A standardized conversion of IgG antibody to bispecific form with inversely altered affinities for Fcγ-receptors II and III

Leong, Weng S.; Thomas, Karen-Anne; Chan, H T Claude; Stevenson, G T

doi:10.1016/j.molimm.2010.11.019

Cited by 4 publications

(4 citation statements)

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“…65 (3) A bispecific FabIgG construct is synthesized by attaching an Fab'γ module, with antibody specificity for FcγRIIIA, to the rituximab hinge. The attachment process deliberately and severely disables the docking of FcγRIIB at its adjoining site, 62,66 giving a KA ratio or more than 1000.…”

Section: One Approach To Enhancing Antibody Cytotoxicitymentioning

confidence: 99%

Three major uncertainties in the antibody therapy of cancer

Stevenson

2014

Haematologica

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Antibodies against surface molecules of human tumors are now frequently administered in combination with strong chemotherapy, increasing therapeutic efficacy but making the task of elucidating immunological events more difficult. Experiments on genetically manipulated mice indicate that antibody efficacy is greatest when IgG antibody coating tumor cells is engaged by the Fcγ-receptors of effector cells, chiefly the monocyte/macrophage lineage. Evidence suggests lesser roles for NK cells, neutrophils, receptor-mediated cytotoxicity and complement-mediated cytotoxicity. The classical mode of killing employed by macrophages is phagocytosis, but much has to be learned about optimally activating macrophages for this task, and about any other modes of cytotoxicity used. There is renewed interest in antigenic modulation, which implies removal of therapeutic antibody linked with antigen from target-cell surfaces. It is now apparent that this removal of immune complexes can be achieved either by internalization by the target cell, or by transfer of the complexes to another cell by trogocytosis. In trials, anti-idiotype antibodies surprisingly proved therapeutically more effective than anti-CD20, despite anti-idiotype being more effectively removed from target-cell surfaces by antigenic modulation. This anomalous result might reflect the fact that persistence of anti-CD20 immune complexes in large amounts induces serious effector modulation, which paralyzes macrophage attacks on antibody-coated cells. The case for effector modulation is argued by analogy with the therapeutic suppression of autoimmune inflammation by effector modulation, achieved by infusion either of normal IgG in large amounts, or of anti-red cell IgG in relatively small amounts. ABSTRACTexamined for tumor Id. Very low levels were detected in all patients, but they all subsequently remained in remission and this has been maintained up to the time of writing; a striking example of tumor dormancy.Anti-Id therapy is now in abeyance due to the logistical difficulties involved in preparing individual antibodies for each patient. However, follicular lymphomas have been found to present an unusual glycan on their variable domains, close to the idiotypic epitopes, so there is a prospect that, for these tumors, an antibody of good affinity aimed at the glycan could be an effective single substitute for multiple anti-Id preparations.

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Section: One Approach To Enhancing Antibody Cytotoxicitymentioning

confidence: 99%

Three major uncertainties in the antibody therapy of cancer

Stevenson

2014

Haematologica

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“…107,108 The affinity for Fc␥RIII is enhanced, affinities for all other Fc␥R collapse, and the FabIgG acquires a ratio of K A (Fc␥RIII) to K A (Fc␥RIIB) increased more than 1000-fold. The other docking sites on Fc␥ 109,110 (Figure 3) do not involve the hinge and are minimally affected.…”

Section: Further Engineering Of the Fc␥ Modulementioning

confidence: 99%

“…110 The contralateral set of sites is obscured. In the FabIgG derivative, 108 the hinge disulfide bonds are cleaved; and a third FabЈ␥ module, with antibody specificity for the activating Fc␥RIIIA, is attached to one of the resulting cysteine residues. The original Fc␥R site is deliberately disabled so that there is little residual affinity for Fc␥RIIB.…”

