ABSTRACT
Pathogen infection of host cells triggers an inflammatory cell death termed pyroptosis via activation of inflammatory caspases. However, blockade of immune signaling kinases by the Yersinia virulence factor YopJ triggers cell death involving both apoptotic caspase-8 and pyroptotic caspase-1. While caspase-1 is normally activated within inflammasomes, Yersinia-induced caspase-1 activation is independent of known inflammasome components. We report that caspase-8 is an essential initiator, while caspase-1 is an essential amplifier of its own activation through two feed-forward loops involving caspase-1 auto-processing and caspase-1-dependent activation of gasdermin D and NLPR3. Notably, while Yersinia-induced caspase-1 activation and cell death are inflammasome-independent, IL-1ß release requires NLPR3 inflammasome activation. Mechanistically, caspase-8 is rapidly activated within multiple foci throughout the cell, followed by assembly of a canonical inflammasome speck, indicating that caspase-8 and canonical inflammasome complex assemblies are kinetically and spatially distinct. Our findings reveal that functionally interconnected but distinct death complexes mediate pyroptosis and IL-1ß release in response to pathogen blockade of immune signaling.
Subject(s)
Caspase 1 , Caspase 8 , Inflammasomes , Interleukin-1beta , Phosphate-Binding Proteins , Pyroptosis , Signal Transduction , Yersinia , Interleukin-1beta/metabolism , Caspase 8/metabolism , Animals , Caspase 1/metabolism , Inflammasomes/metabolism , Yersinia/metabolism , Phosphate-Binding Proteins/metabolism , Mice , Humans , Bacterial Proteins/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Yersinia Infections/immunology , Yersinia Infections/microbiology , Yersinia Infections/metabolism , GasderminsABSTRACT
Caspases are a family of cysteine proteases that act as molecular scissors to cleave substrates and regulate biological processes such as programmed cell death and inflammation. Extensive efforts have been made to identify caspase substrates and to determine factors that dictate substrate specificity. Thousands of putative substrates have been identified for caspases that regulate an immunologically silent type of cell death known as apoptosis, but less is known about substrates of the inflammatory caspases that regulate an immunostimulatory type of cell death called pyroptosis. Furthermore, much of our understanding of caspase substrate specificities is derived from work done with peptide substrates, which do not often translate to native protein substrates. Our knowledge of inflammatory caspase biology and substrates has recently expanded and here, we discuss the recent advances in our understanding of caspase substrate specificities, with a focus on inflammatory caspases. We highlight new substrates that have been discovered and discuss the factors that engender specificity. Recent evidence suggests that inflammatory caspases likely utilize two binding interfaces to recognize and process substrates, the active site and a conserved exosite.
Subject(s)
Caspases , Inflammation , Substrate Specificity , Caspases/metabolism , Caspases/genetics , Humans , Inflammation/metabolism , Animals , Catalytic Domain , PyroptosisABSTRACT
Evaluating HIV preexposure prophylaxis (PrEP) use and HIV risk events concurrently remains challenging. We developed a single question method for measuring prevention-effective adherence with PrEP in self-report questionnaires. In a questionnaire completed by 409 gay and bisexual men, 46% reported condomless anal sex that was not covered by their own PrEP use, and this was more common among younger, lower-income participants. Refining this questionnaire item could improve measurement of prevention-effective adherence.
Subject(s)
HIV Infections , Pre-Exposure Prophylaxis , Male , Humans , HIV Infections/prevention & control , HIV Infections/drug therapy , Homosexuality, Male , Self Report , Sexual Behavior , Surveys and Questionnaires , Pre-Exposure Prophylaxis/methodsABSTRACT
Cancer immunotherapy is a novel pillar of cancer treatment that harnesses the immune system to fight tumors and generally results in robust antitumor immunity. Although immunotherapy has achieved remarkable clinical success for some patients, many patients do not respond, underscoring the need to develop new strategies to promote antitumor immunity. Pyroptosis is an immunostimulatory type of regulated cell death that activates the innate immune system. A hallmark of pyroptosis is the release of intracellular contents such as cytokines, alarmins, and chemokines that can stimulate adaptive immune activation. Recent studies suggest that pyroptosis promotes antitumor immunity. Here, we review the mechanisms by which pyroptosis can be induced and highlight new strategies to induce pyroptosis in cancer cells for antitumor defense. We discuss how pyroptosis modulates the tumor microenvironment to stimulate adaptive immunity and promote antitumor immunity. We also suggest research areas to focus on for continued development of pyroptosis as an anticancer treatment. Pyroptosis-based anticancer therapies offer a promising new avenue for treating immunologically 'cold' tumors.
