Functional characterization of the catalytic site of the tetanus toxin light chain using permeabilized adrenal chromaffin cells

The molecular events underlying the inhibition of exocytosis by tetanus toxin were investigated in permeabilized adrenal chromaffin cells. We found that replacement of amino acid residues within the putative zinc binding domain of the tetanus toxin light chain such as of histidine (position 233) by cysteine or valine, or of glutamate (position 234) by glutamine completely abolished the effect of the light chains on Ca2+ induced catecholamine release. Dipicolinic acid, a strong chelating agent for zinc, also prevented the effect of the tetanus toxin light chain. Zn2+ and, less potently Cu2+ and Ni2+, but not Cd2+ and Co2+, restored the activity of the neurotoxin. These data show that zinc and the putative zinc binding domain constitute the active site of the tetanus toxin light chain. Neither captopril, an inhibitor of synaptobrevin cleavage nor peptides spanning the site of synaptobrevins cleaved by the tetanus toxin in neurons, prevented the inhibition of Ca2+ induced catecholamine release by the tetanus toxin light chain. This suggests that synaptobrevins are not a major target of tetanus toxin in adrenal chromaffin cells

The light chain of tetanus toxin inhibits calcium-dependent vasopressin release from permeabilized nerve endings

The effects of tetanus toxin and its light and heavy chain subunits on vasopressin release were investigated in digitonin-permeabilized neurosecretory nerve terminals isolated from the neural lobe of the rat pituitary gland. Exocytosis was induced by challenging the permeabilized nerve endings with micromolar calcium concentrations. Tetanus toxin inhibited vasopressin release only in the presence of the reducing agent dithiothreitol. This effect was irreversible. The purified light chain of tetanus toxin strongly inhibited exocytosis in a dose-dependent manner with half-maximal effect at c. 10 nM. The action of the light chain was observed after only 2.5 min of preincubation. Separated heavy chain subunit had no effect on hormone secretion. Inhibition of vasopressin release could be prevented by preincubating the light chain of tetanus toxin with an immune serum against tetanus toxin. The data clearly demonstrate that in mammalian neurosecretory nerve endings tetanus toxin acts at a step downstream from the activation by Ca2+ of the exocytotic machinery and that the functional domain of this toxin is confined to its light chain

The Effect of Maternal Tetanus Immunization on Children’s Schooling Attainment in Matlab, Bangladesh: Follow-up of a Randomized Trial

We investigate the effects of ante-natal maternal vaccination against tetanus on the schooling attained by children in Bangladesh. Maternal vaccination prevents the child from acquiring tetanus at birth through blood infection and substantially reduces infant mortality and may prevent impairment in children who would otherwise acquire tetanus but survive. We follow up on a 1974 randomized trial of maternal tetanus toxoid, looking at outcomes for children born in the period 1975-1979. We find significant schooling gains from maternal tetanus vaccination for children whose parents had no schooling, showing a large impact on a small number of children.Vaccination, tetanus, schooling, education, Bangladesh

Synaptobrevin cleavage by the tetanus toxin light chain is linked to the inhibition of exocytosis in chromaffin cells

Exocytosis of secretory granules by adrenal chromaffin cells is blocked by the tetanus toxin light chain in a zinc specific manner. Here we show that cellular synaptobrevin is almost completely degraded by the tetanus toxin light chain within 15 min. We used highly purified adrenal secretory granules to show that synaptobrevin, which can be cleaved by the tetanus toxin light chain, is localized in the vesicular membrane. Proteolysis of synaptobrevin in cells and in secretory granules is reversibly inhibited by the zinc chelating agent dipicolinic acid. Moreover, cleavage of synaptobrevin present in secretory granules by the tetanus toxin light chain is blocked by the zinc peptidase inhibitor captopril and by synaptobrevin derived peptides. Our data indicate that the tetanus toxin light chain acts as a zinc dependent protease that cleaves synaptobrevin of secretory granules, an essential component of the exocytosis machinery in adrenal chromaffin cells

Exploring the functional domain and the target of the tetanus toxin light chain in neurohypophysial terminals

