A review of IgM Hexamers Utilization Over IgM Pentamers and IgG Monomers with Complement-Dependent Cytotoxicity
IgM Hexamer Differences Compared to IgM Pentamers and IgG Monomers
DOI:
https://doi.org/10.58445/rars.3506Keywords:
Immunoglobulin, Complement-Dependent Cytotoxicity, IgM Hexamer, IgM Pentamer, IgG Monomer, Complement SystemAbstract
Antibodies are responsible for the immune system’s response to pathogens or abnormal cells through recognition of specific components known as antigens. They activate complementary pathways that work to neutralize invading pathogens or malfunctioning cells. Immunoglobulin M (IgM) and Immunoglobulin G (IgG) antibody classes and their relation to Complement-Dependent Cytotoxicity (CDC) activation regarding C1q to fragment crystallizable (Fc) region interactions are examined to discuss the extent and reasons behind IgM hexamers demonstrating higher affinities for Fc-C1q interactions, which leads to CDC activity. Comparing and contrasting the structures of IgM hexamers, IgM pentamers, and IgG monomers will help better understand the underlying reasons for their differing affinities and potential applications in therapeutic settings. Furthermore, researching the CDC response to cancers and the potential for in vitro engineering of IgM hexamers is important, as IgM hexamers are typically unable to cross into the lumenal space due to structural abnormalities in comparison to IgM pentamers and IgG structures. This review discusses antibody structural conformations, the potential uses of IgM hexameric antibodies, and their respective impacts on the immune system to explore utilizing IgM Hexamers over traditional antibodies to offer a more effective therapeutic that could result in better targeted treatments.
References
Al Ojaimi, Y., Blin, T., Lamamy, J., Gracia, M., Pitiot, A., Denevault-Sabourin, C., Joubert, N., Pouget, J.-P., Gouilleux-Gruart, V., Heuzé-Vourc’h, N., Lanznaster, D., Poty, S., and Sécher, T. (2022). Therapeutic antibodies – natural and pathological barriers and strategies to overcome them. Pharmacology & Therapeutics, 233, 108022. https://doi.org/10.1016/j.pharmthera.2021.108022
Arlaud, G. J., Gaboriaud, C., Thielens, N. M., Budayova-Spano, M., Rossi, V., and Fontecilla-Camps, J. C. (2002). Structural biology of the C1 complex of complement unveils the mechanisms of its activation and proteolytic activity. Molecular Immunology, 39(7–8), 383–394. https://doi.org/10.1016/s0161-5890(02)00143-8
Azuma, Y., Ishikawa, Y., Kawai, S., Tsunenari, T., Tsunoda, H., Igawa, T., Iida, S., Nanami, M., Suzuki, M., Irie, R. F., Tsuchiya, M., and Yamada-Okabe, H. (2007). Recombinant Human Hexamer-Dominant IgM Monoclonal Antibody to Ganglioside GM3 for Treatment of Melanoma. Clinical Cancer Research, 13(9), 2745–2750. https://doi.org/10.1158/1078-0432.CCR-06-2919
Bally, I., Inforzato, A., Dalonneau, F., Stravalaci, M., Bottazzi, B., Gaboriaud, C., and Thielens, N. M. (2019). Interaction of C1q With Pentraxin 3 and IgM Revisited: Mutational Studies With Recombinant C1q Variants. Frontiers in Immunology, 10, 461. https://doi.org/10.3389/fimmu.2019.00461
Baniel, C. C., Sumiec, E. G., Hank, J. A., Bates, A. M., Erbe, A. K., Pieper, A. A., Hoefges, A. G., Patel, R. B., Rakhmilevich, A. L., Morris, Z. S., and Sondel, P. M. (2020). Intratumoral injection reduces toxicity and antibody-mediated neutralization of immunocytokine in a mouse melanoma model. Journal for Immunotherapy of Cancer, 8(2), e001262. https://doi.org/10.1136/jitc-2020-001262
Boune, S., Hu, P., Epstein, A. L., and Khawli, L. A. (2020). Principles of N-Linked Glycosylation Variations of IgG-Based Therapeutics: Pharmacokinetic and Functional Considerations. Antibodies, 9(2), 22. https://doi.org/10.3390/antib9020022
Charles A Janeway, J., Travers, P., Walport, M., and Shlomchik, M. J. (2001). The structure of a typical antibody molecule. In Immunobiology: The Immune System in Health and Disease. 5th edition. Garland Science, pp: 75-85.
Coulter, A. and Harris, R. (1983). Simplified preparation of rabbit Fab fragments. Journal of Immunological Methods, 59(2), 199–203. https://doi.org/10.1016/0022-1759(83)90031-5
Cruz, A. R., Boer, M. A. den, Strasser, J., Zwarthoff, S. A., Beurskens, F. J., de Haas, C. J. C., Aerts, P. C., Wang, G., de Jong, R. N., Bagnoli, F., van Strijp, J. A. G., van Kessel, K. P. M., Schuurman, J., Preiner, J., Heck, A. J. R., and Rooijakkers, S. H. M. (2021). Staphylococcal protein A inhibits complement activation by interfering with IgG hexamer formation. Proceedings of the National Academy of Sciences, 118(7), e2016772118. https://doi.org/10.1073/pnas.2016772118
Davis, A. C., Roux, K. H., Pursey, J., and Shulman, M. J. (1989). Intermolecular disulfide bonding in IgM: Effects of replacing cysteine residues in the mu heavy chain. The EMBO Journal, 8(9), 2519–2526. https://doi.org/10.1002/j.1460-2075.1989.tb08389.x
Deveuve, Q., Gouilleux-Gruart, V., Thibault, G., and Lajoie, L. (2019). [The hinge region of therapeutic antibodies: Major importance of a short sequence]. Medecine Sciences: M/S, 35(12), 1098–1105. https://doi.org/10.1051/medsci/2019218
Diebolder, C. A., Beurskens, F. J., de Jong, R. N., Koning, R. I., Strumane, K., Lindorfer, M. A., Voorhorst, M., Ugurlar, D., Rosati, S., Heck, A. J. R., van de Winkel, J. G. J., Wilson, I. A., Koster, A. J., Taylor, R. P., Saphire, E. O., Burton, D. R., Schuurman, J., Gros, P., and Parren, P. W. H. I. (2014). Complement Is Activated by IgG Hexamers Assembled at the Cell Surface. Science (New York, N.Y.), 343(6176), 1260–1263. https://doi.org/10.1126/science.1248943
Dillon, T. M., Ricci, M. S., Vezina, C., Flynn, G. C., Liu, Y. D., Rehder, D. S., Plant, M., Henkle, B., Li, Y., Deechongkit, S., Varnum, B., Wypych, J., Balland, A., and Bondarenko, P. V. (2008). Structural and Functional Characterization of Disulfide Isoforms of the Human IgG2 Subclass*. Journal of Biological Chemistry, 283(23), 16206–16215. https://doi.org/10.1074/jbc.M709988200
Edelman, G. M., Cunningham, B. A., Gall, W. E., Gottlieb, P. D., Rutishauser, U., and Waxdal, M. J. (1969). THE COVALENT STRUCTURE OF AN ENTIRE γG IMMUNOGLOBULIN MOLECULE*. Proceedings of the National Academy of Sciences, 63(1), 78–85. https://doi.org/10.1073/pnas.63.1.78
Fazel, S., Wiersma, E. J., and Shulman, M. J. (1997). Interplay of J chain and disulfide bonding in assembly of polymeric IgM. International Immunology, 9(8), 1149–1158. https://doi.org/10.1093/intimm/9.8.1149
Frangione, B., Milstein, C., and Pink, J. R. (1969). Structural studies of immunoglobulin G. Nature, 221(5176), 145–148. https://doi.org/10.1038/221145a0
Frutiger, S., Hughes, G. J., Paquet, N., Lüthy, R., and Jaton, J. C. (1992). Disulfide bond assignment in human J chain and its covalent pairing with immunoglobulin M. Biochemistry, 31(50), 12643–12647. https://doi.org/10.1021/bi00165a014
Gaboriaud, C., Juanhuix, J., Gruez, A., Lacroix, M., Darnault, C., Pignol, D., Verger, D., Fontecilla-Camps, J. C., and Arlaud, G. J. (2003). The crystal structure of the globular head of complement protein C1q provides a basis for its versatile recognition properties. The Journal of Biological Chemistry, 278(47), 46974–46982. https://doi.org/10.1074/jbc.M307764200
