Search

Intracellular binding of small-molecule phospho-Ags to the HMBPP receptor complex in infected cells leads to extracellular detection by T cells expressing the Vγ9Vδ2 TCR, a noncanonical method of Ag detection. The butyrophilin proteins BTN2A1 and BTN3A1 are part of the complex; however, their precise roles are unclear. We suspected that BTN2A1 and BTN3A1 form a tetrameric (dimer of dimers) structure, and we wanted to probe the importance of the BTN2A1 homodimer. We analyzed mutations to human BTN2A1, using internal domain or full-length BTN2A1 constructs, expressed in Escherichia coli or human K562 cells, that might disrupt its structure and/or function. Although BTN2A1 is a disulfide-linked homodimer, mutation of cysteine residues C247 and C265 did not affect the ability to stimulate T cell IFN-γ production by ELISA. Two mutations of the juxtamembrane region (at EKE282) failed to impact BTN2A1 function. In contrast, single point mutations (L318G and L325G) near the BTN2A1 B30.2 domain blocked phospho-Ag response. Size exclusion chromatography and nuclear magnetic resonance (NMR) experiments showed that the isolated BTN2A1 B30.2 domain is a homodimer, even in the absence of its extracellular and transmembrane region. [31P]-NMR experiments confirmed that HMBPP binds to BTN3A1 but not BTN2A1, and binding abrogates signals from both phosphorus atoms. Furthermore, the BTN2A1 L325G mutation but not the L318G mutation prevents both homodimerization of BTN2A1 internal domain constructs in size exclusion chromatography (and NMR) experiments and their binding to HMBPP-bound BTN3A1 in isothermal titration calorimetry experiments. Together, these findings support the importance of homodimerization within the BTN2A1 internal domain for phospho-Ag detection.

The paper proposes a contemporary interdisciplinary method to identify consistent patterns within cyclical dynamics of GDP and its macroeconomics determinants in the Russian Federation. This method may contribute to better recognition of the stages of economic cycle and of potential early predicators to recessions and crises. We first identify the trend component of Russian GDP and then apply the spectral data analysis to its cyclical component which reveals its multi-frequency, and non-linear vibrations. These vibrations are then further investigated by transforming time series data on GDP and its determinants into a frequency spectrum series via Fourier transform techniques. Wavelength scanning of selected macroeconomic indicators shows the basic economic cycle of real GDP with duration time of approx. 3.13 years. Other procyclical indicators nevertheless discover asynchronous behavior towards GDP due to the relative autonomy of the sectors standing behind these indicators. Their autonomy lies behind differences in reaction forces (shifts) and periods (lags) to both internal and external shocks. We estimate differentials between the dynamics of GDP and its determinants by evaluating phase deviations of their pairwise harmonic components, mutual pairwise phase shifts, and by comparison of their pairwise cross-spectrum. The one of output is the quantification of time lags between GDP and key macroeconomic indicators of individual economic sectors. This result reveals the complexity of GDP dynamics that sends an aliased rather than a unit signal to economic agents. Our decomposition of this signal into signals from key economic sectors and quantification of phase discrepancies between sectoral signals may contribute to findings in early crisis predicators. We also estimate the depth and velocity of shocks penetrations into both economy as a whole and its particular sectors.

A plethora of membrane proteins are found along the cell surface and on the convoluted labyrinth of membranes surrounding organelles. Since the advent of various structural biology techniques, a sub-population of these proteins has become accessible to investigation at near-atomic resolutions. The predominant bona fide methods for structure solution, X-ray crystallography and cryo-EM, provide high resolution in three-dimensional space at the cost of neglecting protein motions through time. Though structures provide various rigid snapshots, only an amorphous mechanistic understanding can be inferred from interpolations between these different static states. In this review, we discuss various techniques that have been utilized in observing dynamic conformational intermediaries that remain elusive from rigid structures. More specifically we discuss the application of structural techniques such as NMR, cryo-EM and X-ray crystallography in studying protein dynamics along with complementation by conformational trapping by specific binders such as antibodies. We finally showcase the strength of various biophysical techniques including FRET, EPR and computational approaches using a multitude of succinct examples from GPCRs, transporters and ion channels.

