scholarly journals Expression of avian influenza haemagglutinin (H5) and chicken interleukin 2 (chIL-2) under control of the ptcB promoter in Lactococcus lactis.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Katarzyna Szatraj ◽  
Agnieszka K Szczepankowska ◽  
Violetta Sączyńska ◽  
Katarzyna Florys ◽  
Beata Gromadzka ◽  
...  

Gram-positive and nonpathogenic lactic acid bacteria (LAB) are considered to be promising candidates for the development of new, safe systems of heterologous protein expression. Recombinant LAB has been shown to induce specific local and systemic immune response against selected pathogens, and could be a good alternative to classical attenuated carriers. The main goal of our study was to express the avian influenza haemagglutinin (H5) and chicken interleukin 2 (chIL-2) in Lactococcus lactis. Results of this study were anticipated to lead to construction of lactococcal strain(s) with potential vaccine properties against the avian influenza A (H5N1) virus. Expression of the cloned H5 gene, its His-tagged variant and chIL-2 gene, under the control of the ptcB gene promoter was attested by RT-PCR on transcriptional level and Western or dot blot analysis on translational level, demonstrating that system can be an attractive solution for production of heterologous proteins. The results of the preliminary animal trial conducted in mice are a promising step toward development of a vaccine against avian bird flu using Lactococcus lactis cells as antigen carriers.

2010 ◽  
Vol 47 (9) ◽  
pp. 1675-1685 ◽  
Author(s):  
Sylvia S. Reemers ◽  
Dik van Leenen ◽  
Marian J. Groot Koerkamp ◽  
Daphne van Haarlem ◽  
Peter van de Haar ◽  
...  

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Knut Madslien ◽  
Torfinn Moldal ◽  
Britt Gjerset ◽  
Sveinn Gudmundsson ◽  
Arne Follestad ◽  
...  

Abstract Background Several outbreaks of highly pathogenic avian influenza (HPAI) caused by influenza A virus of subtype H5N8 have been reported in wild birds and poultry in Europe during autumn 2020. Norway is one of the few countries in Europe that had not previously detected HPAI virus, despite widespread active monitoring of both domestic and wild birds since 2005. Results We report detection of HPAI virus subtype H5N8 in a wild pink-footed goose (Anser brachyrhynchus), and several other geese, ducks and a gull, from south-western Norway in November and December 2020. Despite previous reports of low pathogenic avian influenza (LPAI), this constitutes the first detections of HPAI in Norway. Conclusions The mode of introduction is unclear, but a northward migration of infected geese or gulls from Denmark or the Netherlands during the autumn of 2020 is currently our main hypothesis for the introduction of HPAI to Norway. The presence of HPAI in wild birds constitutes a new, and ongoing, threat to the Norwegian poultry industry, and compliance with the improved biosecurity measures on poultry farms should therefore be ensured. [MK1]Finally, although HPAI of subtype H5N8 has been reported to have very low zoonotic potential, this is a reminder that HPAI with greater zoonotic potential in wild birds may pose a threat in the future. [MK1]Updated with a sentence emphasizing the risk HPAI pose to poultry farms, both in the Abstract and in the Conclusion-section in main text, as suggested by Reviewer 1 (#7).


Author(s):  
Jun‐Ling Yu ◽  
Sai Hou ◽  
Ya‐Ting Feng ◽  
Ge Bu ◽  
Qing‐Qing Chen ◽  
...  

2021 ◽  
Vol 7 (3) ◽  
pp. 179
Author(s):  
Kai P. Hussnaetter ◽  
Magnus Philipp ◽  
Kira Müntjes ◽  
Michael Feldbrügge ◽  
Kerstin Schipper

Heterologous protein production is a highly demanded biotechnological process. Secretion of the product to the culture broth is advantageous because it drastically reduces downstream processing costs. We exploit unconventional secretion for heterologous protein expression in the fungal model microorganism Ustilago maydis. Proteins of interest are fused to carrier chitinase Cts1 for export via the fragmentation zone of dividing yeast cells in a lock-type mechanism. The kinase Don3 is essential for functional assembly of the fragmentation zone and hence, for release of Cts1-fusion proteins. Here, we are first to develop regulatory systems for unconventional protein secretion using Don3 as a gatekeeper to control when export occurs. This enables uncoupling the accumulation of biomass and protein synthesis of a product of choice from its export. Regulation was successfully established at two different levels using transcriptional and post-translational induction strategies. As a proof-of-principle, we applied autoinduction based on transcriptional don3 regulation for the production and secretion of functional anti-Gfp nanobodies. The presented developments comprise tailored solutions for differentially prized products and thus constitute another important step towards a competitive protein production platform.


2021 ◽  
pp. 104063872110275
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Linfang Cheng ◽  
Hangping Yao ◽  
...  

Avian influenza A(H5) viruses (avian IAVs) pose a major threat to the economy and public health. We developed an antigen-ELISA (ag-ELISA) and a colloidal gold–based immunochromatographic strip for the rapid detection of avian A(H5) viruses. Both detection methods displayed no cross-reactivity with other viruses (e.g., other avian IAVs, infectious bursal disease virus, Newcastle disease virus, infectious bronchitis virus, avian paramyxovirus). The ag-ELISA was sensitive down to 0.5 hemagglutinin (HA) units/100 µL of avian A(H5) viruses and 7.5 ng/mL of purified H5 HA proteins. The immunochromatographic strip was sensitive down to 1 HA unit/100 µL of avian A(H5) viruses. Both detection methods exhibited good reproducibility with CVs < 10%. For 200 random poultry samples, the sensitivity and specificity of the ag-ELISA were 92.6% and 98.8%, respectively, and for test strips were 88.9% and 98.3%, respectively. Both detection methods displayed high specificity, sensitivity, and stability, making them suitable for rapid detection and field investigation of avian A(H5) viruses.


2021 ◽  
pp. 104063872199481
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Hangping Yao ◽  
Nanping Wu ◽  
...  

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID50)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.


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