Citations

ABSTRACT Knowledge of Treponema pallidum subspecies pallidum ( TPA ) outer membrane protein (OMP) sequence variability is essential for understanding spirochete proliferation within endemic populations as well as the design of a globally effective syphilis vaccine. Our group has identified extracellular loops (ECLs) of TPA BamA (TP0326) and members of the FadL family (TP0548, TP0856, TP0858, TP0859, and TP0865) as potential components of a multivalent vaccine cocktail. As part of a consortium to explore TPA strain diversity, we mapped the variability of BamA and FadL orthologs in 186 TPA strains from Malawi, China, and Colombia onto predicted 3D structures. The 186 genomes fell into eight subclades (five Nichols- and three SS14-lineage) with substantial geographic restriction. Single nucleotide variants accounted for the large majority of proteoforms, with variability notably higher within the Nichols-lineage strains. Most mutations were in regions of the proteins predicted to be extracellular and harboring B cell epitopes. We observed a striking difference in the degree of variability between the six OMPs, suggesting that these proteins are following divergent evolutionary paths. Concatenation of OMP sequences recapitulated the phylogenetic structure of the TPA strains, effectively segregating within clades and largely clustering by subclades. Finally, we noted that BamA and FadL candidate ECL vaccinogens, previously shown to elicit antibodies that kill treponemes during in vitro cultivation, are well conserved. Taken as a whole, our study establishes a structural-phylogenetic approach for analyzing the forces shaping the host-pathogen interface in syphilis within endemic populations while informing the selection of vaccine targets. IMPORTANCE Syphilis remains a major global health concern, reinforcing the need for a safe and effective vaccine. Understanding the variability of TPA OMPs is essential for tracking pathogen evolution and informing vaccine design. Here, we analyzed the variability of six TPA OMPs in 186 strains from Malawi, China, and Colombia, identifying protein-specific evolutionary patterns. Most mutations were localized in extracellular regions and, notably, appeared to correlate with the phylogenetic structure of TPA . Despite OMP heterogeneity, several candidate vaccinogens remained highly conserved, reinforcing their potential as globally effective vaccine targets. Our study establishes a structural-phylogenetic framework for dissecting the forces shaping the host-spirochete interface within endemic populations and provides a foundation for designing a globally effective syphilis vaccine.

Triple-negative breast cancer (TNBC) represents the most malignant subtype of breast cancer. The clinical application of PARP inhibitors (PARPi) is limited by the low frequency of BRCA1/2 mutations in TNBC. Here, we identified that MTAP deletion sensitized genotoxic agents in our clinical cohort of metastatic TNBC. Further study demonstrated that MTAP deficiency or inhibition rendered TNBC susceptibility to chemotherapeutic agents, particularly PARPi. Mechanistically, targeting MTAP that synergized with PARPi by disrupting the METTL16-MAT2A axis involved in methionine metabolism and depleting in vivo s-adenosylmethionine (SAM) levels. Exhausted SAM in turn impaired PARPi-induced DNA damage repair through attenuation of MRE11 recruitment and end resection by diminishing MRE11 methylation. Notably, brain metastatic TNBC markedly benefited from a lower dose of PARPi and MTAP deficiency/inhibition synergy due to the inherently limited methionine environment in the brain. Collectively, our findings revealed a feed-forward loop between methionine metabolism and DNA repair through SAM, highlighting a therapeutic strategy of PARPi combined with MTAP deficiency/inhibition for TNBC.

ABSTRACT Knowledge of Treponema pallidum subspecies pallidum ( TPA ) outer membrane protein (OMP) sequence variability is essential for understanding spirochete proliferation within endemic populations as well as design of a globally effective syphilis vaccine. Our group has identified extracellular loops (ECLs) of TPA BamA (TP0326) and members of the FadL family (TP0548, TP0856, TP0858, TP0859, and TP0865) as potential components of a multivalent vaccine cocktail. As part of a consortium to explore TPA strain diversity, we mapped the variability of BamA and FadL orthologs in 186 TPA strains from Malawi, China and Colombia onto predicted 3D structures. The 186 genomes fell into eight subclades (five Nichols-, three SS14-lineage) with substantial geographic restriction. Single nucleotide variants accounted for the large majority of proteoforms, with variability notably higher within the Nichols-lineage strains. Most mutations were in regions of the proteins predicted to be extracellular and harboring B cell epitopes. We observed a striking difference in the degree of variability between the six OMPs, suggesting that these proteins are following divergent evolutionary paths. Concatenation of OMP sequences recapitulated the phylogenetic structure of the TPA strains, effectively segregating within clades and largely clustering by subclades. Lastly, we noted that BamA and FadL candidate ECL vaccinogens previously shown to elicit antibodies that kill treponemes during in vitro cultivation are well conserved. Taken as a whole, our study establishes a structural-phylogenetic approach for analyzing the forces shaping the host-pathogen interface in syphilis within endemic populations while informing selection of vaccine targets. IMPORTANCE Syphilis remains a major global health concern, reinforcing the need for a safe and effective vaccine. Understanding the variability of TPA OMPs is essential for tracking pathogen evolution and informing vaccine design. Here, we analyzed the variability of six TPA OMPs in 186 strains from Malawi, China, and Colombia, identifying protein-specific evolutionary patterns. Most mutations were localized in extracellular regions and, notably, appeared to correlate with the phylogenetic structure of TPA . Despite OMP heterogeneity, several candidate vaccinogens remained highly conserved, reinforcing their potential as globally effective vaccine targets. Our study establishes a structural-phylogenetic framework for dissecting the forces shaping the host-spirochete interface within endemic populations and provides a foundation for designing a globally effective syphilis vaccine.

