Affinity fine-tuning anti-CAIX CAR-T cells mitigate on-target off-tumor side effects

One of the major hurdles that has hindered the success of chimeric antigen receptor (CAR) T cell therapies against solid tumors is on-target off-tumor (OTOT) toxicity due to sharing of the same epitopes on normal tissues. To elevate the safety profile of CAR-T cells, an affinity/avidity fine-tuned CAR was designed enabling CAR-T cell activation only in the presence of a highly expressed tumor associated antigen (TAA) but not when recognizing the same antigen at a physiological level on healthy cells. Using direct stochastic optical reconstruction microscopy (dSTORM) which provides single-molecule resolution, and flow cytometry, we identified high carbonic anhydrase IX (CAIX) density on clear cell renal cell carcinoma (ccRCC) patient samples and low-density expression on healthy bile duct tissues. A Tet-On doxycycline-inducible CAIX expressing cell line was established to mimic various CAIX densities, providing coverage from CAIX-high skrc-59 tumor cells to CAIX-low MMNK-1 cholangiocytes. Assessing the killing of CAR-T cells, we demonstrated that low-affinity/high-avidity fine-tuned G9 CAR-T has a wider therapeutic window compared to high-affinity/high-avidity G250 that was used in the first anti-CAIX CAR-T clinical trial but displayed serious OTOT effects. To assess the therapeutic effect of G9 on patient samples, we generated ccRCC patient derived organotypic tumor spheroid (PDOTS) ex vivo cultures and demonstrated that G9 CAR-T cells exhibited superior efficacy, migration and cytokine release in these miniature tumors. Moreover, in an RCC orthotopic mouse model, G9 CAR-T cells showed enhanced tumor control compared to G250. In summary, G9 has successfully mitigated OTOT side effects and in doing so has made CAIX a druggable immunotherapeutic target.

Sensitivity to targeted UBA1 inhibition in a myeloid cell line model of VEXAS syndrome

Somatic UBA1 mutations in hematopoietic cells are a hallmark of Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic (VEXAS) syndrome, which is a late-onset inflammatory disease associated with bone marrow failure and high mortality. The majority of UBA1 mutations in VEXAS syndrome comprise hemizygous mutations affecting methionine-41 (M41), leading to the expression of UBA1M41T, UBA1M41V, or UBA1M41L and globally reduced protein polyubiquitination. Here, we used CRISPR-Cas9 to engineer isogenic 32D mouse myeloid cell lines expressing hemizygous Uba1WT or Uba1M41L from the endogenous locus. Consistent with prior analyses of patients with VEXAS syndrome samples, hemizygous Uba1M41L expression was associated with loss of the UBA1b protein isoform, gain of the UBA1c protein isoform, reduced polyubiquitination, abnormal cytoplasmic vacuoles, and increased production of interleukin-1β and inflammatory chemokines. Vacuoles in Uba1M41L cells contained a variety of endolysosomal membranes, including small vesicles, multivesicular bodies, and multilamellar lysosomes. Uba1M41L cells were more sensitive to the UBA1 inhibitor TAK243. TAK243 treatment promoted apoptosis in Uba1M41L cells and led to preferential loss of Uba1M41L cells in competition assays with Uba1WT cells. Knock-in of a TAK243-binding mutation, Uba1A580S, conferred TAK243 resistance. In addition, overexpression of catalytically active UBA1b in Uba1M41L cells restored polyubiquitination and increased TAK243 resistance. Altogether, these data indicate that loss of UBA1b underlies a key biochemical phenotype associated with VEXAS syndrome and renders cells with reduced UBA1 activity vulnerable to targeted UBA1 inhibition. Our Uba1M41L knock-in cell line is a useful model of VEXAS syndrome that will aid in the study of disease pathogenesis and the development of effective therapies.

Unveiling the contourite depositional system in the Vema Fracture Zone (Central Atlantic)

A combination of a high sediment input and intense bottom currents often leads to the formation of contourites (sediments deposited or significantly reworked by bottom currents). Both of these components are present in the Vema Fracture Zone valley which is the most important passageway for the distribution of the Antarctic Bottom Water from the West to the North-East of the Atlantic. However, no contourite drifts, moats or contourite channels have been found in this region in more than half a century of research. The prevailing sedimentation paradigm postulates that turbidity currents have predominantly governed sedimentation in this region during the Pleistocene. This work describes the first example of contourite depositional system identified in the Vema Fracture Zone. The discovery was made through detailed high-resolution sub-bottom profiling, as well as numerical modeling and direct measurements of bottom current velocities. Such systems are exceptionally uncommon in fracture zones. This study highlights the importance of further research of contourites along the Vema Fracture Zone based on modern concepts of contourite and mixed depositional systems. The work also emphasizes the need to reevaluate the impact of bottom currents on sedimentation in this region, and particularly in the narrow segments of the fracture zone valley.

Development of a Patient-Derived 3D Immuno-Oncology Platform to Potentiate Immunotherapy Responses in Ascites-Derived Circulating Tumor Cells

High-grade serous ovarian cancer (HGSOC) is responsible for the majority of gynecology cancer-related deaths. Patients in remission often relapse with more aggressive forms of disease within 2 years post-treatment. Alternative immuno-oncology (IO) strategies, such as immune checkpoint blockade (ICB) targeting the PD-(L)1 signaling axis, have proven inefficient so far. Our aim is to utilize epigenetic modulators to maximize the benefit of personalized IO combinations in ex vivo 3D patient-derived platforms and in vivo syngeneic models. Using patient-derived tumor ascites, we optimized an ex vivo 3D screening platform (PDOTS), which employs autologous immune cells and circulating ascites-derived tumor cells, to rapidly test personalized IO combinations. Most importantly, patient responses to platinum chemotherapy and poly-ADP ribose polymerase inhibitors in 3D platforms recapitulate clinical responses. Furthermore, similar to clinical trial results, responses to ICB in PDOTS tend to be low and positively correlated with the frequency of CD3+ immune cells and EPCAM+/PD-L1+ tumor cells. Thus, the greatest response observed with anti-PD-1/anti-PD-L1 immunotherapy alone is seen in patient-derived HGSOC ascites, which present with high levels of systemic CD3+ and PD-L1+ expression in immune and tumor cells, respectively. In addition, priming with epigenetic adjuvants greatly potentiates ICB in ex vivo 3D testing platforms and in vivo tumor models. We further find that epigenetic priming induces increased tumor secretion of several key cytokines known to augment T and NK cell activation and cytotoxicity, including IL-6, IP-10 (CXCL10), KC (CXCL1), and RANTES (CCL5). Moreover, epigenetic priming alone and in combination with ICB immunotherapy in patient-derived PDOTS induces rapid upregulation of CD69, a reliable early activation of immune markers in both CD4+ and CD8+ T cells. Consequently, this functional precision medicine approach could rapidly identify personalized therapeutic combinations able to potentiate ICB, which is a great advantage, especially given the current clinical difficulty of testing a high number of potential combinations in patients.

Cotargeting a MYC/eIF4A-survival axis improves the efficacy of KRAS inhibitors in lung cancer

Despite the success of KRAS G12C inhibitors in non-small cell lung cancer (NSCLC), more effective treatments are needed. One preclinical strategy has been to cotarget RAS and mTOR pathways; however, toxicity due to broad mTOR inhibition has limited its utility. Therefore, we sought to develop a more refined means of targeting cap-dependent translation and identifying the most therapeutically important eukaryotic initiation factor 4F complex-translated (eIF4F-translated) targets. Here, we show that an eIF4A inhibitor, which targets a component of eIF4F, dramatically enhances the effects of KRAS G12C inhibitors in NSCLCs and together these agents induce potent tumor regression in vivo. By screening a broad panel of eIF4F targets, we show that this cooperativity is driven by effects on BCL-2 family proteins. Moreover, because multiple BCL-2 family members are concomitantly suppressed, these agents are broadly efficacious in NSCLCs, irrespective of their dependency on MCL1, BCL-xL, or BCL-2, which is known to be heterogeneous. Finally, we show that MYC overexpression confers sensitivity to this combination because it creates a dependency on eIF4A for BCL-2 family protein expression. Together, these studies identify a promising therapeutic strategy for KRAS-mutant NSCLCs, demonstrate that BCL-2 proteins are the key mediators of the therapeutic response in this tumor type, and uncover a predictive biomarker of sensitivity.

