Name: spore adsorption as a nonrecombinant display system for enzymes and antigens
Uploaded: 2019-03-19T14:30:00
Description: Watch this Scientific Journal Video about Spore Adsorption as a Nonrecombinant Display System for Enzymes and Antigens at JoVE.com

This work was supported by &#34;Finanziamento di Ricerca di Ateneo&#34; to L. Baccigalupi, project title &#34;SP-LAY: Bacterial spores as live platform for proteins display&#34;.

1. Adsorption reaction
<ol>
	<li>Incubate 2, 5, and 10 &#181;g of mRFP with 2 x 109 of B. subtilis wild-type purified spores in 200 &#181;L of binding buffer, 50 mM sodium citrate, pH 4.0 (16.7 mM sodium citrate dihydrate; 33.3 mM citric acid) for 1 h at 25 &#176;C on a rocking shaker (Figure 1).</li>
	<li>Centrifuge the binding mixtures (13,000 x g for 10 min) to fractionate pellets (P2, P5, and P10) and supernatants (S2, S5, and S10). Store the supernatants f...

<ol>
	<li>Felici, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peptide+and+protein+display+on+the+surface+of+filamentous+bacteriophage.">Peptide and protein display on the surface of filamentous bacteriophage.</a> Biotechnology Annual Review. 1, 149-183 (1995).</li><li>Cortese, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+biologically+active+peptides+using+random+libraries+displayed+on+phage.">Identification of biologically active peptides using random libraries displayed on phage.</a> Current Opinion in Biotechnology. 6, 73-80 (1995).</li><li>Sousa, C., Cebolla, A., de Lorenzo, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+metalloadsorption+of+bacterial+cells+displaying+poly-His+peptides.">Enhanced metalloadsorption of bacterial cells displaying poly-His peptides.</a> Nature Biotechnology. 14, 1017-1020 (1996).</li><li>Richins, R., Kaneva, I., Mulchandani, A., Chen, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodegradation+of+organophosphorus+pesticides+by+surface-expressed+organophosphorus+hydrolase.">Biodegradation of organophosphorus pesticides by surface-expressed organophosphorus hydrolase.</a> Nature Biotechnology. 15, 984-987 (1997).</li><li>Wu, J. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+immunogenic+epitopes+of+hepatitis+B+surface+antigen+with+hybrid+flagellin+proteins+by+a+vaccine+strain+of+Salmonella.">Expression of immunogenic epitopes of hepatitis B surface antigen with hybrid flagellin proteins by a vaccine strain of Salmonella.</a> Proceedings of the National Academy of Sciences of the United States of America. 86, 4726-4730 (1989).</li><li>Newton, S. M., Jacob, C. O., Stocker, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+response+to+cholera+toxin+epitope+inserted+in+Salmonella+flagellin.">Immune response to cholera toxin epitope inserted in Salmonella flagellin.</a> Science. 244, 70-72 (1989).</li><li>Fischetti, V. A., Medaglini, D., Pozzi, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gram-positive+commensal+bacteria+for+mucosal+vaccine+delivery.">Gram-positive commensal bacteria for mucosal vaccine delivery.</a> Current Opinion in Biotechnology. 7, 659-666 (1996).</li><li>Isticato, R., Ricca, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spore+surface+display.">Spore surface display.</a> Microbiology Spectrum. 2 (5), (2014).</li><li>Ricca, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucosal+vaccine+delivery+by+non-recombinant+spores+of+Bacillus+subtilis.">Mucosal vaccine delivery by non-recombinant spores of Bacillus subtilis.</a> Microbial Cell Factories. 13, 115 (2014).</li><li>McKenney, P. T., Driks, A., Eichenberger, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Bacillus+subtilis+assembly+and+functions+of+the+multilayered+coat.">The Bacillus subtilis assembly and functions of the multilayered coat.</a> Nature Reviews Microbiology. 11, 33-44 (2013).</li><li>Knecht, L. D., Pasini, P., Daunert, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+spores+as+platforms+for+bioanalytical+and+biomedical+applications.">Bacterial spores as platforms for bioanalytical and biomedical applications.</a> Analytical and Bioanalytical Chemistry. 400, 977-989 (2011).</li><li>Isticato, R., Cangiano, G., De Felice, M., Ricca, E., Ricca, E., Henriques, A. O., Cutting, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Display+of+molecules+on+the+spore+surface.">Display of molecules on the spore surface.</a> Bacterial Spore Formers: Probiotics and Emerging Applications. , 193-200 (2004).