Chlamydia retesting remains low among young women in Australia: an observational study using sentinel surveillance data, 2018-2022.

BACKGROUND: Chlamydia remains the most notified bacterial sexually transmissible infection in Australia with guidelines recommending testing for re-infection at 3months post treatment. This paper aimed to determine chlamydia retesting and repeat positivity rates within 2-4months among young women in Australia, and to evaluate what factors increase or decrease the likelihood of retesting. METHODS: Chlamydia retesting rates among 16-29-year-old women were analysed from Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of sexually transmissible infection and bloodborne virus (ACCESS) sentinel surveillance data (n =62 sites). Among women with at least one positive test between 1 January 2018 and 31 August 2022, retesting counts and proportions within 2-4months were calculated. Logistic regression was performed to assess factors associated with retesting within 2-4months. RESULTS: Among 8758 women who were positive before 31 August 2022 to allow time for follow up, 1423 (16.2%) were retested within 2-4months, of whom 179 (12.6%) tested positive. The odds of retesting within 2-4months were 25% lower if tested in a coronavirus disease 2019 (COVID-9) pandemic year (2020-2022) (aOR=0.75; 95% CI 0.59-0.95). Among 9140 women with a positive test before 30 November 2022, 397 (4.3%) were retested too early (within 7days to 1month) and 81 (20.4%) of those were positive. CONCLUSIONS: Chlamydia retesting rates remain low with around a sixth of women retested within 2-4months in line with guidelines. Re-infection is common with around one in eight retesting positive. An increase in retesting is required to reduce the risk of reproductive complications and onward transmission.

Engineered Polymer-siRNA Polyplexes Provide Effective Treatment of Lung Inflammation.

Uncontrolled inflammation is responsible for acute and chronic diseases in the lung. Regulating expression of pro-inflammatory genes in pulmonary tissue using small interfering RNA (siRNA) is a promising approach to combatting respiratory diseases. However, siRNA therapeutics are generally hindered at the cellular level by endosomal entrapment of delivered cargo and at the organismal level by inefficient localization in pulmonary tissue. Here we report efficient anti-inflammatory activity in vitro and in vivo using polyplexes of siRNA and an engineered cationic polymer (PONI-Guan). PONI-Guan/siRNA polyplexes efficiently deliver siRNA cargo to the cytosol for highly efficient gene knockdown. Significantly, these polyplexes exhibit inherent targeting to inflamed lung tissue following intravenous administration in vivo. This strategy achieved effective (>70%) knockdown of gene expression in vitro and efficient (>80%) silencing of TNF-α expression in lipopolysaccharide (LPS)-challenged mice using a low (0.28 mg/kg) siRNA dosage.

COX-2 upregulation by tumour cells post-chemotherapy fuels the immune evasive dark side of cancer inflammation.

Cytotoxic therapies, such as chemotherapy and radiotherapy, are mainstays of cancer treatment for both early and unresectable, advanced disease. In addition to debulking the tumour mass through direct killing of proliferating tumour cells, these treatments can promote tumour control via immune-stimulating effects. Nonetheless, chemoresistance and tumour relapse remain huge clinical problems, suggesting that induction of anti-cancer immunity post-cytotoxic therapy is often weak, not durable and/or overcome by immune evasive mechanisms. In our recent study (Nat Commun 13:2063), we demonstrate that cancer cell-intrinsic activation of the cyclooxygenase (COX)-2/prostaglandin E2 (PGE2) pathway post-chemotherapy treatment is a prevalent phenomenon which profoundly alters the inflammatory properties of the treated cancer cells. Of particular translational relevance, our findings support a model whereby upregulation of COX-2 expression and activity post-chemotherapy impairs the efficacy of the combination of PD-1 blockade and chemotherapy. Accordingly, pharmacological inhibition of COX-2 with celecoxib, an anti-inflammatory drug already used clinically, unleashed tumour control in preclinical models when given alongside chemoimmunotherapy combinations.

