Leishmania donovani Rab5 isoforms, LdRab5a and LdRab5b, play distinct roles in the early stages of endocytosis, with LdRab5a primarily regulating fluid-phase uptake and LdRab5b modulating receptor-mediated endocytosis. These functional differences are governed by structural variations within their GTPase domains. Here, we report the crystal structure of the GTPase domain of LdRab5a in its active, GppNHp-bound, form and compare it to the previously solved GDP-bound structure. Binding of the γ-phosphate analog induces a closed conformation of the Switch I and Switch II regions, a characteristic of the active state. Circular Dichroism and thermal stability assessments using Differential Scanning Calorimetry confirmed proper folding of the protein and revealed that guanine nucleotide and Mg2+ binding, significantly enhanced protein stability. Furthermore, molecular dynamics simulations were conducted to explore the conformational dynamics of LdRab5a in both GDP and GppNHp-bound states. The GppNHp-bound form exhibited greater structural stability compared to the GDP-bound inactive form, with significantly reduced flexibility in the Switch I region. We also present the crystal structure of LdRab5b in its GDP-bound state. Structural analysis suggests that LdRab5b may adopt an intermediate conformation during nucleotide exchange, evidenced by weak Mg2+ coordination and a flipped-out conformation of the Switch II residue Ala78. Comparative structural analysis with human Rab5b and Arabidopsis thaliana Ara7 reveals significant differences in helix α1, strand β2, and the positioning of the hydrophobic triad residues, indicating lineage-specific adaptations in LdRab5b. Collectively, our study provides novel insights into the structure-function relationships of Leishmania Rab5 isoforms and their differential roles in endocytic trafficking.

Several recent advancements have transformed solution NMR spectroscopy into a competitive, elegant, and eminently viable technique for determining the solution structures of membrane proteins at the level of atomic resolution. Once a good level of cell-based or cell-free expression and purification of a suitably sized membrane protein has been achieved, then NMR offers a combination of several versatile strategies, for example, choice of appropriate deuterated or non-deuterated detergents, temperature, and ionic strength; isotope labelling with (2)H, (13)C, (15)N, with or without protonation of Ile (δ1), Leu, and Val methyl protons; combinatorial labelling of specific amino acids; transverse relaxation-optimized NMR spectroscopy-based, Nonuniform sampling-based, and other NMR experiments; measurement of residual dipolar couplings using stretched polyacrylamide gels or DNA nanotubes; and spin-labelling and paramagnetic relaxation enhancements. Strategic combinations of these advancements together with availability of highly sensitive cryogenically cooled probes equipped high-field NMR spectrometers (up to 1 GHz (1)H frequency) have allowed the perseverant investigator to successfully overcome several of the conventional pitfalls associated with the NMR technique and membrane proteins, viz., low sensitivity, poor sample stability, spectral crowding, and a limited number of NOEs and other constraints for structure calculations. This has resulted in an unprecedented growth in the number of successfully determined NMR structures of large and complex membrane proteins, and this technique now holds great promise for the structure determination of an ever larger body of membrane proteins.

Mycobacterium tuberculosis (Mtb) effectively suppresses host immunity to ensure its survival. We have earlier shown that the Acr1 protein of Mtb can inhibit the differentiation of dendritic cells (DCs). Consequently, in the current study, we examined the role of Acr1 in mitigating autoimmunity. Initially, we observed that Acr1 skews the differentiation of DCs into functionally competent myeloid-derived suppressor cells (MDSCAcr1) that chiefly secrete immunosuppressive molecules, expand regulatory T cells (TregAcr1) and attenuate inflammatory responses. Further, MDSCAcr1 suppress Th17 cells. Acr1 expanded MDSCs with a concurrent increase in myelin oligodendrocyte glycoprotein (MOG)-specific Tregs and a decline in Th17 cells in a murine experimental autoimmune encephalomyelitis (EAE) model and prevented the onset of the disease. These results were further validated in the prophylactic model of EAE. Mechanistically, Acr1 activates Tregs and MDSCs via the TLR-4 pathway, implicating innate immune recognition in Mtb-induced suppression. The results indicate a potential role of Acr1 against autoimmune diseases.

