title: Recombinant H22(scFv) blocks CD64 and prevents the capture of anti-TNF monoclonal antibody. A potential strategy to enhance anti-TNF therapy.
abstract: Tumor necrosis factor (TNF) is a pro-inflammatory cytokine that plays a critical role in many inflammatory diseases. Soluble TNF can be neutralized by monoclonal antibodies (mAbs), and this is a widely-used therapeutic approach. However, some patients do not respond to anti-TNF therapy due to the increased expression of CD64 on monocytes and macrophages. A recent study has shown that CD64 captures anti-TNF mAbs via their Fcγ domain, which induces the transcription of pro-inflammatory genes. Specific blocking of CD64 could therefore be a promising strategy to improve the response to anti-TNF therapy. We used the CD64-specific antibody fragment H22(scFv) and tested its activity against the human CD64(+) cell line HL-60. When stimulated with interferon gamma (IFN-γ), these cells represent a pro-inflammatory phenotype of the monocyte/macrophage lineage. We found that H22(scFv) binds selectively to and blocks CD64, preventing the capture of anti-TNF mAb. Importantly, H22(scFv) itself does not induce CD64 activation. We also found that transmembrane TNF on HL-60 cells stimulated with IFN-γ also contributes to the capture of anti-TNF mAb, although via their Fab domain. In conclusion, the specific blocking of CD64 by H22(scFv) could be used a possible anti-inflammatory mechanism for potentiating the effect of anti-TNF antibodies.
authors.affiliation: a Department of Experimental Medicine and Immunotherapy; Institute of Applied Medical Engineering ; University Hospital RWTH Aachen ; Aachen , Germany.
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Hristodorov
authors.forename: Radoslav
authors.initials: R
authors.lastname: Mladenov
authors.forename: Hannes
authors.initials: H
authors.lastname: Brehm
authors.forename: Rainer
authors.initials: R
authors.lastname: Fischer
authors.forename: Stefan
authors.initials: S
authors.lastname: Barth
authors.forename: Theo
authors.initials: T
authors.lastname: Thepen
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D000915:Antibody Affinity / Q000276:immunology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D018922:HL-60 Cells; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000494:pharmacology; D018836:Inflammation Mediators / Q000276:immunology / Q000378:metabolism; D007371:Interferon-gamma / Q000276:immunology / Q000494:pharmacology; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding / Q000276:immunology; D017452:Receptors, IgG / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D016209:Interleukin-8; D017452:Receptors, IgG; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma
keywords: AD, atopic dermatitis; ADCC, antibody-dependent cell-mediated cytotoxicity; CD64; CDC, complement-dependent cellular cytotoxicity; Fcγ, fragment crystallizable gamma; H22; IBD, inflammatory bowel disease; IFN-γ, interferon gamma; RA, rheumatoid arthritis; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis; TNF; TNF, tumor necrosis factor; aglycoIgG1, aglycosylated IgG1; chronic inflammation; immunotherapy; mAb(s), monoclonal antibodie(s); mTNF, transmembrane tumor necrosis factor; monoclonal antibodies; scFv, single chain fragment variable