Name: a gpc3-targeting bispecific antibody, gpc3-s-fab, with potent cytotoxicity
Uploaded: 2018-07-12T13:00:00
Description: Watch this Scientific Journal Video about A GPC3-targeting Bispecific Antibody, GPC3-S-Fab, with Potent Cytotoxicity at JoVE.com

This work was financially supported by the R&#38;D Plan of Guangdong Province (PR China) (2016A050503028).

All of the procedures including human blood collection were approved by the Sun Yat-Sen University Ethics Committee.
1. GPC3-S-Fab Design Strategy
<ol>
	<li>Design GPC3-S-Fab by linking a Fab of anti-GPC3 (humanized GC3313) with an anti-CD16 VHH14 (Figure 1).</li>
	<li>Synthesize and clone the VH-CH1-CD16-VHH and VL-CL into the pET26b and pET21a vectors as previously reported12.</li>
</ol>
<...

<ol>
	<li>Weiner, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Building+better+monoclonal+antibody-based+therapeutics.">Building better monoclonal antibody-based therapeutics.</a> Nature Reviews Cancer. 15 (6), 361-370 (2015).</li><li>Rathi, C., Meibohm, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+pharmacology+of+bispecific+antibody+constructs.">Clinical pharmacology of bispecific antibody constructs.</a> The Journal of Clinical Pharmacology. 55, S21-S28 (2015).</li><li>Weidle, U. H., Kontermann, R. E., Brinkmann, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor-antigen-binding+bispecific+antibodies+for+cancer+treatment.">Tumor-antigen-binding bispecific antibodies for cancer treatment.</a> Seminars in Oncology. 41 (5), 653-660 (2014).</li><li>Demarest, S. J., Glaser, 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=Antibody+therapeutics,+antibody+engineering,+and+the+merits+of+protein+stability.">Antibody therapeutics, antibody engineering, and the merits of protein stability.</a> Current Opinion in Drug Discovery and Development. 11 (5), 675-687 (2008).</li><li>Mabry, R., Snavely, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapeutic+bispecific+antibodies:+The+selection+of+stable+single-chain+fragments+to+overcome+engineering+obstacles.">Therapeutic bispecific antibodies: The selection of stable single-chain fragments to overcome engineering obstacles.</a> IDrugs. 13 (8), 543-549 (2010).</li><li>Rothlisberger, D., Honegger, A., Pluckthun, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Domain+interactions+in+the+Fab+fragment:+a+comparative+evaluation+of+the+single-chain+Fv+and+Fab+format+engineered+with+variable+domains+of+different+stability.">Domain interactions in the Fab fragment: a comparative evaluation of the single-chain Fv and Fab format engineered with variable domains of different stability.</a> Journal of Molecular Biology. 347 (4), 773-789 (2005).</li><li>Kijanka, M., Dorresteijn, B., Oliveira, S., van Bergen en Henegouwen, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanobody-based+cancer+therapy+of+solid+tumors.">Nanobody-based cancer therapy of solid tumors.</a> Nanomedicine (London). 10 (1), 161-174 (2015).</li><li>Muyldermans, S., Cambillau, C., Wyns, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recognition+of+antigens+by+single-domain+antibody+fragments:+the+superfluous+luxury+of+paired+domains.">Recognition of antigens by single-domain antibody fragments: the superfluous luxury of paired domains.</a> Trends in Biochemical Sciences. 26 (4), 230-235 (2001).</li><li>Gonzalez-Sapienza, G., Rossotti, M. A., Tabares-da Rosa, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-Domain+Antibodies+As+Versatile+Affinity+Reagents+for+Analytical+and+Diagnostic+Applications.">Single-Domain Antibodies As Versatile Affinity Reagents for Analytical and Diagnostic Applications.</a> Frontiers in Immunology. 8, 977 (2017).</li><li>Fernandes, C. F. 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=Camelid+Single-Domain+Antibodies+As+an+Alternative+to+Overcome+Challenges+Related+to+the+Prevention,+Detection,+and+Control+of+Neglected+Tropical+Diseases.">Camelid Single-Domain Antibodies As an Alternative to Overcome Challenges Related to the Prevention, Detection, and Control of Neglected Tropical Diseases.</a> Frontiers in Immunology. 8, 653 (2017).</li><li>Li, 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=A+novel+bispecific+antibody,+S-Fab,+induces+potent+cancer+cell+killing.">A novel bispecific antibody, S-Fab, induces potent cancer cell killing.</a> Journal of Immunotherapy. 38 (9), 350-356 (2015).</li><li>Li, 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=A+single-domain+antibody-linked+Fab+bispecific+antibody+Her2-S-Fab+has+potent+cytotoxicity+against+Her2-expressing+tumor+cells.">A single-domain antibody-linked Fab bispecific antibody Her2-S-Fab has potent cytotoxicity against Her2-expressing tumor cells.</a> AMB Express. 6 (1), 32 (2016).</li><li>Nakano, 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=Anti-glypican+3+antibodies+cause+ADCC+against+human+hepatocellular+carcinoma+cells.">Anti-glypican 3 antibodies cause ADCC against human hepatocellular carcinoma cells.</a> Biochemical and Biophysical Research Communications. 378 (2), 279-284 (2009).</li><li>Behar, 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=Isolation+and+characterization+of+anti-FcgammaRIII+(CD16)+llama+single-domain+antibodies+that+activate+natural+killer+cells.">Isolation and characterization of anti-FcgammaRIII (CD16) llama single-domain antibodies that activate natural killer cells.</a> Protein Engineering, Design, and Selection. 21 (1), 1-10 (2008).</li><li>Baral, T. N., Arbabi-Ghahroudi, M. <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+single-domain+antibodies+in+bacterial+systems.">Expression of single-domain antibodies in bacterial systems.</a> Methods in Molecular Biology. 911, 257-275 (2012).</li><li>Arbabi-Ghahroudi, M., Tanha, J., MacKenzie, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prokaryotic+expression+of+antibodies.">Prokaryotic expression of antibodies.</a> Cancer and Metastasis Reviews. 24 (4), 501-519 (2005).</li><li>Spiess, 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=Bispecific+antibodies+with+natural+architecture+produced+by+co-culture+of+bacteria+expressing+two+distinct+half-antibodies.">Bispecific antibodies with natural architecture produced by co-culture of bacteria expressing two distinct half-antibodies.</a> Nature Biotechnology. 31 (8), 753-758 (2013).</li><li>Filmus, J., Selleck, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glypicans:+proteoglycans+with+a+surprise.">Glypicans: proteoglycans with a surprise.</a> Journal of Clinical Investigation. 108 (4), 497-501 (2001).</li><li>Baumhoer, D., 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=Glypican+3+expression+in+human+nonneoplastic,+preneoplastic,+and+neoplastic+tissues:+a+tissue+microarray+analysis+of+4,387+tissue+samples.">Glypican 3 expression in human nonneoplastic, preneoplastic, and neoplastic tissues: a tissue microarray analysis of 4,387 tissue samples.</a> American Journal of Clinical Pathology. 129 (6), 899-906 (2008).</li><li>Llovet, 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=A+molecular+signature+to+discriminate+dysplastic+nodules+from+early+hepatocellular+carcinoma+in+HCV+cirrhosis.">A molecular signature to discriminate dysplastic nodules from early hepatocellular carcinoma in HCV cirrhosis.</a> Gastroenterology. 131 (6), 1758-1767 (2006).</li><li>Zhu, Z. 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=Enhanced+glypican-3+expression+differentiates+the+majority+of+hepatocellular+carcinomas+from+benign+hepatic+disorders.">Enhanced glypican-3 expression differentiates the majority of hepatocellular carcinomas from benign hepatic disorders.</a> Gut. 48 (4), 558-564 (2001).</li><li>Hsu, H. C., Cheng, W., Lai, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning+and+expression+of+a+developmentally+regulated+transcript+MXR7+in+hepatocellular+carcinoma:+biological+significance+and+temporospatial+distribution.">Cloning and expression of a developmentally regulated transcript MXR7 in hepatocellular carcinoma: biological significance and temporospatial distribution.</a> Cancer Research. 57 (22), 5179-5184 (1997).</li><li>Flaherty, M. 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=Nonclinical+evaluation+of+GMA161--an+antihuman+CD16+(FcgammaRIII)+monoclonal+antibody+for+treatment+of+autoimmune+disorders+in+CD16+transgenic+mice.">Nonclinical evaluation of GMA161--an antihuman CD16 (FcgammaRIII) monoclonal antibody for treatment of autoimmune disorders in CD16 transgenic mice.</a> Toxicological Sciences. 125 (1), 299-309 (2012).</li><li>Sharma, R., Das, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organ-specific+phenotypic+and+functional+features+of+NK+cells+in+humans.">Organ-specific phenotypic and functional features of NK cells in humans.</a> Immunological Research. 58 (1), 125-131 (2014).</li><li>Li, X. 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=Effect+of+CD16a,+the+surface+receptor+of+Kupffer+cells,+on+the+growth+of+hepatocellular+carcinoma+cells.">Effect of CD16a, the surface receptor of Kupffer cells, on the growth of hepatocellular carcinoma cells.</a> International Journal of Molecular Medicine. 37 (6), 1465-1474 (2016).</li><li>Fiala, G. J., Schamel, W. W., Blumenthal, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blue+native+polyacrylamide+gel+electrophoresis+(BN-PAGE)+for+analysis+of+multiprotein+complexes+from+cellular+lysates.">Blue native polyacrylamide gel electrophoresis (BN-PAGE) for analysis of multiprotein complexes from cellular lysates.</a> Journal of Visualized Experiments. (48), (2011).</li><li>Hwang, A. C., Grey, P. H., Cuddy, K., Oppenheimer, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pouring+and+running+a+protein+gel+by+reusing+commercial+cassettes.">Pouring and running a protein gel by reusing commercial cassettes.</a> Journal of Visualized Experiments. (60), (2012).</li><li>Laemmli, U. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cleavage+of+structural+proteins+during+the+assembly+of+the+head+of+bacteriophage+T4.">Cleavage of structural proteins during the assembly of the head of bacteriophage T4.</a> Nature. 227 (5259), 680-685 (1970).</li><li>Menon, V., Thomas, R., Ghale, A. R., Reinhard, C., Pruszak, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow+cytometry+protocols+for+surface+and+intracellular+antigen+analyses+of+neural+cell+types.">Flow cytometry protocols for surface and intracellular antigen analyses of neural cell types.</a> Journal of Visualized Experiments. (94), (2014).</li><li>Feng, 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=Therapeutically+targeting+glypican-3+via+a+conformation-specific+single-domain+antibody+in+hepatocellular+carcinoma.">Therapeutically targeting glypican-3 via a conformation-specific single-domain antibody in hepatocellular carcinoma.</a> Proceedings of the National Academy of Science U S A. 110 (12), E1083-E1091 (2013).</li></ol>

In this study, we present a strategy to construct a new format of bsAbs, GPC3-S-Fab, which can recruit NK cells targeting GPC3 positive tumor cells. The S-Fab is based on the natural Fab format by adding an anti-CD16 VHH11,12. Compared with the bsAbs containing Fc region, GPC3-S-Fab can easily be produced in the periplasm of bacteria on a large scale.
Using the expression and purification strategy described in the protocol, we obtained...

Monoclonal antibodies are now broadly used for cancer treatment1. Due to the flexibility of antibodies, various antibody-based formats have been actively explored. Compared with monoclonal antibodies, bsAbs have two different antigen binding modules, enabling them to recognize two different targets simultaneously and efficiently trigger the recruitment of immune effector cells to target and kill tumor cells2.
Current recombinant bsAb formats can be generally assigned to two classes: Fc-containing bsAbs and bsAbs without an Fc region. Compared with Fc-containing formats that are mostly produced in mammalian cells, bsAbs without an Fc region have the advantages of smaller sizes, are more readily produced in microorganism expression systems, and can penetrate tumor tissues more efficiently3.
bsAbs without an Fc region are commonly formed by linking individual binding moieties, such as single-chain variable fragments (scFvs) or Fabs3. Without the stabilizing domains, bsAbs based on scFv fragments often have compromised thermal stability, low solubility, or an increased potential for aggregation4,5. In contrast, Fab-based bsAbs are more stable due to the heterodimerization of the CH1 and CL in the native Fab moiety4,6.
Variable domain from heavy-chain-only antibodies (VHHs, also referred to as single domain antibodies) are the active antigen-binding fragment of natural heavy chain antibodies7. VHHs have the characteristics of high affinity, specificity of conventional IgGs8, low immunogenicity, and high yields in bacterial expression9. Compared with Fv fragments, VHHs have higher thermal stability10. Compared with Fab moieties, VHHs have smaller sizes due to the lack of CH1 and CL. Thus, S-Fab, the bsAb format obtained by linking the Fab with a single domain antibody, VHH, was designed and studied for its anti-tumor effects11,12.
In this study, the construction of GPC3-S-Fab by linking the Fab of hGC3313 with an anti-CD16a VHH14 was described. The GPC3-S-Fab can be efficiently produced by periplasmic expression in Escherichia coli (E. coli). Functional studies of GPC3-S-Fab suggested that GPC3-S-Fab is a promising strategy for liver cancer therapy. Thus, the advantages of GPC3-S-Fab over alternative techniques with applicable references to previous studies include easy production and purification, and more stable bsAbs.
Mammalian expression systems and prokaryotic expression systems have been used to express various formats of BsAbs. In contrast to mammalian expression systems, E. coli-based protein expression systems have many benefits, including high yields, low cost and labor-saving, the ease of genetic manipulations, and high transformation efficiency15. For bsAbs expression in E. coli, there are two basic strategies: expression in the cytoplasm and expression in the periplasm between the cytoplasm and outer cell membranes15. Compared to the reducing environment of cytoplasm, the periplasm is a more oxidizing environment, which promotes the correct folding and co-expression of proteins16. Correct folding plays a key role in solubility, stability and function generation of bsAbs. Therefore, a signal sequence pelB was added to the N-terminus of the S-Fab to direct secretion to the periplasm of E. coli17. To ensure correct folding, solubility, thermal stability, and conformational stability, reducing the complexity and the size of an antibody is frequently employed16. The S-Fab format consists of one Fab and one VHH, which is expressed very well in bacterial systems likely due to the simple structure and small size.
GPC3 was chosen in this GPC3-S-Fab bispecific antibody format. Glypican-3 (GPC3) is a member of the heparin sulfate (HS) proteoglycan family that is anchored to the cell surface through glycosylphosphatidylinositol (GPI)18. GPC3 is overexpressed in 70% of hepatocellular carcinoma (HCC) cases, which account for the majority of liver cancers19,20,21,22. Because GPC3 is rarely expressed in normal tissues, GPC3 has been proposed as a potential target for HCC. Multiple mouse mAbs have been produced against GPC3. However, only GC33 exhibited limited anti-tumor activity 22, and it failed to exhibit clinical efficacy in patients. In this study, GPC3-S-Fab was shown to be able to recruit NK cells to kill GPC3 tumor cells14.
To recruit NK cells, anti-CD16 VHH was used. CD16a is a low affinity IgG receptor, expressed mainly on natural killer (NK) cells, macrophages, monocytes and some subtypes of T cells. It is involved in antibody-dependent cell cytotoxicity (ADCC) by NK cells23. Human NK cells can be categorized into two types, CD56-CD16+ and CD56+CD16-. In contrast to CD56+CD16&#8722; NK cells, CD56-CD16+ NK cells can release higher levels of perforin and granzyme B and thus present a strong cytotoxicity24. Kupffer cells (KCs), expressing CD16a, are the resident macrophages in liver. Kupffer cells play an important role in the suppression of liver cancer25. Thus, bsAbs targeting CD16a may be a more promising strategy than engaging T cells against liver cancer.

<table>
	<tbody>
		<tr>
			<td>Shaking incubator</td>
			<td>Thermo Fisher</td>
			<td>MAXQ 4000</td>
			<td></td>
		</tr>
		<tr>
			<td>Shaking incubator</td>
			<td>Zhicheng</td>
			<td>ZWYR-D2402</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Cence</td>
			<td>GL-10MD</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Beckman coulter</td>
			<td>Avanti j-26S XPI</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>eppendorf</td>
			<td>5810R</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultraviolet spectrophotometer</td>
			<td>Thermo Fisher</td>
			<td>Nanodrop</td>
			<td></td>
		</tr>
		<tr>
			<td>Analytical polyacrylamide gel electrophoresis apparatus</td>
			<td>Mini-PROTEAN&#174; Tetra</td>
			<td>Bio-rad</td>
			<td></td>
		</tr>
		<tr>
			<td>Trans-blot apparatus</td>
			<td>Criterion</td>
			<td>Bio-rad</td>
			<td></td>
		</tr>
		<tr>
			<td>Imaging system</td>
			<td>Bio-rad</td>
			<td>chemidoc tm XRS+</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast Protein Liquid chromatogram</td>
			<td>GE Healthcare</td>
			<td>AKTA avant</td>
			<td></td>
		</tr>
		<tr>
			<td>GF column</td>
			<td>GE Healthcare</td>
			<td>28-9909-44 Superdex 200 Increase 10/300 GL</td>
			<td></td>
		</tr>
		<tr>
			<td>Flow Cytometer</td>
			<td>Beckman coulter</td>
			<td>FC500</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>eppendorf</td>
			<td>5702R</td>
			<td></td>
		</tr>
		<tr>
			<td>Envision plate reader</td>
			<td>TECAN</td>
			<td>Infinite F50</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti His-tag</td>
			<td>eBioscience</td>
			<td>14-6657-82</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-Flag-tag</td>
			<td>Sigma</td>
			<td>F1804</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-human(H&#38;L)-488</td>
			<td>A11013</td>
			<td>Invitrogen</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-mouse IgG HRP-linked antibody</td>
			<td>Cell Signaling</td>
			<td>7076S</td>
			<td></td>
		</tr>
		<tr>
			<td>Ni-NTA-Agarose</td>
			<td>Tribioscience</td>
			<td>TBS9202-100</td>
			<td></td>
		</tr>
		<tr>
			<td>IgG-CH1 affinity resin</td>
			<td>Thermo Fisher</td>
			<td>194320005</td>
			<td></td>
		</tr>
		<tr>
			<td>Ficoll-Plaque Plus</td>
			<td>GE Healthcare</td>
			<td>17-1440-03</td>
			<td></td>
		</tr>
		<tr>
			<td>NK cell enrichment kit</td>
			<td>Stemcell</td>
			<td>19055</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnet</td>
			<td>Stemcell</td>
			<td>18000</td>
			<td></td>
		</tr>
		<tr>
			<td>CCK8 kit</td>
			<td>Dojindo</td>
			<td>CK04</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Gibco</td>
			<td>C11995500CP</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI-1640</td>
			<td>Gibco</td>
			<td>C11875500CP</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Sigma</td>
			<td>F2442</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin</td>
			<td>Gibco</td>
			<td>15050-057</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Standard marker</td>
			<td>Sigma Aldrich</td>
			<td>MWGF200</td>
			<td>Gel filtration</td>
		</tr>
		<tr>
			<td>Isopropyl-b-D-thio-galactopyranoside (IPTG)</td>
			<td>VWR chemicals</td>
			<td>VWRC0487-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Dialysis tubing</td>
			<td>Sigma Aldrich</td>
			<td>D0655-100FT</td>
			<td></td>
		</tr>
		<tr>
			<td>Knanamycine</td>
			<td>VWR</td>
			<td>VWRC0408-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Ampicillin</td>
			<td>VWR</td>
			<td>VWRC0339-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Tryptone</td>
			<td>Thermo Fisher</td>
			<td>LP0042B</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast Extract</td>
			<td>Thermo Fisher</td>
			<td>LP0021B</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Sangon Biotech</td>
			<td>A100241</td>
			<td></td>
		</tr>
		<tr>
			<td>Trizma base</td>
			<td>Sigma Aldrich</td>
			<td>T6791-1KG</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA</td>
			<td>Sigma Aldrich</td>
			<td>V900106</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycine</td>
			<td>aladdin</td>
			<td>A110752-500g</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>aladdin</td>
			<td>P112134-500g</td>
			<td></td>
		</tr>
		<tr>
			<td>MgCl</td>
			<td>Sigma Aldrich</td>
			<td>V900020</td>
			<td></td>
		</tr>
		<tr>
			<td>Agar</td>
			<td>Sangon Biotech</td>
			<td>A505255-0250</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Phosphate, Monobasic Anhydrous (KH2PO4)</td>
			<td>VWR</td>
			<td>7778-77-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Phosphate, Dibasic, Anhydrous (Na2HPO4)</td>
			<td>VWR</td>
			<td>7558-79-4</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Mercaptoethanol</td>
			<td>VWR</td>
			<td>60-24-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Phenylmethyl Sulfonyl Fluoride (PMSF)</td>
			<td>VWR</td>
			<td>329-98-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Lysozyme</td>
			<td>Sigma Aldrich</td>
			<td>L6876-25G</td>
			<td></td>
		</tr>
		<tr>
			<td><a name="RANGE!A50">Coomassie Brilliant Blue R250</a></td>
			<td>VWR</td>
			<td>VWRC0472-50G</td>
			<td></td>
		</tr>
		<tr>
			<td>Bromophenol blue</td>
			<td>Sangon Biotech</td>
			<td>A500922-25G</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td>VWR</td>
			<td>VWRC0332-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma Aldrich</td>
			<td>V900122</td>
			<td></td>
		</tr>
		<tr>
			<td>100mm x 20mm plastic dish</td>
			<td>Corning</td>
			<td>430167</td>
			<td></td>
		</tr>
		<tr>
			<td>25cm2 flask</td>
			<td>Corning</td>
			<td>430639</td>
			<td></td>
		</tr>
		<tr>
			<td>96 well cell culture cluster</td>
			<td>Corning</td>
			<td>3599</td>
			<td></td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Sangon Biotech</td>
			<td>A610498-0005</td>
			<td></td>
		</tr>
		<tr>
			<td>CHO</td>
			<td>the Type Culture Collection of the Chinese Academy of Sciences</td>
			<td>GNHa 3</td>
			<td></td>
		</tr>
		<tr>
			<td>MHCC-97H</td>
			<td>the Type Culture Collection of the Chinese Academy of Sciences</td>
			<td>SCSP-528</td>
			<td></td>
		</tr>
		<tr>
			<td>HepG2</td>
			<td>the Type Culture Collection of the Chinese Academy of Sciences</td>
			<td>TCHu 72</td>
			<td></td>
		</tr>
		<tr>
			<td>Huh7</td>
			<td>the Type Culture Collection of the Chinese Academy of Sciences</td>
			<td>TCHu182</td>
			<td></td>
		</tr>
		<tr>
			<td>Hep3B</td>
			<td>the Type Culture Collection of the Chinese Academy of Sciences</td>
			<td>TCHu106</td>
			<td></td>
		</tr>
		<tr>
			<td>NK92</td>
			<td>ATCC</td>
			<td>CRL2408</td>
			<td></td>
		</tr>
	</tbody>
</table>