The pivotal role of mTORC2 in cancer progression and metastasis underscores its potential as drug target. Despite this, selective inhibition of mTORC2 without affecting mTORC1 represents an unmet need in cancer therapy. We aimed to exploit RAS-mSIN1 interaction for selective mTORC2 targeting. We developed an 11-mer peptide (S-016-1034) from the RAS-Binding-Domain of mSIN1. Cell-free Biolayer-Interferometry (BLI) studies, confirmed direct binding of S-016-1034 to Ras, unlike its scrambled counterpart. Confocal microscopy and flow-cytometry studies illustrated peptide’s cell-membrane penetration, through non-endosomal route, Cell-based assays, including immunoprecipitation and in-situ proximity-ligation, illustrated disruption of Ras-mSin1 interaction, achieving selective inhibition of mTORC2 over mTORC1. The specificity of mTORC2 inhibition was further substantiated through transcriptomics, cell-based, small model (C. elegans), and 4T1/Balb/c mouse models of breast cancer. These studies highlight the potential of Ras-binding peptide S-016-1034 in selectively inhibiting mTORC2, whereby further optimization may offer promising strategies to halt cancer cell invasion and metastasis.

The members of the PadR family of transcriptional regulators are important for cell survival in toxic environments and play an important role in detoxification, pathogenicity, and multi-drug resistance. Rv0047c of Mycobacterium tuberculosis H37Rv is annotated as a PadR family protein. We have characterized the stability and structure of Rv0047c. Rv0047c forms a stable dimer in solution. Its stability is characterized by a thermal melting transition temperature (Tm) of 55.3 °C. The crystal structure of Rv0047c was determined at a resolution of 3.15 Å. The structure indicates the biological unit to be a dimer with each monomer having a characteristic N-terminal winged-helix-turn-helix DNA binding domain and a C-terminal dimerization domain. The N-terminal domain is composed of four helices, α1, α2, α3, and α4 and two beta strands β1 and β2. The C-terminal dimerization domain (CTD) consists two long helices α6 and α7. The two domains are connected by helix α5. A short helical turn (helix αa, residue 89-92), leads to compaction of the α4-α5 loop. Rv0047c exhibits specificity in binding to an upstream region having an inverted repeat sequence. This binding is dependent upon Y18 and Y40 residue of Rv0047c, which are highly conserved among the PadR family. Overall, our results suggest a transcription regulatory role for Rv0047c, similar to other PadR family proteins.

In bacteria, peptidyl-tRNA hydrolase (Pth, E.C. 3.1.1.29) is a ubiquitous and essential enzyme for preventing the accumulation of peptidyl-tRNA and sequestration of tRNA. Pth is an esterase that cleaves the ester bond between peptide and tRNA. Here, we present the crystal structure of Pth from Enterococcus faecium (EfPth) at a resolution of 1.92 & Aring;. The two molecules in the asymmetric unit differ in the orientation of sidechain of N66, a conserved residue of the catalytic site. Enzymatic hydrolysis of substrate alpha-N-BODIPY-lysyl-tRNALys (BLT) by EfPth was characterized by Michaelis-Menten parameters KM 163.5 nM and Vmax 1.9 nM/s. Compounds having pyrrolinone scaffold were tested for inhibition of Pth and one compound, 1040-C, was found to have IC50 of 180 nM. Antimicrobial activity profiling was done for 1040-C. It exhibited equipotent activity against drug-susceptible and resistant S. aureus (MRSA and VRSA) and Enterococcus (VSE and VRE) with MICs 2-8 mu g/mL. 1040-C synergized with gentamicin and the combination was effective against the gentamicin resistant S. aureus strain NRS119. 1040-C was found to reduce biofilm mass of S. aureus to an extent similar to Vancomycin. In a murine model of infection, 1040-C was able to reduce bacterial load to an extent comparable to Vancomycin.

