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IL-2 and GM-CSF are potent activators of polymorphonuclear neutrophils (PMN) biologic activity. IL-2 and GM-CSF-mediated activation of STAT proteins was examined in nuclear extracts of human PMN. We found that both cytokines induced STAT5-like DNA-binding complexes that could not be supershifted using C-terminal-specific anti-STAT5 antibodies. Therefore, we performed oligoprecipitation experiments with a STAT5-biotinylated DNA probe (biotin-MGFe) and the precipitated proteins were identified by Western immunoblotting. We found that GM-CSF and IL-2 induced the DNA-binding activity of a C-terminal truncated isoform of STAT5. The truncated STAT5 form was present in the nucleus of PMN but the cytoplasmic extracts contained full-length STAT5, suggesting that PMN proteolytically process full-length STAT5 proteins. Proteolytic experiments demonstrated that PMN express a protease activity capable of producing C-terminal processed STAT5 proteins. In many settings, C-terminal truncation of the STAT5 protein leads to inhibition of STAT5 biological activity. Two known STAT5 regulated genes, encoding pim-1 and OSM proteins, failed to be induced by GM-CSF in PMN. These findings provide new insights to a mechanism by which PMN, a terminally differentiated cell, may regulate gene transcription by alternative proteolytic processing. [Copyright &y& Elsevier]

Presents a study which demonstrated the inhibition by PD180970 of the Stat5 DNA-binding activity in the human K562 chronic myelogenous leukemia cell line. Review of related literature; Methodology; Results and discussion.

Summary: Background: Cutaneous viral infections and immune suppression are risk factors for some forms of nonmelanoma skin cancer; however, their interrelationship is poorly understood. Objectives: To examine cross‐sectional associations between cutaneous viral infections and circulating forkhead‐box P3 (FOXP3)‐expressing T‐regulatory (Treg) cells, suppressive cells that dampen effective antitumour immunity. Materials and methods: Blood, eyebrow hair (EBH) and skin swab (SSW) samples were collected from 352 patients 60 years and older undergoing skin screening, without prevalent skin cancer, while participating in an ongoing prospective cohort study of cutaneous viral infections and skin cancer. DNA corresponding to 98 cutaneous human papillomavirus (HPV) types and five human polyomaviruses (HPyV) was assessed in EBH and SSW. Distinct classes of circulating Treg‐cell subpopulations were defined by flow cytometry including cutaneous lymphocyte antigen (CLA) and CCR4high Treg cells, both previously associated with cutaneous diseases. Age‐ and sex‐adjusted associations between circulating T‐cell populations and infection were estimated using logistic regression. Results: Total Treg‐cell proportion in peripheral blood was not associated with β HPV or HPyV infection. However, the proportion of circulating CLA+ Treg cells was inversely associated with γ HPV EBH infection [odds ratio (OR) 0·54, 95% confidence interval (CI) 0·35–0·84]. Interestingly, circulating Treg cells expressing markers indicative of antigen activation (CD27–CD45RA–FOXP3+CD4+) were also inversely associated with γ HPV infection in SSW (OR 0·55, 95% CI 0·30–0·99) and EBH (OR 0·56, 95% CI 0·36–0·86). Conclusions: Inverse associations between circulating Treg cells and γ HPV infection suggest that localized viral infection may promote immunosuppressive cell migration into skin. What's already known about this topic? Cutaneous viral infections such as the human papillomavirus (HPV) and polyomavirus (HPyV) may play a role in the development of some nonmelanoma skin cancer types, including cutaneous squamous cell carcinoma (cuSCC) and Merkel cell carcinoma (MCC).Immunosuppression is an established risk factor for cuSCC and MCC.The relationship between cutaneous viral infections, immunosuppression and the development of cuSCC and MCC is not well understood. What does this study add? Higher proportions of circulating antigen‐activated CD27–/CD45RA– T‐regulatory (Treg) cells were inversely associated with γ HPV infection in skin swabs and eyebrow hairs, whereas no associations were observed for β human papillomavirus (HPV) or polyomavirus infections.Circulating skin‐homing cutaneous lymphocyte antigen‐positive Treg cells were inversely associated with γ HPV eyebrow hair infection.γ HPV infections may recruit immunosuppressive lymphocytes into the skin, perhaps contributing to cutaneous malignancy development. What is the translational message? In this first study of the associations between Treg cells circulating in the blood and the presence of cutaneous infections with HPVs and HPyVs, circulating immunosuppressive lymphocytes were inversely associated with γ HPV infection.γ HPV infections may recruit immunosuppressive lymphocytes into the skin, perhaps contributing to the development of cutaneous malignancy. Respond to this article Linked Comment: Poyner, Dubois and Haniffa. Br J Dermatol 2019; 180:1294. Plain language summary available online [ABSTRACT FROM AUTHOR]