The theory of electrokinetic ion transport in cylindrical channels of a fixed surface charge density is revisited. Attention is focused on impact of the hydrophobic slippage and mobility of adsorbed surface charges. We formulate generalised Onsager relations for a cylinder of an arbitrary radius and then derive exact expressions for the mean electro-osmotic mobility and conductivity. To employ these expressions we perform additional electrostatic calculations, with the special focus on the non-linear electrostatic effects. Our theory provides a simple explanation of a giant enhancement of the electrokinetic mobility and conductivity of hydrophobic nanotubes by highlighting the role of appropriate electrostatic and hydrodynamic length scales and their ratios. We also propose a novel interpretation of zeta potentials of cylindrical channels., Comment: 12 pages, 10 figures

The ligand-bound (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP) receptor (BTN3A1 and BTN2A1) is detectable by the T cell receptor (TCR) of Vγ9Vδ2 T cells. Although BTN3A1 binds to phosphoantigens (pAgs), the mechanisms resulting in receptor activation are not clear. We used CRISPR-Cas9, ELISA, nano-bioluminescence resonance energy transfer (BRET), and isothermal titration calorimetry (ITC) to evaluate the role of BTN2A1. Depletion of BTN2A1 and rescue experiments demonstrate that its internal domain is essential for pAg detection. Internal hetero-BRET signals are observed between BTN2A1 and BTN3A1 that are increased by pAg. ITC detects a direct interaction between the intracellular domains of BTN3A1 and BTN2A1 only in the presence of pAg. This interaction is abrogated by removal of the BTN2A1 juxtamembrane (JM) region but not by removal of the BTN3A1 JM region. Regional mutations between BTN2A1 316-326 clearly affect the interferon γ (IFNγ) response and hetero-BRET signal. Mutations to amino acids L318, W320, and L325 indicate that these amino acids are crucial. This study demonstrates a pAg-inducible interaction between BTN2A1 and BTN3A1 internal domains.

Profound effects of spaceflight on the physiology of humans and non-human animals are well-documented but incompletely explored. Current goals to undertake interplanetary missions increase the urgency to learn more about adaptation to prolonged spaceflight and readaptation to Earth-normal conditions, especially with the inclusion of radiation exposures greater than those confronted in traditional, orbital flights. The 30-day-long Bion M-1 biosatellite flight was conducted at a relatively high orbit, exposing the mice to greater doses of radiation in addition to microgravity, a combination of factors relevant to Mars missions. Results of the present studies with mice provide insights into the consequences on brain function of long-duration spaceflight. After landing, mice showed profound deficits in vestibular responses during aerial drop tests. Spaceflown mice displayed reduced grip strength, rotarod performance, and voluntary wheel running, each, which improved gradually but incompletely over the 7-days of post-flight testing. Continuous monitoring in the animals’ home cage activity, in combination with open-field and other tests of motor performance, revealed indices of altered affect, expressed as hyperactivity, potentiated thigmotaxis, and avoidance of open areas which, together, presented a syndrome of persistent anxiety-like behavior. A learned, operant response acquired before spaceflight was retained, whereas the acquisition of a new task was impaired after the flight. We integrate these observations with other results from Bion-M1’s program, identifying deficits in musculoskeletal and cardiovascular systems, as well as in the brain and spinal cord, including altered gene expression patterns and the accompanying neurochemical changes that could underlie our behavioral findings.

Improved activity and stability Pt-based catalysts for the oxygen reduction reaction (ORR) are needed to perpetuate the deployment of polymer electrolyte fuel cells (PEFCs) in the transportation sector. Here, we use atomic layer deposition of TiO2 and Pt coupled with thermal reductive annealing to prepare Pt3Ti electrocatalysts. The atomic level synthetic control resulted in Pt3Ti nanoparticles with high ORR performance, including a mass activity of 1.84 A/mgPt and excellent electrochemical stability. The Pt3Ti nanoparticles show excellent specific activity — 5.3-fold higher than commercial Pt/C and 3-fold higher than polycrystalline Pt, exceeding the performance of any PtTi catalysts reported to date. Combined experimental and computational efforts indicate that Pt enrichment on the Pt3Ti enhances the activity, and the intrinsic stability of the Pt3Ti phase provides durability. This knowledge, along with the facile fabrication of alloys by atomic layer deposition, can be leveraged to designed improved performance catalysts.