Harris, L. J., Larson, S. B., Hasel, K. W., and McPherson, A. (1997). Refined structure of an intact IgG2a monoclonal antibody. Biochemistry, 36(7), 1581–1597. https://doi.org/10.1021/bi962514+
Ho, Y., Kiparissides, A., Pistikopoulos, E. N., and Mantalaris, A. (2012). Computational approach for understanding and improving GS-NS0 antibody production under hyperosmotic conditions. Journal of Bioscience and Bioengineering, 113(1), 88–98. https://doi.org/10.1016/j.jbiosc.2011.08.022
Hong, W. X., Haebe, S., Lee, A. S., Westphalen, C. B., Norton, J. A., Jiang, W., and Levy, R. (2020). Intratumoral immunotherapy for early-stage solid tumors. Clinical Cancer Research : An Official Journal of the American Association for Cancer Research, 26(13), 3091–3099. https://doi.org/10.1158/1078-0432.CCR-19-3642
Hozumi, N. and Tonegawa, S. (1976). Evidence for somatic rearrangement of immunoglobulin genes coding for variable and constant regions. Proceedings of the National Academy of Sciences of the United States of America, 73(10), 3628–3632. https://doi.org/10.1073/pnas.73.10.3628
Johansen, F. E., Braathen, R., and Brandtzaeg, P. (2000). Role of J chain in secretory immunoglobulin formation. Scandinavian Journal of Immunology, 52(3), 240–248. https://doi.org/10.1046/j.1365-3083.2000.00790.x
Jones, D., Kroos, N., Anema, R., van Montfort, B., Vooys, A., van der Kraats, S., van der Helm, E., Smits, S., Schouten, J., Brouwer, K., Lagerwerf, F., van Berkel, P., Opstelten, D.-J., Logtenberg, T., and Bout, A. (2003). High-level expression of recombinant IgG in the human cell line per.c6. Biotechnology Progress, 19(1), 163–168. https://doi.org/10.1021/bp025574h
Kaul, M. and Loos, M. (1997). Dissection of C1q Capability of Interacting with IgG: TIME-DEPENDENT FORMATION OF A TIGHT AND ONLY PARTLY REVERSIBLE ASSOCIATION*. Journal of Biological Chemistry, 272(52), 33234–33244. https://doi.org/10.1074/jbc.272.52.33234
Kelow, S. P., Adolf-Bryfogle, J., and Dunbrack, R. L. (2020). Hiding in plain sight: Structure and sequence analysis reveals the importance of the antibody DE loop for antibody-antigen binding. mAbs, 12(1), 1840005. https://doi.org/10.1080/19420862.2020.1840005
Klimovich, V. B. (2011). IgM and its receptors: Structural and functional aspects. Biochemistry. Biokhimiia, 76(5), 534–549. https://doi.org/10.1134/S0006297911050038
Krapp, S., Mimura, Y., Jefferis, R., Huber, R., and Sondermann, P. (2003). Structural analysis of human IgG-Fc glycoforms reveals a correlation between glycosylation and structural integrity. Journal of Molecular Biology, 325(5), 979–989. https://doi.org/10.1016/s0022-2836(02)01250-0
Kunert, R., and Reinhart, D. (2016). Advances in recombinant antibody manufacturing. Applied Microbiology and Biotechnology, 100, 3451–3461. https://doi.org/10.1007/s00253-016-7388-9
Li, Y., Wang, G., Li, N., Wang, Y., Zhu, Q., Chu, H., Wu, W., Tan, Y., Yu, F., Su, X.-D., Gao, N., and Xiao, J. (2020). Structural insights into immunoglobulin M. Science (New York, N.Y.), 367(6481), 1014–1017. https://doi.org/10.1126/science.aaz5425
Liu, H. and May, K. (2012). Disulfide bond structures of IgG molecules. mAbs, 4(1), 17–23. https://doi.org/10.4161/mabs.4.1.18347