a gpc3-targeting bispecific antibody, gpc3-s-fab, with potent cytotoxicity

This protocol describes the construction and functional studies of a bispecific antibody (bsAb), GPC3-S-Fab. bsAbs can recognize two different epitopes through their two different arms. bsAbs have been actively studied for their ability to directly recruit immune cells to kill tumor cells. Currently, the majority of bsAbs are produced in the form of recombinant proteins, either as Fc-containing bsAbs or as smaller bsAb derivatives without the Fc region. In this study, GPC3-S-Fab, an antibody fragment (Fab) based bispecific antibody, was designed by linking the Fab of anti-GPC3 antibody GC33 with an anti-CD16 single domain antibody. The GPC3-S-Fab can be expressed in Escherichia coli and purified by two affinity chromatographies. The purified GPC3-S-Fab can specifically bind to and kill GPC3 positive liver cancer cells by recruiting natural killer cells, suggesting a potential application of GPC3-S-Fab in liver cancer therapy.

GPC3-S-Fab purification
GPC3-S-Fab was purified from E. coli by a two-step affinity purification, first with Ni-NTA-agarose, followed by IgG-CH1 affinity purification. After the two-step affinity purification, GPC3-S-Fab was purified to homogeneity with the two chains close to 1:1 (Figure 2A). The presence of both VH-CH1-CD16 VHH and VL-CL polypeptides can be identified by ...

Watch this Scientific Journal Video about A GPC3-targeting Bispecific Antibody, GPC3-S-Fab, with Potent Cytotoxicity at JoVE.com

A GPC3-targeting Bispecific Antibody, GPC3-S-Fab, with Potent Cytotoxicity

Here, we present a protocol to produce a bispecific antibody GPC3-S-Fab in Escherichia coli. The purified GPC3-S-Fab has potent cytotoxicity against GPC3 positive liver cancer cells.

This protocol describes the construction and functional studies of a bispecific antibody (bsAb), GPC3-S-Fab. bsAbs can recognize two different epitopes ...

Research

JoVE Journal

Cancer Research

Labeling of Breast Cancer Patient-derived Xenografts with Traceable Reporters for Tumor Growth and Metastasis Studies

The use of preclinical models to study tumor biology and response to treatment is central to cancer research. Long-established human cell lines, and many ...

Potentiation of Anticancer Antibody Efficacy by Antineoplastic Drugs: Detection of Antibody-drug Synergism Using the Combination Index Equation

Potentiation of hostile monoclonal antibodies (mAb) by chemotherapeutic agents constitutes a valuable strategy for designing effective and safer therapy ...

In Vivo Immunofluorescence Localization for Assessment of Therapeutic and Diagnostic Antibody Biodistribution in Cancer Research

Monoclonal antibodies (mAbs) are important tools in cancer detection, diagnosis, and treatment. They are used to unravel the role of proteins in ...

Generation of Orthotopic Pancreatic Tumors and Ex vivo Characterization of Tumor-Infiltrating T Cell Cytotoxicity

Generation of Orthotopic Pancreatic Tumors and Ex vivo Characterization of Tumor-Infiltrating T Cell Cytotoxicity

In vivo models of pancreatic cancer provide invaluable tools for studying disease dynamics, immune infiltration and new therapeutic strategies. The ...

Analyzing Tumor and Tissue Distribution of Target Antigen Specific Therapeutic Antibody

Monoclonal antibodies are high affinity multifunctional drugs that work by variable independent mechanisms to eliminate cancer cells. Over the last few ...

An Automated Differential Nuclear Staining Assay for Accurate Determination of Mitocan Cytotoxicity

The contribution of mitochondria to oncogenic transformation is a subject of wide interest and active study. As the field of cancer metabolism becomes ...

Monitoring Cancer Cell Invasion and T-Cell Cytotoxicity in 3D Culture

Significant progress has been made in treating cancer with immunotherapy, although a large number of cancers remain resistant to treatment. A limited ...

Chemical Conjugation of a Purified DEC-205-Directed Antibody with Full-Length Protein for Targeting Mouse Dendritic Cells In Vitro and In Vivo

Chemical Conjugation of a Purified DEC-205-Directed Antibody with Full-Length Protein for Targeting Mouse Dendritic Cells In Vitro and In Vivo

Targeted antigen delivery to cross-presenting dendritic cells (DC) in vivo efficiently induces T effector cell responses and displays a valuable approach ...

Experimental Melanoma Immunotherapy Model Using Tumor Vaccination with a Hematopoietic Cytokine

Fms-like tyrosine kinase 3 ligand (Flt3L) is a hematopoietic cytokine that promotes the survival and differentiation of dendritic cells (DCs). It has been ...

Tracking Bispecific Antibody-Induced T Cell Trafficking Using Luciferase-Transduced Human T Cells

T cell-engaging bispecific antibodies (T-BsAbs) are in various stages of preclinical development and clinical testing for solid tumors. Factors such as ...