Microplastics in large marine herbivores: Florida manatees (Trichechus manatus latirostris) in Tampa Bay

Although there is growing concern about ingestion of microplastics by marine organisms, little research has been conducted on marine herbivores. This is the first study to document microplastic ingestion within the family Sirenia. Subsamples were collected from five locations in the gastrointestinal tracts (GI) of 26 dead manatees (Trichechus manatus latirostris) from Tampa Bay, Florida. During gross necropsies, macroplastic pieces were found in seven individuals (26.9%). Careful visual examination of the subsampled portions of the GI contents indicated that 19 individuals (73.1%) contained plastic particles. As five individuals had both macro and microplastic pieces, the overall frequency of occurrence of plastic ingestion was 76.9%. Due to the large volume of cellulose-rich ingested material, it was not feasible to analyze the entire gut contents, nor was it feasible to conduct chemical or enzymatic digestion; therefore, it is very likely that many microplastic pieces were not detected. Despite these technical challenges, it is clear that manatees in Tampa Bay are routinely consuming microplastics in addition to larger plastic pieces. Currently, nothing is known about the physiological effects of microplastic ingestion in sirenians, however environmental plastics could be concentrated by manatees through ingestion and the subsequent production of microplastics-laden feces

Mucosal vaccination with a live recombinant rhinovirus followed by intradermal DNA administration elicits potent and protective HIV-specific immune responses

Published: 17 November 2016Mucosal immunity is deemed crucial to control sexual transmission of human immunodeficiency virus (HIV). Herein we report the efficacy of a mucosal HIV vaccine strategy comprising intranasal (IN) vaccination with a cocktail of live recombinant human rhinoviruses (HRVs) encoding overlapping fragments of HIV Gag and full length Tat (rHRV-Gag/Tat) followed by intradermal (ID) vaccination with DNA vaccines encoding HIV Gag and Tat (pVAX-Gag-Tat). This heterologous prime-boost strategy will be referred to hereafter as rHRV-DNA. As a control, IN vaccination with wild type (wt)-HRV-A1 followed by a single ID dose of pVAX (wt-HRV-A1/pVAX vaccination) was included. rHRV-DNA vaccination elicited superior multi-functional CD8(+)T cell responses in lymphocytes harvested from mesenteric lymph nodes and spleens, and higher titres of Tat-specific antibodies in blood and vaginal lavages, and reduced the viral load more effectively after challenge with EcoHIV, a murine HIV challenge model, in peritoneal macrophages, splenocytes and blood compared compared with wt-HRV-A1/pVAX vaccination or administration of 3 ID doses of pVAX-Gag-Tat (3X pVAX-Gag-Tat vaccination). These data provide the first evidence that a rHRV-DNA vaccination regimen can induce HIV-specific immune responses in the gut, vaginal mucosa and systemically, and supports further testing of this regimen in the development of an effective mucosally-targeted HIV-1 vaccine.Khamis Tomusange, Danushka Wijesundara, Jason Gummow, Steve Wesselingh, Andreas Suhrbier, Eric J. Gowans, Branka Grubor-Bau

Ingestion of microplastics by copepods in Tampa Bay Estuary, FL

Microplastics have been recognized as an emerging contaminant. Copepods are abundant primary consumers in marine food webs. Interactions between copepods and microplastics can lead to negative health effects to the individual and may have implications for populations and ecosystems through biomagnification. Laboratory and field studies have observed various species of zooplankton ingesting microplastics, however, this is the first study to observe microplastic-copepod interactions in Tampa Bay. Over 2 years (November 2017-January 2020), 14 sampling cruises were conducted with seven stations throughout Tampa Bay. At each station copepods were collected by towing a 200 μm mesh ring net (0.5 m diameter) for 3 min. 1,000 individual Acartia tonsa copepods were picked from each sample and digested to release gut contents. Gut contents were stained in a Nile Red solution and then visualized using epifluorescent microscopy, quantified, photographed and sized using image analysis. In Tampa Bay, A. tonsa consumed fragments over fibers, ranging from 0.018 to 0.642 mm, with an average particle size of 0.076 mm. An overall average of 15.38 particles were ingested per 1,000 copepods, or 6.48 particles m–3 when normalized for environmental copepod concentrations. While significant differences were detected between stations and months, no clear spatial (from head to mouth of estuary) or temporal (between wet and dry seasons) trends in ingestion rate or ingested particle size were evident. These results show that A. tonsa ingested microplastics throughout Tampa Bay. These robust baseline data, for a copepod species that dominates estuarine zooplankton communities around the world, set the stage for valuable comparisons between estuaries with different physical mechanisms and levels of anthropogenic impact, allowing for exploration of how the environmental conditions impact ecological interactions

Increase in DNA vaccine efficacy by virosome delivery and co-expression of a cytolytic protein