Development of the selective micropulse individual retinal therapy depends on age and type on the Fitzpatrick scale

PURPOSE

To develop a selective micropulse individual retinal therapy (SMIRT) based on the age and appearance type of the patient, to derive a formula for calculating power, and evaluate clinical efficacy for the treatment of central serous chorioretinopathy (CSCR).

METHODS

73 patients (aged 30-65 years) with acute CSCR and types 1-4 on the Fitzpatrick scale were divided into 2 groups. In the first group (33 patients), the testing of the micropulse mode (50 µs, 2.4%, 10 ms, 100 µm, 0.4-1.9 W) on the Navilas 577 s laser system defined as selective by computer modeling was performed. A logistic regression function based on probability damage detection (PDD) of the 1584 laser spots from power, age, and type on the Fitzpatrick scale was constructed. PDD is the probability of detecting the laser spots using the autofluorescence method. The second group was divided into 4 subgroups of 10 eyes each. Groups 2.1, 2.2, and 2.3 were treated without preliminary testing. The power for Groups 2.1, 2.2, and 2.3 was obtained with the inverse PDD function, so that PDD was 50%, 70%, and 90%, respectively. Control group 2.4 went without treatment.

RESULTS

The transmission and absorption coefficients of laser radiation of the eye depend on the age and the Fitzpatrick scale type. In Groups 2.1-2.3, complete resorption of subretinal fluid was observed 3 months after CSCR treatment in 5 (P < 0.35), 8 (P < 0.023), and 10 eyes (P < 0.0008) out of 10, respectively.

CONCLUSION

The developed SMIRT is effective for CSCR treatment with PDD 90%.

[The use of photodynamic therapy in the complex treatment of chronic generalized moderate periodontitis]

OBJECTIVE

Improving the effectiveness of the treatment of chronic generalized periodontitis by photodynamic therapy (PDT) due to clinical and functional validation of the effects of a photosensitizer.

MATERIAL AND METHODS

A clinical and functional study and treatment of moderate chronic generalized periodontitis was carried out in 60 people (24 males and 36 females) aged 35 to 50 years without somatic pathology with orthognathic bite. The patients were divided into 2 groups depending on the type of treatment: group 1 (main) included 30 patients (17 males and 13 females, mean age of patients was 42.5±3.3 years) who received comprehensive treatment consisting of oral sanitation, removal of dental plaque and curettage of periodontal pockets followed by PDT with 1% Geleophor gel using an AFS Spektr LED emitter with a wavelength of 660 nm and a power of 2.5 W, the course consisted of 4 procedures with exposure time of 7 minutes each; group 2 (control) included 30 patients (11 males and 19 females, mean age of patients was 43.0±2.1 years) undergoing standard treatment followed by protective capping with no active therapeutic agent. The state of microcirculation in tissues was studied by the laser Doppler flowmetry (LDF) using the LAKK-M device (Lazma, Russia).

RESULTS

According to LDF data in both groups, it was found that the improvement of microcirculation in periodontal tissues after complex treatment is accompanied by an increase in blood flow and its activity, at that the level of oxygenation and specific oxygen consumption increased more pronounced after PDT, the effect persisted after 6 and 12 months.

CONCLUSION

The use of PDT with LED emitter has a normalizing effect on the state of microcirculation and oxygenation in periodontal tissues.

Quantitative method for the determination of antibiotic-resistant gut bacterial strains for the early diagnosis of chronic arthritis

Based on the clinical and microbiological monitoring of two groups of children aged 3 to 17 years with acute (n=78) and chronic (n=46) course of reactive arthritis (ReA), a method for early diagnosis of chronic arthritis was developed by determining the number of antibiotic-resistant coprostrains in patients with ReA, characterized by the absence of the need to isolate a pure culture of the pathogen and its identification; inoculation of faeces at a dilution of 10-5 on solid 1.5% GRM-agar with an antibacterial agents used in the treatment of a particular patient, at a minimum inhibitory concentration in the resistance range, followed by incubation and counting of the colonies of microorganisms grown on the plate. A significant relationship between the number of antibiotic-resistant gut bacterial strains and the course of arthritis (acute, chronic) was revealed, and the borderline value of the number of antibiotic-resistant gut bacterial strains was determined - 5×103 CFU/g, which allows differentiating the acute course from the chronic one: in the acute course< 5×103 CFU/g, with chronic - ≥ 5×103 CFU/g. The method allows, at the stage of completion of anti-inflammatory therapy in the active phase of the disease, to identify a risk group for the development of a chronic course of arthritis among patients with ReA, which can contribute to timely therapeutic measures aimed at preventing recurrence of the disease and making the patient disabled.

Activation of Tumor-Cell STING Primes NK-Cell Therapy

Activation of the stimulator of interferon genes (STING) pathway promotes antitumor immunity but STING agonists have yet to achieve clinical success. Increased understanding of the mechanism of action of STING agonists in human tumors is key to developing therapeutic combinations that activate effective innate antitumor immunity. Here, we report that malignant pleural mesothelioma cells robustly express STING and are responsive to STING agonist treatment ex vivo. Using dynamic single-cell RNA sequencing of explants treated with a STING agonist, we observed CXCR3 chemokine activation primarily in tumor cells and cancer-associated fibroblasts, as well as T-cell cytotoxicity. In contrast, primary natural killer (NK) cells resisted STING agonist-induced cytotoxicity. STING agonists enhanced migration and killing of NK cells and mesothelin-targeted chimeric antigen receptor (CAR)-NK cells, improving therapeutic activity in patient-derived organotypic tumor spheroids. These studies reveal the fundamental importance of using human tumor samples to assess innate and cellular immune therapies. By functionally profiling mesothelioma tumor explants with elevated STING expression in tumor cells, we uncovered distinct consequences of STING agonist treatment in humans that support testing combining STING agonists with NK and CAR-NK cell therapies.

Abstract 333: Activity of the erythropoietin-producing hepatocellular A2 receptor (EphA2) targeting Bicycle® Toxin Conjugate (BTC™) BCY6033 in EGFR inhibitor resistant non-small lung cancer (NSCLC) patient derived xenografts

Introduction: EphA2 regulates cell migration, adhesion, proliferation and differentiation, and is overexpressed in human cancers which have been shown to correlate with tumor progression. BCY6033 contains a bicyclic peptide targeting EphA2, linked to the cytotoxin Monomethyl auristatin E via a molecular spacer and cleavable linker designed to target EphA2 expressing tumors. BCY6033 is analogous to BT5528, a BTC™ currently in phase I/II clinical trial in patients with advanced malignancies associated with EphA2 expression. Recent literature indicate that tumor EphA2 expression may be up regulated in EGFR mutant lung models following 1st, 2nd and possibly 3rd generation EGFR inhibitors. Here we report on EphA2 expression in well characterized and clinically annotated patient derived xenografts (PDX) of NSCLC including EGFR mutant NSCLC derived either from erlotinib or osimertinib resistant patients. In vivo activity of BCY6033 is presented in two EphA2 expressing PDX models.

Experimental procedures: In vivo, an initial tolerability study was conducted with once weekly administration of BCY6033 by intravenous injection in NSG mice. The activity of BCY6033 was evaluated in EphA2 expressing EGFR mutant PDX models, DFCI-161 and DFCI-220 in NSG mice. A TMA was constructed containing FFPE derived from 69 PDX models (NSCLC n=61, SCLC-transformed n=5, de novo SCLC n=3). Of the 69 models, 35 were EGFR mutant. The TMA was subsequently stained via immunohistochemistry (IHC) using an α-EphA2 (R&D Systems) primary antibody. Tumor membranous H-score was assigned by a pathologist and a score of ≥50 was considered positive.

