CIMT 2024: Report on the 21st Annual Meeting of the Association for Cancer Immunotherapy.

The 21st Association for Cancer Immunotherapy (CIMT) Annual Meeting took place from May 15th to May 17th in Mainz, Germany, and was attended by a total of 855 academic and clinical professionals hailing from 33 different countries. The conference served as a platform for these experts to convene and discuss the latest breakthroughs in cancer immunology and immunotherapy research. Dedicated sessions covering advancements in artificial intelligence tools for cancer immunotherapy research, as well as the landscape of cancer care and cancer immunotherapy trials on the African continent, prompted lively and informative discussions among the attendees. This report aims to provide an overview of the most noteworthy highlights and key takeaways from CIMT2024.

Long-lasting mRNA-encoded interleukin-2 restores CD8+ T cell neoantigen immunity in MHC class I-deficient cancers.

Major histocompatibility complex (MHC) class I antigen presentation deficiency is a common cancer immune escape mechanism, but the mechanistic implications and potential strategies to address this challenge remain poorly understood. Studying ß2-microglobulin (B2M) deficient mouse tumor models, we find that MHC class I loss leads to a substantial immune desertification of the tumor microenvironment (TME) and broad resistance to immune-, chemo-, and radiotherapy. We show that treatment with long-lasting mRNA-encoded interleukin-2 (IL-2) restores an immune cell infiltrated, IFNγ-promoted, highly proinflammatory TME signature, and when combined with a tumor-targeting monoclonal antibody (mAB), can overcome therapeutic resistance. Unexpectedly, the effectiveness of this treatment is driven by IFNγ-releasing CD8+ T cells that recognize neoantigens cross-presented by TME-resident activated macrophages. These macrophages acquire augmented antigen presentation proficiency and other M1-phenotype-associated features under IL-2 treatment. Our findings highlight the importance of restoring neoantigen-specific immune responses in the treatment of cancers with MHC class I deficiencies.

Translating Science into Survival: Report on the Seventh International Cancer Immunotherapy Conference.

From September 20 to 23, 2023, the Seventh International Cancer Immunotherapy Conference was hosted jointly by the Cancer Research Institute, the European Network for Cancer Immunotherapy (ENCI), and the American Association for Cancer Research (AACR) in Milan, Italy. The four-day event covered the latest advances in cancer immunology and immunotherapy.

CIMT 2022: Report on the 19th Annual Meeting of the Association for Cancer Immunotherapy.

The 19th Annual Meeting of the Association for Cancer Immunotherapy (CIMT), Europe's cancer immunotherapy meeting, was the first in-person event organized by CIMT since the beginning of the COVID-19 pandemic. As a hybrid event from May 10-12, the meeting attracted 920 academic and clinical professionals from over 40 countries, who met to discuss the latest advances in cancer immunology and immunotherapy research. This report summarizes the highlights of CIMT2022.

Nontarget Approach to Identify Complexing Agents in Atmospheric Aerosol and Rainwater Samples.

Atmospheric particles and droplets contain numerous organic substances, some of which form complexes with metal ions, significantly affecting bulk physicochemical properties and chemical reactivity. However, the detection and identification of complexing agents and their corresponding metal complexes remains an analytical challenge. In this study, we developed an LC/HRMS nontarget screening (NTS) approach which allows the selective detection of complexing agents in aerosol particle extracts and rainwater. To achieve this, a T-junction is installed between the LC outlet and the ion source, and a FeCl3 solution is added for postcolumn complexation. The resulting mass spectra are screened for the three characteristic iron(III)-complexes [M - H + FeCl3]-, [M - 2H + FeCl2]-, and [M - 3H + FeCl]- with mass differences (Δm/z) between the complexing agent and the iron complex of 160.8416, 124.8648, and 89.8959, respectively. Up to 29 di- or tricarboxylic acids were identified as complexing agents in aerosol particle samples from two different sites (Melpitz, Germany, and Wangdu, China) at concentrations as low as 50 nM. Thirteen complexing agents were detected even in measurements without postcolumn iron addition from complexation with background Fe3+ traces from the analytical system. At least for the highest concentrated complexing agents, the proposed screening approach can thus be exploited in a NTS approach without any device modification. Besides carboxylic acids, 4-nitrophenol and 4-nitrocatechol were identified as further complexing agents, demonstrating the applicability of the approach to other matrices and to a range of different complexing agents.

mRNA therapeutics in cancer immunotherapy.