The potential of DNA vaccines has not been realised due to suboptimal delivery, poor antigen expression and the lack of localised inflammation, essential for antigen presentation and an effective immune response to the immunogen. Initially, we examined the delivery of a DNA vaccine encoding a model antigen, luciferase (LUC), to the respiratory tract of mice by encapsulation in a virosome. Virosomes that incorporated influenza virus haemagglutinin effectively delivered DNA to cells in the mouse respiratory tract and resulted in antigen expression and systemic and mucosal immune responses to the immunogen after an intranasal (IN) prime/intradermal (ID) boost regimen, whereas a multidose ID regimen only generated systemic immunity. We also examined systemic immune responses to LUC after ID vaccination with a DNA vaccine, which also encoded one of the several cytolytic or toxic proteins. Although the herpes simplex virus thymidine kinase, in the presence of the prodrug, ganciclovir, resulted in cell death, this failed to increase the humoral or cell-mediated immune responses. In contrast, the co-expression of LUC with the rotavirus non-structural protein 4 (NSP4) protein or a mutant form of mouse perforin, proteins which are directly cytolytic, resulted in increased LUC-specific humoral and cell-mediated immunity. On the other hand, co-expression of LUC with diphtheria toxin subunit A or overexpression of perforin or NSP4 resulted in a lower level of immunity. In summary, the efficacy of DNA vaccines can be improved by targeted IN delivery of DNA or by the induction of cell death in vaccine-targeted cells after ID delivery.Tessa Gargett, Branka Grubor-Bauk, Darren Miller, Tamsin Garrod, Stanley Yu, Steve Wesselingh, Andreas Suhrbier, and Eric J Gowan

Viral vector and route of administration determine the ILC and DC profiles responsible for downstream vaccine-specific immune outcomes

This study demonstrates that route and viral vector can significantly influence the innate lymphoid cells (ILC) and dendritic cells (DC) recruited to the vaccination site, 24 h post delivery. Intranasal (i.n.) vaccination induced ST2/IL-33R+ ILC2, whilst intramuscular (i.m.) induced IL-25R+ and TSLPR+ (Thymic stromal lymphopoietin protein receptor) ILC2 subsets. However, in muscle a novel ILC subset devoid of the known ILC2 markers (IL-25R- IL-33R- TSLPR-) were found to express IL-13, unlike in lung. Different viral vectors also influenced the ILC-derived cytokines and the DC profiles at the respective vaccination sites. Both i.n. and i.m. recombinant fowlpox virus (rFPV) priming, which has been associated with induction of high avidity T cells and effective antibody differentiation exhibited low ILC2-derived IL-13, high NKp46+ ILC1/ILC3 derived IFN-γ and low IL-17A, together with enhanced CD11b+ CD103- conventional DCs (cDC). In contrast, recombinant Modified Vaccinia Ankara (rMVA) and Influenza A vector priming, which has been linked to low avidity T cells, induced opposing ILC derived-cytokine profiles and enhanced cross-presenting DCs. These observations suggested that the former ILC/DC profiles could be a predictor of a balanced cellular and humoral immune outcome. In addition, following i.n. delivery Rhinovirus (RV) and Adenovius type 5 (Ad5) vectors that induced elevated ILC2-derived IL-13, NKp46+ ILC1/ILC3-derived-IFN-γ and no IL-17A, predominantly recruited CD11b- B220+ plasmacytoid DCs (pDC). Knowing that pDC are involved in antibody differentiation, we postulate that i.n. priming with these vectors may favour induction of effective humoral immunity. Our data also revealed that vector-specific replication status and/or presence or absence of immune evasive genes can significantly alter the ILC and DC activity. Collectively, our findings suggest that understanding the route- and vector-specific ILC and DC profiles at the vaccination site may help tailor/design more efficacious viral vector-based vaccines, according to the pathogen of interest.S. Roy, M.I. Jaeson, Z. Li, S. Mahboob, R.J. Jackson, B. Grubor-Bauk, D.K. Wijesundara, E.J. Gowans, C. Ranasingh

Mature autologous dendritic cell vaccines in advanced non-small cell lung cancer: a phase I pilot study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: Overall therapeutic outcomes of advanced non-small-cell lung cancer (NSCLC) are poor. The dendritic cell (DC) immunotherapy has been developed as a new strategy for the treatment of lung cancer. The purpose of this study was to evaluate the feasibility, safety and immunologic responses in use in mature, antigen-pulsed autologous DC vaccine in NSCLC patients. Methods: Five HLA-A2 patients with inoperable stage III or IV NSCLC were selected to receive two doses of 5 x 107 DC cells administered subcutaneous and intravenously two times at two week intervals. The immunologic response, safety and tolerability to the vaccine were evaluated by the lymphoproliferation assay and clinical and laboratorial evolution, respectively. Results: The dose of the vaccine has shown to be safe and well tolerated. The lymphoproliferation assay showed an improvement in the specific immune response after the immunization, with a significant response after the second dose (p = 0.005). This response was not long lasting and a tendency to reduction two weeks after the second dose of the vaccine was observed. Two patients had a survival almost twice greater than the expected average and were the only ones that expressed HER-2 and CEA together. Conclusion: Despite the small sample size, the results on the immune response, safety and tolerability, combined with the results of other studies, are encouraging to the conduction of a large clinical trial with multiples doses in patients with early lung cancer who underwent surgical treatment.30Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Department of Radiology of the Hospital Estadual Sumare UNICAMPSCOGConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq [401327/05-1