Subject(s)
Neoplasms , Pyroptosis , Humans , Immunotherapy , Immunization , Adaptive Immunity , Neoplasms/therapy , Tumor MicroenvironmentABSTRACT
Inflammasomes are multiprotein signaling complexes that activate the innate immune system. Canonical inflammasomes recruit and activate caspase-1, which then cleaves and activates IL-1ß and IL-18, as well as gasdermin D (GSDMD) to induce pyroptosis. In contrast, non-canonical inflammasomes, caspases-4/-5 (CASP4/5) in humans and caspase-11 (CASP11) in mice, are known to cleave GSDMD, but their role in direct processing of other substrates besides GSDMD has remained unknown. Here, we show that CASP4/5 but not CASP11 can directly cleave and activate IL-18. However, CASP4/5/11 can all cleave IL-1ß to generate a 27-kDa fragment that deactivates IL-1ß signaling. Mechanistically, we demonstrate that the sequence identity of the tetrapeptide sequence adjacent to the caspase cleavage site regulates IL-18 and IL-1ß recruitment and activation. Altogether, we have identified new substrates of the non-canonical inflammasomes and reveal key mechanistic details regulating inflammation that may aid in developing new therapeutics for immune-related disorders.
Subject(s)
Caspases , Interleukin-18 , Interleukin-1beta , Caspases/genetics , Caspases/immunology , Interleukin-18/chemistry , Interleukin-18/genetics , Interleukin-18/immunology , Interleukin-1beta/chemistry , Interleukin-1beta/genetics , Interleukin-1beta/immunology , RAW 264.7 Cells , HEK293 Cells , HeLa Cells , THP-1 Cells , Humans , Inflammasomes/immunology , Signal Transduction/genetics , Proteolysis , Protein Binding , Protein Multimerization , Salmonella Infections/enzymology , Salmonella Infections/immunologyABSTRACT
Rationale: The in vivo dynamics of CAR-T cells remain incompletely understood. Novel methods are urgently needed to longitudinally monitor transferred cells non-invasively for biodistribution, functionality, proliferation, and persistence in vivo and for improving their cytotoxic potency in case of treatment failure. Methods: Here we engineered CD19 CAR-T cells ("Thor"-cells) to express a membrane-bound scFv, huC825, that binds DOTA-haptens with picomolar affinity suitable for labeling with imaging or therapeutic radionuclides. We assess its versatile utility for serial tracking studies with PET and delivery of α-radionuclides to enhance anti-tumor killing efficacy in sub-optimal adoptive cell transfer in vivo using Thor-cells in lymphoma models. Results: We show that this reporter gene/probe platform enables repeated, sensitive, and specific assessment of the infused Thor-cells in the whole-body using PET/CT imaging with exceptionally high contrast. The uptake on PET correlates with the Thor-cells on a cellular and functional level. Furthermore, we report the ability of Thor-cells to accumulate cytotoxic alpha-emitting radionuclides preferentially at tumor sites, thus increasing therapeutic potency. Conclusion: Thor-cells are a new theranostic agent that may provide crucial information for better and safer clinical protocols of adoptive T cell therapies, as well as accelerated development strategies.