The tetanus toxin light chain blocks calcium induced vasopressin release from neurohypophysial nerve terminals. Here we show that histidine residue 233 within the putative zinc binding motif of the tetanus toxin light chain is essential for the inhibition of exocytosis, in the rat. The zinc chelating agent dipicolinic acid as well as captopril, an inhibitor of zinc-dependent peptidases, counteract the effect of the neurotoxin. Synthetic peptides, the sequences of which correspond to motifs present in the cytoplasmic domain of the synaptic vesicle membrane protein synaptobrevin 1 and 2, prevent the effect of the tetanus toxin light chain. Our results indicate that zinc bound to the zinc binding motif constitutes the active site of the tetanus toxin light chain. Moreover they suggest that cleavage of synaptobrevin by the neurotoxin causes the inhibition of exocytotic release of vasopressin from secretory granules

Mortality reductions from measles and tetanus immunization : a review of the evidence

In recent years, tetanus and measles are estimated to account for more than 2.5 million childhood deaths annually; measles alone may account for more than 2 million such deaths. The author reviews empirical evidence on the most effective and feasible strategies for measles and tetanus vaccination programs. He found that tetanus and measles immunization programs could significantly reduce deaths among children up to the age of 4 in many developing countries. Vaccinations had a pronounced effect in reducing childhood deaths from measles - with benefits sustained over time, and with the greatest benefits accruing to the most disadvantaged children. He found little support for the existence of a replacement mortality effect. Studies on maternal immunization against tetanus showed a great reduction in the number of neonatal deaths, but considerable uncertainty about the number of doses needed and how long the immunity lasted. Recent evidence suggests that giving the mother two doses of tetanus toxoid may confer significant levels of protection against neonatal death from tetanus for 15 years or more. Evidence on the impact of a single dose is less conclusive.Early Childhood Development,Health Indicators,Early Child and Children's Health,Health Monitoring&Evaluation,Adolescent Health

Amylase release from streptolysin O-permeabilized pancreatic acinar cells. Effects of Ca2+, guanosine 5'-[gamma-thio]triphosphate, cyclic AMP, tetanus toxin and botulinum A toxin

The molecular requirements for amylase release and the intracellular effects of botulinum A toxin and tetanus toxin on amylase release were investigated using rat pancreatic acinar cells permeabilized with streptolysin O. Micromolar concentrations of free Ca2+ evoked amylase release from these cells. Maximal release was observed in the presence of 30 microM free Ca2+. Ca(2+)-stimulated, but not basal, amylase release was enhanced by guanosine 5'-[gamma-thio]triphosphate (GTP[S]) (3-4 fold) or cyclic AMP (1.5-2 fold). Neither the two-chain forms of botulinum A toxin and tetanus toxin, under reducing conditions, nor the light chains of tetanus toxin, inhibited amylase release triggered by Ca2+, or combinations of Ca2+ + GTP[S] or Ca2+ + cAMP. The lack of inhibition was not due to inactivation of botulinum A toxin or tetanus toxin by pancreatic acinar cell proteolytic enzymes, as toxins previously incubated with permeabilized pancreatic acinar cells inhibited Ca(2+)-stimulated [3H]noradrenaline release from streptolysin O-permeabilized adrenal chromaffin cells. These data imply that clostridial neurotoxins inhibit a Ca(2+)-dependent mechanism which promotes exocytosis in neural and endocrine cells, but not in exocrine cells

Noradrenaline release from permeabilized synaptosomes is inhibited by the light chain of tetanus toxin

Noradrenaline release from rat brain cortical synaptosomes permeabilized with streptolysin O can be triggered by μM concentrations of free Ca2+. This process was inhibited within minutes by tetanus toxin and its isolated light chain, but not by its heavy chain. The data demonstrate that the effect of tetanus toxin on NA release from purified synaptosomes is caused by the intraterminal action of its light chain

