Incidence of CD4+ IL-2R alpha+ and CD4+ CD45RA+ T-cells in progressive multiple sclerosis and the influence of short-term (3 months) FK 506 therapy

Pseudolycorine chloride ameliorates Th17 cell-mediated central nervous system autoimmunity by restraining myeloid-derived suppressor cell expansion

CONTEXT

The alkaloids of Narcissus tazetta L. var. Chinensis Roem (Amaryllidaceae) have antitumor and antiviral activities. However, the immunopharmacological effects of one of its constituents, pseudolycorine chloride (PLY), have not been reported yet.

OBJECTIVE

We evaluated the effect of PLY on myeloid-derived suppressor cells (MDSCs) expansion and differentiation into monocyte-like MDSCs (M-MDSCs) and examined whether PLY alleviates Th17 cell-mediated experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS).

MATERIALS AND METHODS

In vitro, MDSCs were treated with PLY (0.67, 2 and 6 μM) or solcitinib (10 μM, positive control) for 48 or 96 h, and their proliferation, expansion, and differentiation into M-MDSCs were examined by flow cytometry. Myelin oligodendrocyte glycoprotein (MOG_35-55) was used to induce EAE in female C57BL/6 mice, and the mice were treated with 40 mg/kg/d PLY or 1 mg/kg/d FK-506 (tacrolimus, positive control) for 21 days. Inflammatory infiltration, spinal cord demyelination, and MDSCs and Th17 cells infiltration into the spinal cord were examined using haematoxylin and eosin staining, Luxol fast blue staining, and immunofluorescence, respectively.

RESULTS

In vitro, PLY (IC50/24 h = 6.18 μM) significantly inhibited IL-6 and GM-CSF-induced MDSCs proliferation, expansion and differentiation into M-MDSCs at all concentrations used. However, these concentrations did not show cytotoxicity. In mice, PLY (40 mg/kg) treatment alleviated EAE and inhibited inflammatory infiltration, demyelination, and MDSCs and Th17 cells infiltration into the spinal cord.

DISCUSSION AND CONCLUSIONS

PLY may be an excellent candidate for the treatment of MS and other autoimmune diseases.

FK506 and a nonimmunosuppressant derivative reduce axonal and myelin damage in experimental autoimmune encephalomyelitis: neuroimmunophilin ligand-mediated neuroprotection in a model of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) in which demyelination and axonal loss result in permanent neurologic disability. We examined the neuroprotective property of the immunosuppressant FK506 (tacrolimus), FK1706 (a nonimmunosuppressant FK506 derivative) and cyclosporin A (CsA) in a chronic relapsing experimental autoimmune encephalomyelitis (EAE) model of MS. Female SJL/J mice were immunized by subcutaneous (s.c.) injection with proteolipid protein 139-151 peptide in complete Freund's adjuvant. At the onset of paralysis, 12-14 days after immunization, mice received daily s.c. injections of FK506 (0.2, 1, and 5 mg/kg), FK1706 (5 mg/kg), CsA (2, 10, and 50 mg/kg), saline or vehicle (30% dimethylsulfoxide) for 30 days. FK506 (at a dose of 5 mg/kg) reduced the severity of the initial disease and suppressed relapses. FK1706 did not significantly alter the clinical course and CsA (at a dose of 50 mg/kg) lessened the severity of the initial episode of EAE but did not alter relapses. In the thoracic spinal cord, FK506 (5 mg/kg), FK1706 (5 mg/kg), and CsA (50 mg/kg) significantly (P < 0.001) reduced the extent of damage in the dorsal, lateral, and ventral white matter by a mean of up to 95, 68, and 30%, respectively. A nonimmunosuppressant dose of FK506 (0.2 mg/kg) also significantly (P < 0.001) reduced the extent of damage in the spinal cord by a mean of up to 45%. Other dosages of these compounds were ineffective. FK506 markedly protects against demyelination and axonal loss in this MS model through immunosuppression and neuroprotection.

Inhibition of the progression of multiple sclerosis by linomide is associated with upregulation of CD4+/CD45RA+ cells and downregulation of CD4+/CD45RO+ cells

In a recent double-blind, phase II study, conducted in our department, we showed that Linomide-treated MS patients had significantly less active lesions (in serial monthly MRI tests) and a tendency for clinical stabilization. Here we present the immunological evaluation of the patients who participated in this study and propose a novel mechanism by which Linomide downregulates autoreactivity. Peripheral blood leukocytes (PBLs), serum, and CSF samples were obtained at two to four time points over the 6 months of the trial. Flow cytometric analysis (FACS) of the CD5/CD19, CD4/CD8, CD14/CD3, CD16/CD3, CD45RA/CD4, and CD45RO/CD4 surface markers on PBLs was performed and the levels of the IL-1beta, IL-2, IL-4, IL-6, IL-10, TNF-alpha, IFN-gamma, and IL-2R were also examined. White blood counts of Linomide-treated patients were consistently elevated throughout the treatment period (P = 0.002-0.04). Cytokines levels in serum and CSF were highly fluctuating and we could not detect any clear trend as a result of Linomide treatment. FACS analysis showed that Linomide treatment significantly increased the percentage of the CD4+/CD45RA+ cells (from 35.5% at baseline to 42.3% at week 24; P = 0.02), and decreased CD4+/CD45RO+ lymphocytes (62.6% at baseline vs 53.7% at week 24, P = 0.02). Linomide also induced a transient increase in the NK-cells, the NK 1.1 cells, and the CD5 B-cells (P = 0.02). Upregulation of naive CD45RA T-lymphocytes and parallel downregulation of memory CD45RO cells seems to be one of the main mechanisms by which Linomide inhibits MS activity and may represent an alternative immunomodulating approach for the treatment of MS and autoimmunity in general.

Influence of FK 506 (tacrolimus) on circulating CD4+ T cells expressing CD25 and CD45RA antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial

We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 alpha chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25+ CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 +/- 0.2 to 0.5 +/- 0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45R+ CD4+ cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25+ CD4+ cells and a reciprocal increase in CD45RA+ CD4+ cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration.