YopJ-Induced Caspase-1 Activation in Yersinia-Infected Macrophages: Independent of Apoptosis, Linked to Necrosis, Dispensable for Innate Host Defense

Yersinia outer protein J (YopJ) is a type III secretion system (T3SS) effector of pathogenic Yersinia (Yersinia pestis, Yersinia enterocolitica and Yersinia pseudotuberculosis) that is secreted into host cells. YopJ inhibits survival response pathways in macrophages, causing cell death. Allelic variation of YopJ is responsible for differential cytotoxicity in Yersinia strains. YopJ isoforms in Y. enterocolitica O:8 (YopP) and Y. pestis KIM (YopJKIM) strains have high cytotoxic activity. In addition, YopJKIM-induced macrophage death is associated with caspase-1 activation and interleukin-1β (IL-1β secretion. Here, the mechanism of YopJKIM-induced cell death, caspase-1 activation, and IL-1β secretion in primary murine macrophages was examined. Caspase-3/7 activity was low and the caspase-3 substrate poly (ADP-ribose) polymerase (PARP) was not cleaved in Y. pestis KIM5-infected macrophages. In addition, cytotoxicity and IL-1β secretion were not reduced in the presence of a caspase-8 inhibitor, or in B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 homologous antagonist/killer (Bak) knockout macrophages, showing that YopJKIM-mediated cell death and caspase-1 activation occur independent of mitochondrial-directed apoptosis. KIM5-infected macrophages released high mobility group protein B1 (HMGB1), a marker of necrosis, and microscopic analysis revealed that necrotic cells contained active caspase-1, indicating that caspase-1 activation is associated with necrosis. Inhibitor studies showed that receptor interacting protein 1 (RIP1) kinase and reactive oxygen species (ROS) were not required for cytotoxicity or IL-β release in KIM5-infected macrophages. IL-1β secretion was reduced in the presence of cathepsin B inhibitors, suggesting that activation of caspase-1 requires cathepsin B activity. Ectopically-expressed YopP caused higher cytotoxicity and secretion of IL-1β in Y. pseudotuberculosis-infected macrophages than YopJKIM. Wild-type and congenic caspase 1 knockout C57BL/6 mice were equally susceptible to lethal infection with Y. pseudotuberculosis ectopically expressing YopP. These data suggest that YopJ-induced caspase-1 activation in Yersinia-infected macrophages is a downstream consequence of necrotic cell death and is dispensable for innate host resistance to a strain with enhanced cytotoxicity

Learning environment, attitudes and anxiety across the transition from primary to secondary school mathematics

Past research has revealed that, relative to primary-school students, high-school students have less-positive attitudes to mathematics and perceive their classroom environments and teacher–student relationships less favourably. This study involved the transition experience of 541 students in 47 classes in 15 primary (year 7) and secondary (year 8) government and Catholic schools in metropolitan and regional South Australia. Scales were adapted from three established instruments, namely, the What Is Happening In this Class?, Test of Mathematics Related Attitudes and Revised Mathematics Anxiety Ratings Scale, to identify changes across the transition from primary to secondary school in terms of the classroom learning environment and students’ attitude/anxiety towards mathematics. Relative to year 7 students, year 8 students reported less Involvement, less positive Attitude to Mathematical Inquiry, less Enjoyment of Mathematics and greater Mathematics Anxiety. Differences between students in Years 7 and 8 were very similar for male and female students, although the magnitude of sex differences in attitudes was slightly different in Years 7 and 8

[CMV-associated enterocolitis due to primary CMV infection in the immunocompetent].

Cytomegalovirus (CMV) plays an important role in non-immunocompetent patients due to its high seroprevalence and life-long persistence. However, cases of severe CMV infections are also described in the immunocompetent. Here in particular, the gastrointestinal involvement is of major importance. We describe the case of a 29-year-old immunocompetent young man, who presented with a primary CMV infection mainly of the colon with clinical signs of bloody diarrhoea, fever, hepatitis and haemolysis. The diagnosis was established on the basis of a suspicious endoscopic finding with immunohistochemical detection of CMV in the colonic mucosa, a positive CMV viral load in the peripheral blood and an immune system response typical for primary infection. Based on this case and previous publications, we suggest that a colonoscopy and diagnostic procedures for CMV should be considered if the patient presents with gastrointestinal symptoms like (bloody) diarrhoea, fever, and hepatitis. In a severe case, we recommend antiviral therapy due to a high mortality that has been reported for CMV colitis in immunocompetent individuals

High prevalence of comorbidities and use of concomitant medication in treated people living with HIV in Germany – results of the BESIDE study

Due to demographic changes in people living with HIV (PLHIV), physicians are challenged with age-related comorbidities and their management. In the absence of comprehensive data collection, the burden of comorbidities and co-medication in addition to antiretroviral therapy (ART) remains unclear for the German real-world setting. BESIDE was an observational, cross-sectional study evaluating the prevalence of comorbidities and use of co-medication in treated PLHIV. Regional distribution of study centers (n = 20), consecutive patient recruitment, and age-stratified sampling in alignment with national epidemiologic data aimed to ensure a representative sample (n = 453). The overall prevalence of comorbidities was 91.2%; 31.6% of patients had ≥4 comorbidities. The most common diagnoses were vitamin D deficiency (29.1%), depressive episode (27.8%), arterial hypertension (16.3%), and hypercholesterolemia (10.8%). 83.7% of patients were on co-medication; 21.2% taking ≥4 medications. The most common medications or supplements were vitamins (31.6%), anti-inflammatory agents (16.1%), renin–angiotensin system agents (12.1%), acid suppressants (11.7%), lipid modifying agents (10.8%); 1.3% of patients were on co-medication that should not be co-administered with ART, 41.5% on co-medication with potential for drug–drug interactions. The prevalence of comorbidities and use of co-medication among treated PLHIV in Germany is consistently high and increases across age groups, illustrating the complexity of HIV care involving appropriate ART selection. </jats:p

High prevalence of recreational and illicit drug use in German people living with HIV with a potential for drug–drug interactions with antiretroviral therapy

Recreational drug use is higher in people living with HIV (PLHIV) than in the general population in Europe. This use increases the risk for drug-drug interactions (DDIs) and adverse events. We assessed the prevalence and clinical consequences of substance abuse among PLHIV. BESIDE was a cross-sectional, multi-center study in 2016/18, evaluating comorbidities, polypharmacy and recreational/illicit drug use in PLHIV on antiretroviral therapy (ART) in Germany. Legal and illicit drug use was recorded using two anonymous patient questionnaires one year apart (Q1 and Q2). The BESIDE study population consisted of 453 PLHIV (22% female, median age 46 years). Recreational drug use was reported by the majority (Q1: ever used 73%, within previous 6 months 56%): nitrite inhalants (“poppers”), cannabis and PDE-5 inhibitors were common across all age groups; ecstasy, (meth-)amphetamine and gamma-hydroxybutyrate/gamma-butyrolactone were predominantly reported by younger PLHIV. Based on Q2, two-thirds of PLHIV (67%) had been informed about potential risks of drug abuse by their doctors, whereas one-third (33%) had talked to their doctors on their own initiative with only 7% considering drug use in combination with ART a problem. Strikingly, 44% and 42% had undergone medical treatment or had been hospitalized due to drug use. These data emphasize the high clinical relevance of recreational drug use in PLHIV and the need for treating physicians to pro-actively communicate the potential risks. </jats:p

Highly specific reasons for nonadherence to antiretroviral therapy: results from the German adherence study

Johanna Boretzki,1,2 Eva Wolf,3 Carmen Wiese,4 Sebastian Noe,4 Annamaria Balogh,3 Anja Meurer,5 Ivanka Krznaric,6 Alexander Zink,7 Christian Lersch,1 Christoph D Spinner1,2 1Department of Medicine II, University Hospital Klinikum rechts der Isar, Munich, 2German Center for Infection Research, Partner Site Munich, 3MUC Research, Munich, 4MVZ Karlsplatz, HIV Clinical Care Center, Munich, 5Center for Infectiology and Internal Medicine, Munich, 6Center for Infectiology Prenzlauer Berg, Berlin, 7Department of Dermatology and Allergology, University Hospital Klinikum rechts der Isar, Munich, Germany Background: Reasons for and frequency of nonadherence to antiretroviral therapy (ART) may have changed due to pharmacological improvements. In addition, the importance of known non-pharmacologic reasons for nonadherence is unclear.Methods: We performed a cross-sectional, noninterventional, multicenter study to identify current reasons for nonadherence. Patients were categorized by physicians into the following adherence groups: good, unstable, or poor adherence. Co-variables of interest included age, sex, time since HIV diagnosis, ART duration, current ART regimen, HIV transmission route, comorbidity, HIV-1 RNA viral load (VL), and CD4 cell count. Patients self-reported the number of missed doses and provided their specific reasons for nonadherent behavior. Statistical analyses were performed using Fisher&rsquo;s extended exact test, Kruskal&ndash;Wallis test, and logistic regression models.Results: Our study assessed 215 participants with good (n=162), unstable (n=36), and poor adherence (n=17). Compared to patients with good adherence, patients with unstable and poor adherence reported more often to have missed at least one dose during the last week (good 11% vs unstable 47% vs poor 63%, p&lt;0.001). Physicians&rsquo; adherence assessment was concordant with patients&rsquo; self-reports of missed doses during the last week (no vs one or more) in 81% cases. Similarly, we found a strong association of physicians&rsquo; assessment with viral suppression. Logistic regression analysis showed that &ldquo;reduced adherence&rdquo; &ndash; defined as unstable or poor &ndash; was significantly associated with patients &lt;30&nbsp;years old, intravenous drug use, history of acquired immune deficiency syndrome (AIDS), and psychiatric disorders (p&lt;0.05). Univariate analyses showed that specific reasons, such as questioning the efficacy/dosing of ART, HIV stigma, interactive toxicity beliefs regarding alcohol and/or party drugs, and dissatisfaction with regimen complexity, correlated with unstable or poor adherence (p&lt;0.05).Conclusion: Identification of factors associated with poor adherence helps in identifying patients with a higher risk for nonadherence. Reasons for nonadherence should be directly addressed in every patient, because they are common and constitute possible adherence intervention points. Keywords: human immunodeficiency virus, HIV, antiretroviral therapy, ART, adherence, nonadherence, patients&rsquo; belief