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The Clp protease system is a promising, noncanonical drug target against Mycobacterium tuberculosis (Mtb). Unlike in Escherichia coli, the Mtb Clp protease consists of two distinct proteolytic subunits, ClpP1 and ClpP2, which hydrolyze substrates delivered by the chaperones ClpX and ClpC1. While biochemical approaches uncovered unique aspects of Mtb Clp enzymology, its essentiality complicates in vivo studies. To address this gap, we leveraged new genetic tools to mechanistically interrogate the in vivo essentiality of the Mtb Clp protease. While validating some aspects of the biochemical model, we unexpectedly found that only the proteolytic activity of ClpP1, but not of ClpP2, is essential for substrate degradation and Mtb growth and infection. Our observations not only support a revised model of Mtb Clp biology, where ClpP2 scaffolds chaperone binding while ClpP1 provides the essential proteolytic activity of the complex; they also have important implications for the ongoing development of inhibitors toward this emerging therapeutic target.

The proteolytic activity of human plasmin (hPm) is utilized by various cells to provide a surface protease that increases the potential of cells to migrate and disseminate. Skin-trophic Pattern D strains of Streptococcus pyogenes (GAS), e.g., GAS isolate AP53, contain a surface M-protein (PAM) that directly and strongly interacts (K-d similar to 1 nM) with human host plasminogen (hPg), after which it is activated to hPm by a specific coinherited bacterial activator, streptokinase (SK2b), or by host activators. Another ubiquitous class of hPg binding proteins on GAS cells includes "moonlighting" proteins, such as the glycolytic enzyme, enolase (Sen). However, the importance of Sen in hPg acquisition, especially when PAM is present, has not been fully developed. Sen forms a complex with hPg on different surfaces, but not in solution. Isogenic AP53 cells with a targeted deletion of PAM do not bind hPg, but the surface expression of Sen is also greatly diminished upon deletion of the PAM gene, thus confounding this approach for defining the role of Sen. However, cells with point deletions in PAM that negate hPg binding, but fully express PAM and Sen, show that hPg binds weakly to Sen on GAS cells. Despite this, Sen does not stimulate hPg activation by SK2b, but does stimulate tissue-type plasminogen activator-catalyzed activation of hPg. These data demonstrate that PAM plays the dominant role as a functional hPg receptor in GAS cells that also contain surface enolase.

Resistance mechanisms and heterogeneity in HER2-positive gastric cancers (GC) limit Trastuzumab benefit in 32% of patients, and other targeted therapies have failed in clinical trials. Using patient samples, patient-derived xenografts (PDXs), partially humanized biological models, and HER2-targeted imaging technologies we demonstrate the role of caveolin-1 (CAV1) as a complementary biomarker in GC selection for Trastuzumab therapy. In retrospective analyses of samples from patients enrolled on Trastuzumab trials, the CAV1-high profile associates with low membrane HER2 density and low patient survival. We show a negative correlation between CAV1 tumoral protein levels - a major protein of cholesterol-rich membrane domains - and Trastuzumab-drug conjugate TDM1 tumor uptake. Finally, CAV1 depletion using knockdown or pharmacologic approaches (statins) increases antibody drug efficacy in tumors with incomplete HER2 membranous reactivity. In support of these findings, background statin use in patients associates with enhanced antibody efficacy. Together, this work provides preclinical justification and clinical evidence that require prospective investigation of antibody drugs combined with statins to delay drug resistance in tumors. Clinical evidences have demonstrated limited efficacy of HER2-targeted therapies in patients with gastric cancer (GC). Here the authors show that survival benefit to anti-HER2 antibody Trastuzumab is reduced in GC patients with high levels of the caveolin-1 and that, in preclinical cancer models, antibody drug efficacy can be improved by modulating caveolin-1 levels with cholesterol-depleting drugs, statins.

Giant condyloma acuminatum, also known as Buschke-Lowenstein tumor (BLT), is a rare disease of the anogenital region. BLT is considered a locally aggressive tumor of benign histological appearance, but with the potential for destructive growth and high recurrence rates. BLT development is strongly associated with infection with low-risk human papillomaviruses (HPVs), mostly HPV-6 and -11. Immunity to HPVs plays a crucial role in the natural control of various HPV-induced lesions. Large condyloma acuminata are frequently reported in patients with primary (e.g., DOCK8 or SPINK5 deficiencies) and secondary (e.g., AIDS, solid organ transplantation) immune defects. Individuals with extensive anogenital warts, including BLT in particular, should therefore be tested for inherited or acquired immunodeficiency. Research into the genetic basis of unexplained cases is warranted. An understanding of the etiology of BLT would lead to improvements in its management. This review focuses on the role of underlying HPV infections, and human genetic and immunological determinants of BLT.

