Cancer vaccines compensate for the insufficient induction of protective tumor-specific immunity of CD3 bispecific antibody therapy.

Background: CD3 bispecific antibody (CD3 bsAb) therapy has become an established treatment modality for some cancer types and exploits endogenous T cells irrespective of their specificity. However, durable clinical responses are hampered by immune escape through loss of tumor target antigen expression. Induction of long-lasting tumor-specific immunity might therefore improve therapeutic efficacy, but has not been studied in detail yet for CD3 bsAbs.

Agnostic B cell selection approach identifies antibodies against K. pneumoniae that synergistically drive complement activation.

Antibody-dependent complement activation plays a key role in the natural human immune response to infections. Currently, the understanding of which antibody-antigen combinations drive a potent complement response on bacteria is limited. Here, we develop an antigen-agnostic approach to stain and single-cell sort human IgG memory B cells recognizing intact bacterial cells, keeping surface antigens in their natural context.

Infrared Spectroscopic Characterization of Early 4d Transition Metal Carbene Cations, ZrCH and NbCH.

IR multiple-photon dissociation (IRMPD) action spectroscopy is combined with quantum chemical calculations to examine the [M,C,2H] species for the early 4d metals, M = Zr and Nb. These ions were formed by reacting laser ablated M ions with cyclopropane (-CH) in a molecular beam apparatus. Both IRMPD spectra exhibit one major band near 700 cm and a second weaker band at about twice that wavenumber, more evident when irradiated in focus.

Immunotherapy-activated T cells recruit and skew late-stage activated M1-like macrophages that are critical for therapeutic efficacy.

Total tumor clearance through immunotherapy is associated with a fully coordinated innate and adaptive immune response, but knowledge on the exact contribution of each immune cell subset is limited. We show that therapy-induced intratumoral CD8 T cells recruited and skewed late-stage activated M1-like macrophages, which were critical for effective tumor control in two different murine models of cancer immunotherapy. The activated CD8 T cells summon these macrophages into the tumor and their close vicinity via CCR5 signaling.

Antibody-epitope conjugates deliver immunogenic T-cell epitopes more efficiently when close to cell surfaces.

Antibody-mediated delivery of immunogenic viral CD8 T-cell epitopes to redirect virus-specific T cells toward cancer cells is a promising new therapeutic avenue to increase the immunogenicity of tumors. Multiple strategies for viral epitope delivery have been shown to be effective. So far, most of these have relied on a free C-terminus of the immunogenic epitope for extracellular delivery.

Impact of structural modifications of IgG antibodies on effector functions.

Immunoglobulin G (IgG) antibodies are a critical component of the adaptive immune system, binding to and neutralizing pathogens and other foreign substances. Recent advances in molecular antibody biology and structural protein engineering enabled the modification of IgG antibodies to enhance their therapeutic potential. This review summarizes recent progress in both natural and engineered structural modifications of IgG antibodies, including allotypic variation, glycosylation, Fc engineering, and Fc gamma receptor binding optimization.

T-cell stimulating vaccines empower CD3 bispecific antibody therapy in solid tumors.

CD3 bispecific antibody (CD3 bsAb) therapy is clinically approved for refractory hematological malignancies, but responses in solid tumors have been limited so far. One of the main hurdles in solid tumors is the lack of sufficient T-cell infiltrate. Here, we show that pre-treatment vaccination, even when composed of tumor-unrelated antigens, induces CXCR3-mediated T-cell influx in immunologically 'cold' tumor models in male mice.

Antibody-mediated delivery of viral epitopes to redirect EBV-specific CD8 T-cell immunity towards cancer cells.

Antibody-mediated delivery of immunogenic epitopes to redirect virus-specific CD8 T-cells towards cancer cells is an emerging and promising new therapeutic strategy. These so-called antibody-epitope conjugates (AECs) rely on the proteolytic release of the epitopes close to the tumor surface for presentation by HLA class I molecules to eventually redirect and activate virus-specific CD8 T-cells towards tumor cells. We fused the immunogenic EBV-BRLF1 epitope preceded by a protease cleavage site to the C-terminus of the heavy and/or light chains of cetuximab and trastuzumab.

