Klebsiella pneumoniae hijacks the Toll-IL-1R protein SARM1 in a type I IFN-dependent manner to antagonize host immunity

Many bacterial pathogens antagonize host defense responses by translocating effector proteins into cells. It remains an open question how those pathogens not encoding effectors counteract anti-bacterial immunity. Here, we show that Klebsiella pneumoniae exploits the evolutionary conserved innate protein SARM1 to regulate negatively MyD88- and TRIF-governed inflammation, and the activation of the MAP kinases ERK and JNK. SARM1 is required for Klebsiella induction of interleukin-10 (IL-10) by fine-tuning the p38-type I interferon (IFN) axis. SARM1 inhibits the activation of Klebsiella-induced absent in melanoma 2 inflammasome to limit IL-1β production, suppressing further inflammation. Klebsiella exploits type I IFNs to induce SARM1 in a capsule and lipopolysaccharide O-polysaccharide-dependent manner via the TLR4-TRAM-TRIF-IRF3-IFNAR1 pathway. Absence of SARM1 reduces the intracellular survival of K. pneumoniae in macrophages, whereas sarm1-deficient mice control the infection. Altogether, our results illustrate an anti-immunology strategy deployed by a human pathogen. SARM1 inhibition will show a beneficial effect to treat Klebsiella infections.

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SARM1 is an evolutionary conserved innate immune protein with a TIR domain

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Klebsiella pneumoniae induces SARM1 to limit inflammation, and to induce IL-10

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SARM1 inhibits the action of AIM2 inflammasome to limit IL-1β production

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In vivo, absence of SARM1 facilitates the clearance of Klebsiella pneumoniae

Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH

The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs) and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO) and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH), and several epitopes such as the LLO peptides, LLO_189−201 and LLO₉₁₋₉₉ and the GAPDH peptide, GAPDH₁₋₂₂. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH₁₋₂₂ peptide conferred higher protection and security against listeriosis than the widely explored LLO₉₁₋₉₉ peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH₁₋₂₂-specific CD4⁺ and CD8⁺ immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4⁺ and CD8⁺ epitopes.

[Prevention of mental retardation]

OBJECTIVE

To present within the general field of the conditions causing mental retardation, the preventive strategies for specific application available at the present time.

DEVELOPMENT

In spite of the fact that in the majority of cases of mental retardation the etiology is unknown, and for that reason, in them it is not possible to establish preventive strategies, within the last three decades, important research advances have helped to prevent thousands of cases of mental retardation of illnesses caused by Haemophilus influenzae B, measles encephalitis, Rh disease and severe jaundice in newborn infants, congenital hypothyroidism, phenylketonuria and congenital rubella; as well as removing lead from the environment, intervention programs for the proper use of seat belts, child safety seats, and motorcycle and bicycle helmets; early and adequate prenatal care, dietary supplementation with folic acid beginning before conception to reduce the risk of neural tube defects, avoidance of toxic substances during pregnancy like alcohol, and the use of newborn screening tests.

CONCLUSION

The primary and secondary prevention of conditions that cause mental retardation continue being a challenge. Require of a review of the present strategies, that frequently inform about the problem, but are not practice in an every day bases (ej. intake of alcohol during pregnancy, the universal use of seat belt and child safety seats during automobile travel). In the future we may have the possibility of prenatal gene therapy.

[Clinical treatment (non surgical) of spasticity in cerebral palsy]

OBJECTIVE

A review about the procedures used in the non surgical management of spasticity in children with cerebral palsy.

DEVELOPMENT

Therapeutic modalities for the management of spasticity in cerebral palsy include: (1) elimination of factors aggravating spasticity: pain, fatigue, stress, excitement, cold, illness, sleep disturbance, immobility, and hormonal changes; (2) rehabilitative therapies, there are four major groups: (a) biomechanical approach, (b) neurophysiologic approach, (c) developmental approach and (d) sensory approach; (3) orthosis; (4) oral pharmacotherapy: baclofen, tizanidine, diacepam and dantroleno; (5) chemical denervation: phenol injections and botulinum toxin injections. The medical management of spasticity in cerebral palsy is based on: 1. Oral pharmacotherapy: (a) baclofen, binds GABAB receptors of spinal interneurons presynaptically, inhibits release of excitatory neurotransmitters in the spinal cord; (b) tizanidine, binds alfa 2 adrenergic receptors presinaptically, inhibits release of excitatory neurotransmitters in the spinal cord; (c) diacepam, augments GABA mediated inhibition in the spinal cord and supraspinally;(d) dantrolene, inhibits release of calcium from sarcoplasmic reticulum in muscle, weakens muscle contraction in response to myofiber excitation. 2. Chemical denervation: (a) phenol injection perineurally or into the motor point disrupts efferent signals from hyperexcitable anterior horn cells causing necrosis of axons or muscle; (b) botulinum toxin injection in selected muscles blocks the release of acetylcholine presynaptically and weakens the force of muscle contraction produced by hyperexcitable motoneurons.