Chemotherapy-induced COX-2 upregulation by cancer cells defines their inflammatory properties and limits the efficacy of chemoimmunotherapy combinations.

Cytotoxic therapies, besides directly inducing cancer cell death, can stimulate immune-dependent tumor growth control or paradoxically accelerate tumor progression. The underlying mechanisms dictating these opposing outcomes are poorly defined. Here, we show that cytotoxic therapy acutely upregulates cyclooxygenase (COX)-2 expression and prostaglandin E2 (PGE2) production in cancer cells with pre-existing COX-2 activity. Screening a compound library of 1280 approved drugs, we find that all classes of chemotherapy drugs enhance COX-2 transcription whilst arresting cancer cell proliferation. Genetic manipulation of COX-2 expression or its gene promoter region uncover how augmented COX-2/PGE2 activity post-treatment profoundly alters the inflammatory properties of chemotherapy-treated cancer cells in vivo. Pharmacological COX-2 inhibition boosts the efficacy of the combination of chemotherapy and PD-1 blockade. Crucially, in a poorly immunogenic breast cancer model, only the triple therapy unleashes tumor growth control and significantly reduces relapse and spontaneous metastatic spread in an adjuvant setting. Our findings suggest COX-2/PGE2 upregulation by dying cancer cells acts as a major barrier to cytotoxic therapy-driven tumor immunity and uncover a strategy to improve the outcomes of immunotherapy and chemotherapy combinations.

Human papillomavirus prevalence and risk factors among Australian women 9-12 years after vaccine program introduction.

BACKGROUND: In Australia, high and widespread uptake of the quadrivalent human papillomavirus (HPV) vaccine has led to substantial population-level reductions in the prevalence of quadrivalent vaccine targeted HPV genotypes 6/11/16/18 in women aged ≤ 35 years. We assessed risk factors for HPV detection among 18-35 year old women, 9-12 years after vaccine program introduction. METHODS: Women attending health services between 2015 and 2018 provided a self-collected vaginal specimen for HPV genotyping (Roche Linear Array) and completed a questionnaire. HPV vaccination status was validated against the National Register. Adjusted odds ratios (aORs) and 95% confidence intervals (CI) were calculated for factors associated with HPV detection. RESULTS: Among 1564 women (median age 24 years; IQR 21-27 years), Register-confirmed ≥ 1-dose vaccine coverage was highest at 69.3% and 68.1% among women aged 18-21 and 22-24 years respectively, decreasing to 42.9% among those aged 30-35 years. Overall prevalence of quadrivalent vaccine-targeted HPV types was very low (2.0%; 95% CI: 1.4-2.8%) and influenced only by vaccination status (5.5% among unvaccinated compared with 0.7% among vaccinated women; aOR = 0.13 (95% CI: 0.05-0.30)). Prevalence of remaining HPV types, at 40.4% (95% CI: 38.0-42.9%), was influenced by established risk factors for HPV infection; younger age-group (p-trend < 0.001), more recent (p < 0.001) and lifetime sexual partners (p-trend < 0.001), but not vaccination status. Prevalence of HPV31/33/45, which shared risk factors with that of non-vaccine targeted HPV types, was also lower among vaccinated (4%) compared with unvaccinated (7%) women (aOR = 0.51; 95% CI: 0.29-0.89), indicative of cross-protection. CONCLUSION: Vaccination has changed the epidemiology of HPV infection in Australian women, having markedly reduced the prevalence of vaccine-targeted types, including amongst women with known risk factors for infection. Vaccinated women appear to be benefiting from modest cross-protection against types 31/33/45 afforded by the quadrivalent HPV vaccine. These results reinforce the importance of HPV vaccination.

Anti-Inflammatory Drugs Remodel the Tumor Immune Environment to Enhance Immune Checkpoint Blockade Efficacy.

