Cell contact-dependent priming and Fc interaction with CD32+ immune cells contribute to the TGN1412-triggered cytokine response.

Abstract

Following inconspicuous preclinical testing, the superagonistic anti-CD28 mAb TGN1412 was applied to six study participants who all developed a devastating cytokine storm. We verified that TGN1412 treatment of fresh PBMCs induced only moderate responses, whereas restoration of tissue-like conditions by high-density preculture (HDC) allowed vigorous cytokine production. TGN1412 treatment of T cells isolated from HDC-PBMCs induced moderate cytokine responses, which upon additional anti-IgG crosslinking were significantly boosted. Moreover, coincubation of TGN1412-treated T cells with B cells expressing the intermediate affinity Fcγ receptor IIB (CD32B), or coincubation with CD32B(+) transfectants, resulted in robust T cell activation. This was surprising because TGN1412 was expressed as an Ig of the subclass 4 (IgG4), which was shown before to exhibit only minor affinity to FcγRs. Transcriptome analysis of TGN1412-treated T cells revealed that similar gene signatures were induced irrespective of whether T cells derived from fresh or HDC-PBMCs were studied. Collectively, these data indicate that HDC-PBMCs and HDC-PBMC-derived T cells mount rapid TGN1412 responses, which are massively boosted by FcγR crosslinking, in particular by CD32-expressing B cells. These results qualify HDC-PBMCs as a valuable in vitro test system for the analysis of complex mAb functions.

• Authors: Patrick Bartholomaeus, Linda Y Semmler, Thomas Bukur, Valesca Boisguerin, Paula S Römer, Paula Tabares, Sergey Chuvpilo, Dmitry Y Tyrsin, Alexey Matskevich, Hartmut Hengel, John Castle, Thomas Hünig, Ulrich Kalinke
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 192 Issue 5 Pg. 2091-8 (Mar 01 2014) ISSN: 1550-6606 [Electronic] United States
• PMID: 24470499 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal, Humanized
• Cytokines
• Fc gamma receptor IIB
• Immunoglobulin Fc Fragments
• Immunoglobulin G
• Receptors, IgG
• TGN-1412

Topics

• Antibodies, Monoclonal, Humanized (immunology, pharmacology)
• Cytokines (immunology)
• Female
• Gene Expression Profiling
• Gene Expression Regulation (drug effects, immunology)
• Humans
• Immunoglobulin Fc Fragments (immunology, pharmacology)
• Immunoglobulin G (immunology, pharmacology)
• Male
• Receptors, IgG (immunology)
• Transcriptome (drug effects, immunology)