</li><li>Sirec, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adsorption+of+&#946;-galactosidase+of+Alicyclobacillus+acidocaldaricus+wild+type+and+mutant+spores+of+Bacillus+subtilis.">Adsorption of &#946;-galactosidase of Alicyclobacillus acidocaldaricus wild type and mutant spores of Bacillus subtilis.</a> Microbial Cell Factories. 11, 100 (2012).</li><li>Cutting, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacillus+probiotics.">Bacillus probiotics.</a> Food Microbiology. 28, 214-220 (2011).</li><li>Baccigalupi, L., Ricca, E., Ghelardi, E., Venema, K., Do Carmo, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-LAB+Probiotics:+Spore+Formers.">Non-LAB Probiotics: Spore Formers.</a> Probiotics and Prebiotics: Current Research and Future Trends. , 93-103 (2014).</li><li>Cutting, S. M., Hong, H. A., Baccigalupi, L., Ricca, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+Vaccine+Delivery+by+Recombinant+Spore+Probiotics.">Oral Vaccine Delivery by Recombinant Spore Probiotics.</a> International Reviews of Immunology. 28, 487-505 (2009).</li><li>Lee, S. Y., Choi, J. H., Xu, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+cell-surface+display.">Microbial cell-surface display.</a> Trends in Biotechnology. 21, 45-52 (2003).</li><li>Isticato, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+display+of+recombinant+proteins+on+Bacillus+subtilis+spores.">Surface display of recombinant proteins on Bacillus subtilis spores.</a> Journal of Bacteriology. 183, 6294-6301 (2001).</li><li>Huang, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mucosal+delivery+of+antigens+using+adsorption+to+bacterial+spores.">Mucosal delivery of antigens using adsorption to bacterial spores.</a> Vaccine. 28, 1021-1030 (2010).</li><li>Isticato, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-recombinant+display+of+the+B+subunit+of+the+heat+labile+toxin+of+Escherichia+coli+wild+type+and+mutant+spores+of+Bacillus+subtilis.">Non-recombinant display of the B subunit of the heat labile toxin of Escherichia coli wild type and mutant spores of Bacillus subtilis.</a> Microbial Cell Factories. 12, 98 (2013).</li><li>Mattossovich, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conversion+of+xylan+by+recyclable+spores+of+Bacillus+subtilis+thermophilic+enzymes.">Conversion of xylan by recyclable spores of Bacillus subtilis thermophilic enzymes.</a> Microbial Cell Factories. 16, 218 (2017).</li><li>Pesce, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+charge+and+hydrodynamic+coefficient+measurements+of+Bacillus+subtilis+by+optical+tweezers.">Surface charge and hydrodynamic coefficient measurements of Bacillus subtilis by optical tweezers.</a> Colloids and Surfaces B: Biointerfaces. 116, 568-575 (2014).</li><li>Donadio, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localization+of+a+red+fluorescence+protein+adsorbed+on+wild+type+and+mutant+spores+of+Bacillus+subtilis.">Localization of a red fluorescence protein adsorbed on wild type and mutant spores of Bacillus subtilis.</a> Microbial Cell Factories. 15, 153 (2016).</li><li>Pan, J. G., Choi, S. K., Jung, H. C., Kim, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Display+of+native+proteins+on+Bacillus+subtilis+spores.">Display of native proteins on Bacillus subtilis spores.</a> FEMS Microbiology Letters. 358, 209-217 (2014).</li><li>Cutting, S., Vander Horn, P. B., Harwood, C., Cutting, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+analysis.">Genetic analysis.</a> Molecular Biological Methods for Bacillus. , (1990).</li><li>Lanzilli, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Display+of+the+peroxiredoxin+Bcp1+of+Sulfolobus+solfataricus+probiotic+spores+of+Bacillus+megaterium.">Display of the peroxiredoxin Bcp1 of Sulfolobus solfataricus probiotic spores of Bacillus megaterium.</a> New Biotechnology. 46, 38 (2018).</li></ol>

This spore adsorption protocol is very simple and straightforward. The reaction is strictly dependent on the pH of the reaction buffer and the efficiency of adsorption is optimal at acidic pH values (pH 5.0 or lower). At neutral pH conditions, the efficiency of adsorption is low, and at alkaline pH values, adsorption may not occur. Optimal adsorption is obtained using a volume of 200 &#181;L in 1.5 mL tubes (or keeping a similar ratio) on a rocking shaker.
Adsorption is very tight, and washes ...