Subject(s)
Antineoplastic Agents , Radioimmunotherapy , Positron Emission Tomography Computed Tomography , Tissue Distribution , Immunotherapy, Adoptive/methods , Radioisotopes/metabolism , Antineoplastic Agents/metabolism , T-Lymphocytes/metabolismABSTRACT
BACKGROUND: In the context of a syphilis outbreak in neighboring states, a multifaceted systems change to increase testing for sexually transmitted infections (STIs) among young Aboriginal people aged 15 to 29 years was implemented at an Aboriginal Community Controlled Health Service (ACCHS) in New South Wales, Australia. The components included electronic medical record prompts and automated pathology test sets to increase STI testing in annual routine health assessments, the credentialing of nurses and Aboriginal health practitioners to conduct STI tests independently, pathology request forms presigned by a physician, and improved data reporting. OBJECTIVE: We aimed to determine whether the systems change increased the integration of STI testing into routine health assessments by clinicians between April 2019 and March 2020, the inclusion of syphilis tests in STI testing, and STI testing uptake overall. We also explored the understandings of factors contributing to the acceptability and normalization of the systems change among staff. METHODS: We used a mixed methods design to evaluate the effectiveness and acceptability of the systems change implemented in 2019. We calculated the annual proportion of health assessments that included tests for chlamydia, gonorrhea, and syphilis, as well as an internal control (blood glucose level). We conducted an interrupted time series analysis of quarterly proportions 24 months before and 12 months after the systems change and in-depth semistructured interviews with ACCHS staff using normalization process theory. RESULTS: Among 2461 patients, the annual proportion of health assessments that included any STI test increased from 16% (38/237) in the first year of the study period to 42.9% (94/219) after the implementation of the systems change. There was an immediate and large increase when the systems change occurred (coefficient=0.22; P=.003) with no decline for 12 months thereafter. The increase was greater for male individuals, with no change for the internal control. Qualitative data indicated that nurse- and Aboriginal health practitioner-led testing and presigned pathology forms proved more difficult to normalize than electronic prompts and shortcuts. The interviews identified that staff understood the modifications to have encouraged cultural change around the role of sexual health care in routine practice. CONCLUSIONS: This study provides evidence for the first time that optimizing health assessments electronically is an effective and acceptable strategy to increase and sustain clinician integration and the completeness of STI testing among young Aboriginal people attending an ACCHS. Future strategies should focus on increasing the uptake of health assessments and promote whole-of-service engagement and accountability.
ABSTRACT
BACKGROUND: In the context of an expanding syphilis epidemic, we assessed the integration of sexually transmissible infection (STI) testing within annual health assessments for Aboriginal and Torres Strait Islander young people aged 16-29years in Aboriginal Community Controlled Health Services between 2018 and 2020. METHODS: Using routinely collected electronic medical record data from a national sentinel surveillance system (ATLAS), we performed a cross-sectional analysis to calculate the proportion of assessments that integrated any or all of the tests for chlamydia, gonorrhoea, syphilis, and HIV. We used logistic regression to identify correlates of integration of any STI test. RESULTS: Of the 13 892 assessments, 23.8% (95% CI 23.1, 24.6) integrated a test for any STI and 11.5% (95% CI 10.9, 12.0) included all four STIs. Of assessments that included a chlamydia/gonorrhoea test, 66.9% concurrently included a syphilis test. Integration of any STI test was associated with patients aged 20-24years (OR 1.2, 95% CI 1.1-1.4) and 25-29years (OR 1.1, 95% CI 1.0-1.2) compared to 16-19years and patients residing in very remote (OR 4.2, 95% CI 3.7-4.8), remote (OR 2.4, 95% CI 2.1-2.8), and regional areas (OR 2.5, 95% CI 2.2-2.8) compared to metropolitan areas. There was no association with patient sex. CONCLUSIONS: Integration of STI testing into annual health assessments for Aboriginal and Torres Strait Islander young people was higher in remote areas where disease burden is greatest. Integration is similar in men and women, which contrasts with most studies that have found higher testing in women.