Background: Hidradenitis suppurativa (HS) is associated with comorbidities that contribute to poor health, impaired life quality, and mortality risk. Objective: To provide evidence-based screening recommendations for comorbidities linked to HS. Methods: Systematic reviews were performed to summarize evidence on the prevalence and incidence of 30 comorbidities in patients with HS relative to the general population. The screening recommendation for each comorbidity was informed by the consistency and quality of existing studies, disease prevalence, and magnitude of association, as well as benefits, harms, and feasibility of screening. The level of evidence and strength of corresponding screening recommendation were graded by using the Strength of Recommendation Taxonomy (SORT) criteria. Results: Screening is recommended for the following comorbidities: acne, dissecting cellulitis of the scalp, pilonidal disease, pyoderma gangrenosum, depression, generalized anxiety disorder, suicide, smoking, substance use disorder, polycystic ovary syndrome, obesity, dyslipidemia, diabetes mellitus, metabolic syndrome, hypertension, cardiovascular disease, inflammatory bowel disease, spondyloarthritis, and sexual dysfunction. It is also recommended to screen patients with Down syndrome for HS. The decision to screen for specific comorbidities may vary with patient risk factors. The role of the dermatologist in screening varies according to comorbidity. Limitations: Screening recommendations represent one component of a comprehensive care strategy. Conclusions: Dermatologists should support screening efforts to identify comorbid conditions in HS.

A recent Perspective article described the "carbohydrate-insulin model (CIM)" of obesity, asserting that it "better reflects knowledge on the biology of weight control" as compared with what was described as the "dominant energy balance model (EBM)," which fails to consider "biological mechanisms that promote weight gain." Unfortunately, the Perspective conflated and confused the principle of energy balance, a law of physics that is agnostic as to obesity mechanisms, with the EBM as a theoretical model of obesity that is firmly based on biology. In doing so, the authors presented a false choice between the CIM and a caricature of the EBM that does not reflect modern obesity science. Here, we present a more accurate description of the EBM where the brain is the primary organ responsible for body weight regulation operating mainly below our conscious awareness via complex endocrine, metabolic, and nervous system signals to control food intake in response to the body's dynamic energy needs as well as environmental influences. We also describe the recent history of the CIM and show how the latest "most comprehensive formulation" abandons a formerly central feature that required fat accumulation in adipose tissue to be the primary driver of positive energy balance. As such, the new CIM can be considered a special case of the more comprehensive EBM but with a narrower focus on diets high in glycemic load as the primary factor responsible for common obesity. We review data from a wide variety of studies that address the validity of each model and demonstrate that the EBM is a more robust theory of obesity than the CIM.

Background: Nonsyndromic craniosynostosis is one of the most common anomalies treated by craniofacial surgeons. Despite optimal surgical management, nearly half of affected children have subtle neurocognitive deficits. Whereas timing and type of surgical intervention have been studied, the possibility of genetic influence on neurodevelopment in nonsyndromic craniosynostosis patients remains unexplored. Methods: The authors performed whole-exome sequencing for 404 case-parent trios with sporadic nonsyndromic craniosynostosis. Statistical analyses were performed to assess the burden of de novo mutations in cases compared to both expectation and 1789 healthy control trios. Individuals with and without each mutation class were analyzed, and the presence or absence of various types of neurodevelopmental delay were recorded alongside demographic information. Results: The authors identified a highly significant burden of damaging de novo mutations in mutation-intolerant [probability of loss of function intolerance (pLI) >0.9] genes in nonsyndromic craniosynostosis probands (p = 5.9 x 10(-6)). Children with these mutations had a two-fold higher incidence of neurodevelopmental delay (p = 0.001) and a more than 20-fold greater incidence of intellectual disability (p = 7.2 x 10(-7)), and were 3.6-fold more likely to have delays that persisted past 5 years of age (p = 4.4 x 10(-4)) in comparison with children with nonsyndromic craniosynostosis without these mutations. Transmitted loss of function mutations in high-pLI genes also conferred a 1.9-fold greater risk of neurodevelopmental delay (p = 4.5 x10(-4)). Conclusions: These findings implicate genetic lesions concurrently impacting neurodevelopment and cranial morphogenesis in the pathoetiology of nonsyndromic craniosynostosis and identify a strong genetic influence on neurodevelopmental outcomes in affected children. These findings may eventually prove useful in determining which children with nonsyndromic craniosynostosis are most likely to benefit from surgical intervention.

During vertebrate embryogenesis, cell collectives engage in coordinated behavior to form tissue structures of increasing complexity. In the avian skin, assembly into follicles depends on intrinsic mechanical forces of the dermis, but how cell mechanics initiate pattern formation is not known. Here, we reconstitute the initiation of follicle patterning ex vivo using only freshly dissociated avian dermal cells and collagen. We find that contractile cells physically rearrange the extracellular matrix (ECM) and that ECM rearrangement further aligns cells. This exchange transforms a mechanically unlinked collective of dermal cells into a continuum, with coherent, long-range order. Combining theory with experiment, we show that this ordered cell-ECM layer behaves as an active contractile fluid that spontaneously forms regular patterns. Our study illustrates a role for mesenchymal dynamics in generating cell-level ordering and tissue-level patterning through a fluid instability-processes that may be at play across morphological symmetry-breaking contexts.

Pathogenic enteric viruses are a major cause of morbidity and mortality, particularly among children in developing countries. The host response to enteric viruses occurs primarily within the mucosa, where the intestinal immune system must balance protection against pathogens with tissue protection and tolerance to harmless commensal bacteria and food. Here, we summarize current knowledge in natural immunity to enteric viruses, highlighting specialized features of the intestinal immune system. We further discuss how knowledge of intestinal anti-viral mechanisms can be translated into vaccine development with particular focus on immunization in the oral route. Research reveals that the intestine is a complex interface between enteric viruses and the host where environmental factors influence susceptibility and immunity to infection, while viral infections can have lasting implications for host health. A deeper mechanistic understanding of enteric anti-viral immunity with this broader context can ultimately lead to better vaccines for existing and emerging viruses.