The Influence of Human IgG Subclass and Allotype on Complement Activation.

Complement activation via the classical pathway is initiated when oligomeric Igs on target surfaces are recognized by C1 of the complement cascade. The strength of this interaction and activation of the complement system are influenced by structural variation of the Ab, including Ab isotype, subclass, and glycosylation profile. Polymorphic variants of IgG have also been described to influence Fc-dependent effector functions.

Comparison of methods generating antibody-epitope conjugates for targeting cancer with virus-specific T cells.

Therapeutic antibody-epitope conjugates (AECs) are promising new modalities to deliver immunogenic epitopes and redirect virus-specific T-cell activity to cancer cells. Nevertheless, many aspects of these antibody conjugates require optimization to increase their efficacy. Here we evaluated different strategies to conjugate an EBV epitope (YVL/A2) preceded by a protease cleavage site to the antibodies cetuximab and trastuzumab.

Mutation of the TGN1412 anti-CD28 monoclonal antibody lower hinge confers specific FcγRIIb binding and retention of super-agonist activity.

The agonistic action of several immunomodulatory monoclonal antibodies (mAbs) requires both target antigen binding and clustering of this mAb:target complex by the Fcs interacting with Fcγ receptors (FcγRs), in particular FcγRIIb, on neighboring bystander cells. Fc mutations were made in the immunoglobulin G4 (IgG4)-based TGN1412 anti-CD28 mAb to define the role of FcγR interactions in its "super-agonist" activity. The dual mutation, IgG4-ED AA, ablated interaction with all human FcγRs and agonistic action was consequentially lost, confirming the FcγR dependence on the action of TGN1412.

Promoting Fc-Fc interactions between anti-capsular antibodies provides strong immune protection against .

is the leading cause of community-acquired pneumonia and an important cause of childhood mortality. Despite the introduction of successful vaccines, the global spread of both non-vaccine serotypes and antibiotic-resistant strains reinforces the development of alternative therapies against this pathogen. One possible route is the development of monoclonal antibodies (mAbs) that induce killing of bacteria via the immune system.

Logic-gated antibody pairs that selectively act on cells co-expressing two antigens.

The use of therapeutic monoclonal antibodies is constrained because single antigen targets often do not provide sufficient selectivity to distinguish diseased from healthy tissues. We present HexElect, an approach to enhance the functional selectivity of therapeutic antibodies by making their activity dependent on clustering after binding to two different antigens expressed on the same target cell. lmmunoglobulin G (lgG)-mediated clustering of membrane receptors naturally occurs on cell surfaces to trigger complement- or cell-mediated effector functions or to initiate intracellular signaling.

Avidity in antibody effector functions and biotherapeutic drug design.

Antibodies are the cardinal effector molecules of the immune system and are being leveraged with enormous success as biotherapeutic drugs. A key part of the adaptive immune response is the production of an epitope-diverse, polyclonal antibody mixture that is capable of neutralizing invading pathogens or disease-causing molecules through binding interference and by mediating humoral and cellular effector functions. Avidity - the accumulated binding strength derived from the affinities of multiple individual non-covalent interactions - is fundamental to virtually all aspects of antibody biology, including antibody-antigen binding, clonal selection and effector functions.

Combining Viedma Ripening and Temperature Cycling Deracemization.

While much data are available for the Viedma ripening and temperature cycling deracemization processes, not much is known about the advantages (or disadvantages) of a combination of the two. We here try to elucidate what happens when Viedma ripening is used in combination with temperature cycling by comparing not only the deracemization times but also the change in the sizes of the crystals. We found that, in the case of NMPA (-(2-methylbenzylidene)-phenylglycine amide) as a model compound, combined experiments significantly increase the deracemization time.

Biophysical Characterization and Stability of Modified IgG1 Antibodies with Different Hexamerization Propensities.