Subject(s)
Chlamydia , Gonorrhea , Sexually Transmitted Diseases , Syphilis , Adolescent , Female , Humans , Male , Australian Aboriginal and Torres Strait Islander Peoples , Cross-Sectional Studies , Gonorrhea/diagnosis , Gonorrhea/epidemiology , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/epidemiology , Syphilis/diagnosis , Syphilis/epidemiology , Young Adult , AdultABSTRACT
BACKGROUND: Sexually transmitted infection (STI) rates continue to rise in Australia, and timely access to testing and treatment is crucial to reduce transmission. Web-based services have been viewed as a way to improve timely access to STI/HIV testing and have proliferated in recent years. However, the regulation of these services in Australia is minimal, leading to concerns about their quality. The purpose of this review was to systematically identify web-based STI/HIV testing services available in Australia and assess them on aspects of quality, reliability, and accessibility. OBJECTIVE: We aim to systematically identify and assess web-based STI/HIV testing services available in Australia. METHODS: A Google search of Australian web-based services was conducted in March 2022 and repeated in September 2022 using Boolean operators and search terms related to test services (eg, on the internet or home), STIs (eg, chlamydia or gonorrhea), and test type (eg, self-test). The first 10 pages were assessed, and services were categorized as self-testing (ST; test at home), self-sampling (SS; sample at home and return to laboratory), or self-navigated pathology (SNP; specimens collected at pathology center). Website reliability was assessed against the Health on the Net Foundation code of conduct, and service quality was assessed using a scorecard that was developed based on similar reviews, Australian guidelines for in-person services, and UK standards. Additionally, we looked at measures of accessibility including cost, rural access, and time to test results. RESULTS: Seventeen services were identified (8 ST, 2 SS, and 7 SNP). Only 4 services offered recommended testing for all 4 infections (chlamydia, gonorrhea, syphilis, and HIV) including genital, anorectal, and oropharyngeal sites, and 5 offered tests other than those recommended by Australian testing guidelines (eg, Ureaplasma). Nine services (1 SNP, 8 self-test) had no minimum age requirements for access. Reliability scores (scale 0-8) were similar between all services (range 4.75-8.0). Quality weighted scores (scale 0-58) were similar between SNP and SS services (average 44.89, SD 5.56 and 44.75, SD 1.77, respectively) but lower for ST services (22.66, SD 8.93; P=.002). Government-funded services were of higher quality than private services (43.54, SD 6.71 vs 29.43, SD 13.55; P=.03). The cost for services varied between SNP (Aus $0-$595; ie, US $0-$381.96), self-sample (Aus $0; ie, US $0), and ST (Aus $0-$135; ie, US $0-$86.66). The time to test results was much shorter for SNP services (~4 days) than for SS (~12 days) and ST (~14 days). CONCLUSIONS: This review identified considerable variability in the quality and reliability of the web-based STI/HIV testing services in Australia. Given the proliferation and use of these services will likely increase, it is imperative that Australia develops national standards to ensure the standard-of-care offered by web-based STI/HIV testing services is appropriate to protect Australian users from the impact of poorly performing and inappropriate tests.
Subject(s)
Gonorrhea , Sexually Transmitted Diseases , Humans , Australia , Reproducibility of Results , Sexually Transmitted Diseases/diagnosis , HIV Testing , InternetABSTRACT
Genetically engineered, cytotoxic, adoptively transferred T cells localize to antigen-positive cancer cells inside patients, but tumor heterogeneity and multiple immune escape mechanisms have prevented the eradication of most solid tumor types. More effective, multifunctional engineered T cells are in development to overcome the barriers to the treatment of solid tumors, but the interactions of these highly modified cells with the host are poorly understood. We previously engineered prodrug-activating enzymatic functions into chimeric antigen receptor (CAR) T cells, endowing them with a killing mechanism orthogonal to conventional T-cell cytotoxicity. These drug-delivering cells, termed Synthetic Enzyme-Armed KillER (SEAKER) cells, demonstrated efficacy in mouse lymphoma xenograft models. However, the interactions of an immunocompromised xenograft with such complex engineered T cells are distinct from those in an immunocompetent host, precluding an understanding of how these physiologic processes may affect the therapy. Herein, we expanded the repertoire of SEAKER cells to target solid-tumor melanomas in syngeneic mouse models using specific targeting with T-cell receptor (TCR)-engineered T cells. We demonstrate that SEAKER cells localized specifically to tumors, and activated bioactive prodrugs, despite host immune responses. We additionally show that TCR-engineered SEAKER cells were efficacious in immunocompetent hosts, demonstrating that the SEAKER platform is applicable to many adoptive cell therapies.
