Tuftsin Promotes an Anti-Inflammatory Switch and Attenuates Symptoms in Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a demyelinating autoimmune disease mediated by infiltration of T cells into the central nervous system after compromise of the blood-brain barrier. We have previously shown that administration of tuftsin, a macrophage/microglial activator, dramatically improves the clinical course of experimental autoimmune encephalomyelitis (EAE), a well-established animal model for MS. Tuftsin administration correlates with upregulation of the immunosuppressive Helper-2 Tcell (Th2) cytokine transcription factor GATA-3. We now show that tuftsin-mediated microglial activation results in shifting microglia to an anti-inflammatory phenotype. Moreover, the T cell phenotype is shifted towards immunoprotection after exposure to tuftsin-treated activated microglia; specifically, downregulation of pro-inflammatory Th1 responses is triggered in conjunction with upregulation of Th2-specific responses and expansion of immunosuppressive regulatory T cells (Tregs). Finally, tuftsin-shifted T cells, delivered into animals via adoptive transfer, reverse the pathology observed in mice with established EAE. Taken together, our findings demonstrate that tuftsin decreases the proinflammatory environment of EAE and may represent a therapeutic opportunity for treatment of MS

Oligodendrocytes: biology and pathology

Oligodendrocytes are the myelinating cells of the central nervous system (CNS). They are the end product of a cell lineage which has to undergo a complex and precisely timed program of proliferation, migration, differentiation, and myelination to finally produce the insulating sheath of axons. Due to this complex differentiation program, and due to their unique metabolism/physiology, oligodendrocytes count among the most vulnerable cells of the CNS. In this review, we first describe the different steps eventually culminating in the formation of mature oligodendrocytes and myelin sheaths, as they were revealed by studies in rodents. We will then show differences and similarities of human oligodendrocyte development. Finally, we will lay out the different pathways leading to oligodendrocyte and myelin loss in human CNS diseases, and we will reveal the different principles leading to the restoration of myelin sheaths or to a failure to do so

The structural effect of systemic NGF treatment on permanently axotomised dorsal root ganglion cells in adult rats

The effect of systemic NGF treatment on loss and shrinkage of dorsal root ganglion cells was studied in adult male rats after permanent axotomy. Nineteen 16 to 18-wk-old rats had their right 5th lumbar spinal nerve ligated and cut approximately 7 mm peripheral to the ganglion. Two days before the operation, treatment with subcutaneous injections of human recombinant NGF (1.0–0.5 mg/kg/day) was started in 9 test rats; 10 controls were given saline injections. After 1 mo the levels of substance P (SP) and calcitonin gene related peptide (CGRP) were significantly increased in intact sciatic nerve. The number and mean volume of perikarya were estimated using assumption-free stereological techniques including vertical sections, the Cavalieri principle, optical disectors, the planar rotator and systematic sampling techniques. Systemic NGF administration had no influence on survival of primary sensory neurons after axotomy. The number of perikarya was 14300 ( S.D.=1800) in axotomised ganglia in control rats versus 14700 ( S.D.=2100) in axotomised ganglia of NGF treated rats. The reduction of perikarya volume after axotomy was significantly less after NGF treatment (11600 μm(3) in the control group versus 8000 μm(3) in the NGF treated group). However, the apparent protection of NGF-treatment on perikaryal volume is explained by a hitherto unrecognised size effect on nonaxotomised dorsal root ganglion cells. The untreated rats had a mean volume of 24700 μm(3) ( S.D.=2700 μm (3)) whereas rats treated with NGF had a volume of 20400 μm(3) ( S.D.=1700 μm(3)) on the nonaxotomised side. In conclusion, systemic NGF treatment in adult rats has no effect on dorsal root ganglion cell loss in permanent axotomy whereas perikaryal size of intact nonaxotomised cells is reduced