The eukaryotic cytoskeleton is essential for structural support and intracellular transport, and is therefore a common target of animal pathogens. However, no phytopathogenic effector has yet been demonstrated to specifically target the plant cytoskeleton. Here we show that the Pseudomonas syringae type III secreted effector HopZ1a interacts with tubulin and polymerized microtubules. We demonstrate that HopZ1a is an acetyltransferase activated by the eukaryotic co-factor phytic acid. Activated HopZ1a acetylates itself and tubulin. The conserved autoacetylation site of the YopJ / HopZ superfamily, K289, plays a critical role in both the avirulence and virulence function of HopZ1a. Furthermore, HopZ1a requires its acetyltransferase activity to cause a dramatic decrease in Arabidopsis thaliana microtubule networks, disrupt the plant secretory pathway and suppress cell wall-mediated defense. Together, this study supports the hypothesis that HopZ1a promotes virulence through cytoskeletal and secretory disruption.

We describe the presenting features and long-term outcome of an unusual cluster of pediatric acute flaccid paralysis cases that occurred in Canada during the 2014 enterovirus D68 outbreak. Children (n = 25; median age 7.8 years) presenting to Canadian centers between July 1 and October 31, 2014, and who met diagnostic criteria for acute flaccid paralysis were evaluated retrospectively. The predominant presenting features included prodromal respiratory illness (n = 22), cerebrospinal fluid lymphocytic pleocytosis (n = 18), pain in neck/back (n = 14) and extremities (n = 10), bowel/bladder dysfunction (n = 9), focal central gray matter lesions found in all regions of the spinal cord within the cohort (n = 16), brain stem lesions (n = 8), and bulbar symptoms (n = 5). Enterovirus D68 was detectable in nasopharyngeal specimens (n = 7) but not in cerebrospinal fluid. Acute therapies (corticosteroids, intravenous immunoglobulins, plasmapheresis) were well tolerated with few side effects. Fourteen of 16 patients who were followed beyond 12 months post onset had neurologic deficits but showed ongoing clinical improvement and motor recovery.

Children with MS demonstrate abnormally increased rates of EBV viral reactivation and a broader range of genetic variants, suggesting a selective impairment in their immunologic control of EBV.

ABBREVIATIONS IVIGIntravenous immunoglobulin MOG Myelin oligodendrocyte glycoproteinThe aim of this study was to evaluate tolerability of and response to rituximab in children with myelin oligodendrocyte glycoprotein (MOG) antibody-positive relapsing neuroinflammatory disease. This was an observational study of prospectively collected data on 12 consecutive children (eight females, four males; median age at onset 10y 6mo [interquartile range {IQR} 7y 2mo-12y 5mo], median follow-up 2y 1mo [IQR 1y 7mo-2y 6mo]) with central nervous system inflammation and persistent serum MOG immunoglobulin G positivity more than 12 weeks after clinical presentation. Patients received a standardized rituximab treatment protocol. MOG antibody testing was performed following standardized cell-based methods. Median clinical follow-up after rituximab induction was 2 years (IQR 1y 7mo-2y 10mo). The relapse rate in the first 12 months posttreatment was 0 (IQR 0-0). After rituximab, two patients relapsed during B-cell suppression and four showed clinical or radiological disease recurrences at B-cell reconstitution. Mild-to-moderate infusion related adverse events occurred in two patients. Leukopenia developed in seven patients and serum immunoglobulin suppression in five patients with no significant age effect on the risk of their development. None developed severe life-threatening events. Rituximab-induced B-cell suppression was associated with absence of relapses in 10 patients who were MOG-positive with recurrent disease. Rituximab was well tolerated. The most frequent adverse effects were hypogammaglobulinemia and leukopenia. We recommend monitoring of complete blood counts and immunoglobulins in this population.Myelin oligodendrocyte glycoprotein (MOG) antibodies are seen in the serum of 25% to 58% of children who present with a first acquired demyelinating syndrome, 1-5 and may also be seen in adults presenting with acute neuroinflammation (4-15%). 3,5-7 Twenty-five per cent to almost 75% will continue to have high titers of MOG antibodies after presenting acutely, 8 with considerable risk of relapse. 9 In one adult-based cohort of 252 patients in the UK with elevated MOG antibodies, 36% had relapses within a median duration of 16 months. 8 Steroids, intravenous immunoglobulin (IVIG), and plasma exchange 10 may be beneficial in reducing symptomatology at the time of an acute event, but are unlikely to decrease the risk of relapse.There is variable support in the literature for the relevance of persistent MOG antibody status for predicting recurrent disease. 11,12 However, prevention of recurrence in the face of repeated neuroinflammatory events prevent future disability. Given the potential for irreversible neurological disability, 13 and the robust response of other antibody-mediated conditions to B-cell suppression with rituximab therapy, 14 we used a standardized treatment protocol using rituximab in children with recurrent central nervous system (CNS) inflammatory disease and persistent MOG antibody positivity 12 weeks or more af...

Epstein-Barr virus (EBV) infection is associated with increased multiple sclerosis (MS) risk. Recently, cytomegalovirus (CMV) infection has been proposed as a protective factor against MS development. We determined EBV, herpes simplex virus, varicella-zoster virus and CMV seroprevalence in 247 prospectively followed children with acquired demyelinating syndromes (ADS). Remote EBV infection was more common in children with MS than those with monophasic ADS while CMV infection was more common in children with monophasic ADS. Children displaying evidence of remote EBV without CMV infection were at highest risk of subsequent MS diagnosis. Viral infection repertoire detected at ADS provides important prognostic information.