Discovery and development of ANV419, an IL-2/anti-IL-2 antibody fusion protein with potent CD8+ T and natural killer cell-stimulating capacity for cancer immunotherapy.

Novel engineered IL-2 agonists strive to increase the therapeutic window of aldesleukin (human IL-2) by increasing selectivity toward effector over regulatory T cells and reducing dose-limiting toxicities. Here we describe ANV419, an IL-2/anti-IL2 antibody fusion protein designed for selective IL-2 receptor ßγ (IL-2 Rßγ) activation by sterically hindering IL-2 from binding to IL-2 Rα. The fusion protein has an IL-2 connected to the light chain complementarity-determining region (CDR) domain of a humanized antibody that binds to IL-2 at the same epitope as IL-2 Rα. Optimization of the selectivity and pharmacological properties led to the selection of ANV419. ANV419 preferentially expands CD8+ T cells and natural killer (NK) cells over Tregs and can be safely administered at doses that elicit strong pharmacodynamic effects and efficacy in mouse tumor models. Its anti-tumor efficacy was enhanced when combined with programmed cell death protein 1 (PD-1) or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) checkpoint inhibitors. ANV419 also enhances the NK cell killing capacity and increases tumor growth inhibition when used alongside trastuzumab in a Her-2+ xenograft mouse model. In cynomolgus monkeys, the estimated half-life of ANV419 is 24 h, and doses that induced sustained expansion of effector cells were well tolerated without the severe toxicities typically observed with high-dose IL-2. These data support the clinical development of ANV419 in solid tumors and hematological malignancies as monotherapy and in combination with checkpoint inhibitors or agents that induce antibody-dependent cellular cytotoxicity. ANV419 is currently in Phase 1/2 clinical development and may provide cancer patients with a wider therapeutic window than aldesleukin.

Fingerprints of CD8+ T cells on human pre-plasma and memory B cells.

Differentiation of B cells is a stringently controlled multi-step process, which is still incompletely understood. Here we identify and characterize a rare population of human B cells, which surprisingly carry CD8AB on their surface. Existence of such cells was demonstrated both in tonsils and in human apheresis material. Gene expression profiling and real time PCR detected however no CD8A or CD8B message in these cells. Instead, we found that surface CD8 was hijacked from activated CD8+ T cells by a transfer process that required direct cell-to-cell contact. A focused transcriptome analysis at single cell level allowed the dissection of the CD8 positive B cell population. We found that the affected cells are characteristically of the CD27+CD200- phenotype, and consist of two discrete late-stage subpopulations that carry signatures of activated memory B like cells, and early plasmablasts. Thus, there is only a restricted time window in the differentiation process during which B cells can intimately interact with CD8+ T cells. The findings point to a novel link between the T and B arms of the adaptive immune system, and suggest that CD8+ T cells have the capability to directly shape the global antibody repertoire.

Human CD180 Transmits Signals via the PIM-1L Kinase.

Toll-like receptors (TLRs) are important sensors of the innate immune system that recognize conserved structural motifs and activate cells via a downstream signaling cascade. The CD180/MD1 molecular complex is an unusual member of the TLR family, since it lacks the components that are normally required for signal transduction by other TLRs. Therefore the CD180/MD 1 complex has been considered of being incapable of independently initiating cellular signals. Using chemogenetic approaches we identified specifically the membrane bound long form of PIM-1 kinase, PIM-1L as the mediator of CD180-dependent signaling. A dominant negative isoform of PIM-1L, but not of other PIM kinases, inhibited signaling elicited by cross-linking of CD180, and this effect was phenocopied by PIM inhibitors. PIM-1L was directed to the cell membrane by its N-terminal extension, where it colocalized and physically associated with CD180. Triggering CD180 also induced increased phosphorylation of the anti-apoptotic protein BAD in a PIM kinase-dependent fashion. Also in primary human B cells, which are the main cells expressing CD180 in man, cross-linking of CD180 by monoclonal antibodies stimulated cell survival and proliferation that was abrogated by specific inhibitors. By associating with PIM-1L, CD180 can thus obtain autonomous signaling capabilities, and this complex is then channeling inflammatory signals into B cell survival programs. Pharmacological inhibition of PIM-1 should therefore provide novel therapeutic options in diseases that respond to innate immune stimulation with subsequently increased B cell activity, such as lupus erythematosus or myasthenia gravis.

The Drosophila PGC-1 homologue Spargel coordinates mitochondrial activity to insulin signalling.

Mitochondrial mass and activity must be adapted to tissue function, cellular growth and nutrient availability. In mammals, the related transcriptional coactivators PGC-1alpha, PGC-1beta and PRC regulate multiple metabolic functions, including mitochondrial biogenesis. However, we know relatively little about their respective roles in vivo. Here we show that the Drosophila PGC-1 family homologue, Spargel, is required for the expression of multiple genes encoding mitochondrial proteins. Accordingly, spargel mutants showed mitochondrial respiration defects when complex II of the electron transport chain was stimulated. Spargel, however, was not limiting for mitochondrial mass, but functioned in this respect redundantly with Delg, the fly NRF-2alpha/GABPalpha homologue. More importantly, in the larval fat body, Spargel mediated mitochondrial activity, cell growth and transcription of target genes in response to insulin signalling. In this process, Spargel functioned in parallel to the insulin-responsive transcription factor, dFoxo, and provided a negative feedback loop to fine-tune insulin signalling. Taken together, our data place Spargel at a nodal point for the integration of mitochondrial activity to tissue and organismal metabolism and growth.