Globally, infections due to multi-drug resistant (MDR) Gram-negative bacterial (GNB) pathogens are on the rise, negatively impacting morbidity and mortality, necessitating urgent treatment alternatives. Herein, we report a detailed bio-evaluation of an ultrashort, cationic lipopeptide 'SVAP9I' that demonstrated potent antibiotic activity and acted as an adjuvant to potentiate existing antibiotic classes towards GNBs. Newly synthesized lipopeptides were screened against ESKAPE pathogens and cytotoxicity assays were performed to evaluate the selectivity index (SI). SVAP9I exhibited broad-spectrum antibacterial activity against critical MDR-GNB pathogens including members of Enterobacteriaceae (MIC 4-8 mg/L), with a favorable CC50 value of >= 100 mg/L and no detectable resistance even after 50th serial passage. It demonstrated fast concentration-dependent bactericidal action as determined via time-kill analysis and also retained full potency against polymyxin B-resistant E. coli, indicating distinct mode of action. SVAP9I targeted E. coli's outer and inner membranes by binding to LPS and phospholipids such as cardiolipin and phosphatidylglycerol. Membrane damage resulted in ROS generation, depleted intracellular ATP concentration and a concomitant increase in extracellular ATP. Checkerboard assays showed SVAP9I's synergism with narrow-spectrum antibiotics like vancomycin, fusidic acid and rifampicin, potentiating their efficacy against MDR-GNB pathogens, including carbapenem-resistant Acinetobacter baumannii (CRAB), a WHO critical priority pathogen. In a murine neutropenic thigh infection model, SVAP9I and rifampicin synergized to express excellent antibacterial efficacy against MDR-CRAB outcompeting polymyxin B. Taken together, SVAP9I's distinct membrane-targeting broad-spectrum action, lack of resistance and strong in vitro andin vivopotency in synergism with narrow spectrum antibiotics like rifampicin suggests its potential as a novel antibiotic adjuvant for the treatment of serious MDR-GNB infections.

Rv1176c of Mycobacterium tuberculosis H37Rv belongs to the PadR-s1 subfamily of the PadR family of protein. Rv1176c forms a stable dimer in solution. Its stability is characterized by a thermal melting transition temperature (Tm) of 39.4 °C. The crystal structure of Rv1176c was determined at a resolution of 2.94 Å, with two monomers in the asymmetric unit. Each monomer has a characteristic N-terminal winged-helix-turn-helix DNA-binding domain. Rv1176c C-terminal is a coiled-coil dimerization domain formed of α-helices α5 to α7. In the Rv1176c dimer, there is domain-swapping of the C-terminal domain in comparison to other PadR homologs. In the dimer, there is a long inter-subunit tunnel in which different ligands can bind. Rv1176c was found to bind to the promoter region of its own gene with high specificity. M. smegmatis MC2 155 genome lacks homolog of Rv1176c. Therefore, it was used as a surrogate to characterize the functional role of Rv1176c. Expression of Rv1176c in M. smegmatis MC2 155 cells imparted enhanced tolerance towards oxidative stress. Rv1176c expressing M. smegmatis MC2 155 cells exhibited enhanced intracellular survival in J774A.1 murine macrophage cells. Overall, our studies demonstrate Rv1176c to be a PadR-s1 subfamily transcription factor that can moderate the effect of oxidative stress.

OBJECTIVE:Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship.METHODS:In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift.RESULTS:A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (β = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results.INTERPRETATION:In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023;93:793-804.