Abstract Background Hemoglobin S (HbS) causes sickling disorders. In the laboratory, confirmation of HbS in patient samples with varying percentages is essential. Assessment is routinely performed using capillary electrophoresis (CE) and/or high-performance liquid chromatography. Sickle solubility (SS) exploits decreased solubility of HbS under reducing conditions and is a confirmatory test. SS is unreliable with low HbS, elevated HbF, severe anemia, erythrocytosis, hyperglobulinemia, extreme leukocytosis, hyperlipidemia, or increased serum proteins. Infant samples commonly have low percentages of HbS, high HbF, and limited sample volume. Intact globin chain Mass Spectrometry (MS) is used to identify abnormal hemoglobin variants by detecting the mass change (normal α/β/γ mass =15127/15867/15996 amu), respectively). MS has potential advantages in sensitivity and efficiency over SS and requires lower input sample volume. Herein we compare the utility of MS versus SS for confirmation of HbS. Methods Twenty-three EDTA-anticoagulated blood samples containing low percentages of HbS were identified. SS was performed on 30μL washed packed cells (requires 200μL whole blood) per standard methods. Intact Quadrupole Time-of-Flight MS (Accurate-Mass Q-TOF LC/MS 6520, Agilent Technologies, California) was performed using 10μL whole blood sample in acetonitrile solution reagent and results were compared. HbS and HbF levels were assayed by capillary electrophoresis (Sebia, France) per standard methods. Results Select results are summarized in Table 1. SS detected HbS percentages to 4.8% when HbF was low but not 6% HbS when Hb F is high. MS showed no HbF interference and identified HbS peaks (at 15837 amu) down to 3.1%. HbS percentages <3.1 were undetected by both methods. Conclusions Overall, MS was superior to SS for confirming HbS, particularly in samples with low variant percentage and/or elevated HbF. MS is also optimal when sample volume is minimal, such as for infants. Percentages of HbS <3% require methods such as IEF or DNA sequencing for confirmation.

Abstract Immune checkpoint blockade (ICB) has revolutionized cancer therapy. However, the response of patients to ICB is difficult to predict. Here, we examined 81 patients with lung cancer under ICB treatment and found that patients with MET amplification were resistant to ICB and had a poor progression-free survival. Tumors with MET amplifications had significantly decreased STING levels and antitumor T-cell infiltration. Furthermore, we performed deep single-cell RNA sequencing on more than 20,000 single immune cells and identified an immunosuppressive signature with increased subsets of XIST- and CD96-positive exhausted natural killer (NK) cells and decreased CD8+ T-cell and NK-cell populations in patients with MET amplification. Mechanistically, we found that oncogenic MET signaling induces phosphorylation of UPF1 and downregulates tumor cell STING expression via modulation of the 3′-UTR length of STING by UPF1. Decreased efficiency of ICB by MET amplification can be overcome by inhibiting MET. Significance: We suggest that the combination of MET inhibitor together with ICB will overcome ICB resistance induced by MET amplification. Our report reveals much-needed information that will benefit the treatment of patients with primary MET amplification or EGFR–tyrosine kinase inhibitor resistant-related MET amplification. This article is highlighted in the In This Issue feature, p. 2659

Background: Racial disparity in pathological consequences in skull growth may impact the treatment plan for different patient populations. This study attempts to explore the differences between Asian and Caucasian cranial morphology in Crouzon syndrome. Method: Ninety-one computed tomographic scans were included (Asian Crouzon syndrome, n = 12; Asian controls, n = 22; Caucasian Crouzon syndrome, n = 16; Caucasian controls, n = 41), and measured using Mimics and 3-matics software. Results: The entire cranial base length was reduced 11.92 mm (P = 0.004) in Asian Crouzon patients, and 14.58 mm (P < 0.001) in Caucasian Crouzon patients, compared to respective controls. The cranial base angle on the facial side of basicranium was more narrowed in Crouzon syndrome in both races, with similar changes of degrees (9.61°, P = 0.002, in Asian Crouzon; 9.20°, P = 0.019, in Caucasian Crouzon). However, the intracranial side was statistically more narrowed only in the Asian group (9.86°, P = 0.003). Both Asian and Caucasian Crouzon patients developed reduced posterior fossa volume, by 15% (P = 0.034) and 17% (P = 0.004), respectively. However, Caucasian Crouzon patients developed a more shortened anterior and middle cranial base, than that of Asian patients. The separation of lateral pterygoids was only significantly increased in Caucasian patients (5.49°, P < 0.001). Conclusion: Crouzon syndrome causes a shortened, widened, and kyphotic cranial base across both races. It also restricts the development of the posterior cranial fossa. However, the skull malformation is not the same between populations: Asian Crouzon patients developed more narrowed cranial base angulation on the intracranial side of basicranium, while Caucasian Crouzon patients developed more widened lateral pterygoids.

