Name: effect of anti-c-fms antibody on osteoclast formation and proliferation of osteoclast precursor in vitro
Uploaded: 2019-03-18T13:30:00
Description: Watch this Scientific Journal Video about Effect of Anti-c-fms Antibody on Osteoclast Formation and Proliferation of Osteoclast Precursor In Vitro at JoVE.com

This work was supported in part by a JSPS KAKENHI grant from the Japan Society for the Promotion of Science (No. 16K11776 to H. K., No. 17K17306 to K. S., No. 16K20637 to K. K., No. 16K20636 to M. S., No. 18K09862 to I. M.).&#160;

All animal procedures and animal care were performed according to Tohoku University rules and regulations.
1. Murine Hindlimb Dissection and Handling
<ol>
	<li>Before dissection, fill a plate with approximately 50 mL of &#945;-MEM depending on the size of the container and place it on ice. This will serve as a collection container until the dissection of all bones is complete. For this and subsequent experiments, use &#945;-MEM containing 10% fetal bovine serum (FBS), 100 IU/mL penicillin G,...

<ol>
	<li>Crotti, T. N., Dharmapatni, A. A., Alias, E., Haynes, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteoimmunology:+Major+and+Costimulatory+Pathway+Expression+Associated+with+Chronic+Inflammatory+Induced+Bone+Loss.">Osteoimmunology: Major and Costimulatory Pathway Expression Associated with Chronic Inflammatory Induced Bone Loss.</a> Journal of Immunology Research. 2015, 281287 (2015).</li><li>Teitelbaum, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+resorption+by+osteoclasts.">Bone resorption by osteoclasts.</a> Science. 289 (5484), 1504-1508 (2000).</li><li>Azuma, Y., Kaji, K., Katogi, R., Takeshita, S., Kudo, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+necrosis+factor-alpha+induces+differentiation+of+and+bone+resorption+by+osteoclasts.">Tumor necrosis factor-alpha induces differentiation of and bone resorption by osteoclasts.</a> Journal of Biological Chemistry. 275 (7), 4858-4864 (2000).</li><li>Kobayashi, K., 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=Tumor+necrosis+factor+alpha+stimulates+osteoclast+differentiation+by+a+mechanism+independent+of+the+ODF/RANKL-RANK+interaction.">Tumor necrosis factor alpha stimulates osteoclast differentiation by a mechanism independent of the ODF/RANKL-RANK interaction.</a> Journal of Experimental Medicine. 191 (2), 275-286 (2000).</li><li>Kim, N., 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=Osteoclast+differentiation+independent+of+the+TRANCE-RANK-TRAF6+axis.">Osteoclast differentiation independent of the TRANCE-RANK-TRAF6 axis.</a> Journal of Experimental Medicine. 202 (5), 589-595 (2005).</li><li>Redlich, K., 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=Osteoclasts+are+essential+for+TNF-alpha-mediated+joint+destruction.">Osteoclasts are essential for TNF-alpha-mediated joint destruction.</a> Journal of Clinical Investestigation. 110 (10), 1419-1427 (2002).</li><li>Abu-Amer, Y., Ross, F. P., Edwards, J., Teitelbaum, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipopolysaccharide-stimulated+osteoclastogenesis+is+mediated+by+tumor+necrosis+factor+via+its+P55+receptor.">Lipopolysaccharide-stimulated osteoclastogenesis is mediated by tumor necrosis factor via its P55 receptor.</a> Journal of Clinical Investestigation. 100 (6), 1557-1565 (1997).</li><li>Zha, L., 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=TNF-alpha+contributes+to+postmenopausal+osteoporosis+by+synergistically+promoting+RANKL-induced+osteoclast+formation.">TNF-alpha contributes to postmenopausal osteoporosis by synergistically promoting RANKL-induced osteoclast formation.</a> Biomedicine &amp; Pharmacotherapy. 102, 369-374 (2018).</li><li>Kitaura, H., 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=M-CSF+mediates+TNF-induced+inflammatory+osteolysis.">M-CSF mediates TNF-induced inflammatory osteolysis.</a> Journal of Clinical Investigation. 115 (12), 3418-3427 (2005).</li><li>Kimura, K., Kitaura, H., Fujii, T., Hakami, Z. W., Takano-Yamamoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anti-c-Fms+antibody+inhibits+lipopolysaccharide-induced+osteoclastogenesis+in+vivo.">Anti-c-Fms antibody inhibits lipopolysaccharide-induced osteoclastogenesis in vivo.</a> FEMS Immunology and Medical Microbiology. 64 (2), 219-227 (2012).</li><li>Kimura, K., 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=An+anti-c-Fms+antibody+inhibits+osteoclastogenesis+in+a+mouse+periodontitis+model.">An anti-c-Fms antibody inhibits osteoclastogenesis in a mouse periodontitis model.</a> Oral Diseases. 20 (3), 319-324 (2014).</li><li>Kitaura, H., 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=An+M-CSF+receptor+c-Fms+antibody+inhibits+mechanical+stress-induced+root+resorption+during+orthodontic+tooth+movement+in+mice.">An M-CSF receptor c-Fms antibody inhibits mechanical stress-induced root resorption during orthodontic tooth movement in mice.</a> Angle Orthodontist. 79 (5), 835-841 (2009).</li><li>Kitaura, H., 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=An+anti-c-Fms+antibody+inhibits+orthodontic+tooth+movement.">An anti-c-Fms antibody inhibits orthodontic tooth movement.</a> Journal of Dental Research. 87 (4), 396-400 (2008).</li><li>Bettina, A., 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=M-CSF+Mediates+Host+Defense+during+Bacterial+Pneumonia+by+Promoting+the+Survival+of+Lung+and+Liver+Mononuclear+Phagocytes.">M-CSF Mediates Host Defense during Bacterial Pneumonia by Promoting the Survival of Lung and Liver Mononuclear Phagocytes.</a> Journal of Immunology. 196 (12), 5047-5055 (2016).</li><li>Dougall, W. C., 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=RANK+is+essential+for+osteoclast+and+lymph+node+development.">RANK is essential for osteoclast and lymph node development.</a> Genes &amp; Develpoment. 13 (18), 2412-2424 (1999).</li><li>Wiktor-Jedrzejczak, W., 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=Total+absence+of+colony-stimulating+factor+1+in+the+macrophage-deficient+osteopetrotic+(op/op)+mouse.">Total absence of colony-stimulating factor 1 in the macrophage-deficient osteopetrotic (op/op) mouse.</a> Proceedings of the National Academy of Sciences of the United States of America. 87 (12), 4828-4832 (1990).</li><li>Yang, P. 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=Increased+expression+of+macrophage+colony-stimulating+factor+in+ankylosing+spondylitis+and+rheumatoid+arthritis.">Increased expression of macrophage colony-stimulating factor in ankylosing spondylitis and rheumatoid arthritis.</a> Annals of the Rheumatic Diseases. 65 (12), 1671-1672 (2006).</li><li>Takei, I., 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=High+macrophage-colony+stimulating+factor+levels+in+synovial+fluid+of+loose+artificial+hip+joints.">High macrophage-colony stimulating factor levels in synovial fluid of loose artificial hip joints.</a> The Journal of Rheumatology. 27 (4), 894-899 (2000).</li></ol>

In this study, we investigated the effect of anti-c-fms antibody on RANKL-induced osteoclast formation, TNF-&#945;-induced osteoclast formation and M-CSF-induced osteoclast precursor proliferation. We found that the effective amount of anti-c-fms antibody for the inhibition of osteoclastogenesis among RANKL-induced osteoclast formation, TNF-&#945; induced osteoclast formation and M-CSF-induced proliferation of osteoclast precursors is different.
RANKL mediates osteoclastogenesis in the presenc...

Osteoclasts are highly specialized cells, and they differentiate from hematopoietic stem cells through the fusion of multiple osteoclast precursors. They are essential for healthy bone remodeling and contribute to pathologic bone resorption associated with inflammatory osteolytic diseases such as rheumatoid arthritis and periodontal disease1.
Osteoclastogenesis and osteoclast function are mediated by two key factors; macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL). Both M-CSF and RANKL are important for osteoclast differentiation2. Another factor which has been shown to induce osteoclast formation from bone marrow macrophages in vitro is tumor necrosis factor alpha (TNF-&#945;)3,4,5. TNF-&#945; mediated osteoclast formation has been shown to be critical for osteolysis in destructive bone diseases such as rheumatoid arthritis6, periodontal disease7, and postmenopausal osteoporosis8.
C-fms is the membrane receptor of M-CSF and mediates its action. The role of c-fms is well documented in the literature as it was demonstrated that the administration of an antibody against c-fms (anti-c-fms antibody) completely arrested osteoclastogenesis in an arthritis model as well as in TNF-&#945; induced bone erosions while osteoclastogenesis distant from the inflamed joint was still robust9. Administration of anti-c-fms antibody inhibited osteoclast formation and bone resorption induced by lipopolysaccharide (LPS) in mouse calvariae10 as well as in LPS-induced&#160; periodontitis model11. Moreover, anti-c-fms antibody inhibited mechanical stress-induced root resorption during orthodontic tooth movement12, as well as orthodontic tooth movement and bone resorption associated with orthodontic tooth movement13.
M-CSF has been reported to have other functions which are essential to the host immune response. The absence of M-CSF in op/op mice with bacterial pneumonia lead to the increase of bacterial burden and bacterial dissemination to the liver with hepatic necrosis14. Therefore, M-CSF is important for immunological response in the protection from infection.
This study demonstrates the effect of anti-c-fms antibody on M-CSF and RANKL or TNF-&#945; induced osteoclast formation in vitro and M-CSF induced proliferation of osteoclast precursors. This protocol demonstrates the isolation of murine bone marrow cells from long bones, and the steps to generate bone marrow macrophages (BMM) which are regarded as osteoclast precursors and to induce the differentiation of BMM into multinuclear osteoclasts by two methods; either RANKL or TNF-&#945;. The protocol also compares the arrest of osteoclastogenesis in both methods using anti-c-fms antibody.
The process by which bone marrow is extracted and subsequently used to generate osteoclast precursors is reliable in producing large quantities of pure osteoclast cultures which can be used in multiple downstream applications such as drug testing. The use of either RANKL or TNF-&#945; to induce osteoclastogenesis in this protocol distinguishes osteoclastogenesis as a physiologic process (RANKL) from osteoclastogenesis as a pathologic process (TNF-&#945;), which in turn provides two alternative procedures to guide the decision of which one is superior in terms of the reagents to be used in downstream applications. This protocol also provides a method by which we can determine a suitable concentration of anti-c-fms antibody that can be safely used for later studies involved in bone resorption and osteolytic diseases.

<table>
	<tbody>
		<tr>
			<td>Anti-c-Fms antibody</td>
			<td></td>
			<td></td>
			<td>AFS98, a rat monoclonal, antimurine, c-Fms antibody (IgG2a)</td>
		</tr>
		<tr>
			<td>TNF-&#945;</td>
			<td></td>
			<td></td>
			<td>Recombinant murine TNF-&#945; prepared in our laboratory. TNF-&#945; cDNA fragment cloned by RT-PCR and cloned into a pGEX-6P-I (Amersham Biosciences, Piscataway, NJ) to generate a GST-fusion protein. GST-TNF-&#945; was expressed in Escherichia coli BL21 cells cells (Stratagene, La Jolla, CA). The cells were lysed under nondenaturing conditions and GST-TNF-&#945; was purified over a glutathione-Sepharose column. GST was cleaved off by PreScission Protease (Amersham Biosciences) by manufacturer&#8217;s directions and was removed by a glutathione-Sepharose column.</td>
		</tr>
		<tr>
			<td>RANKL</td>
			<td>PEPROTECH</td>
			<td>315-11</td>
			<td>Recombinant Murine sRANK Ligand, Source: E.coli</td>
		</tr>
		<tr>
			<td>M-CSF</td>
			<td></td>
			<td></td>
			<td>Recombinant human M-CSF. 1/10 vol of CMG14&#8211;12 cell line culture supernatant at 5X106&#160;cells in a 10-cm suspension culture dish.</td>
		</tr>
		<tr>
			<td>&#945;-MEM</td>
			<td>Wako</td>
			<td></td>
			<td>with L-Glutamine and phenol red</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Biowest</td>
			<td>s1820-500</td>
			<td>Fetal Bovine Serum French Origin</td>
		</tr>
		<tr>
			<td>Culture dish</td>
			<td>Corning</td>
			<td></td>
			<td>100 mm x 20 mm style dish</td>
		</tr>
		<tr>
			<td>96-well plate</td>
			<td>Thermofischer Scientific</td>
			<td></td>
			<td>Nun clon Delta surface</td>
		</tr>
		<tr>
			<td>Cell counting kit-8</td>
			<td>Dojindo, Kumamoto, Japan</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microplate reader</td>
			<td>Sunrise REMOTE; Tekan Japan, Kawasaki, Japan</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cell strainer</td>
			<td>Corning</td>
			<td></td>
			<td>40 &#956;m Nylon</td>
		</tr>
		<tr>
			<td>Centrifuge tube</td>
			<td>Corning</td>
			<td></td>
			<td>50 mL CentriStar cap</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Wako</td>
			<td></td>
			<td>Polyoxyethylene (10) Octyphenyl ether</td>
		</tr>
	</tbody>
</table>

effect of anti-c-fms antibody on osteoclast formation and proliferation of osteoclast precursor in vitro

Bone remodeling is a complex process and it involves periods of deposition and resorption. Bone resorption is a process by which bone is broken down by osteoclasts in response to different stimuli. Osteoclast precursors differentiate into multinuclear osteoclasts in response to macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor Kappa-B ligand (RANKL). Under pathologic conditions, the cytokine profile is different and involves a mixture of inflammatory cytokines. Tumor necrosis factor alpha (TNF-&#945;) is one of the most important cytokines as it is found in large amounts in areas involved with inflammatory osteolysis. The purpose of this protocol is to provide a method by which murine bone marrow is isolated to generate osteoclasts through induction with M-CSF and either RANKL or TNF-&#945; which will be subsequently inhibited by increasing doses of anti-c-fms antibody, the receptor for M-CSF. This experiment highlights the therapeutic value of anti-c-fms antibody in diseases of inflammatory bone resorption.

The purpose of this protocol is to evaluate the effect of anti-c-fms antibody on osteoclast formation in the presence of RANKL or TNF-&#945;, and to determine the effect of M-CSF on osteoclast precursors proliferation. In this protocol, we have provided a reliable process by which large quantities of pure osteoclast cultures are generated. We have also provided a way to test anti-c-fms antibody suitable concentration for inhibiting osteoclast formation under different culture conditions.<...

Watch this Scientific Journal Video about Effect of Anti-c-fms Antibody on Osteoclast Formation and Proliferation of Osteoclast Precursor In Vitro at JoVE.com

Effect of Anti-c-fms Antibody on Osteoclast Formation and Proliferation of Osteoclast Precursor In Vitro

This protocol includes dissection of murine long bones and bone marrow isolation, to generate bone marrow macrophages and produce osteoclasts using macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor Kappa-B ligand (RANKL) or tumor necrosis factor alpha (TNF-&#945;) and their arrest by anti-c-fms antibody, M-CSF receptor.

Bone remodeling is a complex process and it involves periods of deposition and resorption. Bone resorption is a process by which bone is broken down by ...

This experiment highlights the therapeutic value of Anti-c-fms antibody in diseases of inflammatory bone disruption, such as rheumatoid arthritis and periodontitis. The process by which bone marrow is extracted and used to generate osteoclast precursors, yields large quantities of pure osteoclasts, which can be used in multiple downstream applications. This protocol provide two alternative methods of osteoclastogenesis, either using RANKL ligand or TNF alpha.In addition to that, this method provides insight into the effect of Anti-c-fms antibody on osteoclastogenesis. Visual demonstration of this procedure familiarizes the researcher with the process of dissection and obtaining bone marrow cells in large amounts. To begin fill a plate that will serve as a collection container with approximately 50 milliliters of alpha MEM, depending on the size of the container, and place it on ice.Use pins to pierce through the palms and feet of a euthanized mouse to fix it in supine position, and spray thoroughly with 70%ethanol. Use sterile surgical scissors and tweezers to make a skin incision at the level of the hip and extend it down to the feet, exposing the muscles. Locate and cut the tendon attaching the quadriceps muscle.Peel away the muscle and cut it at the level of the hip. Then locate the tendon attaching the hamstring muscle to the bone. Peel away the muscles exposing the bone, and free the hamstring from its attachment, making sure not to cut into the bone.Position the scissors between the head of the femur and the joint space. Cut into it freeing the femur, but keeping the bone intact, which will enable detachment of the bones without risk of exposing the bone marrow. Cutaway the muscles attached to the tibia in a similar fashion.Then cut the tibia free from its attachment at the ankle joint, while keeping the bone intact to avoid contamination. Use the scissor blades and lab wipes to scrape any remaining soft tissue from the femur and tibia and place them in the prepared plate with alpha MEM placed on ice. The dissection should be carried out carefully to minimize contamination.That is why thorough soft tissue removal and bone localization are crucial. Fill a 30 gauge needle syringe with alpha MEM. Disconnect the tibia and femur away from the knee joint, and cut the ends of the long bone from both sides using scissors.Use tweezers to hold the bone from the shaft. Insert the needle into the marrow space to the bone and slowly flush the content of the marrow into a six centimeter culture dish and repeat for all bones. The bone will turn white, indicating the extraction of all bone marrow content.Use a 40 micrometer nylon cell strainer to strain the bone marrow extract into a 50 milliliter conical centrifuge tube. Centrifuge the tube at 300 times G for five minutes. Discard the supernatant.To wash, add five milliliters of alpha MEM to the pellet. Pipette the cells to detach them, centrifuge, and repeat the wash for a total of two times. After counting these isolated cells, as described in the manuscript, seed 10 million cells per 10 milliliters, in a 10 centimeter culture dish, and add M-CSF to the cells.Incubate the culture at 37 degrees Celsius, 5%carbon dioxide for three days. Remove the medium after three days, and wash the cells twice vigorously with 10 milliliters of PBS to remove nonadherent cells. Add five milliliters of room temperature 0.02%trypsin-EDTA and PBS, and incubate at 37 degrees Celsius, 5%carbon dioxide for five minutes.Thoroughly pipette the cells to detach them. Observe the culture under a microscope to make sure the cells have been detached and appear rounded and floating in media. When the cells have been detached, inactivate the reaction by adding five milliliters of the alpha MEM.Collect the cells into a 50 milliliter conical tube and centrifuge at 300 times G for five minutes. After discarding the supernatant, wash with five milliliters of alpha MEM, and centrifuge again at 300 times G for five minutes. Re-suspend the pellet in 10 milliliters of alpha MEM.Seed 1 million cells per 10 milliliters in a 10 centimeter culture dish, and add M-CSF. Incubate the culture at 37 degrees Celsius, 5%carbon dioxide for three days. Harvest the attached cells, which represent BMMs as osteoclast precursors after three days, as done previously during generation of BMMs.Seed the BMMs at 50, 000 cells per 200 micro liters of alpha MEM in a 96 well plate per well. To each well, add desired stimuli. And then add M-CSF for a final concentration of 100 nanograms per milliliter.Add Anti-c-fms antibody to each well. Incubate the plate at 37 degrees Celsius, 5%carbon dioxide for four days, while changing media every other day for four days. And then proceed with staining and assays, as described in the manuscript.The osteoclast formation in M-CSF and RANKL treated culture, with Anti-c-fms antibody, was evaluated. With 101, 000 nanograms per milliliter Anti-c-fms antibody, a significant decrease in the number of osteoclasts was observed compared to control. Whereas, with one in 10 nanograms per milliliter Anti-c-fms antibody, there was no significant decrease.Then, the osteoclast formation in M-CSF and TNF alpha treated culture, with Anti-c-fms antibody, was evaluated. With 10, 100, 1, 000 nanograms per milliliter Anti-c-fms antibody, a significant decrease in the number of osteoclasts was observed compared to control, with no significant decrease at one nanogram per milliliter. And the M-CSF culture with 1, 10, 100 nanograms per milliliter Anti-c-fms antibody, there was no significant decrease in the number of osteoclast precursors compared to control.However, at 1, 000 nanograms per milliliter, there was a significant decrease in the number of osteoclast precursors, indicating that a concentration as high as 1, 000 nanograms per milliliter is needed to significantly inhibit proliferation of osteoclast precursors. Make sure to free the bonds while keeping the bone intact, which will minimize the chance of contamination.

effect-anti-c-fms-antibody-on-osteoclast-formation-proliferation

Research

JoVE Journal

Immunology and Infection

In vitro Biofilm Formation in an 8-well Chamber Slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. Biofilms are community-associated bacteria attached to a surface and encased in a matrix. The role of the extracellular matrix is multifaceted, including facilitating nutrient acquisition, and offers significant protection against environmental stresses (e.g. host immune responses). In an effort to acquire a better understanding as to how the bacteria within a biofilm respond to environmental stresses we have used a protocol wherein we visualize bacterial biofilms which have formed in an 8-well chamber slide. The biofilms were stained with the BacLight Live/Dead stain and examined using a confocal microscope to characterize the relative biofilm size, and structure under varying incubation conditions. Z-stack images were collected via confocal microscopy and analyzed by COMSTAT. This protocol can be used to help elucidate the mechanism and kinetics by which biofilms form, as well as identify components that are important to biofilm structure and stability.

In vitro Biofilm Formation in an 8-well Chamber Slide

This article describes the procedure for the formation and visualization of a bacterial biofilm grown within an 8-well chamber slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. ...

Measurement of Antibody Effects on Cellular Function of Isolated Cardiomyocytes

Dilated cardiomyopathy (DCM) is one of the main causes for heart failure in younger adults1. Although genetic disposition and exposition to toxic substances are known causes for this disease in about one third of the patients, the origin of DCM remains largely unclear. In a substantial number of these patients, autoantibodies against cardiac epitopes have been detected and are suspected to play a pivotal role in the onset and progression of the disease2,3. The importance of cardiac autoantibodies is underlined by a hemodynamic improvement observed in DCM patients after elimination of autoantibodies by immunoadsorption3-5. A variety of specific antigens have already been identified2,3 and antibodies against these targets may be detected by immunoassays. However, these assays cannot discriminate between stimulating (and therefore functionally effective) and blocking autoantibodies. There is increasing evidence that this distinction is crucial6,7. It can also be assumed that the targets for a number of cardiotropic antibodies are still unidentified and therefore cannot be detected by immunoassays. Therefore, we established a method for the detection of functionally active cardiotropic antibodies, independent of their respective antigen. The background for the method is the high homology usually observed for functional regions of cardiac proteins in between mammals8,9. This suggests that cardiac antibodies directed against human antigens will cross-react with non-human target cells, which allows testing of IgG from DCM patients on adult rat cardiomyocytes. Our method consists of 3 steps: first, IgG is isolated from patient plasma using sepharose coupled anti-IgG antibodies obtained from immunoadsorption columns (PlasmaSelect, Teterow, Germany). Second, adult cardiomyocytes are isolated by collagenase perfusion in a Langendorff perfusion apparatus using a protocol modified from previous works10,11. The obtained cardiomyocytes are attached to laminin-coated chambered coverglasses and stained with Fura-2, a calcium-selective fluorescent dye which can be easily brought into the cell to observe intracellular calcium (Ca2+) contents12. In the last step, the effect of patient IgG on the cell shortening and Ca2+ transients of field stimulated cardiomyocytes is monitored online using a commercial myocyte calcium and contractility monitoring system (IonOptix, Milton, MA, USA) connected to a standard inverse fluorescent microscope.

The presented method offers a way to detect functional effective cardiotropic autoantibodies in the plasma of patients with dilated cardiomyopathy, irrespective of the specific antigen, by analysing the impact of isolated patient immunoglobulin on cellular shortening and intracellular calcium transients in isolated rat cardiomyocytes.

Dilated cardiomyopathy  (DCM) is one of the main causes for heart failure in younger adults1.  Although genetic disposition and exposition to toxic ...

The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms

Recently there were several publications on the bactericidal effect of visible light, most of them claiming that blue part of the spectrum (400 nm-500 nm) is responsible for killing various pathogens1-5. The phototoxic effect of blue light was suggested to be a result of light-induced reactive oxygen species (ROS) formation by endogenous bacterial photosensitizers which mostly absorb light in the blue region4,6,7. There are also reports of biocidal effect of red and near infra red8 as well as green light9.
In the present study, we developed a method that allowed us to characterize the effect of high power green (wavelength of 532 nm) continuous (CW) and pulsed Q-switched (Q-S) light on Pseudomonas aeruginosa. Using this method we also studied the effect of green light combined with antibiotic treatment (gentamycin) on the bacteria viability. P. aeruginosa is a common noscomial opportunistic pathogen causing various diseases. The strain is fairly resistant to various antibiotics and contains many predicted AcrB/Mex-type RND multidrug efflux systems10.
The method utilized free-living stationary phase Gram-negative bacteria (P. aeruginosa strain PAO1), grown in Luria Broth (LB) medium exposed to Q-switched and/or CW lasers with and without the addition of the antibiotic gentamycin. Cell viability was determined at different time points. The obtained results showed that laser treatment alone did not reduce cell viability compared to untreated control and that gentamycin treatment alone only resulted in a 0.5 log reduction in the viable count for P. aeruginosa. The combined laser and gentamycin treatment, however, resulted in a synergistic effect and the viability of P. aeruginosa was reduced by 8 log's.
The proposed method can further be implemented via the development of catheter like device capable of injecting an antibiotic solution into the infected organ while simultaneously illuminating the area with light.

The Synergistic Effect of Visible Light and Gentamycin on Pseudomona aeruginosa Microorganisms

We show that a developed biomedical device involving continuous or pulsed visible laser based treatment that is combined with antibiotic treatment (gentamycin), results in a statistically significant synergistic effect leading to a reduction in the viability of P. aeruginosa PAO1, by 8 log's compared to antibiotic treatment alone.

Recently there were several publications on the  bactericidal effect of visible light, most of them claiming that blue part of  the spectrum (400 nm-500 ...

Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay

Adherence of Streptococcus pneumoniae (the pneumococcus) to the epithelial lining of the nasopharynx can result in colonization and is considered a prerequisite for pneumococcal infections such as pneumonia and otitis media. In vitro adherence assays can be used to study the attachment of pneumococci to epithelial cell monolayers and to investigate potential interventions, such as the use of probiotics, to inhibit pneumococcal&#160;colonization.&#160;The protocol described here is used to investigate the effects of the probiotic Streptococcus salivarius on the adherence of pneumococci to the human epithelial cell line CCL-23 (sometimes referred to as HEp-2 cells). The assay involves three main steps: 1) preparation of epithelial and bacterial cells, 2) addition of bacteria to epithelial cell monolayers, and 3) detection of adherent pneumococci by viable counts (serial dilution and plating) or quantitative real-time PCR (qPCR). This technique is relatively straightforward and does not require specialized equipment other than a tissue culture setup. The assay can be used to test other probiotic species and/or potential inhibitors of pneumococcal colonization and can be easily modified to address other scientific questions regarding pneumococcal adherence and invasion.

Investigating the Effects of Probiotics on Pneumococcal Colonization Using an In Vitro Adherence Assay

In vitro adherence assays can be used to study the attachment of Streptococcus pneumoniae to epithelial cell monolayers and to investigate potential interventions such as the use of probiotics for inhibiting pneumococcal colonization.

Adherence of Streptococcus pneumoniae (the pneumococcus) to the epithelial lining of the nasopharynx can result in colonization and is considered a ...

Methods for Quantitative Detection of Antibody-induced Complement Activation on Red Blood Cells

Antibodies against red blood cells (RBCs) can lead to complement activation resulting in an accelerated clearance via complement receptors in the liver (extravascular hemolysis) or leading to intravascular lysis of RBCs. Alloantibodies (e.g. ABO) or autoantibodies to RBC antigens (as seen in autoimmune hemolytic anemia, AIHA) leading to complement activation are potentially harmful and can be - especially when leading to intravascular lysis - fatal1. Currently, complement activation due to (auto)-antibodies on RBCs is assessed in vitro by using the Coombs test reflecting complement deposition on RBC or by a nonquantitative hemolytic assay reflecting RBC lysis1-4. However, to assess the efficacy of complement inhibitors, it is mandatory to have quantitative techniques. Here we describe two such techniques. First, an assay to detect C3 and C4 deposition on red blood cells that is induced by antibodies in patient serum is presented. For this, FACS analysis is used with fluorescently labeled anti-C3 or anti-C4 antibodies. Next, a quantitative hemolytic assay is described. In this assay, complement-mediated hemolysis induced by patient serum is measured making use of spectrophotometric&#160;detection of the released hemoglobin. Both of these assays are very reproducible and quantitative, facilitating studies of antibody-induced complement activation.

Here we describe two assays for measuring complement activation induced by antibodies against red blood cells. The major advantage over the current assays is their quantitative and easy-to-interpret nature.

Antibodies against red blood cells (RBCs) can lead to complement activation resulting in an accelerated clearance via complement receptors in the liver ...

Macrophage Cholesterol Depletion and Its Effect on the Phagocytosis of Cryptococcus neoformans

Cryptococcosis is a life-threatening infection caused by pathogenic fungi of the genus Cryptococcus. Infection occurs upon inhalation of spores, which are able to replicate in the deep lung. Phagocytosis of Cryptococcus by macrophages is one of the ways that the disease is able to spread into the central nervous system to cause lethal meningoencephalitis. Therefore, study of the association between Cryptococcus and macrophages is important to understanding the progression of the infection. The present study describes a step-by-step protocol to study macrophage infectivity by C. neoformansin vitro. Using this protocol, the role of host sterols on host-pathogen interactions is studied. Different concentrations of methyl--cyclodextrin (MCD) were used to deplete cholesterol from murine reticulum sarcoma macrophage-like cell line J774A.1. Cholesterol depletion was confirmed and quantified using both a commercially available cholesterol quantification kit and thin layer chromatography. Cholesterol depleted cells were activated using Lipopolysacharide (LPS) and Interferon gamma (IFN&#947;) and infected with antibody-opsonized Cryptococcus neoformans wild-type H99 cells at an effector-to-target ratio of 1:1. Infected cells were monitored after 2 hr of incubation with C. neoformans and their phagocytic index was calculated. Cholesterol depletion resulted in a significant reduction in the phagocytic index. The presented protocols offer a convenient method to mimic the initiation of the infection process in a laboratory environment and study the role of host lipid composition on infectivity.

Macrophage Cholesterol Depletion and Its Effect on the Phagocytosis of Cryptococcus neoformans

In this article, a protocol for infection of macrophages with Cryptococcus neoformans is described. Also, a method for sterol depletion from the macrophages is explained. These protocols provide a guide to study fungal infections in vitro and examine the role of sterols in such infections.

Cryptococcosis is a life-threatening infection caused by pathogenic fungi of the genus Cryptococcus. Infection occurs upon inhalation of spores, which are ...

Generation of Lymphocytic Microparticles and Detection of their Proapoptotic Effect on Airway Epithelial Cells

Interest in the biological roles of cell membrane&#8211;derived vesicles in cell&#8211;cell communication has increased in recent years. Microparticles (MPs) are one such type of vesicles, ranging in diameter from 0.1 &#956;m to 1 &#956;m, and typically shed from the plasma membrane of eukaryotic cells undergoing activation or apoptosis. Here we describe the generation of T lymphocyte&#8211;derived microparticles (LMPs) from apoptotic CEM T cells stimulated with actinomycin D. LMPs are isolated through a multistep differential centrifugation process and characterized using flow cytometry. This protocol also presents an in situ cell death detection method for demonstrating the proapoptotic effect of LMPs on bronchial epithelial cells derived from mouse primary respiratory bronchial tissue explants. Methods described herein provide a reproducible procedure for isolating abundant quantities of LMPs from apoptotic lymphocytes in vitro. LMPs derived in this manner can be used to evaluate the characteristics of various disease models, and for pharmacology and toxicology testing. Given that the airway epithelium offers a protective physical and functional barrier between the external environment and underlying tissue, use of bronchial tissue explants rather than immortalized epithelial cell lines provides an effective model for investigations requiring airway tract tissue.

Cell membrane&#8211;shed microparticles (MPs) are active biological vesicles that can be isolated and their pathophysiological effects investigated in various models. Here we describe a method for generating MPs derived from T lymphocytes (LMPs) and for demonstrating their proapoptotic effect on airway epithelial cells.

Interest in the biological roles of cell membrane&#8211;derived vesicles in cell&#8211;cell communication has increased in recent years. Microparticles ...

High Throughput Measurement of Extracellular DNA Release and Quantitative NET Formation in Human Neutrophils In Vitro

Neutrophil granulocytes are the most abundant leukocytes in the human blood. Neutrophils are the first to arrive at the site of infection. Neutrophils developed several antimicrobial mechanisms including phagocytosis, degranulation and formation of neutrophil extracellular traps (NETs). NETs consist of a DNA scaffold decorated with histones and several granule markers including myeloperoxidase (MPO) and human neutrophil elastase (HNE). NET release is an active process involving characteristic morphological changes of neutrophils leading to expulsion of their DNA into the extracellular space. NETs are essential to fight microbes, but uncontrolled release of NETs has been associated with several disorders. To learn more about the clinical relevance and the mechanism of NET formation, there is a need to have reliable tools capable of NET quantitation. 
Here three methods are presented that can assess NET release from human neutrophils in vitro. The first one is a high throughput assay to measure extracellular DNA release from human neutrophils using a membrane impermeable DNA-binding dye. In addition, two other methods are described capable of quantitating NET formation by measuring levels of NET-specific MPO-DNA and HNE-DNA complexes. These microplate-based methods in combination provide great tools to efficiently study the mechanism and regulation of NET formation of human neutrophils.

