The tumour-derived extracellular vesicle proteome varies by endometrial cancer histology and is confounded by an obesogenic environment

Endometrial cancer, the most common gynaecological cancer worldwide, is closely linked to obesity and metabolic diseases, particularly in younger women. New circulating biomarkers have the potential to improve diagnosis and treatment selections, which could significantly improve outcomes. Our approach focuses on extracellular vesicle (EV) biomarker discovery by directly profiling the proteome of EVs enriched from frozen biobanked endometrial tumours. We analysed nine tissue samples to compare three clinical subgroups-low BMI (Body Mass Index) Endometrioid, high BMI Endometrioid, and Serous (any BMI)-identifying proteins related to histological subtype, BMI, and shared secreted proteins. Using collagenase digestion and size exclusion chromatography, we successfully enriched generous quantities of EVs (range 204.8-1291.0 µg protein: 1.38 × 1011-1.10 × 1012 particles), characterised by their size (∼150 nm), expression of EV markers (CD63/81), and proposed endometrial cancer markers (L1CAM, ANXA2). Mass spectrometry-based proteomic profiling identified 2075 proteins present in at least one of the 18 samples. Compared to cell lysates, EVs were successfully depleted for mitochondrial and blood proteins and enriched for common EV markers and large secreted proteins. Further analysis highlighted significant differences in EV protein profiles between the high BMI subgroup and others, underlining the impact of comorbidities on the EV secretome. Interestingly, proteins differentially abundant in tissue subgroups were largely not also differential in matched EVs. This research identified secreted proteins known to be involved in endometrial cancer pathophysiology and proposed novel diagnostic biomarkers (EIF6, MUC16, PROM1, SLC26A2).

CD8 T cells compensate for impaired humoral immunity in COVID-19 patients with hematologic cancer

Cancer patients have increased morbidity and mortality from Coronavirus Disease 2019 (COVID-19), but the underlying immune mechanisms are unknown. In a cohort of 100 cancer patients hospitalized for COVID-19 at the University of Pennsylvania Health System, we found that patients with hematologic cancers had a significantly higher mortality relative to patients with solid cancers after accounting for confounders including ECOG performance status and active cancer status. We performed flow cytometric and serologic analyses of 106 cancer patients and 113 non-cancer controls from two additional cohorts at Penn and Memorial Sloan Kettering Cancer Center. Patients with solid cancers exhibited an immune phenotype similar to non-cancer patients during acute COVID-19 whereas patients with hematologic cancers had significant impairment of B cells and SARS-CoV-2-specific antibody responses. High dimensional analysis of flow cytometric data revealed 5 distinct immune phenotypes. An immune phenotype characterized by CD8 T cell depletion was associated with a high viral load and the highest mortality of 71%, among all cancer patients. In contrast, despite impaired B cell responses, patients with hematologic cancers and preserved CD8 T cells had a lower viral load and mortality. These data highlight the importance of CD8 T cells in acute COVID-19, particularly in the setting of impaired humoral immunity. Further, depletion of B cells with anti-CD20 therapy resulted in almost complete abrogation of SARS-CoV-2-specific IgG and IgM antibodies, but was not associated with increased mortality compared to other hematologic cancers, when adequate CD8 T cells were present. Finally, higher CD8 T cell counts were associated with improved overall survival in patients with hematologic cancers. Thus, CD8 T cells likely compensate for deficient humoral immunity and influence clinical recovery of COVID-19. These observations have important implications for cancer and COVID-19-directed treatments, immunosuppressive therapies, and for understanding the role of B and T cells in acute COVID-19.

Deep Immune Profiling of MIS-C demonstrates marked but transient immune activation compared to adult and pediatric COVID-19

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8 T cells that correlated with use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct and implicate CD8 T cells in clinical presentation and trajectory of MIS-C.