Results: Of the 69 PDXs, 16 were determined to be EphA2 positive. No correlation with genotype or clinical history was observed with EphA2 expression. EphA2 IHC was repeated on at least 5 different tumors for 5 PDX models with fast and robust in vivo growth latency. Two models, DFCI-161 and DFCI-220 with the most reproducible EphA2 staining were selected. Treatment with BCY6033 showed that a dose of 3 mg/kg once weekly administered intravenously was well tolerated in female NSG mice. BCY6033 treatment led to significant tumor growth inhibition with &gt;80% tumor regressions in both DFCI-161 and DFCI-220 PDX models. Re-challenge of tumor out-growth showed that they retain sensitivity to BCY6033 treatment.

Conclusion: BCY6033 is a potentially promising drug effective against EphA2 expressing PDX models. Future studies and clinical trials will seek to determine the efficacy of BT5528 in EphA2 expressing tumors.

Citation Format: Kenneth Ngo, Elena V. Ivanova, Tyler J. Teceno, Carly Campbell, Johanna Lahdenranta, Stephen J. Blakemore, Gavin Bennett, Pasi A. Jänne, Cloud P. Paweletz, Prafulla C. Gokhale. Activity of the erythropoietin-producing hepatocellular A2 receptor (EphA2) targeting Bicycle® Toxin Conjugate (BTC™) BCY6033 in EGFR inhibitor resistant non-small lung cancer (NSCLC) patient derived xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 333.

Combined PARP and HSP90 inhibition: preclinical and Phase 1 evaluation in patients with advanced solid tumours

PURPOSE

PARP inhibitor resistance may be overcome by combinatorial strategies with agents that disrupt homologous recombination repair (HRR). Multiple HRR pathway components are HSP90 clients, so that HSP90 inhibition leads to abrogation of HRR and sensitisation to PARP inhibition. We performed in vivo preclinical studies of the HSP90 inhibitor onalespib with olaparib and conducted a Phase 1 combination study.

PATIENTS AND METHODS

Tolerability and efficacy studies were performed in patient-derived xenograft(PDX) models of ovarian cancer. Clinical safety, tolerability, steady-state pharmacokinetics and preliminary efficacy of olaparib and onalespib were evaluated using a standard 3 + 3 dose-escalation design.

RESULTS

Olaparib/onalespib exhibited anti-tumour activity against BRCA1-mutated PDX models with acquired PARPi resistance and PDX models with RB-pathway alterations(CDKN2A loss and CCNE1 overexpression). Phase 1 evaluation revealed that dose levels up to olaparib 300 mg/onalespib 40 mg and olaparib 200 mg/onalespib 80 mg were safe without dose-limiting toxicities. Coadministration of olaparib and onalespib did not appear to affect the steady-state pharmacokinetics of either agent. There were no objective responses, but disease stabilisation ≥24 weeks was observed in 7/22 (32%) evaluable patients including patients with BRCA-mutated ovarian cancers and acquired PARPi resistance and patients with tumours harbouring RB-pathway alterations.

CONCLUSIONS

Combining onalespib and olaparib was feasible and demonstrated preliminary evidence of anti-tumour activity.

Diagnostic cytokine marker of male infertility - interleukin 4

Analysis of the study is to assess the diagnostic significance of cytokines in the sperm plasma of men of reproductive age (20 - 45 years) of two groups: of patients with chronic bacterial prostatitis, not complicated by infertility and with loss of fertility. The study of sperm plasma - the WHO standard. Determination of the level of cytokines in seminal plasma - by enzyme immunoassay («Cytokine», Russia). Two methods of mathematical statistics were used: discriminant analysis and classification trees (decision trees).The similarity of interpretations of discriminant analysis and decision tree was noted, where the main role in both cases belongs to the cytokine IL-4. The level of sperm IL-4 in combination with therapeutic monitoring can be used for the medical management of patients with chronic prostatitis in order to prevent the development of infertility and to develop methods for screening diagnostics of fertility disorders in men.

Semen microbiota and cytokines of healthy and infertile men

In this study, we determined the levels of cytokine secretory inhibitors and the microbiota biofilms of semen from healthy and infertile subjects. A total of 118 clinical bacterial isolates were isolated and tested. Cytokine secretory inhibitors were determined based on the difference in cytokine content between the control and experimental samples of cell-free supernatants of isolated microorganisms. Biofilm formation was studied by determining the adhesion of microorganisms to the surface of a 96-well sterile plate and expressed as the optical density at 630 nm (OD₆₃₀). Cell-free supernatants of Staphylococcus contained higher levels of secretory inhibitor of cytokines in conditionally healthy than in infertile patients. In contrast, in infertile men, the ability to reduce cytokine levels was more characteristic of Enterococcus and Corynebacterium. Seminal Staphylococcus, Corynebacterium, and Enterococcus isolated from infertile subjects showed a greater ability to form biofilms than the same bacteria isolated from healthy men. Further research is needed on this topic, since it is necessary to determine the relationships between decreased secretory inhibitors of cytokines, production of biofilms by bacteria in semen, and infertility. It is likely that the ability of microorganisms to change the concentration of cytokines and increase the level of biofilm formation in semen may be associated with minimal impairments of fertilizing ability, which are not detected using other methods.

Determination of Micropulse Modes with Targeted Damage to the Retinal Pigment Epithelium Using Computer Modeling for the Development of Selective Individual Micropulse Retinal Therapy

PURPOSE

When using a serial laser system for selective impact on the retinal pigment epithelium (RPE), there is a challenge to determine the optimal range of micropulse parameters which result in targeted damage to the RPE. This study proposes a computer model that has identified the optimal parameters to be applied.

METHODS

This study was conducted on 18 patients who were diagnosed with acute central serous chorioretinopathy and transparent optical media, aged 35 to 46 years old, and type 2 and 3 on the Fitzpatrick scale. Testing of the micropulse mode was performed on the Navilas 577s laser system; 864 spots were analyzed in total. Considering the probability of damage visualization at different laser power, the computer simulation of tissue heating and protein denaturation was performed to determine the micropulse modes which resulted in selective damage to the RPE.

RESULTS

The computer model parameter ΔE = 3.34 × 10⁵ J/mol was determined from fitting the model predictions to the autofluorescence test results. The micropulse modes with a micropulse duration of 50-100 µs, duty cycle 2.4-4.8%, 10 ms-pulse envelope (5 micropulses), and spot diameter of 100 µm have efficiency and selectivity above 67% and correspond to the optimal therapeutic window for targeted RPE damage at a certain power. Increasing the micropulse duration, number of micropulses, and duty cycle leads to a decrease in the selective effect on the RPE and higher damage to adjacent tissues.

CONCLUSION

The concepts of efficiency and selectivity have been introduced to quantify the amount of damage caused. The optimal range of micropulse parameters which result in effective and selective damage on the RPE has been determined for the Navilas 577s laser system. The proposed method can be used for any other serial laser system. A comparison of the different micropulse modes, as well as the CW modes, has been performed.

EGFR inhibition enhances the cellular uptake and antitumor-activity of the HER3 antibody drug conjugate HER3-DXd

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) are the standard-of-care treatment for EGFR-mutant non-small cell lung cancers (NSCLC). However, most patients develop acquired drug resistance to EGFR TKIs. HER3 is a unique pseudokinase member of the ERBB family that functions by dimerizing with other ERBB family members (EGFR and HER2) and is frequently overexpressed in EGFR-mutant NSCLC. Although EGFR TKI resistance mechanisms do not lead to alterations in HER3, we hypothesized that targeting HER3 might improve efficacy of EGFR TKI. HER3-DXd is an antibody-drug conjugate (ADC) comprised of HER3-targeting antibody linked to a topoisomerase I inhibitor currently in clinical development. In this study, we evaluated the efficacy of HER3-DXd across a series of EGFR inhibitor-resistant, patient-derived xenografts and observed it to be broadly effective in HER3-expressing cancers. We further developed a preclinical strategy to enhance the efficacy of HER3-DXd through osimertinib pre-treatment, which increased membrane expression of HER3 and led to enhanced internalization and efficacy of HER3-DXd. The combination of osimertinib and HER3-DXd may be an effective treatment approach and should be evaluated in future clinical trials in EGFR-mutant NSCLC patients.