Identifying strategies to improve the efficacy of immune checkpoint blockade (ICB) remains a major clinical need. Here, we show that therapeutically targeting the COX2/PGE2/EP2-4 pathway with widely used nonsteroidal and steroidal anti-inflammatory drugs synergized with ICB in mouse cancer models. We exploited a bilateral surgery model to distinguish responders from nonresponders shortly after treatment and identified acute IFNγ-driven transcriptional remodeling in responder mice, which was also associated with patient benefit to ICB. Monotherapy with COX2 inhibitors or EP2-4 PGE2 receptor antagonists rapidly induced this response program and, in combination with ICB, increased the intratumoral accumulation of effector T cells. Treatment of patient-derived tumor fragments from multiple cancer types revealed a similar shift in the tumor inflammatory environment to favor T-cell activation. Our findings establish the COX2/PGE2/EP2-4 axis as an independent immune checkpoint and a readily translatable strategy to rapidly switch the tumor inflammatory profile from cold to hot. SIGNIFICANCE: Through performing in-depth profiling of mice and human tumors, this study identifies mechanisms by which anti-inflammatory drugs rapidly alter the tumor immune landscape to enhance tumor immunogenicity and responses to immune checkpoint inhibitors.See related commentary by Melero et al., p. 2372.This article is highlighted in the In This Issue feature, p. 2355.

Antagonistic Inflammatory Phenotypes Dictate Tumor Fate and Response to Immune Checkpoint Blockade.

Inflammation can support or restrain cancer progression and the response to therapy. Here, we searched for primary regulators of cancer-inhibitory inflammation through deep profiling of inflammatory tumor microenvironments (TMEs) linked to immune-dependent control in mice. We found that early intratumoral accumulation of interferon gamma (IFN-γ)-producing natural killer (NK) cells induced a profound remodeling of the TME and unleashed cytotoxic T cell (CTL)-mediated tumor eradication. Mechanistically, tumor-derived prostaglandin E2 (PGE2) acted selectively on EP2 and EP4 receptors on NK cells, hampered the TME switch, and enabled immune evasion. Analysis of patient datasets across human cancers revealed distinct inflammatory TME phenotypes resembling those associated with cancer immune control versus escape in mice. This allowed us to generate a gene-expression signature that integrated opposing inflammatory factors and predicted patient survival and response to immune checkpoint blockade. Our findings identify features of the tumor inflammatory milieu associated with immune control of cancer and establish a strategy to predict immunotherapy outcomes.

A Pilot, Double-Blind, Randomized, Controlled Trial of High-Dose Intravenous Vitamin C for Vasoplegia After Cardiac Surgery.

OBJECTIVE: To conduct a pilot feasibility and physiologic efficacy study of high-dose vitamin C in patients with vasoplegia after cardiac surgery. DESIGN: Prospective, double-blind, randomized, controlled trial. SETTING: Two tertiary intensive care units (ICUs). PARTICIPANTS: Post-cardiac surgery patients with vasoplegia. INTERVENTIONS: The authors randomly assigned the patients to receive either high-dose intravenous vitamin C (1,500 mg every 6 hours) or placebo. The primary outcome was time from randomization to resolution of vasoplegia. Secondary outcomes included total norepinephrine equivalent dose in the first 2 days, ICU length of stay, ICU mortality, and in-hospital mortality. MEASUREMENTS AND MAIN RESULTS: The authors studied 50 patients (25 patients in each arms). The mean (standard deviation) time to resolution of vasoplegia was 27.0 (16.5) hours in the vitamin C group versus 34.7 (41.1) hours in the placebo group (mean decrease with vitamin C of 7.7 hours, 95% confidence interval -10.5 to 25.9, p = 0.40). The median (interquartile range) norepinephrine equivalent dose in the first 2 days was 64.9 (23.5-236.5) µg/kg versus 47.4 (21.4-265.9) µg/kg in the vitamin C and placebo group (p = 0.75). The median duration of ICU admission was similar (1.4 [0.5-2.5] days and 1.5 [0.5-3.3] days in the vitamin C and placebo group; p = 0.36). Only 1 patient, in the vitamin C arm, died. CONCLUSION: In patients with post-cardiac surgery vasoplegia, high-dose vitamin C infusion was feasible, appeared safe, and, within the limitations of a pilot study, did not achieve statistically faster resolution of vasoplegia.