Immunologic perturbations in severe COVID-19/SARS-CoV-2 infection

Although critical illness has been associated with SARS-CoV-2-induced hyperinflammation, the immune correlates of severe COVID-19 remain unclear. Here, we comprehensively analyzed peripheral blood immune perturbations in 42 SARS-CoV-2 infected and recovered individuals. We identified broad changes in neutrophils, NK cells, and monocytes during severe COVID-19, suggesting excessive mobilization of innate lineages. We found marked activation within T and B cells, highly oligoclonal B cell populations, profound plasmablast expansion, and SARS-CoV-2-specific antibodies in many, but not all, severe COVID-19 cases. Despite this heterogeneity, we found selective clustering of severe COVID-19 cases through unbiased analysis of the aggregated immunological phenotypes. Our findings demonstrate broad immune perturbations spanning both innate and adaptive leukocytes that distinguish dysregulated host responses in severe SARS-CoV-2 infection and warrant therapeutic investigation.

One Sentence Summary

Broad immune perturbations in severe COVID-19.

Successive annual influenza vaccination induces a recurrent oligoclonotypic memory response in circulating T follicular helper cells

T follicular helper (Tfh) CD4 cells are crucial providers of B cell help during adaptive immune responses. A circulating population of CD4 T cells, termed cTfh, have similarity to lymphoid Tfh, can provide B cell help, and responded to influenza vaccination. However, it is unclear whether human vaccination-induced cTfh respond in an antigen-specific manner and whether they form long-lasting memory. Here, we identified a cTfh population that expressed multiple T cell activation markers and could be readily identified by coexpression of ICOS and CD38. This subset expressed more Bcl-6, c-Maf, and IL-21 than other blood CD4 subsets. Influenza vaccination induced a strong response in the ICOS+CD38+ cTfh at day 7, and this population included hemagglutinin-specific cells by tetramer staining and antigen-stimulated Activation Induced Marker (AIM) expression. Moreover, TCRB sequencing identified a clonal response in ICOS+CD38+ cTfh that correlated strongly with the increased circulating ICOS+CD38+ cTfh frequency and the circulating plasmablast response. In subjects who received successive annual vaccinations, a recurrent oligoclonal response was identified in the ICOS+CD38+ cTfh subset at 7 days after every vaccination. These oligoclonal responses in ICOS+CD38+ cTfh after vaccination persisted in the ICOS-CD38- cTfh repertoire in subsequent years, suggesting clonal maintenance in a memory reservoir in the more-stable ICOS-CD38- cTfh subset. These data highlight the antigen-specificity, lineage relationships and memory properties of human cTfh responses to vaccination, providing new avenues for tracking and monitoring cTfh responses during infection and vaccination in humans.

Identification of flu-specific ICOS+CD38+ cTfh after influenza vaccination

The foundation of successful vaccines lies in the ability to prime the immune system to target a specific pathogen. The interaction between follicular helper T cells (Tfh) and B cells within germinal centers is necessary for the production of class-switched, affinity-matured antibodies. However, the size, diversity, and specificity of the T cell receptor (TCR) repertoire of the Tfh during an immune response remains unknown. We identified a subset of circulating Tfh (cTfh) coexpressing ICOS and CD38 that expresses markers of recent activation, such as the proliferation marker Ki67 and the transcription factor Helios. This activated cTfh subset increases following influenza vaccination. To begin to interrogate how the TCR repertoire changes in human cTfh cells responding to a vaccine, we performed T-cell receptor beta chain sequencing on cTfh from individuals before and after influenza vaccination. Although the ICOS−CD38− cTfh maintained a stable TCR repertoire pre- and 7 days post vaccination, the ICOS+CD38+ cTfh exhibited increased clonality indicative of antigen-driven activation and expansion. Using HLA class II HA306- and HA40-specific tetramer staining on peripheral blood from HLA-DR0401 individuals, we then further assessed the specificity of the responding cTfh at day 7 after vaccination. We found many tetramer-positive cells that expressed ICOS and CD38 in the cTfh subset, confirming that the ICOS+CD38+ response after vaccination contains influenza-specific cells. Ultimately, rational vaccine design will depend on better understanding of the clonotypic response elicited in response to various pathogens and their relevance to the overall immune response.

Infectious diseases approach to immunocompromised patients in the pediatric intensive care unit

The diagnosis and management of infectious diseases in the immunocompromised patient can be challenging, especially when that patient is critically ill. In the diagnostic approach to the immunocompromised patient, clinicians will need to integrate the risks particular to the immunodeficiency with the risks associated with hospital-associated exposures. The potential infectious diagnoses are expanded in the immunocompromised patients, most notably to include diseases due to opportunistic infections, such as fungi, latent viruses, and opportunistic Gram-positive and Gram-negative bacteria. In addition, prior hospital and antibiotic exposure increases the likelihood that these patients will have infections due to resistant organisms. When an infection is diagnosed, the approach to treatment in the immunocompromised patient is also dependent on the degree and type of immunodeficiency, and optimal treatment strategies are often not well studied. This review focuses on general principles that can be used in the diagnosis and management of immunocompromised, critically ill patients with suspected or proven infection and highlights in detail the approach to infections of the blood stream and respiratory tract.

Assessment of an in vitro model of lung epithelial cell stress responses

The ability of cells to adapt and survive environmental and physiological stress relies on activation of cellular stress responses. These include anti-oxidant, inflammatory and apoptotic responses. These cellular responses are mediated by cell signalling pathways, including those controlled by the transcription factors Nrf2 (antioxidant response) and NF-?ß (inflammatory response). As part of a suite of in vitro models for the comparison of different nicotine delivery products, an in vitro lung cell stress response model has been developed. Human bronchial epithelial cells were exposed to positive controls or cigarette smoke aqueous extracts (CSEaq) from 3R4F and 1R5F reference cigarettes for 4hours. Cellular responses were then measured as oxidative, pro-inflammatory, apoptotic and necrotic endpoints. Cellular oxidative stress was characterised by measurement of the intracellular glutathione ratio, intracellular ROS production and activation of the Nrf2-controlled Anti-oxidative Response Elements (ARE). The inflammatory response of the cells was determined through quantification of secreted cytokines, IL-1a, IL-6 and IL-8. Apoptotic and necrotic responses were characterised by measurements of Caspase 3/7 activity and live-cell protease activity. Stably transfected luciferase reporter cell lines were utilised to quantify the transcriptional control of anti-oxidant and inflammatory pathways. All cell stress response endpoints were activated by exposure to positive controls or CSEaq. The observed concentration-dependent lowering of the glutathione ratio and increase in intracellular ROS generation corresponded with an increase in Nrf2 transcriptional activation of the ARE. It has been demonstrated that this model was able to distinguish between CSEaq from the two different reference cigarettes. We propose that this model may be suitably sensitive for biological comparisons of cigarettes against different nicotine delivery products.

ApoE alleles, depression and positive affect in multiple sclerosis

BACKGROUND

The role of apolipoprotein E (ApoE) alleles has received recent attention in depressive disorders, the ApoE epsilon4 conferring greater risk for poorer outcomes, and the ApoE epsilon2 allele providing some protective effects. Depression is common in multiple sclerosis (MS) and the role of ApoE alleles is unknown.

AIMS

To evaluate ApoE alleles in relation to symptoms of depression in a cohort of patients with MS participating in the Sonya Slifka Longitudinal Multiple Sclerosis Study (Slifka Study). To examine risk and protection, depressed mood and positive affect were each investigated with respect to the ApoE epsilon4 and ApoE epsilon2 alleles, respectively.