Clinical Evaluation of Individualized and Navigated Microsecond Pulsing Laser for Acute Central Serous Chorioretinopathy

BACKGROUND AND OBJECTIVE

A computational model has predicted parameters for using a navigated microsecond pulsing laser system to treat central serous chorioretinopathy (CSC).

PATIENTS AND METHODS

A prospective, single-center, interventional case series was conducted for patients with acute CSC who were enrolled following screening and informed consent. Treatment involved laser pulse duration of 50 μs, 2.4% Duty Cycle, 100 μm spot size, and 10 ms pulse duration.

RESULTS

Average best-corrected visual acuity (decimal) of 12 patients improved from 0.86 ± 0.03 at baseline to 0.97 ± 0.01 at 3 months. Baseline central retinal thickness decreased from 452.58 μm ± 24.53 μm at baseline to 249.25 μm ± 2.92 μm at 3 months. Retinal sensitivity improved from 24.1 dB ± 1.09 dB at baseline to 28.98 dB ± 0.23 dB at 3 months. In all cases, subretinal fluid was resorbed.

CONCLUSION

The parameter sets derived from the computer model can be applied safely and effectively for CSC treatment using the navigated microsecond pulsing laser system. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:512-520.].

Abstract 62: Development of dual-targeted fine-tuned immune restoring (DFIR) CAR T cell therapy for clear cell renal cell carcinoma (ccRCC)

Clear cell renal cell carcinoma (ccRCC) is the major type of RCC and is among the 10 most common cancers in both men and women. Treatment of RCC has improved dramatically over the last decade, however, a curative treatment for advanced RCC remains rare. Chimeric Antigen Receptor (CAR) T cell therapy is a new type of “living drug”. The FDA approval of CAR-T cell therapies have ushered this new type of cellular immunotherapy into mainstream cancer therapy for hematologic malignancies. To date, these results have not been translatable to solid tumors due to inefficient homing of CAR-T cells, the immunosuppressive tumor microenvironment (TME), and on-target off-tumor toxicities due to shared antigens on normal tissues. Carbonic anhydrase IX (CAIX) is a therapeutic target against ccRCC that is under the control of HIF1α and becomes overexpressed on the surface of ccRCC cells because of VHL inactivation. The first anti-CAIX CAR-T study using the 1st generation G250-CD3 CAR-T cells plus IL-2 to treat patients with metastatic ccRCC was terminated due to hepatitis that developed after CAR-T cell infusions. The on-target off-tumor side effects were attributed to low expression of CAIX on healthy bile duct cells. To translate CAR-T cell therapy to ccRCC, we designed dual-targeted fine-tuned immune restoring (DFIR) CAR-T cells. The DFIR-CAR T cells secreted immune checkpoint inhibitor (ICI) monoclonal antibodies at the tumor site and exhibited superior efficacy and safety profiling. Increased efficacy is achieved through anti-CD70/CAIX dual-targeting CAR which allows the CAR-T cell activation in response to either antigen to mitigate solid tumor heterogeneity. Elevated safety is addressed through fine-tuned CARs which have the affinities of the scFv targeting moieties tailored so that they are activated only by high density tumor associated antigens (TAAs) but not the same antigens expressed at physiologic levels on normal tissues. The ICI payloads act globally on the TME, not only to prevent CAR-T cell exhaustion but also to restore anti-tumor activity of the educated tumor infiltrated lymphocytes (TILs) that have accumulated in the TME. In summary, our DFIR CAR-T cell therapy holds the promise to achieve cures of ccRCC by killing heterogenous ccRCC cells, mitigating against on-target off-tumor toxicity, reversing TME immunosuppression and restoring host anti-tumor immunity. We believe that DFIR-CAR T cells are ready to be translated to the clinic upon completion of pre-IND studies.

Citation Format: Yufei Wang, Alicia Buck, Marion Grimaud, Sreekumar Kodangattil, Cecile Razimbaud, Atef Fayed, Matthew Chang, Aedin Culhane, David A. Braun, Toni K. Choueiri, Catherine J. Wu, Kevin S. Wei, Leo L. Chan, Brandon P. Piel, Elena V. Ivanova, Cloud P. Paweletz, David A. Barbie, Rebecca Jennings, Miriam Ficial, Maura Aliezah Sticco-Ivins, Sabina Signoretti, Gordon J. Freeman, Quan K. Zhu, Wayne A. Marasco. Development of dual-targeted fine-tuned immune restoring (DFIR) CAR T cell therapy for clear cell renal cell carcinoma (ccRCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 62.

[Evaluation of effectiveness of a mouthwash containing antiseptic octenidine dihydrochloride]

THE AIM OF THE STUDY

Was to assess changes in the oral microbiota when using octenidine dihydrochloride mouthwash.

MATERIALS AND METHODS

Quantitative and qualitative changes in the oral microbiota were studied and evaluated after a single rinse, course application and long-term dates.

RESULTS

A single rinse resulted in a significant decrease in the number of pathogenic microorganisms: S. aureus, C. albicans, and Enterobacteriae. After a seven-day course of mouthwash application, the complete disappearance of pathogenic microorganisms: S. aureus, S. albicans, and Enterobacteriae and an increase in the number of Lactobacillus spp were revealed. 7 days after the mouthwash was canceled, there was some recovery of pathogenic (S. aureus, Candida), the number of Lactobacillus spp. remained the same, normal microflora almost completely restored.

CONCLUSION

Octenidine dihydrochloride mouthwash may be recommended for wide use in dental practice in the treatment of various oral pathological conditions, including candidiasis and dysbiosis.

Dynamic single-cell RNA sequencing identifies immunotherapy persister cells following PD-1 blockade

Resistance to oncogene-targeted therapies involves discrete drug-tolerant persister cells, originally discovered through in vitro assays. Whether a similar phenomenon limits efficacy of programmed cell death 1 (PD-1) blockade is poorly understood. Here, we performed dynamic single-cell RNA-Seq of murine organotypic tumor spheroids undergoing PD-1 blockade, identifying a discrete subpopulation of immunotherapy persister cells (IPCs) that resisted CD8+ T cell-mediated killing. These cells expressed Snai1 and stem cell antigen 1 (Sca-1) and exhibited hybrid epithelial-mesenchymal features characteristic of a stem cell-like state. IPCs were expanded by IL-6 but were vulnerable to TNF-α-induced cytotoxicity, relying on baculoviral IAP repeat-containing protein 2 (Birc2) and Birc3 as survival factors. Combining PD-1 blockade with Birc2/3 antagonism in mice reduced IPCs and enhanced tumor cell killing in vivo, resulting in durable responsiveness that matched TNF cytotoxicity thresholds in vitro. Together, these data demonstrate the power of high-resolution functional ex vivo profiling to uncover fundamental mechanisms of immune escape from durable anti-PD-1 responses, while identifying IPCs as a cancer cell subpopulation targetable by specific therapeutic combinations.

[Manifestations of allergic reactions occurring at a dental appointment]

OBJECTIVE

To analyze the data of modern scientific literature to conduct a study on identifying the true allergic reaction at a dental appointment.

MATERIAL AND METHODS

The article is based on the study of materials from domestic and foreign research databases eLibrary, PubMed, Cochrane Database Systematic Reviews. The research period is 15 years.

RESULTS

Among dental materials, the most common allergens are local anesthetics, metal alloys, components of composite materials, latex.

CONCLUSION

If allergy is suspected, it is necessary to carefully collect an anamnesis and conduct a clinical examination of the patient with the involvement of specialist doctors, with the recommendation of skin tests and test subcutaneous provocation.

[Characterization of the microbiota and cytokine profile of sperm plasma in men with chronic bacterial prostatitis]

BACKGROUND

One of the leading causes of the occurrence of chronic bacterial prostatitis (CBP) in men is infection, microecological disorders of the urogenital tract and cytokine-mediated mechanisms of inflammation of the prostate gland, which actualizes a comprehensive study of the clinical and bacteriological features of CBP from the perspective of a symbiotic approach in the framework of a new scientific field - "infectious symbiology".