The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice.In a pooled patient-level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II, and SELECT, EVT functional outcomes (modified Rankin Scale score distribution) were compared between general anesthesia (GA) vs non-GA in a propensity-matched sample. Furthermore, we evaluated the association of collateral flow on perfusion imaging, assessed by hypoperfusion intensity ratio (HIR) - Tmax > 10 seconds/Tmax > 6 seconds (good collaterals - HIR < 0.4, poor collaterals - HIR ≥ 0.4) on the association between anesthesia type and EVT outcomes.Of 725 treated with EVT, 299 (41%) received GA and 426 (59%) non-GA. The baseline characteristics differed in presentation National Institutes of Health Stroke Scale score (median [interquartile range] GA: 18 [13-22], non-GA: 16 [11-20], p < 0.001) and ischemic core volume (GA: 15.0 mL [3.2-38.0] vs non-GA: 9.0 mL [0.0-31.0], p < 0.001). In addition, GA was associated with longer last known well to arterial access (203 minutes [157-267] vs 186 minutes [138-252], p = 0.002), but similar procedural time (35.5 minutes [23-59] vs 34 minutes [22-54], p = 0.51). Of 182 matched pairs using propensity scores, baseline characteristics were similar. In the propensity score-matched pairs, GA was independently associated with worse functional outcomes (adjusted common odds ratio [adj. cOR]: 0.64, 95% CI: 0.44-0.93, p = 0.021) and higher neurologic worsening (GA: 14.9% vs non-GA: 8.9%, aOR: 2.10, 95% CI: 1.02-4.33, p = 0.045). Patients with poor collaterals had worse functional outcomes with GA (adj. cOR: 0.47, 95% CI: 0.29-0.76, p = 0.002), whereas no difference was observed in those with good collaterals (adj. cOR: 0.93, 95% CI: 0.50-1.74, p = 0.82), pinteraction: 0.07. No difference was observed in infarct growth overall and in patients with good collaterals, whereas patients with poor collaterals demonstrated larger infarct growth with GA with a significant interaction between collaterals and anesthesia type on infarct growth rate (pinteraction: 0.020).GA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals in a propensity score-matched analysis from a pooled patient-level cohort from 3 randomized trials and 1 prospective cohort study. The confounding by indication may persist despite the doubly robust nature of the analysis. These findings have implications for randomized trials of GA vs non-GA and may be of utility for clinicians when making anesthesia type choice.This study provides Class III evidence that use of GA is associated with worse functional outcome in patients undergoing EVT.EXTEND-IA: ClinicalTrials.gov (NCT01492725); EXTEND-IA TNK: ClinicalTrials.gov (NCT02388061); EXTEND-IA TNK part II: ClinicalTrials.gov (NCT03340493); and SELECT: ClinicalTrials.gov (NCT02446587).

Statement The authors have withdrawn their manuscript owing to the authors decision of withdrawing of the manuscript until all experiments are completed. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

Background: The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice. Methods: In a pooled patient level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II and SELECT, EVT Functional outcomes (mRS distribution) were compared between general anesthesia (GA) vs non-general anesthesia (non-GA). Further, we assessed the impact of collateral flow on perfusion imaging evaluated by hypoperfusion intensity ratio (HIR) - Tmax10 sec/Tmax6 sec) on the association between anesthesia type and EVT outcomes. Results: Of 731 treated with EVT, 305 (42%) received GA and 426 (58%) non-GA. The baseline characteristics were similar, except for presentation NIHSS (median [IQR] GA 18 [13-22], non-GA 16[11-20], p<0.001) and ischemic core volume (GA 14.1mL [3-37] vs non-GA 9mL [0-31], p=0.002). GA was associated with longer LKW to arterial access (203min [158-267] vs 186min [138-252], p=0.002), but similar procedural time (36min [23-59] vs 34min [22-54], p=0.36). Non-GA was independently associated with improved functional outcomes (adj cOR 1.42, 95%CI 1.05-1.93, p=0.024) and lower mortality (17% vs 11.3%, p=0.025). Patients with poor collaterals (HIR≥0.4) had improved functional outcomes with non-GA (adj cOR 1.53, 95%CI 1.02-2.29, p=0.038), while no difference was observed in those with good collaterals-HIR<0.4 (adj cOR 1.38, 95% CI 0.84-2.27, p=0.21). Conclusion: GA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals. These findings have implications for randomized trials of GA vs non-GA.

Mycobacterium tuberculosis (Mtb) is a smart and successful pathogen since it can persist in the intimidating environment of the host by taming and tuning the immune system. Mtb releases MPT64 (Rv1980c) protein in high amounts in patients with active tuberculosis (TB). Consequently, we were curious to decipher the role of MPT64 on the differentiating dendritic cells (DCs) and its relation to evading the immune system. We observed that pre-exposure of differentiating DCs to MPT64 (DCMPT64) transformed them into a phenotype of myeloid-derived suppressor cells (MDSCs). DCMPT64 expressed a high level of immunosuppressive molecules PD-L1, TIM-3, nitric oxide (NO), arginase 1, IDO-1, IL-10 and TGF-β, but inhibited the production of pro-inflammatory cytokines TNF-α, IL-6 and IL-12. DCMPT64 chemotaxis function was diminished due to the reduced expression of CCR7. DCMPT64 promoted the generation of regulatory T cells (Tregs) but inhibited the differentiation of Th1 cells and Th17 cells. Further, high lipid and methylglyoxal content, and reduced glucose consumption by DCMPT64, rendered them metabolically quiescent and consequently, reduced DCMPT64 ability to phagocytose Mtb and provided a safer shelter for the intracellular survival of the mycobacterium. The mechanism identified in impairing the function of DCMPT64 was through the increased production and accumulation of methylglyoxal. Hence, for the first time, we demonstrate the novel role of MPT64 in promoting the generation of MDSCs to favor Mtb survival and escape its destruction by the immune system.

