Abstract A113: Harnessing lymphoid organ neogenesis as a novel prognostic biomarker and therapeutic target

Lymphoid organ neogenesis takes place in chronically inflamed tissues including cancer and yields the development of tertiary lymphoid structures (TLS). TLS are ectopic lymphoid organs that activate antigen specific T-cells and B cells in infection and autoimmunity and correlate with prolonged survival in various cancer types. This suggests that TLS contribute to protective anti-tumor immunity. Therefore, promoting the development of tumor-associated TLS could be a novel immunotherapeutic approach. However, the molecular and cellular mechanisms of TLS development in human cancer or how TLS contribute to survival are largely not understood. Here we used multiparameter immunofluorescence and digital pathology to quantify TLS and to characterize their cellular composition and tissue context in cohorts of lung squamous cell carcinoma (LSCC, n=138), colorectal cancer (CRC, n=111), clear cell renal cell carcinoma (ccRCC, n=50) and bladder cancer (BC, n=33) patients. Furthermore, we established an experimental model to characterize TLS development and its impact on tumor-specific immunity. We discovered that TLS development and maturation followed the same steps in all analyzed tumor types as well as in the lungs of mice in our experimental model. First, B and T lymphocytes accumulated around blood vessels. Second, a network of follicular dendritic cells developed within the lymphocytic aggregate, and third, a germinal center (GC) reaction was activated. Additionally, we identified a niche of CXCL13+ perivascular stroma and CXCL12+LTB+ and PD-L1+ epithelial cells that were associated with TLS in LSCC. We found that the number of tumor-associated TLS was an independent prognostic factor for prolonged survival in untreated LSCC, CRC and BC, but not in ccRCC patients or in LSCC and BC patients who were treated with neoadjuvant chemotherapy. By comparing the chemotherapy-treated and untreated cohorts we observed that the number of TLS was not changed but TLS maturation (i.e. GC formation) was significantly impaired after chemotherapy. This difference was at least partially dictated by corticosteroids, which are commonly used to treat the side effects of chemotherapy of LSCC patients. We further studied the mechanisms underlying TLS development using the experimental model. We identified a combination of stimuli that induces the development of mature TLS in the lungs of mice. Besides inflammatory stimuli, a foreign antigen was necessary to achieve a significant increase in TLS numbers and maturation stage, suggesting that cognate interactions are crucial for lymphoid organ neogenesis. This is further supported by our observation that CRC patients with microsatellite instability, which presumably results in more neoantigens, had an increased proportion of mature TLS. The negative impact of corticosteroids on TLS development was confirmed in this model. In summary, we propose that GC+ TLS represent the relevant TLS phenotype contributing to survival in different tumor types. Lymphoid organ neogenesis is negatively affected by corticosteroids, which might impair the spontaneous as well as therapy-induced anti-tumor immunity. The established experimental model will allow investigation of the mechanisms of TLS development and function in cancer and assessment of their therapeutic potential.

Citation Format: Karina Silina, Alex Soltermann, Chiara Burkhardt, Farkhondeh Movahedian Attar, Ruben Casanova, Alessandra Curioni-Fontecedro, Holger Moch, Florian Posch, Thomas Winder, Nick van Dijk, Charlotte Voskuilen, Michiel van der Heijden, Maries van den Broek. Harnessing lymphoid organ neogenesis as a novel prognostic biomarker and therapeutic target [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A113.

A Quantitative Pathology Approach to Analyze the Development of Human Cancer-Associated Tertiary Lymphoid Structures

Tertiary lymphoid structures (TLS) develop in the human tumor microenvironment and correlate with prolonged survival in most cancer types. We recently demonstrated that TLS development follows sequential maturation stages and culminates in the generation of a germinal center (GC) reaction. This maturation process is crucial for the prognostic relevance of TLS in lung and colorectal cancer patients.The mechanisms underlying TLS development in various inflammatory conditions or their functional relevance in tumor immunity are not fully understood. Investigating which cell types and soluble mediators orchestrate lymphoid neogenesis in human tissues requires a method that allows simultaneous detection of multiple markers.Here, we describe a quantitative pathology approach to identify and quantify different TLS maturation stages in combination with other parameters. This approach consists of seven-color immunofluorescence protocol using tyramide signal amplification combined with multispectral microscopy and quantitative data acquisition from histological images.

Design study of a miniaturized displacement transducer (MDT) for an active middle ear implant system

People suffering from moderate to severe hearing loss can be treated with active middle ear implants. A new approach in this field is to implant an electromechanical transducer onto the round window membrane in order to improve coupling and be able to treat patients with middle-ear problems. In this paper the design study for a miniaturized displacement transducer (MDT) for the round window is presented. Based on a requirement analysis, the basic principle and analytical modeling of the actuator is shown. A parameter variation study results in an optimized actuator configuration that is able to generate an amplification of 110 dB SPL theoretically. As a next step this actuator has to be manufactured and tested.