OBJECTIVE

to study the characteristics of spermogram, microbiota, and the cytokine profile in men with chronic bacterial prostatitis (CBP) and CBP complicated by infertility.

MATERIALS AND METHODS

A comprehensive study of patients with CBP and CBP complicated by infertility, in comparison with conditionally healthy individuals, was conducted. Species identification of microorganisms was carried out according to biochemical characteristics and the genetic method (sequencing of strains). The biological properties of the microbiota were evaluated: growth properties, biofilm formation, antipeptide activity against the cytokines IL-10, RAIL-1, TNF-, INF- and IL-17 (8 parameters). Immunological parameters of sperm plasma included 13 parameters: the content of cytokines TNF-, INF-, Rail, interleukins (IL) -1, 2, 4, 6, 8, 10, 17, immunoglobulin (Ig) A, lactoferrin and lysozyme. To evaluate sperm plasma, the following quantities were determined: ejaculate volume, pH, sperm plasma liquefaction, total sperm count, sperm count per 1 ml, motility, number of progressively motile, non-progressive motile and motionless spermatozoa, number of round cells, white blood cells, spermatogenesis cells, erythrocytes, erythrocytes, cells, sperm agglutination and aggregation (16 parameters in total). The results are statistically processed.

RESULTS

Data were obtained on changes in biofilm formation, antipeptide activity of microbiota (especially pronounced in corynebacteria), sperm plasma cytokine profile (increased TNF , IL-2, 6, 17), as well as IgA and lactoferrin, which can be used to build a prognostic model of reproductive pathology tract of men and their fertile activity.

CONCLUSION

The study of the antipeptide activity of microbiota in combination with the cytokine profile of ejaculate allows us to recommend them as a "biotarget" for diagnostic, preventive and therapeutic measures for chronic prostatitis in men, which contribute to solving the medical and social problem of preventing male infertility and contributes to the development of health-saving technologies with incorporating elements of personalized medicine.

Overcoming MET-Dependent Resistance to Selective RET Inhibition in Patients with RET Fusion-Positive Lung Cancer by Combining Selpercatinib with Crizotinib

PURPOSE

The RET proto-oncogene encodes a receptor tyrosine kinase that is activated by gene fusion in 1%-2% of non-small cell lung cancers (NSCLC) and rarely in other cancer types. Selpercatinib is a highly selective RET kinase inhibitor that has recently been approved by the FDA in lung and thyroid cancers with activating RET gene fusions and mutations. Molecular mechanisms of acquired resistance to selpercatinib are poorly understood.

PATIENTS AND METHODS

We studied patients treated on the first-in-human clinical trial of selpercatinib (NCT03157129) who were found to have MET amplification associated with resistance to selpercatinib. We validated MET activation as a targetable mediator of resistance to RET-directed therapy, and combined selpercatinib with the MET/ALK/ROS1 inhibitor crizotinib in a series of single patient protocols (SPP).

RESULTS

MET amplification was identified in posttreatment biopsies in 4 patients with RET fusion-positive NSCLC treated with selpercatinib. In at least one case, MET amplification was clearly evident prior to therapy with selpercatinib. We demonstrate that increased MET expression in RET fusion-positive tumor cells causes resistance to selpercatinib, and this can be overcome by combining selpercatinib with crizotinib. Using SPPs, selpercatinib with crizotinib were given together generating anecdotal evidence of clinical activity and tolerability, with one response lasting 10 months.

CONCLUSIONS

Through the use of SPPs, we were able to offer combination therapy targeting MET-amplified resistance identified on the first-in-human study of selpercatinib. These data suggest that MET dependence is a recurring and potentially targetable mechanism of resistance to selective RET inhibition in advanced NSCLC.

Retrosynthetic Analysis of α-Alkenyl-β-Diketones: Regio- and Stereoselective Two-Step Synthesis of Highly Arylated Representatives from Acetylenes, Ketones, and Acyl Chlorides

Highly arylated α-alkenyl-β-diketones are synthesized via a two-step sequence consisting of (i) potassium tert-butoxide/DMSO-catalyzed (E)-stereoselective C-H functionalization of ketones with acetylenes followed by (ii) magnesium bromide etherate/DIPEA-soft enolization of the formed β,γ-unsaturated ketones and regioselective acylation with acyl chlorides. The method is compatible with a broad range of substrates and shown to be applicable as an intermediate stage in the construction of polyarylated heterocycles.

Genome sequence data announcement of Bifidobacterium bifidum strain ICIS-202 isolated from a healthy human intestine stimulating active nitrogen oxide production in macrophages

This report presents the data on the draft genome sequence of Bifidobacterium bifidum strain ICIS-202. The strain, isolated from the intestine of a young healthy woman, was deposited in the State Collection of Microorganisms of Normal Microbiota in Gabrichevsky Institute of Epidemiology and Microbiology, Moscow, Russian Federation as a prospective candidate for probiotic development. The size of the genome was 2,265,060 bp (62,4% G + C content). The annotation revealed 1771 coding sequences, including 1771 proteins, 5 rRNA, 52 tRNA, and 3 ncRNA genes. The draft genome sequence data of B. bifidum strain ICIS-202 is available in DBJ/EMBL/GenBank under the accession nos. SSMS00000000.1, PRJNA412271 and SAMN07709009 for Genome, Bioproject and Biosample databases, respectively.

P6482Stress echocardiography in the assessment of long-term outcomes results of aortic valve replacement with mechanical prostheses of small size

Relevance

Evaluation of the function of aortic mechanical prostheses of small size in the long-term period is an topical problem, due to the fact that a narrow fibrous ring occurs in 20–35% of cases of patients with aortic stenosis.

Objective

To study clinical and hemodynamic parameters of small size aortic prostheses using stress echocardiography in the long-term period after valve replacement

Materials and methods

The study included 89 patients (54 women, 35 men) who underwent aortic valve replacement with a landing diameter of 21 mm or less.

The average was 48,1±11,3 years. BSA of 1,8 m2 (1.3 to 2.2). The following models of prostheses were used: On-X, ATS-AP, Carbomedics, St. Jude Medical. All patients after surgical correction in the long-term period (an average of 5,9±3,3 years from 1 to 11 years) underwent a comprehensive clinical and instrumental examination, including an ECG and stress - echocardiography with bicycle exercise.

Results

In the long-term period after aortic valve replacement of mechanical prostheses of small size, the ECG showed regression of hypertrophy and overload of the left ventricle.

According to stress-echocardiography, there was a significant increase in load tolerance. At the peak of the load, the following were recorded: improvement of the pumping function and cardiac performance (stroke volume, cardiac output, cardiac index), improvement of myocardial work index (Tei - index), increase in speed parameters on the aortic valve prosthesis no more than 30% of the initial values.

In repose, the maximum and mean pressure gradients were 26.3±9 mm Hg and 14.3±5.4 mm Hg, effective orifice area (EOA) 1,7±0,3 cm2, index effective orifice area (EOAi) 0,93±0,2 cm2/m2. When the submaximal load levels were reached, the maximum and mean pressure gradients were 33,5±6,0 mm Hg and 17,1±4,0 mm Hg, EOA - 1,5±0,4 cm2, EOAi - 0,79±0,6 cm2/m2.

Conclusions

The findings suggest that modern models of aortic prostheses with an increased effective orifice area provide good clinical results in the long term. Stress echocardiography is a necessary and highly informative method for assessing the parameters of mechanical aortic prostheses and heart function.

Regioselective Synthesis of 2-Acylbutadienes from β,γ-Unsaturated Ketones

2-Acylbuta-1,3-dienes have been synthesized regioselectively from aromatic and heteroaromatic β,γ-unsaturated ketones (readily accessible via base-catalyzed addition of ketones to acetylenes) and aldehydes. The reaction smoothly proceeds with piperidine (10 mol%)/acetic acid (10 mol%) catalytic pair in boiling toluene to provide synthetically attractive polyconjugated electron-deficient dienes in up to 94% yield.