Frequency and phenotype of natural killer cells and natural killer cell subsets in bovine lymphoid compartments and blood.

Natural killer (NK) cells are widely distributed in lymphoid and non-lymphoid tissues, but little is known about the recirculation of NK cells between blood and tissues. This is relevant to understanding recirculation in the steady-state and also for determining the roles for NK cells in vaccine-induced immunity and responses to infection. Therefore, the percentage of NK cells and their phenotype across peripheral blood, afferent lymph and lymph nodes in steady-state conditions was investigated in cattle using the pseudo-afferent lymphatic cannulation model. CD2+ CD25lo NK cells were the predominant subset of NK cells within the blood. In contrast, CD2- CD25hi NK cells were the main subset present within the skin-draining afferent lymphatic vessels and lymph nodes, indicating that CD2- NK cells are the principal NK cell subset trafficking to lymph nodes via the afferent lymphatic vessel. Furthermore, a low percentage of NK cells were present in efferent lymph, which were predominantly of the CD2- subset, indicating that NK cells can egress from lymph nodes and return to circulation in steady-state conditions. These compartmentalization data indicate that NK cells represent a population of recirculating lymphocytes in steady-state conditions and therefore may be important during immune responses to vaccination or infection.

The risks of using allogeneic cell lines for vaccine production: the example of Bovine Neonatal Pancytopenia.

INTRODUCTION: Bovine neonatal pancytopenia (BNP) is a hemorrhagic disease that emerged in calves across Europe in 2007. Its occurrence is attributed to immunization of the calf's mother with a vaccine produced using an allogeneic cell line. Vaccine-induced alloantibodies specific for major-histocompatibility class I antigens are transferred from the mother to the calf via colostrum, leading to profound depletion of peripheral blood and bone marrow cells that is often fatal. Areas covered: Pubmed and Web of Science were used to search for literature relevant to BNP and the use of allogeneic vaccine cell lines. Following a review of the pathology and pathogenesis of this novel condition, we discuss potential risks associated with the use of allogeneic vaccine cell lines. Expert commentary: Although BNP is associated with a specific vaccine, it highlights safety concerns common to all vaccines produced using allogeneic cell lines. Measures to prevent similar vaccine-induced alloimmune-mediated adverse events in the future are discussed.

Human Papillomavirus Prevalence in Unvaccinated Heterosexual Men After a National Female Vaccination Program.

Background: In Australia, high uptake of the quadrivalent human papillomavirus (4vHPV) vaccine has led to reductions in the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, and 18 in women and girls aged ≤25 years. We evaluated the impact of the program impact on HPV prevalence in unvaccinated male subjects. Methods: Sexually active heterosexual male subjects aged 16-35 years were recruited in 2014-2016. Participants provided a self-collected penile swab sample for HPV genotyping (Roche Linear Array) and completed a demographic and risk factor questionnaire. Results: The prevalence of 4vHPV genotypes among 511 unvaccinated male subjects was significantly lower in those aged ≤25 than in those aged >25 years: 3.1% (95% confidence interval, 1.5%-5.7%) versus 13.7% (8.9%-20.1%), respectively (P < .001); adjusted prevalence ratio, 0.22 (.09-.51; P < .001). By contrast, the prevalence of high-risk HPV genotypes other than 16 and 18 remained the same across age groups: 16.8% (95% confidence interval, 12.6%-21.9%) in men aged ≤25 years and 17.9% (12.4%-25.0%) in those aged >25 years (P = .76); adjusted prevalence ratio, 0.98, (.57-1.37; P = .58). Conclusions: A 78% lower prevalence of 4vHPV genotypes was observed among younger male subjects. These data suggest that unvaccinated men may have benefited from herd protection as much as women from a female-only HPV vaccination program with high coverage.

Trends and predictors of recent HIV testing over 22 years among a clinic sample of men who have sex with men in South Australia.