Background: Liver injury is of prognostic importance in acute pancreatitis. We previously demonstrated that Kupffer cell-derived cytokines mediate liver injury. Aim: To determine the role of Fas Ligand (FasL) in liver injury during acute pancreatitis. Methods: CCK was used to induce pancreatitis in mice; serum FasL (ELISA), AST, and liver FasL, p38-MAPK and Caspase-3 (western) were measured. Rat Kupffer cells were treated with elastase (1U/ml) to mimic acute pancreatitis; FasL and its receptor (Fas) (western) and FasL mRNA (RT-PCR) were determined. Apoptosis was measured by flow cytometry. Immunoblots were done in triplicates and quantified with densitometry. Results: CCK-induced pancreatitis increased serum AST and FasL, upregulated liver FasL (1315 ± 111, vs. 310 ± 164, p = 0.002 vs. sham), and induced phosphorylation of p38-MAPK (p < 0.01 vs. sham) and cleavage of Caspase-3 (p < 0.04 vs. sham); all of which were attenuated by pre-treatment with the Kupffer cell inhibitor, Gadolinium (all p < 0.003). In-vitro, elastase induced a time-dependent increase in Kupffer cell FasL protein (FasL= 512 ± 53 vs. 170 ± 40, p = 0.01, 2hrs vs. control), a 100-fold increase in FasL mRNA and upregulated FasL receptor (Fas) (Figure; E: elastase, G: Gadolinium, ′: min). Gadolinium significantly attenuated the elastase-induced increase in FasL and FasL mRNA (FasL= 230 ± 20 vs. 512 ± 53, p = 0.01, Gadolinium vs. elastase) but had little effect on Fas (receptor). The medium of elastase-primed Kupffer cells induced apoptosis in fresh rat hepatocytes (29 ± 1 vs. 16 ± 1%; vs. control, p < 0.001). Conclusions: Acute pancreatitis induced liver injury and hepatocyte death, upregulated FasL production and activated hepatic p38-MAPK and Caspase-3. Utilizing Gadolinium, Kupffer cell-derived FasL production was significantly attenuated both in-vivo and in-vitro. Similar to other immune cells, FasL receptor (Fas) was upregulated within Kupffer cells suggesting that FasL may auto-regulate its production by inducing its originator-cell death. The ability to manipulate interactions between Kupffer cells and hepatocytes may have important therapeutic implications. [Copyright &y& Elsevier]

Abstract: Acquired amegakaryocytic thrombocytopenia and pure red cell aplasia rarely occur concurrently. We report a case in which these disorders were associated with an occult large granular lymphocyte leukemia. The peripheral blood cytopenias improved after glucocorticoids and intravenous immunoglobulin were administered, and response was maintained with cyclosporine. Large granular lymphocyte leukemia should be suspected in the setting of unexplained bone marrow failure. [Copyright &y& Elsevier]

Abstract: We report on the clinico-biological characteristics of 20 cases of γδ T cell large granular lymphocyte (LGL) leukemia. All the data were compared to that of 196 cases with αβ T cell subtype, which represents the majority of T cell LGL leukemias. Clinical findings were quite similar in the two groups regarding age, sex ratio, recurrent infections, and association with auto-immune diseases especially rheumatoid arthritis. γδ LGL predominantly expressed a CD3+/CD4−/CD8+/CD16+/CD57+ phenotype, in 50% of cases. Clinical outcome was favorable for these patients with overall survival of 85% at 3 years. Fifty percent of γδ patients required treatment and the response to therapy was estimated at 55%. γδ and αβ T cell LGL leukemia harbor a very similar clinico-biological behavior and represent part of an antigen-driven T cell lymphoproliferation. [Copyright &y& Elsevier]

Liver injury is a clinical prognostic indicator in acute pancreatitis (AP). We have demonstrated that Kupffer cell-derived FasL mediates liver injury during AP and sought to determine its role in AP-induced hepatocyte apoptosis. AP was induced in National Institutes of Health (NIH) Swiss mice, C57/C57, and Fas-/-, FasL-/- mice by a choline-deficient ethionine-supplement diet. Liver Fas, FasL, p38-mitogen activated phosphokinase (p38-MAPK), poly-ADP ribose polymerase (PARP), and cytochrome C were measured by immunoblotting. Apoptosis was assessed by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) and DNA fragmentation (ELISA). AP upregulated liver FasL (4280 ± 580 vs. 733 ± 336), Fas (2866 ± 595 vs. 649 ± 111), cytochrome C (6980 ± 237 vs. 903 ± 156), and PARP (6393 ± 591 vs. 466 ± 261) as well as increased TUNEL staining (40 ± 2 vs. 14 ± 1) and DNA fragmentation (all P < 0.03 vs. control). In FasL-/- and Fas-/- mice, AP-induced upregulation of p38-MAPK, PARP, and cytochrome C was significantly attenuated (all P < 0.01 compared to C57/C57 control). In addition, AP-induced DNA fragmentation was reduced 60% in Fas-/- and FasL-/- mice (P < 0.01 vs. C57/C57). AP induces apoptosis by transcriptional activation of Fas/FasL. AP-induced apoptosis was significantly reduced in Fas and FasL knockout mice along with downregulation of p38-MAPK, PARP, and cytochrome C, thereby suggesting a central role for Fas/FasL in hepatocyte apoptosis. The manipulation of interactions between Kupffer cell–derived FasL and hepatocytes may have important therapeutic implications. [Copyright &y& Elsevier]

