Background Vaccines that incorporate multiple SARS‐CoV‐2 antigens can further broaden the breadth of virus‐specific cellular and humoral immunity. This study describes the development and immunogenicity of SARS‐CoV‐2 VLP vaccine that incorporates the four structural proteins of SARS‐CoV‐2. Methods VLPs were generated in transiently transfected HEK293 cells, purified by multimodal chromatography, and characterized by tunable‐resistive pulse sensing, AFM, SEM, and TEM. Immunoblotting studies verified the protein identities of VLPs. Cellular and humoral immune responses of immunized animals demonstrated the immune potency of the formulated VLP vaccine. Results Transiently transfected HEK293 cells reproducibly generated vesicular VLPs that were similar in size to and expressing all four structural proteins of SARS‐CoV‐2. Alum adsorbed, K3‐CpG ODN‐adjuvanted VLPs elicited high titer anti‐S, anti‐RBD, anti‐N IgG, triggered multifunctional Th1‐biased T‐cell responses, reduced virus load, and prevented lung pathology upon live virus challenge in vaccinated animals. Conclusion These data suggest that VLPs expressing all four structural protein antigens of SARS‐CoV‐2 are immunogenic and can protect animals from developing COVID‐19 infection following vaccination.

Rhodobacter sphaeroides is a purple non-sulfur bacterium which photoheterotrophically produces hydrogen from organic acids under anaerobic conditions. A gene coding for putative chlorophyll a synthase (chlG) from cyanobacterium Prochlorococcus marinus was amplified by nested polymerase chain reaction and cloned into an inducible-expression plasmid which was subsequently transferred to R. sphaeroides for heterologous expression. Induced expression of chlG in R. sphaeroides led to changes in light absorption spectrum within 400-700 nm. The hydrogen production capacity of the mutant strain was evaluated on hydrogen production medium with 15 mM malate and 2 mM glutamate. Hydrogen yield and productivity were increased by 13.6 and 22.6%, respectively, compared to the wild type strain. The results demonstrated the feasibility of genetic engineering to combine chlorophyll and bacteriochlorophyll biosynthetic pathways which utilize common intermediates. Heterologous expression of key enzymes from biosynthetic pathways of various pigments is proposed here as a general strategy to improve absorption spectra and yield of photosynthesis and hydrogen gas production in bacteria.

Leishmania parasites harbor a unique network of circular DNA known as kinetoplast DNA (kDNA). The role of kDNA in leishmania infections is poorly understood. Herein, we show that kDNA delivery to the cytosol of Leishmania major infected THP-1 macrophages provoked increased parasite loads when compared to untreated cells, hinting at the involvement of cytosolic DNA sensors in facilitating parasite evasion from the immune system. Parasite proliferation was significantly hindered in cGAS- STING- and TBK-1 knockout THP-1 macrophages when compared to wild type cells. Nanostring nCounter gene expression analysis on L. major infected wild type versus knockout cells revealed that some of the most upregulated genes including, Granulysin (GNLY), Chitotriosidase-1 (CHIT1), Sialomucin core protein 24 (CD164), SLAM Family Member 7 (SLAMF7), insulin-like growth factor receptor 2 (IGF2R) and apolipoprotein E (APOE) were identical in infected cGAS and TBK1 knockout cells, implying their involvement in parasite control. Amlexanox treatment (a TBK1 inhibitor) of L. major infected wild type cells inhibited both the percentage and the parasite load of infected THP-1 cells and delayed footpad swelling in parasite infected mice. Collectively, these results suggest that leishmania parasites might hijack the cGAS-STING-TBK1 signaling pathway to their own advantage and the TBK1 inhibitor amlexanox could be of interest as a candidate drug in treatment of cutaneous leishmaniasis.

SARS-CoV-2 vakalarının yetersiz sağlık sistemine sahip ülkelerde beklenenin altında olması kafalarda soru işareti yaratmaktadır. Burada biz farklı ülkelerin benimsediği verem (BCG) aşısı politikalarındaki ve aşılamadaki suş tercihlerindeki farklılıkların SARS-CoV-2'nin bulaşma modeli ve/veya COVID-19 ile ilişkilendirilen hastalık ve ölüm oranlarını etkileyebileceği hipotezini öne sürmekteyiz. Ayrıca SARS-CoV-2'ye özgü bir aşı geliştirilene kadar, enfeksiyona yakalanma riski yüksek olan popülasyonların BCG aşısı ile bağışıklanması ile yeni korona virüse karşı özgül olmayan heterolog bir koruma sağlanabileceğini öne sürmekteyiz. İncelemelerimiz sonunda BCG aşısı kullanan ülkeler arasında en iyi COVID-19'dan korunma sağlayanların özellikle Grup I tipi BCG aşılaması uygulayan ülkeler olduğunu ortaya çıkarmaktadır. Bunların arasında ise Rusya suşunu kullanan ülkelerin diğer BCG aşısı kullanan ülkelerden daha da iyi korunma düzeyi gösterdikleri anlaşılmaktadır.

Background Vaccines that incorporate multiple SARS-CoV-2 antigens can further broaden the breadth of virus-specific cellular and humoral immunity. This study describes the development and immunogenicity of SARS-CoV-2 VLP vaccine that incorporates the 4 structural proteins of SARS-CoV-2. Methods VLPs were generated in transiently transfected HEK293 cells, purified by multimodal chromatography and characterized by tunable resistive pulse sensing, AFM, SEM, and TEM. Immunoblotting studies verified the protein identities of VLPs. Cellular and humoral immune responses of immunized animals demonstrated the immune potency of the formulated VLP vaccine. Results Transiently transfected HEK293 cells reproducibly generated vesicular VLPs that were similar in size to and expressing all four structural proteins of SARS-CoV-2. Alum adsorbed, K3-CpG ODN adjuvanted VLPs elicited high titer anti-S, anti-RBD, anti-N IgG, triggered multifunctional Th1 biased T cell responses, reduced virus load and prevented lung pathology upon live virus challenge in vaccinated animals. Conclusion These data suggest that VLPs expressing all four structural protein antigens of SARS-CoV-2 are immunogenic and can protect animals from developing COVID-19 infection following vaccination.