Increasing the frequency of HIV testing is crucial for effective HIV prevention and care. The aim of the present study was to determine whether there has been a change in HIV testing among men who have sex with men (MSM) at the South Australia Specialist Sexual Health (SASSH) clinic over the past two decades. METHODS: Computerised medical records of MSM who attended the SASSH at their first visit between 1994 and 2015 were used to determine whether HIV testing had changed among MSM. First HIV tests in each calendar year and return tests within 12 months were analysed. Factors associated with recent HIV testing were also examined. RESULTS: There were 24036 HIV tests conducted among 8163 individual MSM over the study period. The proportion of newly registered MSM who reported ever being tested for HIV declined (Ptrend=0.030), the proportion who reported recent HIV testing did not change (Ptrend=0.955) and the proportion who have had current HIV testing increased (Ptrend=0.008). The proportion of MSM who returned to the clinic for HIV testing within 12 months did not change (Ptrend >0.05), with less than 40% of MSM returning for HIV testing. Factors independently associated with recent HIV testing included MSM aged ≥20 years, (odds ratio (OR) 1.79; 95% confidence interval (CI) 1.53-2.10), higher education (OR 1.28; 95% CI 1.12-1.45), non-Caucasian (African OR 1.68; 95% CI 1.30-2.17), having multiple sex partners (OR 1.47; 95% CI 1.29-1.69), having had sex interstate (OR 1.61; 95% CI 1.42-1.82) or overseas (OR 1.53; 95% CI 1.33-1.76) and injecting drug use (OR 1.56; 95% CI 1.29-1.88). CONCLUSIONS: HIV testing rate among MSM attending SASSH was suboptimal. New approaches are needed to increase the uptake and early detection of HIV infection among the high-priority MSM population.

The role of proton dynamics in the development and maintenance of multidrug resistance in cancer.

With a projected 382.4 per 100,000 people expected to suffer from some form of malignant neoplasm in 2015, improving treatment is an essential focus of cancer research today. Multi-drug resistance (MDR) is the leading cause of chemotherapeutic failure in the treatment of cancer, the term denoting a characteristic of the disease-causing agent to avoid damage by drugs designed to bring about their destruction. MDR is also characterised by a reversal of the pH gradient across cell membranes leading to an acidification of the outer milieu and an alkalinisation of the cytosol that is maintained by the proton pump vacuolar-type ATPase (V-ATPase) and the proton transporters: Na(+)/H(+) exchanger (NHE1), Monocarboxylate Transporters (MCTs), Carbonic anhydrases (CAs) (mainly CA-IX), adenosinetriphosphate synthase, Na(+)/HCO3(-) co-transporter and the Cl(-)/HCO3(-)exchanger. This review aims to give an introduction to MDR. It will begin with an explanation for what MDR actually is and go on to look at the proposed mechanisms by which a state of drug resistance is achieved. The role of proton-pumps in creating an acidic extracellular pH and alkaline cytosol, as well as key biomechanical processes within the cell membrane itself, will be used to explain how drug resistance can be sustained.

Reproduction of bovine neonatal pancytopenia (BNP) by feeding pooled colostrum reveals variable alloantibody damage to different haematopoietic lineages.

Bovine neonatal pancytopenia (BNP) is a recently described haemorrhagic disease of calves characterised by thrombocytopenia, leucopenia and bone marrow depletion. Feeding colostrum from cows that have previously produced a BNP affected calf has been shown to induce the disease in some calves, leading to the hypothesis that alloantibodies in colostrum from dams of affected calves mediate destruction of blood and bone marrow cells in the recipient calves. The aims of the current experimental study were first to confirm the role of colostrum-derived antibody in mediating the disease and second to investigate the haematopoietic cell lineages and maturation stages depleted by the causative antibodies. Clinical, haematological and pathological changes were examined in 5 calves given a standardised pool of colostrum from known BNP dams, and 5 control calves given an equivalent pool of colostrum from non-BNP dams. All calves fed challenge colostrum showed progressive depletion of bone marrow haematopoietic cells and haematological changes consistent with the development of BNP. Administration of a standardised dose of the same colostrum pool to each calf resulted in a consistent response within the groups, allowing detailed interpretation of the cellular changes not previously described. Analyses of blood and serial bone marrow changes revealed evidence of differential effects on different blood cell lineages. Peripheral blood cell depletion was confined to leucocytes and platelets, while bone marrow damage occurred to the primitive precursors and lineage committed cells of the thrombocyte, lymphocyte and monocyte lineages, but only to the more primitive precursors in the neutrophil, erythrocyte and eosinophil lineages. Such differences between lineages may reflect cell type-dependent differences in levels of expression or conformational nature of the target antigens.