Synthetic mRNA provides a template for the synthesis of any given protein, protein fragment or peptide and lends itself to a broad range of pharmaceutical applications, including different modalities of cancer immunotherapy. With the ease of rapid, large scale Good Manufacturing Practice-grade mRNA production, mRNA is ideally poised not only for off-the shelf cancer vaccines but also for personalized neoantigen vaccination. The ability to stimulate pattern recognition receptors and thus an anti-viral type of innate immune response equips mRNA-based vaccines with inherent adjuvanticity. Nucleoside modification and elimination of double-stranded RNA can reduce the immunomodulatory activity of mRNA and increase and prolong protein production. In combination with nanoparticle-based formulations that increase transfection efficiency and facilitate lymphatic system targeting, nucleoside-modified mRNA enables efficient delivery of cytokines, costimulatory receptors, or therapeutic antibodies. Steady but transient production of the encoded bioactive molecule from the mRNA template can improve the pharmacokinetic, pharmacodynamic and safety properties as compared to the respective recombinant proteins. This may be harnessed for applications that benefit from a higher level of expression control, such as chimeric antigen receptor (CAR)-modified adoptive T-cell therapies. This review highlights the advancements in the field of mRNA-based cancer therapeutics, providing insights into key preclinical developments and the evolving clinical landscape.

Essential biodiversity variables for mapping and monitoring species populations.

Species distributions and abundances are undergoing rapid changes worldwide. This highlights the significance of reliable, integrated information for guiding and assessing actions and policies aimed at managing and sustaining the many functions and benefits of species. Here we synthesize the types of data and approaches that are required to achieve such an integration and conceptualize 'essential biodiversity variables' (EBVs) for a unified global capture of species populations in space and time. The inherent heterogeneity and sparseness of raw biodiversity data are overcome by the use of models and remotely sensed covariates to inform predictions that are contiguous in space and time and global in extent. We define the species population EBVs as a space-time-species-gram (cube) that simultaneously addresses the distribution or abundance of multiple species, with its resolution adjusted to represent available evidence and acceptable levels of uncertainty. This essential information enables the monitoring of single or aggregate spatial or taxonomic units at scales relevant to research and decision-making. When combined with ancillary environmental or species data, this fundamental species population information directly underpins a range of biodiversity and ecosystem function indicators. The unified concept we present links disparate data to downstream uses and informs a vision for species population monitoring in which data collection is closely integrated with models and infrastructure to support effective biodiversity assessment.

A non-functional neoepitope specific CD8+ T-cell response induced by tumor derived antigen exposure in vivo.

Cancer-associated mutations, mostly single nucleotide variations, can act as neoepitopes and prime targets for effective anti-cancer T-cell immunity. T cells recognizing cancer mutations are critical for the clinical activity of immune checkpoint blockade (ICB) and they are potent vaccine antigens. High frequencies of mutation-specific T cells are rarely spontaneously induced. Hence, therapies that broaden the tumor specific T-cell response are of interest. Here, we analyzed neoepitope-specific CD8+ T-cell responses mounted either spontaneously or after immunotherapy regimens, which induce local tumor inflammation and cell death, in mice bearing tumors of the widely used colon carcinoma cell line CT26. A comprehensive immune reactivity screening of 2474 peptides covering 628 transcribed CT26 point mutations was conducted. All tested treatment regimens were found to induce a single significant CD8+ T-cell response against a non-synonymous D733A point mutation in the Smc3 gene. Surprisingly, even though Smc3 D733A turned out to be the immune-dominant neoepitope in CT26 tumor bearing mice, neither T cells specific for this neoepitope nor their T cell receptors (TCRs) were able to recognize or lyse tumor cells. Moreover, vaccination with the D733A neoepitope did not result in anti-tumoral activity despite induction of specific T cells. This is to our knowledge the first report that neoepitope specific CD8+ T cells primed by tumor-released antigen exposure in vivo can be functionally irrelevant.