Computation of likelihood ratios in fingerprint identification for configurations of any number of minutiae.

Recent court challenges have highlighted the need for statistical research on fingerprint identification. This paper proposes a model for computing likelihood ratios (LRs) to assess the evidential value of comparisons with any number of minutiae. The model considers minutiae type, direction and relative spatial relationships. It expands on previous work on three minutiae by adopting a spatial modeling using radial triangulation and a probabilistic distortion model for assessing the numerator of the LR. The model has been tested on a sample of 686 ulnar loops and 204 arches. Features vectors used for statistical analysis have been obtained following a preprocessing step based on Gabor filtering and image processing to extract minutiae data. The metric used to assess similarity between two feature vectors is based on an Euclidean distance measure. Tippett plots and rates of misleading evidence have been used as performance indicators of the model. The model has shown encouraging behavior with low rates of misleading evidence and a LR power of the model increasing significantly with the number of minutiae. The LRs that it provides are highly indicative of identity of source on a significant proportion of cases, even when considering configurations with few minutiae. In contrast with previous research, the model, in addition to minutia type and direction, incorporates spatial relationships of minutiae without introducing probabilistic independence assumptions. The model also accounts for finger distortion.

Evidence evaluation in fingerprint comparison and automated fingerprint identification systems--modelling within finger variability.

Recent challenges and errors in fingerprint identification have highlighted the need for assessing the information content of a papillary pattern in a systematic way. In particular, estimation of the statistical uncertainty associated with this type of evidence is more and more called upon. The approach used in the present study is based on the assessment of likelihood ratios (LRs). This evaluative tool weighs the likelihood of evidence given two mutually exclusive hypotheses. The computation of likelihood ratios on a database of marks of known sources (matching the unknown and non-matching the unknown mark) allows an estimation of the evidential contribution of fingerprint evidence. LRs are computed taking advantage of the scores obtained from an automated fingerprint identification system and hence are based exclusively on level II features (minutiae). The AFIS system attributes a score to any comparison (fingerprint to fingerprint, mark to mark and mark to fingerprint), used here as a proximity measure between the respective arrangements of minutiae. The numerator of the LR addresses the within finger variability and is obtained by comparing the same configurations of minutiae coming from the same source. Only comparisons where the same minutiae are visible both on the mark and on the print are therefore taken into account. The denominator of the LR is obtained by cross-comparison with a database of prints originating from non-matching sources. The estimation of the numerator of the LR is much more complex in terms of specific data requirements than the estimation of the denominator of the LR (that requires only a large database of prints from an non-associated population). Hence this paper addresses specific issues associated with the numerator or within finger variability. This study aims at answering the following questions: (1) how a database for modelling within finger variability should be acquired; (2) whether or not the visualisation technique or the choice of different minutiae arrangements may influence that modelling and (3) what is the magnitude of LRs that can be expected from such a model. Results show that within finger variability is affected by the visualisation technique used on the mark, the number of minutiae and the minutiae configuration. They also show that the rates of misleading evidence in the likelihood ratios obtained for one of the configurations examined are low.

Computation of likelihood ratios in fingerprint identification for configurations of three minutiae.

Recent challenges to fingerprint evidence have brought forward the need for peer-reviewed scientific publications to support the evidential value assessment of fingerprint. This paper proposes some research directions to gather statistical knowledge of the within-source and between-sources variability of configurations of three minutiae on fingermarks and fingerprints. This paper proposes the use of the likelihood ratio (LR) approach to assess the value of fingerprint evidence. The model explores the statistical contribution of configurations of three minutiae using Tippett plots and related measures to assess the quality of the system. Features vectors used for statistical analysis have been obtained following a preprocessing step based on Gabor filtering and image processing to extract minutia position, type, and direction. Spatial relationships have been coded using Delaunay triangulation. The metric, used to assess similarity between two feature vectors is based on an Euclidean distance measure. The within-source variability has been estimated using a sample of 216 fingerprints from four fingers (two donors). Between-sources variability takes advantage of a database of 818 ulnar loops from randomly selected males. The results show that the data-driven approach adopted here is robust. The magnitude of LRs obtained under the prosecution and defense propositions stresses upon the major evidential contribution that small portions of fingermark, containing three minutiae, can provide regardless of its position on the general pattern.

Survey of crowbar and household paints in burglary cases-population studies, transfer and interpretation.

Experimental data useful for the interpretation of paint evidence recovered during burglary cases were obtained. A population study was carried out on 41 blue crowbars seized on suspects in Switzerland and 37 blue paints traces found at burglary scenes. Paint traces were also searched on the blades of 207 crowbars seized by the police in Switzerland and 24 white traces were analysed: these paints were analysed using infrared spectroscopy (FTIR) in order to estimate relative frequencies of each paint type. Simulated contacts were carried out between crowbars and painted wood in order to study the phenomenon of transfer and to evaluate the amount of paint transferred: a total of 198 simulations were carried out including individual, successive and cross transfer. The paint properties such as the chemical composition and its age influenced the amount of paint transferred. Cross transfer from the tool paint to the wood and vice versa was regularly observed. Moreover, secondary transfer of paint coming from the preceding wooden surfaces was also systematically observed: this could establish links between several burglary scenes and a suspected tool. A scenario of a burglary case involving the cross transfer between tool and household paints is proposed as a numerical example: the evaluation of such case was formalised using likelihood ratios based on the experimental data obtained.