Elektronenmikroskopische Untersuchungen an mit FIB-Präparation hergestellten Grenzflächen von biologischen Materialien und Werkstoffen: erste Ergebnisse

Für die Untersuchung der Ultrastruktur von biologischen Zellen und Geweben ist die Elektronenmikroskopie ein wichtiges Hilfsmittel. Damit mit dieser Methode auch die Grenzfläche von biologischen Systemen und Werkstoffoberflächen gezielt untersucht werden kann, wurden in der vorliegenden Arbeit klassische Methoden der biologischen Präparation, die kritische Punkt- Trocknung und das Einbetten von kontrastierten Zellen in einem Polymer mit der Focused-Ion-Beam-Technik (FIB) kombiniert. Die Arbeiten wurden in einem Zwei-Strahl-Gerät durchgeführt, so dass die FIB-Präparation eines Querschnitts bei hoher Auflösung im Rasterelektronenmikroskop beobachtet werden kann. Es wird gezeigt, dass es möglich ist, Zellen und die Kontaktstellen der Zellen zu einem Substrat auf einer Sub-Mikrometer-Skala zu präparieren und abzubilden.

Influence of repeated treadmill exercise on quality and freezability of stallion semen

The objective of this study was to investigate changes of quality and freezability of stallion semen in response to repeated acute treadmill exercise. Ejaculates from 11 stallions were collected, evaluated and frozen weekly during four periods of 4 weeks each defined as before (period 1), during (period 2) and after (periods 3 and 4) intense exercise. In fresh semen the gel-free volume, sperm concentration, motility, normal sperm and sperm with major defects (acrosome defects, nuclear vacuoles, abnormal heads, midpiece defects and proximal droplets) were evaluated. In frozen-thawed semen, motility as well as viability (SYBR-14/PI) were examined. In period 2, all stallions were exercised on an indoor high speed treadmill twice a week (total of eight sessions) using an incremental workload test. Heart rate was monitored telemetrically during exercise and blood samples were taken for determination of cortisol, testosterone and lactate. Results of our investigation demonstrate that heart rate and the plasma concentrations of cortisol, testosterone and lactate significantly (P < 0.05) increased during each exercise session. Furthermore, significantly more major sperm defects were present in periods 3 (69.5+/-2.1%) and 4 (66.8+/-2.1%) than in periods 1 (62.2+/-2.4%) and 2 (62.5+/-2.2%). Acrosome defects increased towards the end of exercise but improved 3 weeks later to values observed before exercise. In frozen-thawed semen, motility was significantly lower in period 2 (45.4+/-2.3%) compared to period 4 (51.6+/-1.7%) and viability was significantly lower in period 2 (49.2+/-2.0%) than in periods 1 (53.8+/-2.1%) and 4 (53.7+/-1.6%). Our results clearly demonstrate that in the stallion repeated strenuous treadmill exercise can negatively influence semen quality and freezability.

Patch-clamping of primary cardiac cells with micro-openings in polyimide films

Patch-clamping is a powerful method for investigating the function and regulation of ionic channels. Currently, great efforts are being made to automate this method. As a step towards this goal, the feasibility of patch-clamping primary cells with a microscopic opening in a planar substrate was tested. Using standard microfabrication and ion beam technology, small-diameter openings (2 and 4 microm) were formed in polyimide films (thickness 6.5 microm). Single cells (sheep Purkinje heart cells, Chinese hamster ovary cells) in a suspension were positioned on top of the opening and sucked towards the opening to improve adhesion of the cell to the planar substrate, hence increasing the seal resistance. Voltage/current measurements yielded a median seal resistance of 1.3 Mohms with 4 microm openings (n=24) and 26.0 Mohms with 2 microm openings (n = 75), respectively. With 2 microm openings, successful loose-patch recordings of TTX-sensitive inward currents and action potentials in sheep Purkinje heart cells (n = 18) were made. In rare cases, gigaseals (n = 4) were also measured, and a whole-cell configuration (n = 1) could be established. It was concluded that the simple planar patch approach is suitable for automated loose-patch recordings from cells in suspension but will hardly be suitable for high-throughput whole-cell patch-clamping with high-resistance seals.