Subject(s)
Immunotherapy, Adoptive , Melanoma , Mice , Animals , Humans , T-Lymphocytes, Cytotoxic , Genetic Engineering , Receptors, Antigen, T-Cell/geneticsABSTRACT
Genetically engineered, cytotoxic, adoptive T cells localize to antigen positive cancer cells inside patients, but tumor heterogeneity and multiple immune escape mechanisms have prevented the eradication of most solid tumor types. More effective, multifunctional engineered T cells are in development to overcome the barriers to the treatment of solid tumors, but the interactions of these highly modified cells with the host are poorly understood. We previously engineered prodrug-activating enzymatic functions into chimeric antigen receptor (CAR) T cells, endowing them with an orthogonal killing mechanism to conventional T-cell cytotoxicity. These drug-delivering cells, termed Synthetic Enzyme-Armed KillER (SEAKER) cells, demonstrated efficacy in mouse lymphoma xenograft models. However, the interactions of an immunocompromised xenograft with such complex engineered T cells are distinct from those in an immunocompetent host, precluding an understanding of how these physiologic processes may affect the therapy. Here, we also expand the repertoire of SEAKER cells to target solid-tumor melanomas in syngeneic mouse models using specific targeting with TCR-engineered T cells. We demonstrate that SEAKER cells localize specifically to tumors, and activate bioactive prodrugs, despite host immune responses. We additionally show that TCR-engineered SEAKER cells are efficacious in immunocompetent hosts, demonstrating that the SEAKER platform is applicable to many adoptive cell therapies.
ABSTRACT
In the 2 years since the inception of Black in Cancer, we have modeled an action-oriented commitment to improving Black representation across all levels of the cancer spectrum. We reflect on our successes and consider new ways to innovate and inspire the cancer community.
Subject(s)
Neoplasms , Humans , Power, PsychologicalABSTRACT
OBJECTIVES: To examine changes in the positive infectious syphilis test rate among women and heterosexual men in major Australian cities, and rate differences by social, biomedical, and behavioural determinants of health. DESIGN, SETTING: Analysis of data extracted from de-identified patient records from 34 sexual health clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of Sexually Transmissible Infections and Blood Borne Viruses (ACCESS). PARTICIPANTS: First tests during calendar year for women and heterosexual men aged 15 years or more in major cities who attended ACCESS sexual health clinics during 2011-2019. MAIN OUTCOME MEASURES: Positive infectious syphilis test rate; change in annual positive test rate. RESULTS: 180 of 52 221 tested women (0.34%) and 239 of 36 341 heterosexual men (0.66%) were diagnosed with infectious syphilis. The positive test rate for women was 1.8 (95% confidence interval [CI], 0.9-3.2) per 1000 tests in 2011, 3.0 (95% CI, 2.0-4.2) per 1000 tests in 2019 (change per year: rate ratio [RR], 1.12; 95% CI, 1.01-1.25); for heterosexual men it was 6.1 (95% CI, 3.8-9.2) per 1000 tests in 2011 and 7.6 (95% CI, 5.6-10) per 1000 tests in 2019 (RR, 1.10; 95% CI, 1.03-1.17). In multivariable analyses, the positive test rate was higher for women (adjusted RR [aRR], 1.85; 95% CI, 1.34-2.55) and heterosexual men (aRR, 2.39; 95% CI, 1.53-3.74) in areas of greatest socio-economic disadvantage than for those in areas of least socio-economic disadvantage. It was also higher for Indigenous women (aRR, 2.39; 95% CI, 1.22-4.70) and for women who reported recent injection drug use (aRR, 4.87; 95% CI, 2.18-10.9) than for other women; it was lower for bisexual than heterosexual women (aRR, 0.48; 95% CI, 0.29-0.81) and for women who reported recent sex work (aRR, 0.35; 95% CI, 0.29-0.44). The positive test rate was higher for heterosexual men aged 40-49 years (aRR, 2.11; 95% CI, 1.42-3.12) or more than 50 years (aRR, 2.36; 95% CI, 1.53-3.65) than for those aged 15-29 years. CONCLUSION: The positive test rate among both urban women and heterosexual men tested was higher in 2019 than in 2011. People who attend reproductive health or alcohol and drug services should be routinely screened for syphilis.