Remote Ischemic Preconditioning With the Use of Lower Limb Before Coronary Artery Bypass Surgery With Cardiopulmonary Bypass and Anesthesia With Propofol

OBJECTIVE

to study potantial of remote ischemic preconditioning (RIP) as method of cardioprotection during coronary artery bypass surgery with cardiopulmonary bypass (CPB) and anesthesia with propofol.

MATERIALS AND METHODS

We included in this study 87 patients (7 were excluded) with ischemic heart disease, hospitalized in the clinic of aortic and cardiovascular surgery of the I. M. Sechenov First Moscow State Medical University clinical hospital № 1. All patients had indications for direct myocardial revascularization by coronary artery bypass surgery. One day before operation patients were randomly assigned to 2 groups depending on preparation scheme: main group of RIP and the control group. The frequency of complications during surgery and in the postoperative period was assessed. Troponin I level was measured before, and in 2 and 24 hours after surgery. The level of lactate in the venous blood was measured before and after surgery.

RESULTS

Numbers of intraoperative and early postoperative complications in the main and control groups were similar. There were no differences between groups in troponin I and lactate levels after surgery.

CONCLUSIONS

Remote ischemic preconditioning has no effect on the outcome of coronary artery bypass surgery with cardiopulmonary bypass and anesthesia with propofol.

Acetylene-based two-step diastereoselective synthesis of bridgehead dihydro-oxadiazines using ketones and hydrazine as the only reactants

Bridgehead dihydro-1,3,4-oxadiazines are synthesized by the acid-catalyzed diastereoselective reaction of hydrazine with 6,8-dioxabicyclo[3.2.1]octanes, the products of the superbase-promoted self-organization of acetylene with ketones.

[Forensic medical examinations of living persons: modern problems of legal regulation, administration, procedure, and the evaluation of expert opinions]

The aim of the study is an analysis of the significant problems of legal regulation and procedure in the administration and conduct of forensic medical examinations of living persons. The authors, based on an analysis of the opinions of scientists, specialists and legal and forensic experts, draw conclusions and make suggestions aimed at improving forensic examinations in the conduct of these types of investigations.

Amplification of Wild-type KRAS Imparts Resistance to Crizotinib in MET Exon 14 Mutant Non-Small Cell Lung Cancer

PURPOSE

MET inhibitors can be effective therapies in patients with MET exon 14 (METex14) mutant non-small cell lung cancer (NSCLC). However, long-term efficacy is limited by the development of drug resistance. In this study, we characterize acquired amplification of wild-type (WT) KRAS as a molecular mechanism behind crizotinib resistance in three cases of METex14-mutant NSCLC and propose a combination therapy to target it.

EXPERIMENTAL DESIGN

The patient-derived cell line and xenograft (PDX) DFCI358 were established from a crizotinib-resistant METex14-mutant patient tumor with massive focal amplification of WT KRAS. To characterize the mechanism of KRAS-mediated resistance, molecular signaling was analyzed in the parental cell line and its KRAS siRNA-transfected derivative. Sensitivity of the cell line to ligand stimulation was assessed and KRAS-dependent expression of EGFR ligands was quantified. Drug combinations were screened for efficacy in vivo and in vitro using viability and apoptotic assays.

RESULTS

KRAS amplification is a recurrent genetic event in crizotinib-resistant METex14-mutant NSCLC. The key characteristics of this genetic signature include uncoupling MET from downstream effectors, relative insensitivity to dual MET/MEK inhibition due to compensatory induction of PI3K signaling, KRAS-induced expression of EGFR ligands and hypersensitivity to ligand-dependent and independent activation, and reliance on PI3K signaling upon MET inhibition.

CONCLUSIONS

Using patient-derived cell line and xenografts, we characterize the mechanism of crizotinib resistance mediated by KRAS amplification in METex14-mutant NSCLC and demonstrate the superior efficacy of the dual MET/PI3K inhibition as a therapeutic strategy addressing this resistance mechanism.

BET Bromodomain Inhibition Cooperates with PD-1 Blockade to Facilitate Antitumor Response in Kras-Mutant Non-Small Cell Lung Cancer

KRAS mutation is present in approximately 30% of human lung adenocarcinomas. Although recent advances in targeted therapy have shown great promise, effective targeting of KRAS remains elusive, and concurrent alterations in tumor suppressors render KRAS-mutant tumors even more resistant to existing therapies. Contributing to the refractoriness of KRAS-mutant tumors are immunosuppressive mechanisms, such as increased presence of suppressive regulatory T cells (Treg) in tumors and elevated expression of the inhibitory receptor PD-1 on tumor-infiltrating T cells. Treatment with BET bromodomain inhibitors is beneficial for hematologic malignancies, and they have Treg-disruptive effects in a non-small cell lung cancer (NSCLC) model. Targeting PD-1-inhibitory signals through PD-1 antibody blockade also has substantial therapeutic impact in lung cancer, although these outcomes are limited to a minority of patients. We hypothesized that the BET bromodomain inhibitor JQ1 would synergize with PD-1 blockade to promote a robust antitumor response in lung cancer. In the present study, using Kras^+/LSL-G12D ; Trp53^L/L (KP) mouse models of NSCLC, we identified cooperative effects between JQ1 and PD-1 antibody. The numbers of tumor-infiltrating Tregs were reduced and activation of tumor-infiltrating T cells, which had a T-helper type 1 (Th1) cytokine profile, was enhanced, underlying their improved effector function. Furthermore, lung tumor-bearing mice treated with this combination showed robust and long-lasting antitumor responses compared with either agent alone, culminating in substantial improvement in the overall survival of treated mice. Thus, combining BET bromodomain inhibition with immune checkpoint blockade offers a promising therapeutic approach for solid malignancies such as lung adenocarcinoma. Cancer Immunol Res; 6(10); 1234-45. ©2018 AACR.

Nuclear localization of amyloid-β precursor protein-binding protein Fe65 is dependent on regulated intramembrane proteolysis

Fe65 is an adaptor protein involved in both processing and signaling of the Alzheimer-associated amyloid-β precursor protein, APP. Here, the subcellular localization was further investigated using TAP-tagged Fe65 constructs expressed in human neuroblastoma cells. Our results indicate that PTB2 rather than the WW domain is important for the nuclear localization of Fe65. Electrophoretic mobility shift of Fe65 caused by phosphorylation was not detected in the nuclear fraction, suggesting that phosphorylation could restrict nuclear localization of Fe65. Furthermore, both ADAM10 and γ-secretase inhibitors decreased nuclear Fe65 in a similar way indicating an important role also of α-secretase in regulating nuclear translocation.

ANALYSIS OF POPULATION IMMUNITYAGAINST INFLUENZA PRIOR TO 2014 AND 2015 EPIDEMIC SEASONS

AIM

Control for the population herd immunity against seasonal influenza viruses as well as for emergence of antibodies against influenza with pandemic potential in human blood sera.

MATERIALS AND METHODS

HAI reaction against vaccine and epidemic influenza viruses as well as HPAI viruses A/rook/Chany/32/2015 (H5N1) (clade 2.3.2. lc.) andA/Anhui/01/2013 (H7N9).

RESULTS

Among all the sera samples collected in the autumn of 2014 and 2015, none had reacted in HAI against A(H5N 1) and A(H7N9) antigens even at 1:10 dilution. Among samples collected in autumn 2014, 41% were positive to A/California/07/09(H1Nlpdm9) virus, 36% - A/Texas/50/2012 (H3N2), 40% - B/Brisbane/60/2008 (Vict.lin.) and 47% reacted in HAI against the B/Massachusetts/2/2012 (Yam.lin.) strain. 22% of all the samples had a titer of at least 40 against all the antigens and only 10% in HAI had a titer of 40 or more against all the vaccine strains. Among the samples collected in autumn 2015, the number of seropositive against A/California/07/09(HlNlpdmO9) varied from 31% in the Urals FD to 46% in the Southern FD. The amount of seropositive against A/Switzerland/9715293/13 (H3N2) strain was at the level of 4 - 13% in all the FDs except Urals, where this parameter was slightly above 30%. The amount of seropositive against vaccine influenza B viruses varied from 23 to 76%. Only 2% of sera had titers in HAI of 40 or above against all the vaccine strains, 29% of all the samples were seronegative.