Importance of the difference in surface pressures of the cell membrane in doxorubicin resistant cells that do not express Pgp and ABCG2.

P-glycoprotein (Pgp) represents the archetypal mechanism of drug resistance. But Pgp alone cannot expel drugs. A small but growing body of works has demonstrated that the membrane biophysical properties are central to Pgp-mediated drug resistance. For example, a change in the membrane surface pressure is expected to support drug-Pgp interaction. An interesting aspect from these models is that under specific conditions, the membrane is predicted to take over Pgp concerning the mechanism of drug resistance especially when the surface pressure is high enough, at which point drugs remain physically blocked at the membrane level. However it remains to be determined experimentally whether the membrane itself could, on its own, affect drug entry into cells that have been selected by a low concentration of drug and that do not express transporters. We demonstrate here that in the case of the drug doxorubicin, alteration of the surface pressure of membrane leaflets drive drug resistance.

Demonstration of early functional compromise of bone marrow derived hematopoietic progenitor cells during bovine neonatal pancytopenia through in vitro culture of bone marrow biopsies.

BACKGROUND: Bovine neonatal pancytopenia (BNP) is a syndrome characterised by thrombocytopenia associated with marked bone marrow destruction in calves, widely reported since 2007 in several European countries and since 2011 in New Zealand. The disease is epidemiologically associated with the use of an inactivated bovine virus diarrhoea (BVD) vaccine and is currently considered to be caused by absorption of colostral antibody produced by some vaccinated cows ("BNP dams"). Alloantibodies capable of binding to the leukocyte surface have been detected in BNP dams and antibodies recognising bovine MHC class I and ß-2-microglobulin have been detected in vaccinated cattle. In this study, calves were challenged with pooled colostrum collected from BNP dams or from non-BNP dams and their bone marrow hematopoietic progenitor cells (HPC) cultured in vitro from sternal biopsies taken at 24 hours and 6 days post-challenge. RESULTS: Clonogenic assay demonstrated that CFU-GEMM (colony forming unit-granulocyte/erythroid/macrophage/megakaryocyte; pluripotential progenitor cell) colony development was compromised from HPCs harvested as early as 24 hour post-challenge. By 6 days post challenge, HPCs harvested from challenged calves failed to develop CFU-E (erythroid) colonies and the development of both CFU-GEMM and CFU-GM (granulocyte/macrophage) was markedly reduced. CONCLUSION: This study suggests that the bone marrow pathology and clinical signs associated with BNP are related to an insult which compromises the pluripotential progenitor cell within the first 24 hours of life but that this does not initially include all cell types.

Targeted screening for Trichomonas vaginalis in women, a pH-based approach.

In the genitourinary medicine clinic setting, the most practical and widely used method of diagnosing Trichomonas vaginalis (TV) is direct microscopy of a wet mount preparation (WMP) of a sample taken from the posterior vaginal fornix. We retrospectively reviewed the potential impact of further limiting WMP to women with a vaginal pH > or =4.5. In total, 5/100 women with TV diagnosed on WMP had a recorded vaginal pH <4.5. One case of TV was identified in 1000 consecutive WMPs performed in women with vaginal pH <4.5. Our review demonstrates that, in our two groups, TV as diagnosed by WMP is strongly associated with a vaginal pH > or =4.5.