognition. On the whole, our findings suggest that tre8tment of PUJ mice with non depleting antlCD4 mAb befors MBP challanga Induces MBPspecific hoies in the peripheral CM call repettoire.

w: In OUTUnit, previous studies have shown an increase in CD4+CD29+ cells, inductors of B lymphocytes (LB) in peripheral lymphcwte subset? in Multiole Sclerosis (MS) pati&. This finding has not been reported so far. These results were validated in different groups of patients. w: To know the phenotypical characteristics of the CD4+cD29+ cells in patients with MS. Eptirptp: Thirty-six patients (25 women, I1 men) with clinically definite MS. Mean aae: 36 “ears. Mean ;ime of evolution: 5 years. Twenty-five pat&its with other neurological diseases were used as conuols. hff&o&: Quantification of lymphocyte subsets and releasing of cytokines. Descriptive and non-parametric statistic techniques. Ees.t&: Seventeen patients with MS (47.2%) and 3 of the 25 with other neurolonical diseases (10.6%) displayed abnormal lymphncyte subsets (significant differences: pCg.02). The most frequent alterations were: ?CD4+CD29+ cells; ?CDS+CDl lb- cells and tCD4+CD45+ cells. The cytokines released in MS patients were IL2 and gamma interferon (THI Phenotype). We did not find IL4 release. m: The most frequent altwations in lymphaeyte subsets in the seturn of patients with MS were ‘?CD4tCD29t cells (ind. LB), with Tl phenotype. We suggest to consider this alteration in the laboratory-support diagnosis and take it into account when

This work was supportad by granta from Italian Multipls Association (AISM), MURST 6W, and Vsnato [email protected]

Sckrosir

IFN &lb

IN MS

REVERSES

ELEVATED

LYMPHOCYTE

Kiirsad GWIQ and Anthony 1 Reder University of Chicago, Chiigo, Illinois,

87-l

OF CD4+CDZ9+

CELLS

IN PATIENTS

WITH

MULTIPLE

SCLEROSIS

considering which patimtr csn be responsive to p-lnterfemn.

IMMUNOREGULATORY EFFECTS OF INTERFERON-B AND INTERACTING CYTOKINES ON HUMAN VASCULAR ENDOTHELIAL CELLS IMPLICATIONS

USA

FOR MULTIPLE

SCLEROSIS

Ariel Miller, Naomi Lanir, Sarah Shapiro. Michel Revel, Silvia Honigman, Amalia Kinarty. and NitzaLahat Curmel and Rumbam Medical Centers, Haifa; und The Weimann Imtitute of Science, Rehovot. Israel. The mechanism(s) of action responsible for the anti-inflammatory effects

Costlmulat~ molea~les help determIne T cell responses to antigens. 87 co&mulatory proteins a’! antigen pmSefitin!J &ls (moncqtes and a&ated B &ls) bind to CD28 on T cells. B7-CD28 costknulation induces T cell adtuatbt~ la& of CMEB7 stlmulatlon results in anegy. B7-1 enhances Thl w; 87-2 increases Th2 lunctlon. Thl cells and m am bnpH&ed in MS exac8rbetions and onset of EAE. IFNr Md adbatbncauseexp~skm0fB7on immune cells. We hypothesized Ihat 87 w affects immune rs~ufaUon In MS. DtHillQ active MS, 87-l expreadon On m B C9ltS increases (l&8.2%* in 15 acuve MS vs a9i2.576In 16stable MS patients; 9.8&8.4% In 30 NL, both pcO.OCX]. In amtm!#, 87-2 expressIon decreasesinauiveMSanmonocytes[24~16Winactive MS vs 4!322% in NL, pcO.02: 41k339b in stabbe MS, not signify. In V&D, IFN+i and IFNq tnduw! 87-l and B7-2 on monocytes. In vhm. howmmr, IFN &lb thempy caused a mafked reduction in B-I-l+Bcells[for9~~3~MSpatieclts,base(ine= 7.9358%’ wi after IFN @-lb at l-4 weeks = 2.W.fl%, pcO.05; and alter IFN p-1 b at 1-Q montha = 2.&3.2%, p&.01]. This decm&~ in 87 cotlelated with cllnw hnpmt. [email protected] and Is diminished with IFN &lb thempy. 87 expm&on may pmdkl exacerbaficm3, amWe w&h elleols ol lhempy or the eventual course of MS and other inmmafofydis03ws. MadMcetion of 87 costknulatlon could potenualb be used to alter the coutsa of Ms.

mediated by IFN-p are still elusive although suggestions include anti-viral effects. the enhancement of NK or suppressor T cell activity and opposition to the effects of inflammatory cytokines. As vascular endothelial cells are active pticipants in infl ammatoty and demyelinating processes, we decided to examine the effects of IFN-p on the expression of major

histocompatibility complex (MHC) gene products and the adhesion molecule ICAMon human vascular endothelial cells (ECs). Human umbilical u3s demonstrated constitutive expression of ICAM- I and MHC class-l molecules but did not express MHC class-11 molecules. Basal expnsssion of ICAMmolecules was enhanced by TNFn and to a lesser extent by IF?&p but was not affected by 1FN-y. MHC class-l expression on ECs was enhanced by IFN-l3, lFN7. and TNFa. Furthermore, a synergistic effect was observed to combinations of these interacting cytokinos. incubation of ECs with IFNr , but not IFN-p, induced class-11 expression in a dose dependent manner. Moreover, co-incubation of ECs with IFN-p and lFNr resulted in significant down-regulation of class-11 molecules expression which was directly dependent on IFN-8 concentration. Northern blot analysis of DRa and ~microglobulin mRNA expression suggested that cytokine-mediated regulation of MHC molecules is at the transcriptional level, while modulation of ICAMexpression appears to be at the transcriptional as well as post-transcriptional level. Thus, our study demonstrated that IFN-fi and interacting cytokines exert complex immunoregulatory effects on endothelial cells with differential modulatory effects on various cell surface markers. Understanding the biological significance of these immunomodulatory effects mediated by IFN-8 may have important implications for cytokine-based strategies in the treatment of inflammatory and autoimmune diseases.

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