Artificial Pancreas Systems for People With Type 2 Diabetes: Conception and Design of the European CLOSE Project.

In the last 10 years tremendous progress has been made in the development of artificial pancreas (AP) systems for people with type 1 diabetes (T1D). The pan-European consortium CLOSE (Automated Glu cose Contro l at H ome for People with Chronic Disea se) is aiming to develop integrated AP solutions (APplus) tailored to the needs of people with type 2 diabetes (T2D). APplus comprises a product and service package complementing the AP system by obligatory training as well as home visits and telemedical consultations on demand. Outcome predictors and performance indicators shall help to identify people who could benefit most from AP usage and facilitate the measurement of AP impact in diabetes care. In a first step CLOSE will establish a scalable APplus model case working at the interface between patients, homecare service providers, and payers in France. CLOSE will then scale up APplus by pursuing geographic distribution, targeting additional audiences, and enhancing AP functionalities and interconnectedness. By being part of the European Institute of Innovation and Technology (EIT) Health public-private partnership, CLOSE is committed to the EIT "knowledge triangle" pursuing the integrated advancement of technology, education, and business creation. Putting stakeholders, education, and impact into the center of APplus advancement is considered key for achieving wide AP use in T2D care.

Widespread winners and narrow-ranged losers: Land use homogenizes biodiversity in local assemblages worldwide.

Human use of the land (for agriculture and settlements) has a substantial negative effect on biodiversity globally. However, not all species are adversely affected by land use, and indeed, some benefit from the creation of novel habitat. Geographically rare species may be more negatively affected by land use than widespread species, but data limitations have so far prevented global multi-clade assessments of land-use effects on narrow-ranged and widespread species. We analyse a large, global database to show consistent differences in assemblage composition. Compared with natural habitat, assemblages in disturbed habitats have more widespread species on average, especially in urban areas and the tropics. All else being equal, this result means that human land use is homogenizing assemblage composition across space. Disturbed habitats show both reduced abundances of narrow-ranged species and increased abundances of widespread species. Our results are very important for biodiversity conservation because narrow-ranged species are typically at higher risk of extinction than widespread species. Furthermore, the shift to more widespread species may also affect ecosystem functioning by reducing both the contribution of rare species and the diversity of species' responses to environmental changes among local assemblages.

Selection of Antibodies with Tailored Properties by Application of High-Throughput Multiparameter Fluorescence-Activated Cell Sorting of Yeast-Displayed Immune Libraries.

In this study, we present a multiparameter screening procedure for the identification of target-specific antibodies with prescribed properties. Based on B cell receptor gene repertoires from transgenic rats, yeast surface display libraries were generated, and high-affinity human antibodies were readily isolated. We demonstrate that specific desirable features, i.e., species' cross-reactivity and a broad epitope coverage can be integrated into the screening procedure using high-throughput fluorescence-activated cell sorting. We show that the applied screening stringencies translate directly into binding properties of isolated human antibody variants.

CIMT 2018: Pushing frontiers in cancer immunotherapy - Report on the 16th Annual Meeting of the Association for Cancer Immunotherapy.

The 16th Annual Meeting of the Association for Cancer Immunotherapy (CIMT), Europe's largest meeting series of its kind, took place in Mainz, Germany from 15-17 May, 2018. Cutting-edge advancements in cancer immunotherapy were discussed among more than 700 scientists under the motto "Pushing Frontiers in Cancer Immunotherapy". This meeting report is a summary of some of the CIMT 2018 highlights.

Isolation of pH-Sensitive Antibody Fragments by Fluorescence-Activated Cell Sorting and Yeast Surface Display.

Fluorescence-activated cell sorting (FACS) in combination with yeast surface display (YSD) has proven to be a valuable tool for the engineering of antibodies. It enables the fast and robust identification and isolation of candidates with prescribed characteristics from combinatorial libraries. A novel application for FACS and YSD that has recently evolved addresses the engineering of antibodies toward pH-switchable antigen binding, aiming at reduced binding at acidic pH, compared to neutral pH. Therefore, we give guidance for the incorporation of such pH switches into antibody variable domains using combinatorial histidine scanning libraries. The protocol describes a flow cytometric sorting technique for the enrichment of antigen-specific molecules. Moreover, we provide information on how to screen the obtained antibody pools from initial sorting to isolate and characterize pH-sensitive variants.