Subject(s)
HIV Infections , Sexually Transmitted Diseases , Syphilis , Male , Humans , Female , Syphilis/diagnosis , Syphilis/epidemiology , Heterosexuality , Cities , Sentinel Surveillance , Australia/epidemiology , Sexual Behavior , HIV Infections/epidemiology , Sexually Transmitted Diseases/epidemiologyABSTRACT
Chimeric antigen receptor (CAR) T-cell therapy has shown success in the treatment of hematopoietic malignancies; however, relapse remains a significant issue. To overcome this, we engineered "Orexi" CAR T cells to locally secrete a high-affinity CD47 blocker, CV1, at the tumor and treated tumors in combination with an orthogonally targeted monoclonal antibody. Traditional CAR T cells plus the antibody had an additive effect in xenograft models, and this effect was potentiated by CAR T-cell local CV1 secretion. Furthermore, OrexiCAR-secreted CV1 reversed the immunosuppression of myelomonocytoid cells both in vitro and within the tumor microenvironment. Local secretion of the CD47 inhibitor bypasses the CD47 sink found on all cells in the body and may prevent systemic toxicities. This combination of CAR T-cell therapy, local CD47 blockade, and orthogonal antibody may be a combinatorial strategy to overcome the limitations of each monotherapy.
Subject(s)
CD47 Antigen , Neoplasms , Humans , Neoplasm Recurrence, Local , Neoplasms/pathology , T-Lymphocytes , Immunotherapy, Adoptive , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/pharmacology , Tumor MicroenvironmentABSTRACT
The 'Australian Sexually Transmitted Infection (STI) Management Guidelines For Use In Primary Care' (www.sti.guidelines.org.au ) provide evidence-based, up-to-date guidance targeted at use in primary care settings. A major review of the guidelines was undertaken in 2020-22. All content was reviewed and updated by a multi-disciplinary group of clinical and non-clinical experts, and assessed for appropriateness of recommendations for key affected populations and organisational and jurisdictional suitability. The guidelines are divided into six main sections: (1) standard asymptomatic check-up; (2) sexual history; (3) contact tracing; (4) STIs and infections associated with sex; (5) STI syndromes; and (6) populations and situations. This paper highlights important aspects of the guidelines and provides the rationale for significant changes made during this major review process.
Subject(s)
Sexually Transmitted Diseases , Humans , Australia , Sexually Transmitted Diseases/epidemiology , Sexual Behavior , Contact Tracing , Primary Health CareABSTRACT
BACKGROUND: The sexual and reproductive health care of people with HIV and those at risk of HIV has largely been delivered face-to-face in Australia. These services adapted to the coronavirus disease 2019 (COVID-19) pandemic with a commitment to continued care despite major impacts on existing models and processes. Limited attention has been paid to understanding the perspectives of the sexual and reproductive health care workforce in the research on COVID-19 adaptations. METHODS: Semi-structured interviews were conducted between June and September 2021 with 15 key informants representing a diverse range of service settings and professional roles in the Australian sexual and reproductive health sector. Inductive themes were generated through a process of reflexive thematic analysis, informed by our deductive interest in clinical adaptations. RESULTS: The major adaptations were: triage (rapidly adapting service models to protect the most essential forms of care); teamwork (working together to overcome ongoing threats to service quality and staff wellbeing), and the intwined themes of telehealth and trust (remaining connected to marginalised communities through remote care). Despite impacts on care models and client relationships, there were sustained benefits from the scaleup of remote care, and attention to service safety, teamwork and communication. CONCLUSIONS: Attending to the experiences of those who worked at the frontline of the COVID-19 response provides essential insights to inform sustained, meaningful system reform over time. The coming years will provide important evidence of longer-term impacts of COVID-19 interruptions on both the users and providers of sexual and reproductive health services.
Subject(s)
COVID-19 , HIV Infections , Humans , Pandemics , Reproductive Health , AustraliaABSTRACT
Specialised sexual health clinics (SHCs) play an important role in addressing the staggering rates of STIs seen in many high-income nations. Despite increasing healthcare coverage in the US and nationalised health care in some countries, there is a continued need for SHCs to meet the needs of patients and the community, especially for high-priority populations: those at high risk of STI acquisition and/or groups historically marginalised and underserved in the traditional healthcare system. We need to mobilise resources to support a stronger clinical infrastructure in specialised SHCs. This review describes the importance of SHCs, their future role, and some of the innovative programs housed within SHCs in the US, Australia, and the Netherlands to address both STI and HIV prevention for the populations they serve.
Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , Sexual Health , Sexually Transmitted Diseases , Ambulatory Care Facilities , HIV Infections/epidemiology , HIV Infections/prevention & control , Humans , Public Health , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/prevention & controlABSTRACT
Biological tubes serve as conduits through which gas, nutrients and other important fluids are delivered to tissues. Most biological tubes consist of multiple cells connected by epithelial junctions. Unlike these multicellular tubes, seamless tubes are unicellular and lack junctions. Seamless tubes are present in various organ systems, including the vertebrate vasculature, C.elegans excretory system, and Drosophila tracheal system. The Drosophila tracheal system is a network of air-filled tubes that delivers oxygen to all tissues. Specialized cells within the tracheal system, called terminal cells, branch extensively and form seamless tubes. Terminal tracheal tubes are polarized; the lumenal membrane has apical identity whereas the outer membrane exhibits basal characteristics. Although various aspects of membrane trafficking have been implicated in terminal cell morphogenesis, the precise secretory pathway requirements for basal and apical membrane growth have yet to be elucidated. In the present study, we demonstrate that anterograde trafficking, retrograde trafficking and Golgi-to-plasma membrane vesicle fusion are each required for the complex branched architecture of the terminal cell, but their inputs during seamless lumen formation are more varied. The COPII subunit, Sec31, and ER exit site protein, Sec16, are critical for subcellular tube architecture, whereas the SNARE proteins Syntaxin 5, Syntaxin 1 and Syntaxin 18 are more generally required for seamless tube growth and maintenance. These data suggest that distinct components of the secretory pathway have differential contributions to basal and apical membrane growth and maintenance during terminal cell morphogenesis.
Subject(s)
Drosophila Proteins , Drosophila , Animals , Caenorhabditis elegans/metabolism , Drosophila/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Drosophila melanogaster/metabolism , Morphogenesis , Secretory Pathway , Trachea/metabolismABSTRACT
BACKGROUND: Chlamydia is the most commonly diagnosed bacterial sexually transmissible infection (STI) in Australia. Partner management is key to reducing transmission and a cornerstone of best practice chlamydia management. While most patients will opt for telling their partner(s) themselves, patient-delivered partner therapy (PDPT) offers an alternative way to inform and treat partners where usual management is inappropriate or unlikely to be undertaken. Guidelines for PDPT vary across Australia. Recent research found that general practitioners (GP)s want practical guidance for using PDPT in appropriate situations. OBJECTIVE: The aim of this article is to provide an overview of the process of offering PDPT and note the challenges GPs may face in its provision. DISCUSSION: PDPT is one option for partner management when sexual partner(s) are unlikely or unable to seek timely care themselves. However, there are challenges to the use of PDPT in general practice. The provision of clear guidelines is an essential step to promote its appropriate use.
Subject(s)
Chlamydia Infections , General Practice , General Practitioners , Chlamydia Infections/diagnosis , Chlamydia Infections/drug therapy , Contact Tracing , Humans , Sexual PartnersABSTRACT
Exploring the repertoire of peptides presented on major histocompatibility complexes (MHCs) helps identify targets for immunotherapy in many hematologic malignancies. However, there is a paucity of such data for diffuse large B-cell lymphomas (DLBCLs), which might be explained by the profound downregulation of MHC expression in many DLBCLs, and in particular in the enhancer of zeste homolog 2 (EZH2)-mutated subgroup. Epigenetic drug treatment, especially in the context of interferon-γ (IFN-γ), restored MHC expression in DLBCL. In DLBCL, peptides presented on MHCs were identified via mass spectrometry after treatment with tazemetostat or decitabine alone or in combination with IFN-γ. Such treatment synergistically increased the expression of MHC class I surface proteins up to 50-fold and the expression of class II surface proteins up to threefold. Peptides presented on MHCs increased to a similar extent for both class I and class II MHCs. Overall, these treatments restored the diversity of the immunopeptidome to levels described in healthy B cells for 2 of 3 cell lines and allowed the systematic search for new targets for immunotherapy. Consequently, we identified multiple MHC ligands from the regulator of G protein signaling 13 (RGS13) and E2F transcription factor 8 (E2F8) on different MHC alleles, none of which have been described in healthy tissues and therefore represent tumor-specific MHC ligands that are unmasked only after drug treatment. Overall, our results show that EZH2 inhibition in combination with decitabine and IFN-γ can expand the repertoire of MHC ligands presented on DLBCLs by revealing suppressed epitopes, thus allowing the systematic analysis and identification of new potential immunotherapy targets.