CONCLUSIONS

At the present time, there is not irrefutable evidence of a sustain benefit of physical rehabilitation in the management of spasticity. There are few studies with oral pharmacological agents involving children with cerebral palsy to define its role. On the other hand, botulinum toxin A is effective, well tolerated, and safe in the treatment of spasticity in children with cerebral palsy.

[Treatment of spasticity in cerebral palsy with botulinum toxin]

OBJECTIVE

A review of the pathophysiological and developmental basis, measurement scales and the usefulness of botulinum toxin A injections in selected muscles for the treatment of spasticity in children with cerebral palsy.

DEVELOPMENT

Cerebral palsy is the most common cause of spasticity in children. The increase in muscle length is achieved through the addition of sarcomeres in series at the level of the muscle tendinous junction. The regulation of the number of sarcomeres seems to be determined by the lengthening of the muscle. The muscle contracture is a shortening of the length of a muscle as a result of a decrease in the number of sarcomeres. Spasticity and motor function assessment scales used in children with cerebral palsy: a) Modified Ashworth scale for the assessment of spasticity; b) modified Tardieu scale for the assessment of dynamic muscle length; c) muscle spasms frequency scale; d) modified Medical Research Council scale for muscle strength; e) hip adductor muscle tone scale; f) global pain scale with affective facial expression represented in a drawing; g) goniometric measurement of the joint range of movement; h) Palisano gross motor function measure; i) observational video gait analysis scale. Recommended guidelines for dosing the botulinum toxin A: 1. Total maximum dose administered per visit up to 15 U/kg or a total of 400 U; 2. Dose range of large muscles 3 to 6 U/kg per visit; 3. Dose range of small muscles 1 to 3 U/kg per visit; 4. Maximum dose per injection site: 50 U dividing the total planned unit dose/muscle into equal amounts/injection site; 5. Frequency: no more than one injection every 3 months, frequently once every 6 or more months.

CONCLUSION

Botulinum toxin A injection is a well tolerated, safe and effective procedure in the treatment of children with spastic cerebral palsy.

[Controversial or arguable therapies in neurodevelopmental disorders]

OBJECTIVE

To analyze the therapies and methods not scientifically documented that more frequently are offer and used for the treatment of neurodevelopmental disorders.

DEVELOPMENT

These therapies are divided into three main groups: a) Therapies directed upon brain functioning; b) Therapies directed upon nutritional needs, and c) Others. Parents and close relatives of children with developmental disorders are vulnerable to any person, institution or method that offers a quick and easy solution to their problem. It is a priority that all health professionals are familiar with the unproven therapies, that are offered for the therapy of developmental disorders, so that they can inform, educate and advise correctly to parents and close relatives of their patients. To deal with unproven treatments involves more than analyzing the available scientific data. It is required a comprehension and understanding of the personal and family dynamics in front of a threat of illness or disfunction.

CONCLUSION

Responsible and well informed parents in relation to an unproven therapy should be free and have the right to decide whether or not to use a controversial procedure prior to a scientific determination of its validity; they also must keep in mind that at least some procedures, beside of not been useful, could be harmful for the physical, emotional and economical well-being of the patient and/or his family.

[The clinical phenomenology of Rett's syndrome]

The work was done to facilitate the clinical diagnosis and understanding of Rett syndrome (RS) by grouping the symptoms and signs in areas of neurological disfunction. This is a retrospective, longitudinal and observational study of 30 young females whose clinical manifestations were grouped using a modified Fitzgerald et al. scale for motor and behavior evaluation of patients with RS. All patients were videotaped at least during one or several appointments during their follow-up for a period of 1 to 10 years. All patients and videotapes were reviewed independently by the three authors. We followed the clinical diagnostic criteria of classic RS, and grouped the symptoms and signs in 12 groups of clinical phenomenology that represented specific areas of central or peripheral nervous system involvement: 1) dementia syndrome (fronto-temporo-parietal and limbic dysfunction); 2) extrapyramidal syndrome (basal ganglia dysfunction); 3) respiratory function disorders (brain stem reticular system disfunction); 4) sleep disorders (reticular system and limbic dysfunction); 5) epilepsy (cortico-subcortical paroxysmal bioelectrical dysfunction); 6) lower motor neuron syndrome (neuropathic dysfunction and/or peripheral neuropathy); 7) body growth retardation; 8) tonic-postural skeletal deformities; 9) deficit of pain sensation (nociceptive deficit); 10) pseudobulbar dysfunction; 11) autonomic dysfunction and 12) others (microcephaly and bruxism). In clinical practice, we recommend the use of this grouping of symptoms and signs because it makes facilities the clinical study, definition of areas of dysfunction and diagnosis of the patient with RS.