Engineering bispecific antibodies with defined chain pairing.

Bispecific IgG-like antibodies can simultaneously interact with two epitopes on the same or on different antigens. Therefore, these molecules facilitate novel modes of action, which cannot be addressed by conventional monospecific IgGs. However, the generation of such antibodies still appears to be demanding due to their specific architecture comprising four different polypeptide chains that need to assemble correctly. This review focusses on different strategies to circumvent this issue or to enforce a correct chain association with a focus on common-chain bispecific antibodies.

Generation of human bispecific common light chain antibodies by combining animal immunization and yeast display.

Bispecific antibodies (bsAbs) pave the way for novel therapeutic modes of action along with potential benefits in several clinical applications. However, their generation remains challenging due to the necessity of correct pairings of two different heavy and light chains and related manufacturability issues. We describe a generic approach for the generation of fully human IgG-like bsAbs. For this, heavy chain repertoires from immunized transgenic rats were combined with either a randomly chosen common light chain or a light chain of an existing therapeutic antibody and screened for binders against tumor-related targets CEACAM5 and CEACAM6 by yeast surface display. bsAbs with subnanomolar affinities were identified, wherein each separate binding arm mediated specific binding to the respective antigen. Altogether, the described strategy represents a combination of in vivo immunization with an in vitro selection method, which allows for the integration of existing therapeutic antibodies into a bispecific format.

Structure of the Dispase Autolysis-inducing Protein from Streptomyces mobaraensis and Glutamine Cross-linking Sites for Transglutaminase.

Transglutaminase from Streptomyces mobaraensis (MTG) is an important enzyme for cross-linking and modifying proteins. An intrinsic substrate of MTG is the dispase autolysis-inducing protein (DAIP). The amino acid sequence of DAIP contains 5 potential glutamines and 10 lysines for MTG-mediated cross-linking. The aim of the study was to determine the structure and glutamine cross-linking sites of the first physiological MTG substrate. A production procedure was established in Escherichia coli BL21 (DE3) to obtain high yields of recombinant DAIP. DAIP variants were prepared by replacing four of five glutamines for asparagines in various combinations via site-directed mutagenesis. Incorporation of biotin cadaverine revealed a preference of MTG for the DAIP glutamines in the order of Gln-39 ≫ Gln-298 > Gln-345 ∼ Gln-65 ≫ Gln-144. In the structure of DAIP the preferred glutamines do cluster at the top of the seven-bladed ß-propeller. This suggests a targeted cross-linking of DAIP by MTG that may occur after self-assembly in the bacterial cell wall. Based on our biochemical and structural data of the first physiological MTG substrate, we further provide novel insight into determinants of MTG-mediated modification, specificity, and efficiency.

Midpoint attractors and species richness: Modelling the interaction between environmental drivers and geometric constraints.

We introduce a novel framework for conceptualising, quantifying and unifying discordant patterns of species richness along geographical gradients. While not itself explicitly mechanistic, this approach offers a path towards understanding mechanisms. In this study, we focused on the diverse patterns of species richness on mountainsides. We conjectured that elevational range midpoints of species may be drawn towards a single midpoint attractor - a unimodal gradient of environmental favourability. The midpoint attractor interacts with geometric constraints imposed by sea level and the mountaintop to produce taxon-specific patterns of species richness. We developed a Bayesian simulation model to estimate the location and strength of the midpoint attractor from species occurrence data sampled along mountainsides. We also constructed midpoint predictor models to test whether environmental variables could directly account for the observed patterns of species range midpoints. We challenged these models with 16 elevational data sets, comprising 4500 species of insects, vertebrates and plants. The midpoint predictor models generally failed to predict the pattern of species midpoints. In contrast, the midpoint attractor model closely reproduced empirical spatial patterns of species richness and range midpoints. Gradients of environmental favourability, subject to geometric constraints, may parsimoniously account for elevational and other patterns of species richness.