Dysphagia in Elderly Women: Consider Tetanus

Background:: Dysphagia is seldom caused by tetanus; however, it is a common symptom of tetanus. Treating patients with tetanus is a rare event in industrialized countries and awareness is needed to recognize early signs of this serious disease. In Switzerland, the most recently reported tetanus cases occurred in elderly women with insufficient seroprotection. Patients:: We report on three elderly women presenting with dysphagia as an initial symptom of tetanus. Results:: Generalized tetanus was diagnosed in two patients upon admission, the third presented with cephalic tetanus with secondary generalization. All three patients had undetectable levels of tetanus antibodies and had no documented prior tetanus immunizations. Cultures of wound swabs grew Clostridium tetani in all cases. Electromyography was highly suggestive for tetanus in two patients. Treatment involved mechanical ventilation, intravenous benzodiazepine and metronidazole therapy, and active and passive tetanus immunization. The disease had a favorable outcome in two cases and was fatal in one. Conclusion:: Tetanus remains a threat in patients with insufficient seroprotection and efforts are needed to improve tetanus immunization in these individuals. Tetanus should be considered in the differential diagnosis of dysphagi

FAKTOR-FAKTOR YANG BERKAITAN DENGAN PERILAKU IBU TERHADAP IMUNISASI TETANUS TOXOID DI KELURAHAN BRUMBUNGAN KECAMATAN SEMARANG TENGAH KOTAMADIA SEMARANG

20% dari kematian bayi disebabkan oleh Tetanus Neonatorum. Faktor resiko yang berari untuk terjadinya Tetanus Neonatorum adalah ibu pada waktu hami tidak mendapat imunisai Tetanus Toxoid lengkap. Untuk mencapai kondisi bebas Tetanus Neonatorum di Jawa dan Bali pada akhir pelita Variabel maka salah satu usahanya meningakatakan cakupan imunisasi TT2 minimal 80%. Pada kenyataanya di Kel. Brumbungan Kecamatan Semarang Tengah cakupan imunisasi TT2 masih jauh seperti yang diharapkan. Tujuan penelitian untuk mengetahui faktor-faktor yang berkaitan dengan perilaku ibu tetang imunisasi Tetanus Toxoid sehingga pada akhirnya dapat meningkatkan cakupan imunisasi TT2. Penelitian ini adalah penelitian diskriptif dengan pendekatan Cross Sectional dengan metode survei sampel. Dari analisa didapatkan hasi sebagai berikut; Ada pengaruh antara: 1. Pendidikan formal dengan pengetahuan ibu tentanng imunisai Tetanus toxoid. 2. pengetahuan dengan praktek ibu dalam menerima imunisasi Tetanus toxoid. 3. lamanya bekrja dalam sehari dengan praktek ibu dalam menerima imunisasi Tetanus toxoid. Tidak ada pengaruh antara: 1. Jumlah kehamilan dengan pengetahuan ibu tentang imunisasi Tetanus Toxoid. 2. pendapatan kelurga dengan pengetahuan ibu tentang imunisasi Tetanus Toxoid. 3. keterlibatan dalam organsisasi kemsayarakatan dengan pengetahuan ibu tentang imunisasi Tetanus Toxoid. 4. sikap dengan praktek ibu dalam menerima imunisasi Tetanus Toxoid. 5. jarak dengan praktek ibu dalam menerima imunisasi Tetanus Toxoid. 6. jumlah balita dengan praktek ibu dalam menerima imunisasi Tetanus Toxoid. Sebagian besar (82,90%) ibu mepunyai pengetahuan tentang imunisasi Tetanus Toxoid tidak utuh dan sebagian besar (71,05%) ibu mendapat informasi tentang imunisasi Tetanus Toxoid dari petugas kesehatan di komponen statik pelayanan kesehatan pemerintah (pukesmas). Posyandu belum berfngsi secara baik sebagai tempat tukar informasi/komunikasi dan pelayanan imunisasi Tetanus Toxoid. Dari penelitian tersebut disimpulkan bahwa faktor pendidikan formal mempengaruhi pengetahuan ibu tentang imunisasi Tetanus Toxoid, pengatahuan ibu tentang imunisasi Tetanus Toxoid dan lamanya bekrja dalam sehari mempengaruhi praktek ibu dalam menerima imunisasi Tetanus Toxoid. Dengan memperhatikan hasil dan kesimpulan tersebut maka dapat dijadikan perhatian bagi pelaksana program, pengambil keputusan maupun pembuat kebijaksanaan ditingkat pukesmas sampai DinKes kotamadia dati II semarang. Kata Kunci: IMUNISASI TETANUS TOXOI