Background— Preoperative factors associated with increased mortality and worse outcome after tricuspid valve replacement in patients with severe tricuspid regurgitation are poorly understood. Methods and Results— We retrospectively analyzed 189 patients (37% men; age, 67.5±11.3 years) who underwent tricuspid valve replacement for severe tricuspid regurgitation. Operative mortality rate was 10%, and was associated with intra-aortic balloon pump (odds ratio, 3.2; 95% confidence interval, 1.9 to 5.6; P <0.0001) or the presence of severe symptoms (New York Heart Association class IV relative to classes II and/or III) at the time of surgery (1.7; 95% confidence interval, 1.05 to 2.8; P =0.02). At the end of follow-up (29.3±27.1 months), 70 patients (37%) died, 6 (3%) needed tricuspid reoperation, and 41 (21.7%) were readmitted for heart failure. Seventy-eight patients (41.3%) were free from cardiovascular events (death, tricuspid reoperation, or heart failure admissions). The only echocardiographic parameter independently associated with adverse outcomes was a decrease in the right index of myocardial performance ratio. All-cause mortality was independently associated with a higher Charlson index (hazard ratio, 1.18; 95% confidence interval, 1.01 to 1.36; P =0.03), shorter right index of myocardial performance ratio (0.91; 95% confidence interval, 0.87 to 0.96; P =0.005), and preoperative New York Heart Association IV class (1.71; 95% confidence interval, 1.3 to 2.2; P <0.0001). In 68 patients with isolated tricuspid valve replacement, the associations between short right index of myocardial performance ratio, high Charlson index, New York Heart Association class IV, and increased mortality remained significant. Conclusions— Tricuspid valve replacement for severe tricuspid regurgitation can be performed with an acceptable operative mortality if patients undergo surgery before the onset of advanced heart failure symptoms. Late mortality is associated with a high preoperative Charlson index, short right index of myocardial performance ratio, and advanced New York Heart Association class.

It has been suggested that leukotrienes C4 (LTC4) and D4 (LTD4) released from upper respiratory mucosa influence mucociliary transport during allergic reactions. We studied the in vitro effects of leukotrienes C4 and D4 on the ciliary beat frequency (CBF) of human adenoid explants over a 5‐hour period. Tissue explants were cultured at 35° C in Minimum Essential Medium Eagle (MEM). The CBF was measured using phase contrast microscopy and microphotometry. Measurements of CBF were recorded in medium alone and in medium containing LTC4 or LTD4 at concentrations of 10−8 and 10−6 M. LTC4 and LTD4 increased CBF at concentrations of 10−8 and 10−6 M with increases of 20.51% ± 2.69% and 29.84% ± 4.06%, respectively. To determine the specificity of the LTC4 and LTD4 effects, the ciliated epithelium was treated with the specific leukotriene receptor antagonist LY‐171,883 before administration of LTC4 and LTD4. LY‐171,883 (10−6 M) significantly inhibited the ciliostimulatory effects of both leukotrienes. Our findings indicate that LTC4 and LTD4 increase CBF in vitro by activation of the LTD4 receptor.

The purpose of this study was to compare the effects on human nasal cilia of various freezing and thawing methods in order to determine a reliable method of cryopreservation. Ten samples each were preserved by a slow freezing and a fast freezing method. All samples were stored in liquid nitrogen (–196°C) for 1 week. The frozen samples were thawed by one of two methods: 1) rapid thawing—37°C water bath for 3–4 minutes; and 2) slow thawing—room temperature for 15 minutes. Prefreeze and postthaw ciliary beat frequency (CBF) was measured. The slow freezing and fast thawing method (SFFT) resulted in the best viability. An additional 10 samples preserved using the SFFT method stored at –70°C to –90°C did not retain ciliary function. Thirty ciliated samples preserved by the SFFT method were examined after freezing in liquid nitrogen (–196°C) for 1 week, 2 weeks, and 1 month. There was no significant decrease in CBF after cryopreservation at –196°C for 1 week or 2 weeks (P> 0.05). As the storage time increased to 1 month, postthaw CBF decreased 7.25 ± 0.87% when compared to the prefreeze CBF (P < 0.05). We conclude that human nasal cilia preserved by SFFT at –196°C retain activity for up to 1 month.