Display systems are aimed at presenting biologically active molecules on the surface of microorganisms and finding applications in a variety of fields, from industrial to medical and environmental biotechnologies. In addition to phages1,2 and cells of various Gram-negative and -positive species3,4,5,6,7, bacterial spores have also been proposed as display systems by two approaches8,9.
Because of its peculiar structure, namely a dehydrated cytoplasm surrounded by a series of protective layers10, the spore provides several advantages over phage- and cell-based display systems8,9. A first advantage comes from the extreme robustness and stability of spores at conditions that would be deleterious to all other cells10,11. Spore-displayed antigens and enzymes are stable after prolonged storage at room temperature12 and protected from degradation at low pH and high temperatures13. A second advantage of spores is the safety of many spore-forming species. B. subtilis, B. clausii, B. coagulans, and several other species are used worldwide as probiotics and have been on the market for human or animal use for decades14,15. This exceptional safety record is an obvious general requirement for a surface display system and is of particular relevance when the system is intended for human or animal use16. A third, important advantage of a spore-based display system is that it does not have limitations for the size of the molecule that has to be exposed. In phage-based systems, a large heterologous protein may affect the structure of the capsid, while in cell-based systems, it may affect the structure of the membrane or may limit/impair the membrane translocation step17. The protective layers surrounding the spore are composed of more than 70 different proteins10 and are flexible enough to accept large foreign proteins without any evident structural defect or functional impairment8. In addition, with both spore-based display systems, the membrane translocation of the heterologous protein is not required8,9. Indeed, heterologous proteins are either produced in the mother cell cytoplasm and assembled on the spore that is forming in the same cytoplasm or adsorbed on the mature spore8,9.
Spore display was initially obtained by developing a genetic system to engineer the spore surface18. This genetic system was based on i) the construction of a gene fusion between the gene coding for a spore coat protein (used as a carrier) and the gene coding for the protein to be displayed - the presence of the transcriptional and translational signals of the endogenous gene will control the expression of the fusion, and ii) integration of the chimeric gene on the B. subtilis chromosome to grant genetic stability. A variety of antigens and enzymes have been displayed by this recombinant approach, using various spore surface proteins as carriers and aiming at various potential applications, ranging from mucosal vaccine to biocatalyst, biosensor, bioremediation, or bioanalytical tool8,13.
More recently, a different approach of spore display has been developed19. This second system is nonrecombinant and relies on the spontaneous and extremely tight adsorption of molecules on the spore surface9. Antigens19,20 and enzymes13,21 have been efficiently displayed and have revealed that this method is significantly more efficient than the recombinant one. This nonrecombinant approach allows the display of proteins in the native form20 and can also be used with autoclaved, death spores19. The molecular mechanism of adsorption has not been fully clarified yet. The negative charge and the hydrophobicity of the spore have been proposed as properties relevant for the adsorption13,19,22. Recently, it has been shown that a model protein, the red autofluorescent protein (mRFP) of the coral Discosoma, when adsorbed to the spore, was able to infiltrate through the surface layers localizing in the inner coat23. If proved true for other proteins, the internal localization of the heterologous proteins could explain their increased stability when adsorbed to spores23.
In a recent study, two enzymes catalyzing two successive steps of the xylan degradation pathway were independently displayed on spores of B. subtilis and, when incubated together, were able to perform both degradation steps21. Spores collected after the reaction were still active and able to continue the xylan degradation upon the addition of fresh substrate21. Even if a loss of about 15% of the final product was observed in the second reaction21, the reusability of adsorbed enzymes for single, as well as multi-step, reactions is an additional important advantage of the spore display system.
Pan et al.24 reported an additional approach to display heterologous proteins on the spore surface: heterologous proteins (an endoglucanase protein and a beta-galactosidase one) produced in the mother cell during sporulation were spontaneously encased in the forming spore coat, without the need of a carrier. This additional spore display system is a combination of the two approaches described so far. Indeed, it is recombinant since the heterologous proteins were engineered to be expressed in the mother cell during sporulation, while their assembly within the coat was spontaneous and, therefore, nonrecombinant24. However, the efficiency of display of this additional approach remains to be tested and compared with the other two approaches by using the same heterologous proteins.
The present protocol excludes the processes of spore production and purification, which have been described extensively elsewhere24. It includes the adsorption reaction, the evaluation of the efficiency of adsorption by dot-blotting and fluorescence microscopy, and the recycling of adsorbed enzymes for additional reaction rounds.

