Bouwen in turbulente tijden. Het werk van Ingenieurs-Bureau Ingenegeren-Vrijburg (IBIV) (1936-1957)

This article describes the work of Ingenieurs-Bureau Ingenegeren-Vrijburg (IBIV), an engineering firm located in Bandung (Indonesia). Founded by A.C. Ingenegeren and G.S. Vrijburg, IBIV was in operation from 1936 to 1957. In other words, the firm operated during the Dutch administration of the archipelago, under the Japanese occupation and in the newly independent Republic of Indonesia. What were the challenges for architects in the Dutch East Indies in general and for IBIV in particular? What were the design tasks and what did the designs look like? Did political changes affect the work and the organization of IBIV , and if so, which works illustrate these changes? The answers to these questions shed light on an intriguing aspect of Dutch architecture and architectural history.The scanty but well-documented materials (including images) relating to IBIV reveals a typologically and stylistically rich and varied body of work designed during a politically and socially turbulent period. ibiv worked for a wide variety of clients: Billiton, land development companies and Philips, as well as the University of Indonesia, the Indonesian government, Pusat Perkebunan Negara (National Agriculture Centre) and Perhimpunan Ilmu Alam Indonesia (Natural Science Association). It was not the major political upheavals (the Japanese occupation in 1942, the declaration of in dependence in 1945, the transfer of sovereignty in 1949), but a relatively minor issue (the political impasse over New Guinea in 1957) that led to the firm’s closure.IBIV appears to have transitioned effortlessly from a colonial to a post-colonial regime, from colonial to republican clients, and from colonial (Dutch East Indian) to post-colonial (Jenki) architecture. By studying IBIV ’s entire output, and so not just the colonial or the postcolonial work, it becomes clear that colonial and postcolonial are by no means self-contained entities. Professional developments did not cease when the colonial regime came to an end, any more than professional developments had to begin from scratch with the dawning of the post-colonial period.An examination of developments in the colonial and post-colonial periods from the perspective of professional continuity between the two periods, produces not necessarily simple, but certainly interesting insights into the colonial and post-colonial past. It shows that professional developments do not necessarily run parallel to political developments and as such argues for a (considerably) less rigid compartmentalization of research into colonial and post-colonial architecture. This initial study of the work and developments in and around IBIV shows what interesting results such an approach can produce

SynGEM: An intranasal prefusion-like RSV F subunit vaccine

Respiratory syncytial virus (RSV) is an important cause of respiratory tract disease in (naive) young infants, older infants, the elderly and immune-compromised. Despite the medical need and the market potential, no licensed vaccine is available. Mucosis B.V. is a Dutch biotech company developing innovative mucosal vaccines, based on the Bacterium-Like Particles (BLP) technology. Such vaccines can be administered needle-free, e.g. through the nasal mucosa. In support of the mucosal approach, there is accumulating evidence that RSV F-specific local S-IgA antibodies secreted in the upper respiratory tract of humans correlate well with protection. Because of its ability to induce broadly neutralizing antibodies the RSV F protein is the most attractive antigen. The current view is that in particular serum antibodies directed against the prefusion form of RSV F belong to the most potent neutralizing antibodies and the ability to elicit these is a pivotal attribute for a successful RSV vaccine. We studied different variants of F with respect to their conformation using neutralizing monoclonal antibodies (mAbs), following the view that F proteins mimicking the meta-stable prefusion form of F expose a more extensive and relevant epitope repertoire than F proteins corresponding to the postfusion F structure. Both addition of a trimerization motif and mutation of the furin cleavage sites increased the reactivity of F with the prefusion-specific mAb D25, with the highest reactivity being observed for F proteins in which both these features were combined. This candidate antigen, called Flys-GCN, is suitable in the development of mucosal as well as intramuscular RSV vaccines. Here we describe the development of our intranasal candidate RSV vaccine, SynGEM, which is based on the validated BLP technology. The non-living BLPs allow for presentation of stable, trimeric prefusion-like RSV F proteins bound to the particle surface. Intranasal vaccination of naïve and convalescent mice with SynGEM induced long-lasting virus neutralizing RSV-specific serum IgG and robust levels of local IgA. Cotton rats immunized intranasally with SynGEM were protected upon RSV challenge, as represented by a low viral load in the lungs. Enhanced levels of pre- versus postfusion specific antibodies were observed in individual animals, confirming the ability of the SynGEM vaccine to induce potent neutralizing antibodies. A clinical Phase I study with intranasal SynGEM is planned for 2016