CONCLUSION

Population immunity in Russia against influenza A(H3N2) is at a very low level, thus socially significant consequences of influenza epidemics in many aspects will depend on the vaccination campaign of autumn 2016.

Defining an inflamed tumor immunophenotype in recurrent, metastatic squamous cell carcinoma of the head and neck

OBJECTIVES

Immune checkpoint inhibitors have demonstrated clinical benefit in recurrent, metastatic (R/M) squamous cell carcinoma of the head and neck (SSCHN), but lacking are biomarkers that predict response. We sought to define an inflamed tumor immunophenotype in this R/M SCCHN population and correlate immune metrics with clinical parameters and survival.

METHODS

Tumor samples were prospectively acquired from 34 patients to perform multiparametric flow cytometry and multidimensional clustering analysis integrated with next-generation sequencing data, clinical parameters and outcomes.

RESULTS

We identified an inflamed subgroup of tumors with prominent CD8+ T cell infiltrates and high PD-1/TIM3 co-expression independent of clinical variables, with improved survival compared with a non-inflamed subgroup (median overall survival 84.0 vs. 13.0months, p=0.004). The non-inflamed subgroup demonstrated low CD8+ T cells, low PD-1/TIM3 co-expression, and higher T_regs. Overall non-synonymous mutational burden did not correlate with response to PD-1 blockade in a subset of patients.

CONCLUSION

R/M SCCHN patients with an inflamed tumor immunophenotype demonstrate improved survival. Further prospective studies are needed to validate these findings and explore the use of immunophenotype to guide patient selection for immunotherapeutic approaches.

[METABOLIC PROFILE OF BIFIDOFLORA UNDER DIFFERENT MICROECOLOGICAL CONDITIONS OF THE COLON BIOTOPE IN HUMAN]

AIM

To study the spectrum and level of short-chained fatty acids (SCFA) in supernatant of bifidobacteria under different microecological conditions ofthe colon biotope in human.

MATERIALS AND METHODS

Metabolites of 88 bifidobacteria strains isolated from patients when examined for dysbiosis of the colon were investigated. Definition of concentration of SCFA was performed on acidified supernatant samples by a separation method on chromatograph GC-2010 Plus, Shimadzu (Japan).

RESULTS

Monobasic acids were found in metabolites of 50 - 100% study cultures of bifidobacteria where the spectrum and level of carboxylic acids in supernatants varied depen- ding on microecological condition of the origin of the discharge. In severe damages of microsymbiocenosis in metabolites of Bifidobacterium spp., summarized concentrations of SCFA, structural index, levels of aceitic and propionic acids were decreased. Strain-specific differences in a metabolic profile of bifidofloia in a composition of individual consortiums were determined. Data obtained indicate the variation of functional (metabolic) activity of dominant strains in different microecological conditions of the human colon.

CONCLUSION

Uniquieness of metabolome of every other strain due to their strain specifity determines their functional activity, but a metabolic profile of bifidoflora can serve as the most important criterion for the selection of effective probi- otic drugs for treatment and prevention of dysbioisis in the colon.

Phase II and Biomarker Study of Cabozantinib in Metastatic Triple-Negative Breast Cancer Patients

Currently, no targeted therapies are available for metastatic triplenegative breast cancer (mTNBC). We evaluated the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with mTNBC. We conducted a single arm phase II and biomarker study that enrolled patients with measurable mTNBC. Patients received cabozantinib (60 mg daily) on a 3-week cycle and were restaged after 6 weeks and then every 9 weeks. The primary endpoint was objective response rate. Predefined secondary endpoints included progression-free survival (PFS), toxicity, and tissue and blood circulating cell and protein biomarkers. Of 35 patients who initiated protocol therapy, 3 (9% [95% confidence interval (CI): 2, 26]) achieved a partial response (PR). Nine patients achieved stable disease (SD) for at least 15 weeks, and thus the clinical benefit rate (PR+SD) was 34% [95% CI: 19, 52]. Median PFS was 2.0 months [95% CI: 1.3, 3.3]. The most common toxicities were fatigue, diarrhea, mucositis, and palmar-plantar erythrodysesthesia. There were no grade 4 toxicities, but 12 patients (34%) required dose reduction. Two patients had TNBCs with MET amplification. During cabozantinib therapy, there were significant and durable increases in plasma placental growth factor, vascular endothelial growth factor (VEGF), VEGF-D, stromal cell-derived factor 1a, and carbonic anhydrase IX, and circulating CD3 + cells and CD8 + T lymphocytes, and decreases in plasma soluble VEGF receptor 2 and CD14+ monocytes (all p < .05). Higher baseline concentrations of soluble MET (sMET) associated with longer PFS (p = .03). In conclusion, cabozantinib showed encouraging safety and efficacy signals but did not meet the primary endpoint in pretreated mTNBC. Exploratory analyses of circulating biomarkers showed that cabozantinib induces systemic changes consistent with activation of the immune system and antiangiogenic activity, and that sMET should be further evaluated a potential biomarker of response.

IMPLICATIONS FOR PRACTICE

Triple-negative breast cancer (TNBC)-a disease with a dearth of effective therapies-often overexpress MET, which is associated with poor clinical outcomes. However, clinical studies of agents targeting MET and VEGF pathways-alone or in combination-have shown disappointing results. This study of cabozantinib (a dual VEGFR2/MET) in metastatic TNBC, while not meeting its prespecified endpoint, showed that treatment is associated with circulating biomarker changes, and is active in a subset of patients. Furthermore, this study demonstrates that cabozantinib therapy induces a systemic increase in cytotoxic lymphocyte populations and a decrease in immunosuppressive myeloid populations. This supports the testing of combinations of cabozantinib with immunotherapy in future studies in breast cancer patients.

[GUT MICROSYMBIOCENOSIS IN CHILDREN WITH REACTIVE ARTHRITIS]

AIM

To study the state of gut microsymbiocenosis in children with reactive arthritis (RA), with the assessment of biofilm formation (BFF) of microsymbionts and the ability to change cytokine levels (their anticyokine activity) in vitro.

MATERIALS AND METHODS

The investigation of gut microsymbiocenosis by means of bacteriological method was conducted in 34 children with RA and 25 relatively healthy 3 - 16 year- old children. Microorganisms were identified with the help of MALDI-TOF mass-spectrometry, anticytokine activity (ACA) of microsymbionts - according to Bukharin O.V et al. (2011), biofilm formation - according to O'Toole G.A., Kolter R. (1998).

RESULTS

On the ground of species composition differences of gut microbiota discrimination model was created which allowed to separate the group of children with RA from healthy individuals. Microsymbiocenosis of patients with RA was characterized by increasing number of opportunistic microorganisms (OM) (enterobacteria, clostridia, bacteroides, and Candida), BFF and ACA level.

CONCLUSION

The obtained data greatly contribute.to the deciphering of spondylo- arthritis and disclose the role of microbial factor under given pathology. Hypercolonisation of human gut with OM, having pronounced ability to BFF and regulating cytokine level, promotes strengthening of arthritogenic potential and serves as additional marker of arthritis development risk in children.

Multiparametric profiling of non-small-cell lung cancers reveals distinct immunophenotypes

BACKGROUND. Immune checkpoint blockade improves survival in a subset of patients with non-small-cell lung cancer (NSCLC), but robust biomarkers that predict response to PD-1 pathway inhibitors are lacking. Furthermore, our understanding of the diversity of the NSCLC tumor immune microenvironment remains limited. METHODS. We performed comprehensive flow cytometric immunoprofiling on both tumor and immune cells from 51 NSCLCs and integrated this analysis with clinical and histopathologic characteristics, next-generation sequencing, mRNA expression, and PD-L1 immunohistochemistry (IHC). RESULTS. Cytometric profiling identified an immunologically "hot" cluster with abundant CD8⁺ T cells expressing high levels of PD-1 and TIM-3 and an immunologically "cold" cluster with lower relative abundance of CD8⁺ T cells and expression of inhibitory markers. The "hot" cluster was highly enriched for expression of genes associated with T cell trafficking and cytotoxic function and high PD-L1 expression by IHC. There was no correlation between immunophenotype and KRAS or EGFR mutation, or patient smoking history, but we did observe an enrichment of squamous subtype and tumors with higher mutation burden in the "hot" cluster. Additionally, approximately 20% of cases had high B cell infiltrates with a subset producing IL-10. CONCLUSIONS. Our results support the use of immune-based metrics to study response and resistance to immunotherapy in lung cancer. FUNDING. The Robert A. and Renée E. Belfer Family Foundation, Expect Miracles Foundation, Starr Cancer Consortium, Stand Up to Cancer Foundation, Conquer Cancer Foundation, International Association for the Study of Lung Cancer, National Cancer Institute (R01 CA205150), and the Damon Runyon Cancer Research Foundation.