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			<td height="26" style="height:27px;width:247px;">0.1% Poly-L-lysine solution</td>
			<td style="width:151px;">Sigma</td>
			<td style="width:173px;">P8920</td>
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			<td height="26" style="height:27px;width:247px;">0.45 &#181;m Nitrocellulose Blotting Membrane</td>
			<td>Sartorius</td>
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			<td height="26" style="height:27px;width:247px;">100&#215; objective UPlanF1&#160;</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:173px;">microscope equipment</td>
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			<td height="26" style="height:27px;width:247px;">Bacillus subtilis&#160;strain NCIB3610</td>
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			<td style="width:173px;">3A1</td>
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			<td height="26" style="height:27px;width:247px;">BD ACCURI C6 PLUS</td>
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			<td height="26" style="height:27px;width:247px;">BX51</td>
			<td style="width:151px;">Olympus</td>
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			<td height="26" style="height:27px;width:247px;">Clarity</td>
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			<td style="width:173px;">1705060</td>
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			<td height="26" style="height:27px;width:247px;">DP70 digital camera a</td>
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			<td height="42" style="height:42px;width:247px;">Goat anti-Rabbit IgG (H+L) Cross-Adsorbed Secondary Antibody, FITC</td>
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			<td height="21" style="height:21px;width:247px;">Goat Anti-Rabbit IgG H&#38;L (HRP)&#160;</td>
			<td style="width:151px;">Abcam</td>
			<td style="width:173px;">ab6721</td>
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		<tr height="42">
			<td height="42" style="height:42px;width:247px;">Monoclonal Anti-polyHistidine&#8722;Peroxidase antibody</td>
			<td style="width:151px;">Sigma</td>
			<td style="width:173px;">A7058-1VL</td>
			<td style="width:337px;">used to detect adsorbed proteins presenting a 6xhistidine-tag at C- or N- terminal&#160;</td>
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			<td height="21" style="height:21px;width:247px;">SecureSlip&#160;glass coverslip</td>
			<td style="width:151px;">Sigma</td>
			<td style="width:173px;">S1815-1PAK</td>
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			<td height="42" style="height:42px;width:247px;">Superwhite Uncharged Microscope Slides</td>
			<td style="width:151px;">VWR</td>
			<td>75836-190</td>
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			<td height="21" style="height:21px;width:247px;">U-CA Magnification Changer&#160;</td>
			<td style="width:151px;">Olympus</td>
			<td style="width:173px;">microscope equipment</td>
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spore adsorption as a nonrecombinant display system for enzymes and antigens

The bacterial spore is a metabolically quiescent cell, formed by a series of protective layers surrounding a dehydrated cytoplasm. This peculiar structure makes the spore extremely stable and resistant and has suggested the use of the spore as a platform to display heterologous molecules. So far, a variety of antigens and enzymes have been displayed on spores of Bacillus subtilis and of a few other species, initially by a recombinant approach and, then, by a simple and efficient nonrecombinant method. The nonrecombinant display system is based on the direct adsorption of heterologous molecules on the spore surface, avoiding the construction of recombinant strains and the release of genetically modified bacteria in the environment. Adsorbed molecules are stabilized and protected by the interaction with spores, which limits the rapid degradation of antigens and the loss of enzyme activity at unfavorable conditions. Once utilized, spore-adsorbed enzymes can be collected easily with a minimal reduction of activity and reused for additional reaction rounds. In this paper is shown how to adsorb model molecules to purified spores of B. subtilis, how to evaluate the efficiency of adsorption, and how to collect used spores to recycle them for new reactions.

Successful adsorption can be assessed by western blotting. Upon the reaction, the mixture is fractionated by centrifugation and washed, and the pellet fraction (Figure 1) is used to extract the surface proteins. The extract is fractionated by SDS polyacrylamide gel electrophoresis (PAGE), electrotransferred to a polyvinylidene fluoride (PVDF) membrane, and reacted against primary and secondary antibodies. The presence of proteins of the expected size, only in...

Watch this Scientific Journal Video about Spore Adsorption as a Nonrecombinant Display System for Enzymes and Antigens at JoVE.com

Spore Adsorption as a Nonrecombinant Display System for Enzymes and Antigens

This protocol focuses on the use of bacterial spores as a &#34;live&#34; nanobiotechnological tool to adsorb heterologous molecules with various biological activities. The methods to measure the efficiency of adsorption are also shown.

The bacterial spore is a metabolically quiescent cell, formed by a series of protective layers surrounding a dehydrated cytoplasm. This peculiar structure ...

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