RESULTS

Of the total 101 participants, 22.8% were ApoE epsilon2 carriers and 21.8% were ApoE epsilon4 carriers. Hierarchical linear regression analyses suggested that after controlling for demographics, disease duration, and disability, ApoE epsilon2 significantly predicted increased positive affect (R2Delta=0.05, F(1,94)=5.44, P=0.02) and was associated with decreased severity of depressive symptoms, although this did not reach statistical significance (R2Delta=0.03, F(1,94)=3.44, P=0.06). ApoE epsilon4 did not significantly predict depression status.

CONCLUSION

The presence of the ApoE epsilon2 allele in this study is suggested to be protective against depressive symptoms in our subsample of patients recruited from the Slifka Study. These findings are consistent with reports in psychiatric populations linking ApoE epsilon2 with decreased incidence of depressive disorders. Further investigation would be warranted to understand the role of ApoE genotypes and risk for depressive symptoms.

Salmonella excretion in adult cattle on the Maltese island of Gozo

A cross-sectional study was conducted, between June and November 1993, to determine the prevalence of Salmonella excretion in a representative sample (n = 300) of adult cattle, chosen by strict random sampling of the isolated bovine population in Gozo. Salmonellae were found in 41.3% of the cattle investigated, and seven animals yielded multiple Salmonella serovars. The total number of Salmonella isolates was 131. These included Salmonella Croft (55 isolates), S. Telaviv (29), S. Montevideo (17), S. Kpeme (7), S. Infantis (2) and S. Abadina (1). A seventh serovar (14 isolates) was found to have a novel antigenic structure: the name S. Gozo was proposed, and was accepted by the World Health Organisation Salmonella Reference Centre. All isolates were sensitive to four antibiotics, while 43% of the Salmonella strains were sensitive to nine antibiotics. No resistance was detected to cefuroxime, ciprofloxacin and gentamicin.

Sunburn presenting to the accident & emergency department of two north Dublin hospitals

A retrospective study was carried out in two North Dublin hospitals to determine how many patients attended the Accident & Emergency Departments of these hospitals with sunburn. 30 patients presented to Beaumont Hospital over a nine month period from January to September 1992, 28 of whom attended during the four months from 1st May 1992 to 31st August 1992. During the same four month period, 27 children attended the Accident & Emergency Department of Temple Street Hospital for treatment of sunburn. This was a marked increase from the previous year, when only six children presented to Temple Street Hospital with sunburn.

Role of Drugs and Alcohol in Patients with Head Injury

In an effort to define the role that substance abuse has to play in head injuries, a prospective study of 204 patients presenting to the Accident and Emergency (A&E) Department over a 10-week period was carried out. Urine samples were collected and assayed for the presence of common drugs of abuse and alcohol. One or other substance (drugs or alcohol) was detected in 43% of patients. The association between alcohol and head injuries has been confirmed and the importance of drugs in this area has been addressed and found to be of some significance. More rapid and accurate methods of assaying these substances may improve our management of head injury patients.

Comparison of the antiemetics metoclopramide and promethazine in labour

A double blind trial was conducted in 477 mothers in labour to compare the antiemetics metoclopramide 10 mg and promethazine 25 mg and placebo when added to the first dose of pethidine. Metoclopramide and promethazine were equally effective, and both better than placebo, in reducing the incidence of nausea and vomiting after the administration of pethidine. Seventy seven per cent of mothers were drowsy, and 8% slept in the hour after the pethidine injection, with no difference between the groups. The sedative effect was more persistent in the promethazine group, 66% of whom were still drowsy after delivery. One third of the mothers in each group needed further analgesia, with 77% of these ultimately requesting an epidural. The reduction in pain half an hour and one hour after pethidine, assessed by a visual analogue scale, were, respectively, 22% and 22% for placebo; 26% and 23% for metoclopramide; 13% and 9% for promethazine. Analgesia after metoclopramide was significantly better than that after promethazine in terms of pain score, duration of first injection, and need for Entonox. Metoclopramide is therefore to be preferred to promethazine as an antiemetic in labour.