Lu, Y. and Zhao, F. (2025). Strategies to overcome tumour relapse caused by antigen escape after CAR T therapy. Molecular Cancer, 24(1), 126. https://doi.org/10.1186/s12943-025-02334-6
Melixetian, M. B., Pavlenko, M. A., Beriozkina, E. V., Kovaleva, Z. V., Sorokina, E. A., Ignatova, T. N., and Grinchuk, T. M. (2003). Mouse myeloma cell line Sp2/0 multidrug-resistant variant as parental cell line for hybridoma construction. Hybridoma and Hybridomics, 22(5), 321–327. https://doi.org/10.1089/153685903322538854
Merle, N. S., Church, S. E., Fremeaux-Bacchi, V., and Roumenina, L. T. (2015). Complement System Part I – Molecular Mechanisms of Activation and Regulation. Frontiers in Immunology, 6. https://doi.org/10.3389/fimmu.2015.00262
Michaelsen, T. E., Frangione, B., and Franklin, E. C. (1977). Primary structure of the “hinge” region of human IgG3. Probable quadruplication of a 15-amino acid residue basic unit. The Journal of Biological Chemistry, 252(3), 883–889.
Miletic, V. D. and Frank, M. M. (1995). Complement-immunoglobulin interactions. Current Opinion in Immunology, 7(1), 41–47. https://doi.org/10.1016/0952-7915(95)80027-1
Morrison, S. L. and Koshland, M. E. (1972). Characterization of the J Chain from Polymeric Immunoglobulins. Proceedings of the National Academy of Sciences of the United States of America, 69(1), 124–128. https://doi.org/10.1073/pnas.69.1.12
Mortensen, S. A., Sander, B., Jensen, R. K., Pedersen, J. S., Golas, M. M., Jensenius, J. C., Hansen, A. G., Thiel, S., and Andersen, G. R. (2017). Structure and activation of C1, the complex initiating the classical pathway of the complement cascade. Proceedings of the National Academy of Sciences, 114(5), 986–991. https://doi.org/10.1073/pnas.1616998114
Müller, R., Grüwert, M. A., Kern, T., Madl, T., Peschek, J., Sattler, M., Groll, M., and Buchner, J. (2013). High-resolution structures of the IgM Fc domains reveal principles of its hexamer formation. Proceedings of the National Academy of Sciences of the United States of America, 110(25), 10183–10188. https://doi.org/10.1073/pnas.1300547110
Noris, M. and Remuzzi, G. (2013). Overview of Complement Activation and Regulation. Seminars in Nephrology, 33(6), 479–492. https://doi.org/10.1016/j.semnephrol.2013.08.001
Olson, B. M. and McNeel, D. G. (2012). Antigen loss and tumor-mediated immunosuppression facilitate tumor recurrence. Expert Review of Vaccines, 11(11), 1315–1317. https://doi.org/10.1586/erv.12.107
Oskam, N., Ooijevaar-de Heer, P., Derksen, N. I. L., Kruithof, S., de Taeye, S. W., Vidarsson, G., Reijm, S., Kissel, T., Toes, R. E. M., and Rispens, T. (2022). At Critically Low Antigen Densities, IgM Hexamers Outcompete Both IgM Pentamers and IgG1 for Human Complement Deposition and Complement-Dependent Cytotoxicity. Journal of Immunology (Baltimore, Md.: 1950), 209(1), 16–25. https://doi.org/10.4049/jimmunol.2101196
Pan, S., Manabe, N., and Yamaguchi, Y. (2021). 3D Structures of IgA, IgM, and Components. International Journal of Molecular Sciences, 22(23), 12776. https://doi.org/10.3390/ijms222312776
Papavasiliou, F. N. and Schatz, D. G. (2002). Somatic Hypermutation of Immunoglobulin Genes: Merging Mechanisms for Genetic Diversity. Cell, 109(2, Supplement 1), S35–S44. https://doi.org/10.1016/S0092-8674(02)00706-7