Modelling ion binding to AA platform motifs in RNA: a continuum solvent study including conformational adaptation

Binding of monovalent and divalent cations to two adenine-adenine platform structures from the Tetrahymena group I intron ribozyme has been studied using continuum solvent models based on the generalised Born and the finite-difference Poisson-Boltzmann approaches. The adenine-adenine platform RNA motif forms an experimentally characterised monovalent ion binding site important for ribozyme folding and function. Qualitative agreement between calculated and experimental ion placements and binding selectivity was obtained. The inclusion of solvation effects turned out to be important to obtain low energy structures and ion binding placements in agreement with the experiment. The calculations indicate that differences in solvation of the isolated ions contribute to the calculated ion binding preference. However, Coulomb attraction and van der Waals interactions due to ion size differences and RNA conformational adaptation also influence the calculated ion binding affinity. The calculated alkali ion binding selectivity for both platforms followed the order K(+) > Na(+) > Rb(+) > Cs(+) > Li(+) (Eisenman series VI) in the case of allowing RNA conformational relaxation during docking. With rigid RNA an Eisenman series V was obtained (K(+) > Rb(+) > Na(+) > Cs(+) > Li(+)). Systematic energy minimisation docking simulations starting from several hundred initial placements of potassium ions on the surface of platform containing RNA fragments identified a coordination geometry in agreement with the experiment as the lowest energy binding site. The approach could be helpful to identify putative ion binding sites in nucleic acid structures determined at low resolution or with experimental methods that do not allow identification of ion binding sites.

Conditional gene targeting in macrophages and granulocytes using LysMcre mice

Conditional mutagenesis in mice has recently been made possible through the combination of gene targeting techniques and site-directed mutagenesis, using the bacteriophage P1-derived Cre/loxP recombination system. The versatility of this approach depends on the availability of mouse mutants in which the recombinase Cre is expressed in the appropriate cell lineages or tissues. Here we report the generation of mice that express Cre in myeloid cells due to targeted insertion of the cre cDNA into their endogenous M lysozyme locus. In double mutant mice harboring both the LysMcre allele and one of two different loxP-flanked target genes tested, a deletion efficiency of 83-98% was determined in mature macrophages and near 100% in granulocytes. Partial deletion (16%) could be detected in CD11c+ splenic dendritic cells which are closely related to the monocyte/macrophage lineage. In contrast, no significant deletion was observed in tail DNA or purified T and B cells. Taken together, LysMcre mice allow for both specific and highly efficient Cre-mediated deletion of loxP-flanked target genes in myeloid cells.

Dynamics of middle ear prostheses - simulations and measurements

The efficient and systematic development of a middle ear prosthesis necessitates the use of computer models for the prosthesis itself and the reconstructed middle ear. The structure and parameters of the computer model have to be verified by specific measurements of the implant and the reconstructed ear. To obtain a realistic model of a reconstructed ear, three steps of modeling and measurements have been carried out. To get a first approach of the coupling elements a mechanical test rig representing a simplified reconstructed middle ear was built. The velocity of the stapedial footplate was measured with a laser Doppler vibrometer. The corresponding computer model was formulated, and the respective parameters were determined using the measured dynamical transfer functions. In the second step, a prosthesis was implanted into a human temporal bone without inner ear. Exciting this system with noise, the velocity of the stapes footplate was measured with the laser Doppler vibrometer. Based on the multibody system approach, a mechanical computer model was generated to describe the spatial motions of the reconstructed ossicular chain. Varying some significant parameters, simulations have been carried out. To describe the dynamical behavior of the system consisting of middle and inner ear, the computer model used in the second step has been enlarged by adding a simplified structure of the inner ear. The results were compared with in situ measurements taken from living humans.

[Laser vibrometry. A middle ear and cochlear analyzer for noninvasive studies of middle and inner ear function disorders]

A complete battery of audiometric methods is required for the differential diagnosis of different hearing disabilities (including puretone audiometry, impedance, stapes reflex, speech audiometry, brainstam evoked response audiometry, otoacoustic emissions, etc.). In many cases, a comprehensive diagnosis is not possible. Here we describe a new technique based on a laser-Doppler vibrometer that has the potential for non-invasive diagnosis not only middle ear disease but also cochlear pathologies. Disturbance of cochlear function can be ascertained because the input impedance of the cochlea acts as a mechanical load on the middle ear and therefore influences motion of the umbo. In the present study vibration of the umbo and eardrum were measured with a commercially available laser-Doppler vibrometer coupled directly into a standard surgical microscope. The use of the microscope allowed non-invasive measurements of vibrations without having to introduce reflecting material onto the tympanic membrane. Sound pressure was measured with a calibrated probe microphone placed near the tympanic membrane. The displacement response and the specific acoustic impedance of the umbo were calculated from the velocity and sound pressure measured. For normal hearing subjects, the amplitude of the umbo's displacement for frequencies from 0.1 kHz to 1 kHz was 1 nm at 60 dB SPL and decreased with a slope of 6 dB/octave for frequencies between 1 and 5 kHz. A strong correlation was found between the specific acoustic impedance of the umbo and hearing thresholds for hearing-impaired subjects (having otosclerosis or sensorineural hearing losses). The frequency response of the umbo proved to be a means for evaluating the function of both the middle ear and the cochlea under pathological conditions. The measurement technique described is also suitable for intraoperative investigation of the frequency response of the opened middle ear, as well as for the in situ frequency response of partial and total ossicular replacement prostheses.