Section: Further Engineering Of the Fc␥ Modulementioning

confidence: 99%

Follicular lymphoma and the immune system: from pathogenesis to antibody therapy

Stevenson

2012

Blood

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Follicular lymphoma (FL) is a B-cell tumor arising in germinal centers and retaining features of its normal B-cell counterpart.Lymphomagenesis appears stepwise from the t(14;18) translocation, through FL-like cells, to FL in situ, then to overt FL. Surface Ig is mandatory and carries a striking V-region modification because of introduction of glycan addition sites during somatic mutation. These are positively selected and acquire unusual high mannoses, which interact with lectins.The Ig-associated mannoses appear essential for FL, providing a diseasespecific target for antibody attack. Antibody therapy is currently focused on anti-CD20 (rituximab), which appears to rely predominantly on the Fc␥ module recruiting suitably activated macrophages. Immunogloblulin and, to some extent, CD20, can each escape antibody attack in vitro by modulation, but this is difficult to demonstrate clinically. Instead, studies of anti-CD20 therapy of FL suggest that effector modulation, similar to that seen in the suppression of autoimmune inflammation by infusions of normal human IgG, may be important. Both antigenic and effector modulations might be minimized by repeated small doses of more potent antibodies. Clearly, mechanisms of attack vary with the malignancy, the target molecule, and the antibody design, offering opportunities for optimizing this promising strategy. (Blood. 2012;119(16): 3659-3667) IntroductionAntibody is now a major contributor to the treatment of B-cell malignancies. However, there remains a pressing need to understand better how to encourage the destruction of antibody-coated neoplastic cells. We direct our attention to human follicular lymphoma (FL), to its pathogenesis and a therapeutic opportunity this reveals. We focus on 2 of its cell-surface antigens: first, the key receptor of B cells, surface immunoglobulin (Ig), which has a renewed target potential; and second, an established target, CD20. Antibodies against each molecule are clinically effective but may differ in the mechanism of killing. They differ in susceptibility to endocytosis/modulation after engagement by antibody and illustrate the need to understand the behavior of the target molecule to optimize strategies for attack. Development of FLFL occupies the immune system, surviving and proliferating mainly in the germinal centers (GCs) of lymph nodes. The architecture of normal GCs tends to be retained, with lymphoma cells located in a network of follicular dendritic cells, follicular CD4 ϩ T cells, and stromal elements. For normal B cells, GCs are the sites where Darwinian evolution occurs with binding to antigen being the positive selector and death awaiting nonselected B cells. To persist in this hostile environment, FL cells need to escape the default death pathways. One protective factor evident in the majority of cases is the up-regulated expression of the antiapoptotic BCL2 protein via the t(14;18)(q32;q21) translocation. The translocation appears to occur principally as an error during Ig VDJ recombination in the bone marrow, which pla...

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“…Macrophages play an important role in immune defense. Activated macrophages suppress tumor cells through the ADCC pathway via FcγRIII (CD16) and directly or indirectly by cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-1 or certain enzymes ( 4 ). As part of the mono-nuclear phagocytic system, Kupffer cells (KCs) are the main type of hepatic macrophages, and they play an important role in the inhibition of liver tumors and their surface receptors are the mediator in this pathway ( 5 ).…”

Section: Introductionmentioning

confidence: 99%

Effect of CD16a, the surface receptor of Kupffer cells, on the growth of hepatocellular carcinoma cells

Liu¹,

et al. 2016

International Journal of Molecular Medicine

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FcγRIIIa (CD16) is a low-affinity Fc receptor of IgG. As the idio-binding receptor of IgG Fc, it plays an important role in the antibody-dependent cellular cytotoxicity of natural killer cells. The aim of the present study was to investigate the distribution of Kupffer cells (KCs) and the expression of their surface receptor FcγRIIIa in hepatocellular carcinoma. Furthermore, we also aimed to observe the functional mechanism of FcγRIIIa. Immunohistochemical analysis was employed to study KCs and FcγRIIIa. In order to explore the role of FcγRIIIa in the growth of cancer cells, KCs and H22 tumor cells were co-cultured in different serum. The mRNA expression levels of tumor necrosis factor (TNF)-α and FcγRIIIa were analyzed by RT-qPCR; the TNF-α and FcγRIIIa protein expression levels were examined by enzyme-linked immunosorbent assay and western blot analysis, respectively. Our results showed that the number of Kuppfer cells in cancerous tissues (21.6±7.8) was lower than those in para-cancerous (68.8±9.1) tissues and adjacent normal hepatic tissues (62.0±1.9) (P<0.01); this decreased with the reduction in the differentiation degree of cancer (P<0.05). FcγRIIIa-positive cells were similar in morphology to KCs, and their distributive tendency was coincident (P<0.05). The increase in CD16a mRNA levels in the group treated with immune serum was 3.9-, 4.9- and 3.9-fold greater than that in the ordinary serum group at different time points, and CD16a protein expression also markedly increased (P<0.05). However, these effects were inhibited by the addition of anti-IgG Fc serum (P<0.05). The results of the present study suggested that FcγRIIIa resided in KCs, and it contributed to the inhibition of the growth of liver tumor cells.

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A standardized conversion of IgG antibody to bispecific form with inversely altered affinities for Fcγ-receptors II and III

Cited by 4 publications

References 49 publications

Three major uncertainties in the antibody therapy of cancer

Three major uncertainties in the antibody therapy of cancer

Follicular lymphoma and the immune system: from pathogenesis to antibody therapy

Effect of CD16a, the surface receptor of Kupffer cells, on the growth of hepatocellular carcinoma cells

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