Bacterium-like particles as multi-epitope delivery platform for Plasmodium berghei circumsporozoite protein induce complete protection against malaria in mice

Contains fulltext : 110364.pdf (publisher's version ) (Open Access)BACKGROUND: Virus-like particles have been regularly used as an antigen delivery system for a number of Plasmodium peptides or proteins. The present study reports the immunogenicity and protective efficacy of bacterium-like particles (BLPs) generated from Lactococcus lactis and loaded with Plasmodium berghei circumsporozoite protein (PbCSP) peptides. METHODS: A panel of BLP-PbCSP formulations differing in composition and quantity of B-cell, CD4+ and CD8+ T-cell epitopes of PbCSP were tested in BALB/c mice. RESULTS: BLP-PbCSP1 induced specific humoral responses but no IFN-gamma ELISPOT response, protecting 30-40% of the immunized mice. BLP-PbCSP2, with reduced length of the non-immunogenic part of the T-cell-epitopes construct, increased induction of IFN-gamma responses as well as protection up to 60-70%. Compared to controls, lower parasitaemia was observed in unprotected mice immunized with BLP-PbCSP1 or 2, suggestive for partial immunity. Finally, further increase of the number of B-cell epitopes and codon optimization (BLP-PbCSP4) induced the highest anti-CSP antibody levels and number of IFN-gamma spots, resulting in sterile immunity in 100% of the immunized mice. CONCLUSION: Presentation of Plasmodium-derived antigens using BLPs as a delivery system induced complete protection in a murine malaria model. Eventually, BLPs have the potential to be used as a novel versatile delivery platform in malaria vaccine development

Shigella IpaB and IpaD displayed on L. lactis bacterium-like particles induce protective immunity in adult and infant mice

Shigella spp. are among the enteric pathogens with the highest attributable incidence of moderate-to-severe diarrhea in children under 5 years of age living in endemic areas. There are no vaccines available to prevent this disease. In this work, we investigated a new Shigella vaccine concept consisting of non-living, self-adjuvanted, Lactococcus lactis bacterium-like particles (BLP) displaying Shigella invasion plasmid antigen (Ipa) B and IpaD and examined its immunogenicity and protective efficacy in adult and newborn/infant mice immunized via the nasal route. Unique advantages of this approach include the potential for broad protection due to the highly conserved structure of the Ipas and the safety and practicality of a probiotic-based mucosal/adjuvant delivery platform. Immunization of adult mice with BLP-IpaB and BLP-IpaD (BLP-IpaB/D) induced high levels of Ipa-specific serum IgG and stool IgA in a dose-dependent manner. Immune responses and protection were enhanced by BLP delivery. Vaccine-induced serum antibodies exhibited opsonophagocytic and cytotoxic neutralizing activity, and IpaB/D IgG titers correlated with increased survival post-challenge. Ipa-specific antibody secreting cells were detected in nasal tissue and lungs, as well as IgG in bronchoalveolar lavage. Bone marrow cells produced IpaB/D-specific antibodies and contributed to protection after adoptive transfer. The BLP-IpaB/D vaccine conferred 90% and 80% protection against S. flexneri and S. sonnei, respectively. Mice immunized with BLP-IpaB/D as newborns also developed IpaB and IpaD serum antibodies; 90% were protected against S. flexneri and 44% against S. sonnei. The BLP-IpaB/D vaccine is a promising candidate for safe, practical and potentially effective immunization of children against shigellosis

Biophysical Characterization of the Type III Secretion Tip Proteins and the Tip Proteins Attached to Bacterium-Like Particles