[First comparisons with laser vibrometry measurements and computer simulation of ear ossicle movements]

The dynamic behavior of the ossicular chain is very complex and is frequency-dependent. To date, this has still not been fully investigated or understood. There remains a lack of measurement procedures to pick up the motion of the ossicles and ear drum simultaneously with sufficient resolution. The presented paper reports simultaneous measurements with laser-Doppler vibrometry at two points of the ossicular chain of cadaver specimens. Motions not observed were derived using mechanical simulation models on a computer and then evaluating appropriate mathematical equations. Using a sound stimulus, the displacement velocities of the umbo and stapes footplate were measured, and the corresponding transfer functions were derived by Fourier transform. Results were used for verification of the computer models. In the current investigations these models were refined and allow for the detailed investigation of the dynamic behavior of the ossicular chain, facilitating the optimal design of passive and active middle-ear implants.

An HLA-DRB alpha-helix motif shared by DR11 and DR8 alleles is implicated in the pluriallelic restriction of peptide-specific T-cell lines

The T-cell recognition of HLA-DR-peptide complexes is generally restricted by the polymorphism of the DRB molecules but pluriallelic restriction has been described. The molecular basis of restriction and promiscuity of such peptide-specific responses is poorly understood. We isolated a panel of T-cell lines specific for the tetanus toxin peptide p2 (TT830-843) exhibiting pluriallelic restriction by DR11 and DR8 alleles. Fine restriction specificity of the T-cell lines was examined in functional assays against DR oligotyped APCs expressing different variants of DR11 and DR8 alleles. Our results show that (a) polymorphisms between serologically related alleles are relevant in terms of restriction of the peptide-specific T-cell response; in some instances, a single amino acid substitution can determine the restriction of a T-cell line; (b) different patterns of restriction are not the result of specific differences in DR-p2 binding as p2 peptide binds to all DR11 and DR8 alleles tested (DRB1* 1101, -1102, -1103, -1104, 110X, -0801, -0802, -0803, and -0806); and (c) pluriallelic restriction of the peptide-specific T-cell response correlates with the presence of a DRB1 alpha-helix motif (67-71-86) shared by some DR11 and DR8 alleles. Possible implications of pluriallelic restriction of peptide-specific T-cell response in autoimmune disorders associated with DR11 and DR8 are discussed.

Neuroleptic medications inhibit complex I of the electron transport chain

Neuroleptic medications are prescribed to millions of patients, but their use is limited by potentially irreversible extrapyramidal side effects. Haloperidol shows striking structural similarities to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which produces parkinsonism apparently through inhibition of NADH:ubiquinone oxidoreductase (complex I) of the mitochondrial electron transport chain. We now report that haloperidol, chlorpromazine, and thiothixene inhibit complex I in vitro in rat brain mitochondria. Clozapine, an atypical antipsychotic reported to have little or no extrapyramidal toxicity, also inhibits complex I, but at a significantly higher concentration. Neuroleptic treated patients have significant depression of platelet complex I activity similar to that seen in idiopathic Parkinson's disease. Complex I inhibition may be associated with the extrapyramidal side effects of these drugs.

Metkephamid (Tyr-D-ala-Gly-Phe-N(Me)Met-NH2), a potent opioid peptide: receptor binding and analgesic properties

The interaction of metkephamid (Tyr-D-Ala-Gly-Phe-N(Me)Met-NH2) with 3H-dihydromorphine and 3H-D-Ala2-D-Leu5-enkephalin binding has been examined in rat brain homogenates. Displacements of both 3H-ligands by metkephamid indicate that metkephamid interacts competitively with greatest potency to the high affinity binding component for both ligands (mu1 site). Unlike most enkephalins and opiates, metkephamid binds equipotently to both morphine-selective (mu2) and enkephalin-selective (delta) binding sites. Metkephamid is differentiated from morphine by its better than 12-fold higher affinity for the delta receptor. Blockade of the high affinity (mu1) binding in vivo with high doses of naloxazone dramatically reduces metkephamid's analgesic potency.

[Craniolacunia ("Lückenschädel") as an isolated finding (author's transl)]

Case report of congenital craniolacunia ("Lückenschädel" or lacunar skull) only associated with several noncerebral malformations but lacking the CNS findings usually associated with this condition, such as dysraphism. Presentation and discussion of etiology and prognosis of this anomaly and its differential diagnosis.