High Throughput Measurement of Extracellular DNA Release and Quantitative NET Formation in Human Neutrophils In Vitro

High throughput assays are presented that in combination provide excellent tools to quantitate NET release from human neutrophils.

Neutrophil granulocytes are the most abundant leukocytes in the human blood. Neutrophils are the first to arrive at the site of infection. Neutrophils ...

Zika Virus Infectious Cell Culture System and the In Vitro Prophylactic Effect of Interferons

Zika Virus (ZIKV) is an emerging pathogen that is linked to fetal developmental abnormalities such as microcephaly, eye defects, and impaired growth. ZIKV is an RNA virus of the Flaviviridae family. ZIKV is mainly transmitted by mosquitoes, but can also be spread by maternal to fetal vertical transmission as well as sexual contact. To date, there are no reliable treatment or vaccine options available to protect those infected by the virus. The development of a reproducible, effective Zika virus infectious cell culture system is critical for studying the molecular mechanisms of ZIKV replication as well as drug and vaccine development. In this regard, a protocol describing a mammalian cell-based in vitro Zika virus culture system for viral production and growth analysis is reported here. Details on the formation of plaques by Zika virus on a cell monolayer and plaque assay for measuring viral titer are presented. Viral genome replication kinetics and double-stranded RNA genome replicatory intermediates are determined. This culture platform was utilized to screen against a library of a small set of cytokines resulting in the identification of interferon-&#945; (IFN-&#945;), IFN-&#946; and IFN-&#947; as potent inhibitors of Zika viral growth. In summary, an in vitro infectious Zika viral culture system and various virological assays are demonstrated in this study, which has the potential to greatly benefit the research community in elucidating further the mechanisms of viral pathogenesis and the evolution of viral virulence. Antiviral IFN-alpha can further be evaluated as a prophylactic, post-exposure prophylactic, and treatment option for Zika virus infections in high-risk populations, including infected pregnant women.

Zika Virus Infectious Cell Culture System and the In Vitro Prophylactic Effect of Interferons

Zika Virus (ZIKV), an emerging pathogen, is linked to fetal developmental abnormalities and microcephaly. The establishment of an effective infectious cell culture system is crucial for studies of ZIKV replication as well as vaccine and drug development. In this study, various virological assays pertaining to ZIKV are illustrated and discussed.

Zika Virus (ZIKV) is an emerging pathogen that is linked to fetal developmental abnormalities such as microcephaly, eye defects, and impaired growth. ZIKV ...

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

This protocol describes noninvasive sampling of undisturbed upper airway mucosal lining fluid. It also details the extraction procedure used prior to the analysis of immune mediators in fluid eluates for the study of the airway topical immune signature, without the need for stimulation procedures (often used by other techniques). The mucosal lining fluid is sampled on a strip of filter paper placed at the anterior part of the inferior turbinate and left for 2 min of absorption. Analytes are eluted from the filter papers, and the extracted protein-based eluates are analyzed by an electrochemiluminescence-based immunoassay, allowing for the high-sensitivity quantification of low- and high-level analytes in the same sample. We measured the in vivo levels of 20 preselected immune mediators related to specific immune signaling pathways in the upper airway mucosa, but the technique is not limited to that specific panel or sampling site. The technique was first implemented in 7-year-old children from the Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) cohort with allergic rhinitis. It was thereafter used in the longitudinal COPSAC2010 birth cohort, sampled at 1 month, 2 years, and 6 years of age and at instances of acute respiratory symptoms. We successfully obtained and analyzed samples from 620 (89%) of 700 1-month-old children; a few samples were below the assay detection limit (reported as the median (Inter-Quartile Range (IQR)). The number of samples below the detection limit (i.e.&#160;from 0 to the set point for the lower limit of detection) for each mediator was 29 (7.25 - 119.5). This technique enables the quantification of the in vivo airway mucosal immune profile from birth, can be applied longitudinally, and can be applied to studies on the effect of genetics and early-life environmental exposures, pathophysiology, endotyping, and monitoring of respiratory diseases, and development and evaluation of novel therapeutics.

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

This protocol describes a noninvasive technique for the sampling of undisturbed mucosal lining fluid from the upper airways. It can be used to perform the quantification of in vivo levels of protein mediators, such as cytokines and chemokines, in subjects of all ages.

This protocol describes noninvasive sampling of undisturbed upper airway mucosal lining fluid. It also details the extraction procedure used prior to the ...