Anti-CD52 blocks EAE independent of PD-1 signals and promotes repopulation dominated by double-negative T cells and newly generated T and B cells.

Lymphocyte depletion using anti-CD52 antibody effectively reduces relapses of multiple sclerosis (MS). To begin to understand what mechanisms might control this outcome, we examined the effect of a murine-CD52-specific mAb on the depletion and repopulation of immune cells in mice with experimental autoimmune encephalomyelitis (EAE), a model of MS. We tested whether the tolerance-promoting receptor programmed cell death protein-1 (PD-1) is required for disease remission post anti-CD52, and found that PD-1-deficient mice with a more severe EAE were nevertheless effectively treated with anti-CD52. Anti-CD52 increased the proportions of newly generated T cells and double-negative (DN) T cells while reducing newly generated B cells; the latter effect being associated with a higher expression of CD52 by these cells. In the longer term, anti-CD52 caused substantial increases in the proportion of newly generated lymphocytes and DN T cells in mice with EAE. Thus, the rapid repopulation of lymphocytes from central lymphoid organs post anti-CD52 may limit further disease. Furthermore, these data identify DN T cells, a subset with immunoregulatory potential, as a significant hyperrepopulating subset following CD52-mediated depletion.

Circulating mesenchymal stem cells, stromal derived factor (SDF)-1 and IP-10 levels increased in clinically active multiple sclerosis patients but not in clinically stable patients treated with beta interferon.

BACKGROUND: Mesenchymal stem cells (MSCs) have the capacity to migrate into the inflammatory regions in response to chemokines such as, IP-10 and SDF-1α and function as anti-inflammatory and immunomodulatory cells. METHODS: In this study we investigated the MSCs frequency in peripheral blood of Relapsing-Remitting Multiple Sclerosis (RRMS) patients in clinically active and not on disease-modifying therapy (DMT) (n = 22) and clinically stable on DMT (Interferon-ß (IFN-ß) therapy) for at least 6 months (n = 22) in comparison to sex and age-matched healthy controls (n = 25) using flow cytometry. The serum and gene expression levels of IP-10 and SDF-1a were also measured in studied groups by ELISA and Real time- PCR. RESULTS: We obtained significant high levels of circulating CD45-CD34- CD90+ and CD45-CD34- CD105+ cells in clinically active patients, not on DMT and patients under IFNß therapy compared with control group. Furthermore, a significant increase in the percentage of circulating CD45-CD34- CD105+ CD90+ cells was found in clinically active patients and not on DMT compared with control group. Serum analysis of IP-10 and SDF-1α showed a significant increase in IP10 concentration in both clinically active not on DMT (P = 0.02) and on DMT (P = 0.005) RRMS patients in comparison with controls. The expression level of SDF-1α mRNA significantly increased in clinically active not on DMT (P = 0.03), while decreased in patients under IFNß therapy (P = 0.04). The mRNA expression of IP-10 only increased in patients on DMT compared with controls (P = 0.05). CONCLUSION: Circulating MSCs, IP-10 and SDF-1α levels, increased in RRMS patients with clinically active not on DMT and IFN-ß therapy reduced circulating MSCs and SDF-1α levels.

Differential serostatus of Epstein-Barr virus in Iranian MS patients with various clinical patterns.

Background: Epidemiological evidence suggests a role of Epstein-Barr virus (EBV) in triggering the pathogenesis of Multiple Sclerosis (MS). The aim of this study was to assess the EBV-specific antibodies in MS patients with various clinical patterns and their association with the production of IFN-γ, IL-12, and IL-4 cytokines compared with healthy individuals. Methods: We measured EBNA-1 IgG, VCA IgG, and production of IFN-γ, IL-12 and IL-4 cytokines in patients with different clinical patterns and healthy controls using ELISA method. Results: There was a higher titer of anti-EBV antibodies in MS patients compared to healthy controls. SPMS patients generated higher EBNA-1 levels than those with RRMS and PPMS patients whereas; the level of VCA IgG was higher in the RRMS patients than PPMS. In PPMS patients, a significant increase was found in IFN-γ and IL-12 cytokines compared to other subtypes, whereas IL-4 cytokine had a decreased level compared to RRMS patients. Higher anti-EBV antibodies are associated with increased IL-12 cytokine in RRMS patients. However, no significant correlation was found between these antibodies and other secreted cytokines. Conclusion: EBV infection is one of the strong risk factors for MS. Acting on these factors could be useful to decrease the incidence and disease exacerbation of MS. Study of the antibody levels to EBV virus could be useful for evaluating MS risk score in each clinical subtypes.

Combination of stem cell mobilized by granulocyte-colony stimulating factor and human umbilical cord matrix stem cell: therapy of traumatic brain injury in rats.

OBJECTIVES: Clinical studies of treating traumatic brain injury (TBI) with autologous adult stem cells led us to examine the impression of a combination therapy. This was performed by intravenous injection of human umbilical cord matrix stem cell (hUCMSC-Wharton(,)s jelly stem cell) with bone marrow cell mobilized by granulocytecolony stimulating factor (G-CSF) in rats injured with cortical compact device. MATERIALS AND METHODS: Adult male Wistar rats (n= 50) were injured with controlled cortical impact device and divided into five groups. All injections were performed 1 day after injury into the tail veins of rats. Neurological functional evaluation of animals was performed before and after injury using modified neurological severity scores (mNSS). Animals were sacrificed 42 days after TBI and brain sections were stained by Brdu immunohistochemistry. RESULTS: Statistically significant improvement in functional outcome was observed in treatment groups when compared with control (P< 0.01). mNSS showed no significant differences among the hUCMSC and G-CSF treated groups at any time point (end of trial). Rats with hUCMSC + G-CSF treatment had a significant improvement on mNSS at 5 and 6 week compared to other treatment group (P< 0.01). CONCLUSION: Histological analysis in G-CSF+ hUCMSC treated traumatic rats exhibited significant increase in numbers of Brdu immunoreactive cells in their traumatic core compared with other labeled group.

Comparison of transplantation of bone marrow stromal cells (BMSC) and stem cell mobilization by granulocyte colony stimulating factor after traumatic brain injury in rat.

BACKGROUND: Recent clinical studies of treating traumatic brain injury (TBI) with autologous adult stem cells led us to compare effect of intravenous injection of bone marrow mesenchymal stem cells (BMSC) and bone marrow hematopoietic stem cell mobilization, induced by granulocyte colony stimulating factor (G-CSF), in rats with a cortical compact device. METHODS: Forty adult male Wistar rats were injured with controlled cortical impact device and divided randomly into four groups. The treatment groups were injected with 2 × 106 intravenous bone marrow stromal stem cell (n = 10) and also with subcutaneous G-CSF (n = 10) and sham-operation group (n = 10) received PBS and "bromodeoxyuridine (Brdu)" alone, i.p. All injections were performed 1 day after injury into the tail veins of rats. All cells were labeled with Brdu before injection into the tail veins of rats. Functional neurological evaluation of animals was performed before and after injury using modified neurological severity scores (mNSS). Animals were sacrificed 42 days after TBI and brain sections were stained by Brdu immunohistochemistry. RESULTS: Statistically, significant improvement in functional outcome was observed in treatment groups compared with control group (P<0.01). mNSS showed no significant difference between the BMSC and G-CSF-treated groups during the study period (end of the trial). Histological analyses showed that Brdu-labeled (MSC) were present in the lesion boundary zone at 42nd day in all injected animals. CONCLUSION: In our study, we found that administration of a bone marrow-stimulating factor (G-CSF) and BMSC in a TBI model provides functional benefits.