The results of long-term follow-up of patients (pts) with chronic myeloid leukemia (CML) do not lose their importance. Data from routine clinical practice are of particular interest. The use of 1 st (imatinib, IM) and 2nd generation TKI (2G TKI) led to a significant increase in survival, so the probability of death associated with CML could be significantly lower than the probability of death due to common causes of death other than CML. To analyze the overall survival (OS) and causes of mortality in CML pts treated in routine clinical practice in Russian Federation for a long period (>15 years) of time. The long-term follow-up data of the Russian part of the European LeukemiaNet (ELN) OSP EUTOS multicenter observational study were evaluated. The analyzed cohort consisted of 678 Ph/BCR-ABL-positive CML pts from 35 regions of Russia diagnosed in 2002-2006 with IM therapy initiation ≤6 months (mo) after diagnosis. Median (Me) age was 47(range 18-81) years (y), 47% males. Chronic phase, accelerated phase and blast crisis at diagnosis was in 631 (93%), 41(6%) and 6(1%) pts, respectively. The annual number of newly diagnosed pts was as follows: 2002 - 15 pts, 2003 - 38 pts, 2004 - 46 pts, 2005 - 206 pts, 2006 - 302 pts. The last update for 209 pts was done in Jun. 2021; last contact for 100 pts - in 2020, for 39pts - in 2019, for the other - before 2018. The date of the last contact/death could not be established for 14 pts. Statistical analysis included 661 pts, the OS was evaluated by Kaplan-Mayer method using the SAS 9.4 package. In total, 331 (50%) pts of the analyzed cohort were alive with the Me follow-up of 180 (range 2-232) mo or 15 y (range 2 mo-19,3 y). All pts started therapy with IM with 25% switched to 2G TKI in subsequent therapy lines. In total, 218 (66%) pts achieved MR4, 183 (55%) pts got MMR; 46 (21%) of these pts with deep molecular response (DMR) were observed in hematology centers of Moscow. The 15-y OS in the total cohort was 63% (CI 59-70%)(fig.1). The OS by age groups was as follows: 18-40yy-75% (CI 73-82%), 40-60yy- 63% (CI 59-70%), 60-80yy- 37% (CI 30-45%). The most complete information was provided by Moscow centers (2 centers, 113 pts). The 15-y OS of pts receiving treatment in Moscow was significantly higher vs pts from other regions (32 centers, 548 pts): 75% vs 60%, p=0,0030 (fig.2). The mortality in the whole cohort of 661 pts was 35% (233 pts). Of these 233 pts, 112(48%) pts deaths were due to CML progression to AP or BP (including non-compliant cases); 3pts (1,5%) died after allogenic stem cell transplantation (infection complications); the cause of death was unknown in 50 (21,5%) pts. The highest death rate from CML progression was at 4-9 y of follow-up. Deaths caused by concomitant diseases were in 68 (29%) pts: coronary artery disease/myocardial infarction/heart failure in 42 (62%) of 68 pts, acute ischemic stroke in 10 (15%) pts, second malignancies (Cr- cancer) in 10 (15%) pts (lung tumor, metastatic esophageal Cr, stomach Cr, brain tumor, sigmoid colon Cr, rectal colon Cr, melanoma, renal Cr, breast tumor, other hematological malignancies), accidents - 1 pt, liver cirrhosis - 2 pts, in 2 cases - respiratory virus infections complicated with pneumonia, 1 pt died due to Covid-19. Conclusions. The long-term follow-up of the multicenter study EUTOS OSP in 35 regions of Russian Federation allows not only to characterize the 15-y OS in CML pts but also provides the long-term outlook of the routine clinical practice. Probably, better OS of CML patients receiving treatment in Moscow (2 centers) may be related to organizational issues of interaction with the federal center, better monitoring and timely switching to 2G TKI therapy. The organization and support of multicenter studies may improve the situation with the treatment of diseases of the blood system. Figure 1 Figure 1. Disclosures Chelysheva: Novartis Pharma: Speakers Bureau; Pfizer: Speakers Bureau; Pharmstandart: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Vinogradova: Pharmstandart: Speakers Bureau; Novartis Pharma: Speakers Bureau; Pfizer: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau. Lomaia: Novartis: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Pharmstandard: Honoraria. Voloshin: Abbvie: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Astra Zeneca: Consultancy, Speakers Bureau; Pfizer: Consultancy; Biacad: Consultancy, Speakers Bureau. Turkina: Pharmstandart: Speakers Bureau; Pfizer: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau; Novartis Pharma: Speakers Bureau.