Engineering Approach to Identifying Patients with Colon Tumors on the Basis of Electrophotonic Imaging Technique Data

Background:

Colonic neoplasms are quite a serious problem today. Screening methods play an important role in diagnosing the disease. Colorectal cancer screening is a complex undertaking, having various options, which require a lot of efforts both from the doctor and from the patient, including the use of sedatives and the necessity of the presence of an assistant for some procedures such as colonoscopy. This is why it is very important to find a method by which one can make a diagnosis quickly, easily, and painlessly.

Methods:

The ability to identify patients with tumors of the colon using the Electrophotonic Imaging (EPI) technique, as well as using it for differential diagnosis of tumors of the colon by their morphology, size and quantity was investigated. Selection of the most significant parameters of the EPI-graphy for the separation of the control group and the group of patients with tumors of the colon was developed. 137 people were studied with the EPI camera, with ages ranging from 16 to 86 years, including 49 males and 88 females. Based on the results of the colonoscopy and histological findings all subjects were divided into 2 groups: control group of 55 people, 9 males, 46 females; and patients with tumors (benign or malignant) of the colon - 82 people; 40 males and 42 females. Then all subjects were divided into smaller groups based on morphology, size, number of tumors and localization.

Results:

Based on the identified indicators decision rules to determine the patients with tumors of the colon were constructed. The specificity of the resulting function was 80.0% and sensitivity 75.6%. Decision rule was built as well with logistic regression. The specificity of the resulting function was 78.2% and sensitivity 90.0%. The accuracy of this approach was higher than using discriminant analysis.

Conclusions:

The results of this study have proven the ability to identify patients with tumors of the colon using EPI technology, as well as use it for differential diagnosis of tumors of the colon by their morphology, size and quantity. EPI testing is non-invasive, takes less than five minutes, and equipment is relatively cheap and accessible in mass production. This opens up good prospects for further research for implementation as a first step of the screening process. This paper presents the pilot study developing methodological approach to the GDV data processing. That is why we tried different methods of data processing. At the same time we do not pretend to develop a diagnostic method – sample size is too small for this, and other cancer types were not studied. Further research is needed.

Biosynthesis of poly(3-hydroxybutyrate) copolymers by Azotobacter chroococcum 7B: A precursor feeding strategy

A precursor feeding strategy for effective biopolymer producer strain Azotobacter chroococcum 7B was used to synthesize various poly(3-hydroxybutyrate) (PHB) copolymers. We performed experiments on biosynthesis of PHB copolymers by A. chroococcum 7B using various precursors: sucrose as the primary carbon source, various carboxylic acids and ethylene glycol (EG) derivatives [diethylene glycol (DEG), triethylene glycol (TEG), poly(ethylene glycol) (PEG) 300, PEG 400, PEG 1000] as additional carbon sources. We analyzed strain growth parameters including biomass and polymer yields as well as molecular weight and monomer composition of produced copolymers. We demonstrated that A. chroococcum 7B was able to synthesize copolymers using carboxylic acids with the length less than linear 6C, including poly(3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) (PHB-4MHV) using Y-shaped 6C 3-methylvaleric acid as precursor as well as EG-containing copolymers: PHB-DEG, PHB-TEG, PHB-PEG, and PHB-HV-PEG copolymers using short-chain PEGs (with n ≤ 9) as precursors. It was shown that use of the additional carbon sources caused inhibition of cell growth, decrease in polymer yields, fall in polymer molecular weight, decrease in 3-hydroxyvalerate content in produced PHB-HV-PEG copolymer, and change in bacterial cells morphology that were depended on the nature of the precursors (carboxylic acids or EG derivatives) and the timing of its addition to the growth medium.

Anchoring of FRET Sensors-A Requirement for Spatiotemporal Resolution

FRET biosensors have become a routine tool for investigating mechanisms and components of cell signaling. Strategies for improving them for particular applications are continuously sought. One important aspect to consider when designing FRET probes is the dynamic distribution and propagation of signals within living cells. We have addressed this issue by directly comparing an anchored (taFS) to a non-anchored (naFS) cleavable FRET sensor. We chose a microtubule-associated protein tau as an anchor, as microtubules are abundant throughout the cytosol of cells. We show that tau-anchored FRET sensors are concentrated at the cytoskeleton and enriched in the neurite-like processes of cells, providing high intensity of the total signal. In addition, anchoring limits the diffusion of the sensor, enabling spatiotemporally resolved monitoring of subcellular variations in enzyme activity. Thus, anchoring is an important aspect to consider when designing FRET sensors for deeper understanding of cell signaling.

[Proteasome and calpain activities in colon cancer: the relation with metastasis and prognosis]

The chymotrypsin-like total proteasome activity and activity of 26S and 20S pools of proteasomes as well as calpain activitiy were found to be significantly increased in colon cancer tissue as compared to normal colon tissue. Patients with stage T2-4N1-3M0-lcolon cancer had higher activity level of the 26/20S proteasome and total calpain activities than patients with stage T2-4NOMO-1 colon cancer. The chymotrypsin-like total activity of proteasomes and the total activity of caplains in patients with stage T2-4N0-3M1 colon cancer were re- spectively 1.6 and 2.0-fold higher compared to those in patients with stage T2-4N0-3M0 colon cancer. Survival analysis of patients with colon cancer showed that the high level of chymotrypsin-like protesome activity in colon cancer and normal colon tissues (more than 72-1000 units/mg protein and 35-1000 units/mg protein, respectively) and the high level of total calpain activity in colon cancer and normal colon tissues (more than 100.5-1000 Units/mg protein and 52-1000 Units/ mg protein, respectively) were unfavorable factors in terms of 2-year metastasis-free survival.

[THE ROLE OF BIFIDOBACTERIA IN THE FORMATION OF HUMAN IMMUNE HOMEOSTASIS]

In the review the materials on the formation of intestinal immune homeostasis through involvement of bifidobacteria which are the key species of microbiota of human colon biotype are presented. Key function of dominant microorganisms, bifidoflora in particular, in intestinal biotype of a host is carried out by means of maintenance of self microorganisms and pronounced antagonism concerning non-self. Realization of this principle in intermicrobial relations allowed to develop algorithm of microbial self-non-self discrimination in microsymbiocenosis on the basis of detected opposite phenomenon (enhancement/suppression) of the main physiological functions of microsymbionts survival (reproduction and adaptation) in dominant-associant pair. Primary discrimination of foreign,material by bifidobacteria is the initial stage of the following "signaling" in the regulation of host immune homeostasis. Further stages of regulation occur by activation of dendritic cells by bifidobacteria with the sequential influence on differentiation of Th0 towards regulatory lymphocytes. The formation of Treg and regulation of immune homeostasis are carried out by bifidobacteria: due to direct activation of dendritic cells (ligand-receptor interactions) and maintenance of optimal cytokine balance.

[Diagnosis of bullous dermatoses with lesions of the oral mucosa]

Bullous dermatoses affecting oral mucosa are autoimmune diseases in the majority of cases. The most common diseases in this group are pemphigus vulgaris, bullous pemphigoid, lichen planus. In the early stages of bullous dermatoses, especially for isolated lesions of the oral mucosa, prompt diagnosis is not always possible requiring an interdisciplinary approach to the differential diagnosis.