Perelson, A. S. and Wiegel, F. W. (1979). A calculation of the number of IgG molecules required per cell to fix complement. Journal of Theoretical Biology, 79(3), 317–332. https://doi.org/10.1016/0022-5193(79)90349-7
Porter, R. R. (1959). The hydrolysis of rabbit γ-globulin and antibodies with crystalline papain. Biochemical Journal, 73(1), 119–127. https://doi.org/10.1042/bj0730119
Randall, T. D., Parkhouse, R. M. E., and Corley, R. B. (1992). J Chain Synthesis and Secretion of Hexameric IgM is Differentially Regulated by Lipopolysaccharide and Interleukin 5. Proceedings of the National Academy of Sciences of the United States of America, 89(3), 962–966. https://doi.org/10.1073/pnas.89.3.962
Rawal, N. and Pangburn, M. K. (2003). Formation of high affinity C5 convertase of the classical pathway of complement. The Journal of Biological Chemistry, 278(40), 38476–38483. https://doi.org/10.1074/jbc.M307017200
Ricklin, D., Hajishengallis, G., Yang, K., and Lambris, J. D. (2010). Complement: A key system for immune surveillance and homeostasis. Nature Immunology, 11(9), 785–797. https://doi.org/10.1038/ni.1923
Rojas, R., and Apodaca, G. (2002). Immunoglobulin transport across polarized epithelial cells. Nature Reviews. Molecular Cell Biology, 3(12), 944–955. https://doi.org/10.1038/nrm972
Roumenina, L. T., Kantardjiev, A. A., Atanasov, B. P., Waters, P., Gadjeva, M., Reid, K. B. M., Mantovani, A., Kishore, U., and Kojouharova, M. S. (2005). Role of Ca2+ in the Electrostatic Stability and the Functional Activity of the Globular Domain of Human C1q. Biochemistry, 44(43), 14097–14109. https://doi.org/10.1021/bi051186n
Saphire, E. O., Parren, P. W., Pantophlet, R., Zwick, M. B., Morris, G. M., Rudd, P. M., Dwek, R. A., Stanfield, R. L., Burton, D. R., and Wilson, I. A. (2001). Crystal structure of a neutralizing human IGG against HIV-1: A template for vaccine design. Science (New York, N.Y.), 293(5532), 1155–1159. https://doi.org/10.1126/science.1061692
Scapin, G., Yang, X., Prosise, W. W., McCoy, M., Reichert, P., Johnston, J. M., Kashi, R. S., and Strickland, C. (2015). Structure of full-length human anti-PD1 therapeutic IgG4 antibody pembrolizumab. Nature Structural & Molecular Biology, 22(12), 953–958. https://doi.org/10.1038/nsmb.3129
Schroeder, H. W., and Cavacini, L. (2010). Structure and function of immunoglobulins. Journal of Allergy and Clinical Immunology, 125(2), S41–S52. https://doi.org/10.1016/j.jaci.2009.09.046
Sharp, T. H., Boyle, A. L., Diebolder, C. A., Kros, A., Koster, A. J., and Gros, P. (2019). Insights into IgM-mediated complement activation based on in situ structures of IgM-C1-C4b. Proceedings of the National Academy of Sciences of the United States of America, 116(24), 11900–11905. https://doi.org/10.1073/pnas.1901841116
Sitia, R., Neuberger, M., Alberini, C., Bet, P., Fra, A., Valetti, C., Williams, G., and Milstein, C. (1990). Developmental regulation of IgM secretion: The role of the carboxy-terminal cysteine. Cell, 60(5), 781–790. https://doi.org/10.1016/0092-8674(90)90092-S