BACKGROUND AND OBJECTIVES:The effect of anesthesia choice on endovascular thrombectomy (EVT) outcomes is unclear. Collateral status on perfusion imaging may help identify the optimal anesthesia choice. METHODS:In a pooled patient-level analysis of EXTEND-IA, EXTEND-IA TNK, EXTEND-IA TNK part II, and SELECT, EVT functional outcomes (modified Rankin Scale score distribution) were compared between general anesthesia (GA) vs non-GA in a propensity-matched sample. Furthermore, we evaluated the association of collateral flow on perfusion imaging, assessed by hypoperfusion intensity ratio (HIR) - Tmax > 10 seconds/Tmax > 6 seconds (good collaterals - HIR < 0.4, poor collaterals - HIR ≥ 0.4) on the association between anesthesia type and EVT outcomes. RESULTS:Of 725 treated with EVT, 299 (41%) received GA and 426 (59%) non-GA. The baseline characteristics differed in presentation National Institutes of Health Stroke Scale score (median [interquartile range] GA: 18 [13-22], non-GA: 16 [11-20], p < 0.001) and ischemic core volume (GA: 15.0 mL [3.2-38.0] vs non-GA: 9.0 mL [0.0-31.0], p < 0.001). In addition, GA was associated with longer last known well to arterial access (203 minutes [157-267] vs 186 minutes [138-252], p = 0.002), but similar procedural time (35.5 minutes [23-59] vs 34 minutes [22-54], p = 0.51). Of 182 matched pairs using propensity scores, baseline characteristics were similar. In the propensity score-matched pairs, GA was independently associated with worse functional outcomes (adjusted common odds ratio [adj. cOR]: 0.64, 95% CI: 0.44-0.93, p = 0.021) and higher neurologic worsening (GA: 14.9% vs non-GA: 8.9%, aOR: 2.10, 95% CI: 1.02-4.33, p = 0.045). Patients with poor collaterals had worse functional outcomes with GA (adj. cOR: 0.47, 95% CI: 0.29-0.76, p = 0.002), whereas no difference was observed in those with good collaterals (adj. cOR: 0.93, 95% CI: 0.50-1.74, p = 0.82), p interaction: 0.07. No difference was observed in infarct growth overall and in patients with good collaterals, whereas patients with poor collaterals demonstrated larger infarct growth with GA with a significant interaction between collaterals and anesthesia type on infarct growth rate (p interaction: 0.020). DISCUSSION:GA was associated with worse functional outcomes after EVT, particularly in patients with poor collaterals in a propensity score-matched analysis from a pooled patient-level cohort from 3 randomized trials and 1 prospective cohort study. The confounding by indication may persist despite the doubly robust nature of the analysis. These findings have implications for randomized trials of GA vs non-GA and may be of utility for clinicians when making anesthesia type choice. CLASSIFICATION OF EVIDENCE:This study provides Class III evidence that use of GA is associated with worse functional outcome in patients undergoing EVT. TRIAL REGISTRATION INFORMATION:EXTEND-IA: ClinicalTrials.gov (NCT01492725); EXTEND-IA TNK: ClinicalTrials.gov (NCT02388061); EXTEND-IA TNK part II: ClinicalTrials.gov (NCT03340493); and SELECT: ClinicalTrials.gov (NCT02446587).