The hexamerization of natural, human IgG antibodies after cell surface antigen binding can induce activation of the classical complement pathway. Mutations stimulating Fc domain-mediated hexamerization can potentiate complement activation and induce the clustering of cell surface receptors, a finding that was applied to different clinically investigated antibody therapeutics. Here, we biophysically characterized how increased self-association of IgG1 antibody variants with different hexamerization propensity may impact their developability, rather than functional properties.

Rapid analysis of gunshot residues with single-particle inductively coupled plasma time-of-flight mass spectrometry.

Gunshot residues (GSRs) from different types of ammunition have been characterized using a new method based on single-particle inductively coupled plasma time-of-flight mass spectrometry (sp-ICP-TOF-MS). This method can analyze thousands of particles per minute enabling rapid sample screening for GSR detection with minimal sample preparation. GSR particles are multi-elemental nanoparticles that are mainly defined by the elements lead, barium, and antimony.

Efficacy of an Experimental Gonococcal Lipooligosaccharide Mimitope Vaccine Requires Terminal Complement.

A safe and effective vaccine against multidrug-resistant gonorrhea is urgently needed. An experimental peptide vaccine called TMCP2 that mimics an oligosaccharide epitope in gonococcal lipooligosaccharide, when adjuvanted with glucopyranosyl lipid adjuvant-stable emulsion, elicits bactericidal immunoglobulin G and hastens clearance of gonococci in the mouse vaginal colonization model. In this study, we show that efficacy of TMCP2 requires an intact terminal complement pathway, evidenced by loss of activity in C9-/- mice or when C7 function was blocked.

Synthetic DNA Delivery of an Optimized and Engineered Monoclonal Antibody Provides Rapid and Prolonged Protection against Experimental Gonococcal Infection.

Monoclonal antibody (MAb) 2C7 recognizes a lipooligosaccharide epitope expressed by most clinical isolates and mediates complement-dependent bactericidal activity. We recently showed that a recombinant human IgG1 chimeric variant of MAb 2C7 containing an E430G Fc modification (2C7_E430G), which enhances complement activation, outperformed the parental MAb 2C7 (2C7_WT) Because natural infection with often does not elicit protective immunity and reinfections are common, approaches that prolong bacterial control are of great interest. Advances in DNA-based approaches have demonstrated the combined benefit of genetic engineering, formulation optimizations, and facilitated delivery via CELLECTRA-EP technology, which can induce robust expression of protective DNA-encoded monoclonal antibodies (DMAbs) with durable serum activity relative to traditional recombinant MAb therapies.

Generating Informative Sequence Tags from Antigen-Binding Regions of Heavily Glycosylated IgA1 Antibodies by Native Top-Down Electron Capture Dissociation.

Immunoglobulins A (IgA) include some of the most abundant human antibodies and play an important role in defending mucosal surfaces against pathogens. The unique structural features of the heavy chain of IgA subclasses (called IgA1 and IgA2) enable them to polymerize via the joining J-chain, resulting in IgA dimers but also higher oligomers. While secretory sIgA oligomers are dominant in milk and saliva, IgAs exist primarily as monomers in serum.

Staphylococcal protein A inhibits complement activation by interfering with IgG hexamer formation.

Immunoglobulin (Ig) G molecules are essential players in the human immune response against bacterial infections. An important effector of IgG-dependent immunity is the induction of complement activation, a reaction that triggers a variety of responses that help kill bacteria. Antibody-dependent complement activation is promoted by the organization of target-bound IgGs into hexamers that are held together via noncovalent Fc-Fc interactions.

Overcoming Challenges for CD3-Bispecific Antibody Therapy in Solid Tumors.

Immunotherapy of cancer with CD3-bispecific antibodies is an approved therapeutic option for some hematological malignancies and is under clinical investigation for solid cancers. However, the treatment of solid tumors faces more pronounced hurdles, such as increased on-target off-tumor toxicities, sparse T-cell infiltration and impaired T-cell quality due to the presence of an immunosuppressive tumor microenvironment, which affect the safety and limit efficacy of CD3-bispecific antibody therapy. In this review, we provide a brief status update of the CD3-bispecific antibody therapy field and identify intrinsic hurdles in solid cancers.