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The oncogenic Epstein-Barr virus (EBV)-encoded latent infection membrane protein 1 (LMP1) constitutively activates the ‘canonical’ NF-?B pathway that involves the phosphorylation and degradation of I?Ba downstream of the I?B kinases (IKKs). In this study, we show that LMP1 also promotes the proteasome-mediated proteolysis of p100 NF-?B2 resulting in the generation of active p52, which translocates to the nucleus in complex with the p65 and RelB NF-?B subunits. LMP1-induced NF-?B transactivation is reduced in nf-kb2-/- mouse embryo fibroblasts, suggesting that p100 processing contributes to LMP1-mediated NF-?B transcriptional effects. This pathway is likely to operate in vivo, as the expression of LMP1 in primary EBV-positive Hodgkin's lymphoma and nasopharyngeal carcinoma biopsies correlates with the nuclear accumulation of p52. Interestingly, while the ability of LMP1 to activate the canonical NF-?B pathway is impaired in cells lacking IKK?/NEMO, the regulatory subunit of the IKK complex, p100 processing remains unaffected. As a result, nuclear translocation of p52, but not p65, occurs in the absence of IKK?. These data point to the existence of a novel signalling pathway that regulates NF-?B in LMP1-expressing cells, and may thereby play a role in both oncogenic transformation and the establishment of persistent EBV infection.Oncogene (2003) 22, 7557-7569. doi:10.1038/sj.onc.1207120 [ABSTRACT FROM AUTHOR]

The article discusses the serpinopathies have a diverse set of conformational diseases that involve the aberrant self-association of proteins to ordered aggregates. Topics include genetic variants such as the severe Z allele of 1-antitrypsin promote proteasomal degradation and the formation of ordered linear polymers; and the structure of the pathological polymers accumulate in patients has not been demonstrated.

Objective: Tissue-resident memory T cells (T RM ) are vital immune sentinels that provide protective immunity. While hepatic CD8 + T RM have been well described, little is known about the location, phenotype and function of CD4 + T RM ., Design: We used multiparametric flow cytometry, histological assessment and novel human tissue coculture systems to interrogate the ex vivo phenotype, function and generation of the intrahepatic CD4 + T-cell compartment. We also used leukocytes isolated from human leukocyte antigen (HLA)-disparate liver allografts to assess long-term retention., Results: Hepatic CD4 + T cells were delineated into three distinct populations based on CD69 expression: CD69 - , CD69 INT and CD69 HI . CD69 HI CD4 + cells were identified as tissue-resident CD4 + T cells on the basis of their exclusion from the circulation, phenotypical profile (CXCR6 + CD49a + S1PR1 - PD-1 + ) and long-term persistence within the pool of donor-derived leukcoocytes in HLA-disparate liver allografts. CD69 HI CD4 + T cells produced robust type 1 polyfunctional cytokine responses on stimulation. Conversely, CD69 INT CD4 + T cells represented a more heterogenous population containing cells with a more activated phenotype, a distinct chemokine receptor profile (CX 3 CR1 + CXCR3 + CXCR1 + ) and a bias towards interleukin-4 production. While CD69 INT CD4 + T cells could be found in the circulation and lymph nodes, these cells also formed part of the long-term resident pool, persisting in HLA-mismatched allografts. Notably, frequencies of CD69 INT CD4 + T cells correlated with necroinflammatory scores in chronic hepatitis B infection. Finally, we demonstrated that interaction with hepatic epithelia was sufficient to generate CD69 INT CD4 + T cells, while additional signals from the liver microenvironment were required to generate liver-resident CD69 HI CD4 + T cells., Conclusions: High and intermediate CD69 expressions mark human hepatic CD4 + T RM and a novel functionally distinct recirculating population, respectively, both shaped by the liver microenvironment to achieve diverse immunosurveillance., Competing Interests: Competing interests: BW collaborated with and received funding from Bioniz. LJP sat on advisory boards/provided consultancy for Gilead Sciences and SQZ Biotech. KA was funded by a studentship with Dr Falk. MKM received research funding from Gilead Sciences, Hoffmann La Roche and Immunocore. MKM sat on advisory boards/provided consultancy for Gilead, Hoffmann La Roche, Immunocore, VIR, Galapagos NV, GSK, Abbvie and Freeline. ZS collaborated with Bioniz and AstraZeneca and consulted for Boehringer Ingelheim. All other authors declare no conflict of interest., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