Treatment for hepatitis C virus (HCV) with direct-acting antivirals (DAA) is advantageous over previous treatment options due to high efficacy, short treatment duration, and relatively few drug interactions. Similarly, direct oral anticoagulants (DOAC) are generally preferred over warfarin for the management of thrombosis and atrial fibrillation due to a favourable safety profile. Direct-acting antivirals inhibit DOAC transport through P-glycoprotein inhibition leading to a theoretical increase in bleeding risk. We evaluated the incidence of bleeding in patients who received concurrent DAA and DOAC therapy and stratified the analysis based on the patient's cirrhosis status. We conducted a multicenter, retrospective cohort study to evaluate bleeding in patients with HCV and cirrhosis compared to patients with HCV without cirrhosis. Patients receiving at least 1 month of overlapping DAA and DOAC therapy between May 2017 and August 2020 at 11 medical centers in the United Kingdom and three medical centers in the United States were included. Charts were manually reviewed to identify baseline characteristics as well as thromboembolic or bleeding events. Bleeding events were categorized as major bleeding (MB) and clinically relevant non-major bleeding (CRNMB). Of 204 total patients, 36 patients (18%) had cirrhosis and 168 patients (82%) did not have cirrhosis. The majority of patients were male (79%) and Caucasian (75%). Sofosbuvir/velpatasvir (32%) and rivaroxaban (57%) were the most commonly prescribed DAA and DOAC, respectively. Leading indications for anticoagulation included thrombosis (75%) and atrial fibrillation (21%). There were three MB events (1.5%) all of which occurred in patients with additional risk factors (age over 65 and on antiplatelet therapy) and no CRNMB occurred while on DOAC and DAA therapy. Of the three MB, one occurred in a patient with cirrhosis and two in patients without cirrhosis, RR 1.23 (0.56-2.76). In conclusion, in this multicenter cohort study of concurrent DAA and DOAC use, MB was uncommon and there was no CRNMB. There was no significant difference in bleeding events among patients with cirrhosis compared to those without cirrhosis. These findings support the use of DAA among patients requiring DOAC.

Tuberculosis remains a serious global health problem. BCG is the only prophylactic TB vaccine and it shows variable protective efficacy. Chimeric protein subunit vaccines hold great potential as stand-alone vaccines or heterologous BCG prime boosters. We have designed a protein chimera, PP31, by combining Mtb ESAT-6 family antigen Rv1198 and MoCo biosynthesis family antigen Rv3111. Further, PP31 was extended by addition of latency antigen Rv1813c to yield PP43. Immunization of BALB/c mice with PP31 or PP43 with FIA adjuvant elicited strong humoral immune response. Restimulation of splenocytes of the immunized mice lead to significant proliferation of lymphocytes, secretion of cytokines IFN-γ, TNF, IL-2 of the Th1 class, IL-17A of the Th17 class, and IL-6. PP31 and PP43 also induced intracellular cytokine expression (IFN-γ, TNF, and IL-2) from both CD4+-CD44high and CD8+-CD44high T-cells. Antigen-specific IFN-γ+/IL-2+ double positive CD4+ T-cells were significantly higher in case of PP43 than PP31-immunized mice and control group. PP43 showed protection equivalent to heat-inactivated BCG in response to challenge of the immunized mice with Mtb H37Ra. Based on its immunogenicity and protective efficacy, PP43 appears to be a potential candidate for further development as a subunit vaccine against TB.

We have studied the cucurbit[7]uril inclusion complexes of two anti-cancer drugs, palbociclib and ribociclib, in the solution and solid-state with the help of experimental and computational approaches. The formation of the cucurbit[7]uril inclusion complex, binding stoichiometry, and binding free energies in aqueous solution was determined from 1H-NMR, UV-spectroscopy and ITC studies. The binding of drugs in the ionized and unionized forms with cucurbit[7]uril was studied with the help of QTAIM analysis and free energy computations. We report the development of new co-amorphous solids of the cucurbit[7]uril inclusion complexes of drugs with enhanced thermal stability. We also report three new crystalline salt forms of palbociclib oxalate and a new dimethyl sulfoxide solvate of ribociclib succinate dihydrate in the study. The phase interrelationship between the palbociclib oxalate forms (1a, 1b, and 1c) was established from DSC and PXRD study.

OBJECTIVE:To evaluate the comparative safety and efficacy of direct endovascular thrombectomy (dEVT) compared to bridging therapy (BT; IV tissue plasminogen activator + EVT) and to assess whether BT potential benefit relates to stroke severity, size, and initial presentation to EVT vs non-EVT center. METHODS:In a prospective multicenter cohort study of imaging selection for endovascular thrombectomy (Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke [SELECT]), patients with anterior circulation large vessel occlusion (LVO) presenting to EVT-capable centers within 4.5 hours from last known well were stratified into BT vs dEVT. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] score 0-2). Secondary outcomes included a shift across 90-day mRS grades, mortality, and symptomatic intracranial hemorrhage. We also performed subgroup analyses according to initial presentation to EVT-capable center (direct vs transfer), stroke severity, and baseline infarct core volume. RESULTS:We identified 226 LVOs (54% men, mean age 65.6 ± 14.6 years, median NIH Stroke Scale [NIHSS] score 17, 28% received dEVT). Median time from arrival to groin puncture did not differ in patients with BT when presenting directly (dEVT 1.43 [interquartile range (IQR) 1.13-1.90] hours vs BT 1.58 [IQR 1.27-2.02] hours, p = 0.40) or transferred to EVT-capable centers (dEVT 1.17 [IQR 0.90-1.48] hours vs BT 1.27 [IQR 0.97-1.87] hours, p = 0.24). BT was associated with higher odds of 90-day functional independence (57% vs 44%, adjusted odds ratio [aOR] 2.02, 95% confidence interval [CI] 1.01-4.03, p = 0.046) and functional improvement (adjusted common OR 2.06, 95% CI 1.18-3.60, p = 0.011) and lower likelihood of 90-day mortality (11% vs 23%, aOR 0.20, 95% CI 0.07-0.58, p = 0.003). No differences in any other outcomes were detected. In subgroup analyses, patients with BT with baseline NIHSS scores <15 had higher functional independence likelihood compared to those with dEVT (aOR 4.87, 95% CI 1.56-15.18, p = 0.006); this association was not evident for patients with NIHSS scores ≥15 (aOR 1.05, 95% CI 0.40-2.74, p = 0.92). Similarly, functional outcomes improvements with BT were detected in patients with core volume strata (ischemic core <50 cm3: aOR 2.10, 95% CI 1.02-4.33, p = 0.044 vs ischemic core ≥50 cm3: aOR 0.41, 95% CI 0.01-16.02, p = 0.64) and transfer status (transferred: aOR 2.21, 95% CI 0.93-9.65, p = 0.29 vs direct to EVT center: aOR 1.84, 95% CI 0.80-4.23, p = 0.15). CONCLUSIONS:BT appears to be associated with better clinical outcomes, especially with milder NIHSS scores, smaller presentation core volumes, and those who were "dripped and shipped." We did not observe any potential benefit of BT in patients with more severe strokes. TRIAL REGISTRATION INFORMATION:ClinicalTrials.gov Identifier: NCT02446587. CLASSIFICATION OF EVIDENCE:This study provides Class III evidence that for patients with ischemic stroke from anterior circulation LVO within 4.5 hours from last known well, BT compared to dEVT leads to better 90-day functional outcomes.

NMR spectroscopy has proven itself to be invaluable in probing the structures of proteins that are not amenable to crystallization. In addition, NMR spectroscopy is of great value in characterizing the weak interactions that form the basis of drug-like action of potential hits. While 2D NMR methods for the characterization of small molecules were developed in the 1970s, in recent times, there has been a significant growth in the macromolecular NMR field, which has potentiated structure determination of several drug target proteins and protein–ligand complexes and discovery of inhibitors through NMR-based screening methods. In this chapter, our aim will be to describe the state-of-the-art methods adopted for isotope labeling of proteins, which will be followed by description of the multidimensional NMR experiments and their utilization for determination of solution structure of the proteins. NMR-based structure determination begins with suitable isotope labeling of proteins using many innovative methods. Once a double or triple isotopically labeled sample has been made, a series of multidimensional NMR experiments are carried out for the assignment of chemical shifts of the backbone and side-chain resonances and for measuring the NOE between identified protons. An ensemble of structures can then be calculated by incorporating the experimentally derived dihedral angle and distance constraints. Refinement of structural quality is done through additional constraints derived from Residual Dipolar Couplings and Paramagnetic Relaxation Enhancements. Using this technique and protocols, structures of several drug target proteins have been successfully determined with high precision. Further, NMR has been used to screen the small molecules that bind to the target protein and to study the structural and dynamics aspects of protein-ligand complexes.