Bacterium-like particles (BLPs), derived from Lactococcus lactis, offer a self-adjuvanting delivery vehicle for subunit protein vaccines. Proteins can be specifically loaded onto the BLPs via a peptidoglycan anchoring domain (PA). In this study, the tip proteins IpaD, SipD and LcrV belonging to type three secretion systems of Shigella flexneri, Salmonella enterica and Yersinia enterocolitica, respectively, were fused to the PA and loaded onto the BLPs. Herein, we biophysically characterized these nine samples and condensed the spectroscopic results into three-index empirical phase diagrams (EPDs). The EPDs show distinctions between the IpaD/SipD and LcrV subfamilies of tip proteins, based on their physical stability, even upon addition of the PA. Upon attachment to the BLPs, the BLPs become defining moiety in the spectroscopic measurements, leaving the tip proteins to have a subtle yet modulating effect on the structural integrity of the tip proteins-BLPs binding. In summary, this work provides a comprehensive view of physical stability of the tip proteins and tip protein-BLPs and serves as a baseline for screening of excipients to increase the stability of the tip protein-BLPs for future vaccine formulation

High-salinity growth conditions promote tat-independent secretion of tat substrates in Bacillus subtilis

The Gram-positive bacterium Bacillus subtilis contains two Tat translocases, which can facilitate transport of folded proteins across the plasma membrane. Previous research has shown that Tat-dependent protein secretion in B. subtilis is a highly selective process and that heterologous proteins, such as the green fluorescent protein (GFP), are poor Tat substrates in this organism. Nevertheless, when expressed in Escherichia coli, both B. subtilis Tat translocases facilitated exclusively Tat-dependent export of folded GFP when the twin-arginine (RR) signal peptides of the E. coli AmiA, DmsA, or MdoD proteins were attached. Therefore, the present studies were aimed at determining whether the same RR signal peptide-GFP precursors would also be exported Tat dependently in B. subtilis. In addition, we investigated the secretion of GFP fused to the full-length YwbN protein, a strict Tat substrate in B. subtilis. Several investigated GFP fusion proteins were indeed secreted in B. subtilis, but this secretion was shown to be completely Tat independent. At high-salinity growth conditions, the Tat-independent secretion of GFP as directed by the RR signal peptides from the E. coli AmiA, DmsA, or MdoD proteins was significantly enhanced, and this effect was strongest in strains lacking the TatAy-TatCy translocase. This implies that high environmental salinity has a negative influence on the avoidance of Tat-independent secretion of AmiA-GFP, DmsA-GFP, and MdoD-GFP. We conclude that as-yet-unidentified control mechanisms reject the investigated GFP fusion proteins for translocation by the B. subtilis Tat machinery and, at the same time, set limits to their Tat-independent secretion, presumably via the Sec pathway

Local and Systemic Immunity against Respiratory Syncytial Virus Induced by a Novel Intranasal Vaccine. A Randomized, Double-Blind, Placebo-controlled Clinical Trial

RATIONALE:Needle-free intranasal vaccines offer major potential advantages, especially against pathogens entering via mucosal surfaces. As yet, there is no effective vaccine against respiratory syncytial virus (RSV), a ubiquitous pathogen of global importance that preferentially infects respiratory epithelial cells; new strategies are urgently required. OBJECTIVES:Here, we report the safety and immunogenicity of a novel mucosal RSV F protein vaccine linked to an immunostimulatory bacterium-like particle (BLP). METHODS:In this phase I, randomised, double-blind placebo-controlled trial, 48 healthy volunteers aged 18-49 years were randomly assigned to receive placebo or SynGEM (low- or high-dose) intranasally by prime-boost administration. The primary outcome was safety and tolerability, with secondary objectives assessing virus-specific immunogenicity. MEASUREMENTS AND MAIN RESULTS:There were no significant differences in adverse events between placebo and vaccinated groups. SynGEM induced systemic plasmablast responses and significant, durable increases in RSV-specific serum antibody in healthy seropositive adults. Volunteers given low-dose SynGEM (140 µg F, 2mg BLP) required a boost at day 28 to achieve plateau responses with a maximum fold-change of 2.4, whereas high-dose recipients (350 µg F, 5mg BLP) achieved plateau responses with a fold-change of 1.5 after first vaccination that remained elevated up to 180 days post-vaccination irrespective of further boosting. Palivizumab-like antibodies were consistently induced, but F protein site Ø-specific antibodies were not detected and virus-specific nasal IgA responses were heterogeneous, with strongest responses in individuals with lower pre-existing antibody levels. CONCLUSIONS:SynGEM is thus the first non-replicating intranasal RSV subunit vaccine to induce persistent antibody responses in human volunteers. Clinical trial registration available at www.clinicaltrials.gov, ID NCT02958540