Sequential transmigration of polymorphonuclear cells and naive CD3(+) T lymphocytes across the blood-cerebrospinal-fluid barrier in vitro following infection with Echovirus 30
VIRUS RESEARCH
Authors: Dahm, Tobias; Frank, Franziska; Adams, Ortwin; Lindner, Holger A.; Ishikawa, Hiroshi; Weiss, Christel; Schwerk, Christian; Schroten, Horst; Tenenbaum, Tobias; Rudolph, Henriette
Abstract
Viral meningitis by non-polio enteroviruses (NPEV) is a major public health burden causing fatal outcomes especially in the younger population. Strong evidence exists that the blood-cerebrospinal-fluid (CSF) barrier (BCSFB) serves as an entry point for enterovirus and leucocytes into the central nervous system (CNS). Moreover, analysis of clinical CSF specimens of patients with a NPEV infection revealed a predominance of polymorphonuclear granulocytes (PMN) in the early phase and mononuclear cells in the later course of meningitis. By applying a functional in vitro model of the BCSFB consisting of human choroid plexus papilloma (HIBCPP) cells, we aimed to analyse the mechanisms of sequential migration of PMN and naive CDT3(+) T lymphocytes following infection with Echovirus 30 (EV30). EV30 infection led to increased transmigration of PMN and naive CD3(+) T lymphocytes. Transmigration of PMN was significantly enhanced in the presence of naive CD3(+) T lymphocytes, but not vice versa. The barrier function was not differentially altered under the respective conditions. Infection with EV30 led to an upregulation of CXCL3 and CXCL11 on the RNA-level. Additional analysis of cytokine secretion revealed relatively high concentrations of IL-8, CCL20, CXCL3, CXCL10 and M-CSF. Overall, there was a predominantly polar direction of cytokine secretion to the basolateral side. IL-7 was the only cytokine which was strongly secreted to the apical side and that was enhanced following EV30 infection in our model. In conclusion, this study highlights the role of the choroid plexus and cytokines in regulating leucocyte entry into the CNS in the context of EV30 infection. (C) 2017 Elsevier B.V. All rights reserved.
Microbial pathogen removal from domestic effluent using coral sand in Kiribati
JOURNAL OF APPLIED MICROBIOLOGY
Authors: Humphries, B.; Weaver, L.; Burbery, L.; Webber, J.; Morgan, L.; Gregor, J.
Abstract
Aim Infiltration experiments aimed to show the effectivity of coral sand to remove micro-organisms in septic tank wastewater treatment system, in South Tarawa, Kiribati. Methods and Results Laboratory experiments evaluated effective microbial removal properties of a packed bed of coral beach sand conditioned with domestic effluent. Bacterial and viral indicators Escherichia coli J6-2, Enterococci faecalis and f-RNA (MS2) bacteriophage, along with viral pathogens adenovirus, echovirus, norovirus and rotavirus, were dosed (at 10(6)-10(7) CFU, PFU or genome copies per ml concentration) with effluent to unsaturated coral sand-packed columns. For the conditions simulated, all organisms showed removal efficiencies of >4-Log Removal Values (LRVs) (i.e. >99 center dot 99% effective reduction in number). Results revealed that the conditioned coral sand had a higher affinity for attenuating viruses than the bacteria tested. MS2 phage, adenovirus, echovirus, norovirus and rotavirus were absent in leachate from the base of the sand columns. E. coli J6-2 and E. faecalis were recovered at 10(0)-10(1) CFU (colony forming units) per ml in the column effluent, following a dosage of 10(6) CFU per ml. Destructive sampling of the columns after experiments revealed that a high proportion of viral pathogens were retained in the top 30 mm of the sand. Conclusions On the basis of the relative spatial distribution of trace organisms in the sand, we speculate that adsorption processes likely dominated attenuation of the viral pathogens, more so than physical straining effects. Further study is required to fully elucidate the removal mechanisms. Significance and Impact of the Study To the best of our knowledge this is the first study of the effective microbial removal capacity of coral sand under unsaturated conditions. The work represents an initial exploratory step of developing some standardized design practice of on-site wastewater treatment systems in Kiribati, to offer enhanced protection of groundwater resources and reduce diarrhoeal disease.