Background: Not everyone with CML responds optimally to TKI-therapy, especially those with BCR::ABL1T315I. PF-114 is a 4 th-generation oral tyrosine kinase-inhibitor (TKI) active against wild-type and mutated BCR::ABL1 isoforms including BCR::ABL1T315I. We present final results of a phase-1 study (NCT02885766). Methods: 3+3 dose-escalation study to determine maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). Secondary objectives included safety and efficacy based on haematological, cytogenetic and molecular response criteria. Adverse events (AEs) were graded using NCI-CTCAE v4.03. Results: 51 subjects (5 with accelerated phase CML, 46 - with chronic CML), 23 males, were studied. Daily doses were 50-600 mg/d given once daily continuously. Median age was 50 y (range, 29-82 y). Median CML duration pre-study was 10 y (range, 0.3-23 y). 16 subjects had BCR::ABL1T315I. 25 subjects received ≥ 3 prior TKIs. Median follow-up was ≥ 31 mo and median exposure, 6 mo (range, 0.4-52). Therapy was ongoing in 7 subjects at study termination. Others discontinued because of progression (n = 20), AEs (n = 2), consent withdrawal (n = 5), entry into another study (n = 3) or other reasons (n = 14). The MTD was 600 mg with the grade-3 psoriasis-like skin AE as the DLT. There were no vascular occlusive events or deviations of ankle-brachial index. Complete haematologic response (CHR) was achieved in 14 of 30 subjects, major cytogenetic response (MCyR) in 15 of 44 subjects, complete cytogenetic response (CCyR) in 11 of 50 subjects and major molecular response (MMR) in 8 of 51 subjects. Median duration of CHR was 12 mo and has not been reached for MCyR, CCyR and MMR. The best safety/efficacy dose was 300 mg/d with 6 of 9 subjects achieving a MCyR, 5, a CCyR and 4, MMR. 5 of 16 subjects with BCR::ABL1T315I responded, including 4 achieving a MCyR, 2, a CCyR and 1, a MMR. 2 of 6 subjects failing ponatinib achieved a CHR. Conclusion: PF-114 was safe and effective in subjects failing ≥ 2 TKIs and those with BCR::ABL1T315I including those failing ponatinib. The PF-114 dose for further study is 300 mg/d. Disclosures Turkina: Bristol Myers Squibb: Speakers Bureau; Pfizer: Speakers Bureau; Pharmstandart: Speakers Bureau; Novartis Pharma: Speakers Bureau. Vinogradova: Bristol Myers Squibb: Speakers Bureau; Novartis Pharma: Speakers Bureau; Pfizer: Speakers Bureau; Pharmstandart: Speakers Bureau. Lomaia: Novartis: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Pharmstandard: Honoraria. Chelysheva: Pfizer: Speakers Bureau; Novartis Pharma: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau; Pharmstandart: Speakers Bureau. Petrova: Pfizer: Speakers Bureau; Novartis Pharma: Speakers Bureau. Cortes: Bio-Path Holdings, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sun Pharma: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Bristol Myers Squibb, Daiichi Sankyo, Jazz Pharmaceuticals, Astellas, Novartis, Pfizer, Takeda, BioPath Holdings, Incyte: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Baccarani: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ottmann: Fusion: Honoraria; Incyte: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Novartis: Honoraria. Mikhailov: Fusion Pharma: Current Employment. Novikov: Fusion Pharma: Current Employment. Shulgina: Fusion Pharma: Current Employment. Chilov: Fusion Pharma: Current Employment.