Spiteri, V. A., Goodall, M., Doutch, J., Rambo, R. P., Gor, J., and Perkins, S. J. (2021). Solution structures of human myeloma IgG3 antibody reveal extended Fab and Fc regions relative to the other IgG subclasses. Journal of Biological Chemistry, 297(3). https://doi.org/10.1016/j.jbc.2021.100995
van Osch, T. L. J., Nouta, J., Derksen, N. I. L., van Mierlo, G., van der Schoot, C. E., Wuhrer, M., Rispens, T., and Vidarsson, G. (2021). Fc Galactosylation Promotes Hexamerization of Human IgG1, Leading to Enhanced Classical Complement Activation. The Journal of Immunology Author Choice, 207(6), 1545–1554. https://doi.org/10.4049/jimmunol.2100399
Venkatraman Girija, U., Gingras, A. R., Marshall, J. E., Panchal, R., Sheikh, Md. A., Harper, J. A. J., Gál, P., Schwaeble, W. J., Mitchell, D. A., Moody, P. C. E., and Wallis, R. (2013). Structural basis of the C1q/C1s interaction and its central role in assembly of the C1 complex of complement activation. Proceedings of the National Academy of Sciences, 110(34), 13916–13920. https://doi.org/10.1073/pnas.1311113110
Vidarsson, G., Dekkers, G., and Rispens, T. (2014). IgG Subclasses and Allotypes: From Structure to Effector Functions. Frontiers in Immunology, 5. https://doi.org/10.3389/fimmu.2014.00520
Walport, M. J. (2001). Complement. First of two parts. The New England Journal of Medicine, 344(14), 1058–1066. https://doi.org/10.1056/NEJM200104053441406
Wang, G., de Jong, R. N., van den Bremer, E. T. J., Beurskens, F. J., Labrijn, A. F., Ugurlar, D., Gros, P., Schuurman, J., Parren, P. W. H. I., and Heck, A. J. R. (2016). Molecular Basis of Assembly and Activation of Complement Component C1 in Complex with Immunoglobulin G1 and Antigen. Molecular Cell, 63(1), 135–145. https://doi.org/10.1016/j.molcel.2016.05.016
Weiss, V., Fauser, C., and Engel, J. (1986). Functional model of subcomponent C1 of human complement. Journal of Molecular Biology, 189(3), 573–581. https://doi.org/10.1016/0022-2836(86)90325-6
Wiersma, E. J., Chen, F., Bazin, R., Collins, C., Painter, R. H., Lemieux, R., and Shulman, M. J. (1997). Analysis of IgM structures involved in J chain incorporation. Journal of Immunology (Baltimore, Md.: 1950), 158(4), 1719–1726.
Zeller, J., Cheung Tung Shing, K. S., Nero, T. L., McFadyen, J. D., Krippner, G., Bogner, B., Kreuzaler, S., Kiefer, J., Horner, V. K., Braig, D., Danish, H., Baratchi, S., Fricke, M., Wang, X., Kather, M. G., Kammerer, B., Woollard, K. J., Sharma, P., Morton, C. J., … Eisenhardt, S. U. (2022). A novel phosphocholine‐mimetic inhibits a pro‐inflammatory conformational change in C‐reactive protein. EMBO Molecular Medicine, 15(1), e16236. https://doi.org/10.15252/emmm.202216236
Zwarthoff, S. A., Widmer, K., Kuipers, A., Strasser, J., Ruyken, M., Aerts, P. C., de Haas, C. J. C., Ugurlar, D., den Boer, M. A., Vidarsson, G., van Strijp, J. A. G., Gros, P., Parren, P. W. H. I., van Kessel, K. P. M., Preiner, J., Beurskens, F. J., Schuurman, J., Ricklin, D., and Rooijakkers, S. H. M. (2021). C1q binding to surface-bound IgG is stabilized by C1r2s2 proteases. Proceedings of the National Academy of Sciences of the United States of America, 118(26), e2102787118. https://doi.org/10.1073/pnas.2102787118
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