CD4 + T cells play critical roles in directing immunity, both as T helper and as regulatory T (Treg) cells. Here, we demonstrate that hepatocytes can modulate T cell populations through engulfment of live CD4 + lymphocytes. We term this phenomenon enclysis to reflect the specific enclosure of CD4 + T cells in hepatocytes. Enclysis is selective for CD4 + but not CD8 + cells, independent of antigen-specific activation, and occurs in human hepatocytes in vitro, ex vivo, and in vivo. Intercellular adhesion molecule 1 (ICAM-1) facilitates T cell early adhesion and internalization, whereas hepatocytes form membrane lamellipodia or blebs to mediate engulfment. T cell internalization is unaffected by wortmannin and Rho kinase inhibition. Hepatocytes engulf Treg cells more efficiently than non-Treg cells, but Treg cell-containing vesicles preferentially acidify overnight. Thus, enclysis is a biological process with potential effects on immunomodulation and opens a new field for research to fully understand CD4 + T cell dynamics in liver inflammation., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Sphingosine-1-phosphate (S1P) and the enzyme primarily responsible for its production, sphingosine kinase-1 (SphK-1), are dysregulated in multiple human diseases including cancer, multiple sclerosis (MS), diabetes, neurological diseases, fibrosis, and certain pathologies associated with impaired angiogenesis such as age-related macular degeneration (AMD). Antibody-based techniques to identify and localize S1P and SphK-1 within cells and tissue specimens represent a powerful tool, not only to understand biological role of these molecules but also to validate these unique in-class targets in multiple state diseases. Consequently, the potential applications of these molecules for therapy and diagnostic purposes are currently under investigation. Here, we describe a new improved technique, Agitated Low Temperature Epitope Retrieval (ALTER) for staining procedures, to identify expression of S1P and SphK-1 in human frozen tissue samples. The challenges encountered in the process of localization in tissue samples of lipid molecules such as S1P are discussed.

The expression of steroid receptors by tumours offers a therapeutic advantage if functionally responsive to exogenous hormones. Insulinomas represent a highly symptomatic group of pancreatic tumours and the steroid receptor status of these tumours is poorly understood. The object of the study was to characterise the sex steroid receptor status of human insulinomas and to investigate whether sex steroids alter insulin expression therein. At our tertiary referral University Hospital, archival and prospective tissues from 25 insulinoma patients collected over 14 years were analysed for oestrogen receptor-alpha (ERalpha), oestrogen receptor beta (ERbeta) and progesterone receptor (PR) expression. Tissue explants of insulinoma and control pancreatic tissue from two new insulinoma patients were cultured and treated with oestrogen and progesterone and insulin expression measured by RT-PCR and ELISA. The main outcome measures were established before data collection and included sex steroid receptor status of tumours and insulin expression in fresh tissue in response to exogenous sex steroids. PR was expressed in 24 out of 25, ERalpha in 10 out of 25 and ERbeta in 21 out of 25 insulinomas. In fresh insulinoma cultures, insulin expression was increased by oestrogen or progesterone, whereas no significant effect was observed in adjacent pancreatic tissue. This study demonstrates widespread expression of sex steroid receptors on human insulinoma tissue and provides in vitro evidence of functionality with increased expression of insulin by insulinoma explants in response to exogenous oestrogen or progesterone. Confirmation of these results may provide a therapeutic mechanism for reducing symptomatic insulin secretion by receptor blockade.

Previous studies have suggested that common breast cancers are associated with EBV. We used a highly sensitive quantitative real-time PCR method to screen whole tumor sections of breast cancers for the presence of the EBV genome. EBV DNA was detected in 19 of 92 (21%) tumors, but viral load was very low in positive samples (mean = 1.1 copy EBV/1000 cells, maximum = 7.1 copies EBV/1000 cells). Importantly, quantitative real-time PCR failed to detect the EBV genome in microdissected tumor cells from any case. Using a monoclonal antibody (2B4-1) reactive against the EBV nuclear antigen-1, we noted strong staining of tumor nuclei in a proportion of those breast cancers that had tested negative for the presence of the EBV genome. Because nuclear staining with the 2B4-1 antibody was previously observed more frequently in poor prognosis breast cancers, we examined a larger series of breast cancers with complete clinical follow-up. Strong punctate staining of tumor cell nuclei was observed in 47 of 153 (31%) breast cancers; 2B4-1-positive tumors were significantly more likely to be ER-negative (P < 0.0001), to be of higher grade (P = 0.001) and larger (P = 0.03), to involve more regional lymph nodes (P = 0.01), and to have higher Nottingham Prognostic Index scores (P = 0.0003). Conclusions are: (a) EBV can be regularly detected in whole sections of breast cancers but viral copy number is very low; (b) in these cases, tumor cells do not harbor virus; and (c) reactivity with the monoclonal antibody 2B4-1 is detectable in the absence of the EBV genome and is strongly associated with ER-negative breast tumors and with prognostically unfavorable disease. Additional studies should be directed to the identification of this protein and to elucidation of its role in breast cancer.