[Congenital myasthenia gravis. Presentation of a case with dysphagia as the only clinical manifestation]

Myasthenia gravis is an infrequent disease seen at the neonatal stage. Two main groups are identified: a) one with a genetic origin which can be secondary to pre- or postsynaptic defects and b) of an acquired origin, as transitory neonatal myasthenia seen in 10-15% of those children with myasthenic mothers. Few cases with a genetic origin have been reported in the literature; the most common symptoms being bilateral eyelid ptosis, ophtalmoparesis, easy fatigability, respiratory and feeding difficulties. This is a report of a genetic neonatal case of myasthenia gravis with dysphagia as the only clinical manifestation seen since the first days of the child's life, confirming the diagnosis using a repetitive supramaximal stimulation test and obtaining excellent results with pyridostigmine. We conclude that, although this a rare form of the disease, genetic neonatal myasthenia gravis should be considered in the differential diagnosis of newborns with difficulties to swallow. The repetitive supramaximal stimulation test is the diagnostic procedure of first choice to be used in the neonatal period.

[Migraine. Various current concepts]

Migraine is a common disorder in children with a prevalence of 2.5% under seven years of age, 5% in those between the ages of seven and puberty and in postpuberal females it may be as prevalent as 10%. It is transmitted as an autosomally dominant trait and is frequently caused by precipitating factors. The vascular theory which stated that the aura was due to an intracranial vessel constriction and that the headache was due to an extracranial vasodilation has now be questioned due to new clinical and experimental data. Recently it is believed to be due to an unstable inherited serotonigenic neurotransmission which favors an increase in the frequency of neuronal discharge of the mid-brain raphe. Included is a classification and the diagnostic headache criteria used by the International Headache Society (1988). Treatment for migraine can be: a) abortive and b) preventive. Propranolol at a dosage of 2 mg/kg per day taken divided into three has shown to be the most beneficial in the prevention of migraine headaches. Certain calcium channel blockers, particularly flunarizine seem to have prophylactic value.

[Febrile convulsion. A clinical study of 303 patients]

The clinical characteristics of 303 patients who had episodes of feverish convulsions (FC) were retrospectively reviewed. No preference was seen for either sex (1.3/1). In 75.3% of the cases, the convulsions occurred in children under two. There was some predominance of tonic-clonic crisis and generalized clonic-tonic convulsions (85.5%) with 21.8% of complex partial crisis. In 44.8% of the cases a perinatal history of high risk was noted. A comparative investigation was carried out in a subgroup of 244 children in who FC vs non-febrile convulsions (NFC) were during two years. In 35.2% of the patients neurological abnormalities were found associated, among them were language difficulties (27.4%) and psychomotor retardation (11.9%). In 36.4% of the cases, the EEG was found to be abnormal, and paroxysmal in 27%. The predominating perinatal pathological complications were perinatal hypoxia-anoxia and prematurity. In 84% of the patients, anti-convulsive medication was administered. Of the 244 patients, 62 (25.4) of them had NFC which were directly related to the number of risk factors and their characteristics. Among those risk factors were partial convulsions, neurological deficit, abnormal EEG, convulsions lasting over 10 minutes and a previous family history of epilepsy. It is noteworthy that 15.7% of the patients had no risk factors related to epilepsy. In those patients who suffered from convulsions from an early age, who had convulsions of a partial--complex type, which lasted over 20 minutes and repeated frequently--were seen to be the most likely to develop epilepsy. The medications prescribed prevented the occurrence of the FC but did not significantly diminish the development of epilepsy. Febrile convulsions; epilepsy; perinatal.

[Conductive education in integral rehabilitation of patients with cerebral palsy]

"Conductive education" was thought out and developed by Andres Peto in Budapest. Its main goal is "orthofunction". Such a system was used in 22 children with cerebral palsy. These children were divided in two groups, one with 10 pre-school and school age children and the other of "parents and babies" with 12 infants. From the first group, six children had received physiotherapy in our Center following an eclectic method at least for one year and from the second group seven infants had received also physiotherapy at least for six months; these children were used as controls. The rest of the children were new admissions. A special evaluating scale was developed to evaluate all the children involved. In the control group the evaluation was performed before the initiation of the program (12 and six months respectively), at the beginning in all of them and at 12 and 16 months in the pre-school and school age group, and at six and 12 months in the infants of the "parents and babies" group. The results showed a definite advantage in both groups of Conductive education in the motor, cognitive and social areas compared with the results with physiotherapy in the control group.