Background: Liver injury is an important prognostic indicator in acute pancreatitis. We previously demonstrated that Kupffer cell-derived cytokines mediate liver injury. In this work, we sought to characterize the role of Fas Ligand (FasL) in liver injury during acute pancreatitis. Methods: Acute pancreatitis was induced in mice using cerulein; serum FasL, AST, ALT, liver FasL, p38-MAPK, and caspase-3 were measured. FasL mRNA and protein and its receptor (Fas) were determined in rat Kupffer cells treated with elastase (1 U/ml) to mimic acute pancreatitis. Apoptosis was measured by flow cytometry. Results: Cerulein-induced pancreatitis increased serum AST, ALT, and FasL and up-regulated liver FasL (1315 ± 111 versus 310 ± 164 pg/ml, P = 0.002 versus sham), while inducing p38-MAPK phosphorylation (P < 0.01 versus sham) and cleavage of caspase-3 (P < 0.04 versus sham); all were attenuated by pretreatment with the Kupffer cell inhibitor, gadolinium (all P < 0.003). In vitro, elastase induced a time-dependent increase in Kupffer cell FasL protein (FasL = 404 ± 94 versus 170 ± 40, P = 0.02, versus control), a 100-fold increase in FasL mRNA, and up-regulated Fas (FasL receptor). Gadolinium significantly attenuated the elastase-induced increase in FasL and FasL mRNA (FasL = 230 ± 20 versus 404 ± 94, P = 0.01, versus elastase) but had little effect on Fas. Additionally, elastase-primed Kupffer cell media induced apoptosis in hepatocytes (29 ± 1 versus 16% ± 1%; versus control, P < 0.001). Conclusions: Acute pancreatitis induces liver injury and hepatocyte death while up-regulating FasL, p38-MAPK, and caspase-3. Fas is up-regulated within Kupffer cells, suggesting that FasL may autoregulate its production by inducing its originator-cell death. The ability to manipulate interactions between Kupffer cells and hepatocytes may have important therapeutic implications. [Copyright &y& Elsevier]

Liver injury is an important prognostic indicator during acute pancreatitis. The aim of this study was to determine the role of Fas ligand (FasL) in hepatocyte injury. Liver parenchymal enzymes were measured in cocultures of hepatocytes and Kupffer cells treated with elastase. FasL and FasL mRNA were measured in elastase-treated Kupffer cells. Hepatocytes were treated with FasL and their viability was assessed by monotetrazolium (MTT), apoptosis by flow cytometry, as well as caspase-3 and p38–mitogen-activated protein kinase (MAPK) by immunoblotting. Elastase increased aspartate aminotransferase and lactate dehydrogenase in cocultures of hepatocyte and Kupffer cells (P<0.040). Elastase increased FasL production from Kupffer cells (P = 0.02) and upregulated FasL mRNA (FasL/beta-2 microglobulin (BMG): 0.23±0.03 vs. 0.11±0.003; P = 0.04). FasL increased alanine aminotransferase and lactate dehydrogenase (P<0.03) and reduced hepatocyte viability by 45% (P = 0.01). FasL increased the number of dually labeled cells with AnnexinV/7AAD (P = 0.03) while upregulating cleavage of caspase-3 and the phosphorylation of p38-MAPK. FasL antibody attenuated the FasL-related increase in dually labeled cells (P = 0.02), the cleavage of caspase-3, and phosphorylation of p38-MAPK. Pancreatic elastase upregulates FasL within Kupffer cells. FasL induces hepatocyte injury and death and upregulates p38-MAPK and caspase-3 within hepatocytes. The ability to manipulate interactions between Kupffer cells and hepatocytes may have important therapeutic implications. [Copyright &y& Elsevier]

We have demonstrated that pancreatitis-associated ascitic fluid contributes to hepatocyte injury during acute pancreatitis; a phenomenon independent of ascites'' enzymatic content and Kupffer cell-derived cytokines. Our aim is to characterize the mechanisms of pancreatitis-associated ascitic fluid induced hepatocyte death. NIH mice were injected intraperitoneally with pathogen-free pancreatitis-associated ascitic fluid. Twenty-four hours later, serum AST, ALT, LDH, and hepatocyte apoptosis (TUNEL) were measured. Human hepatocytes (CCL-13) were treated with pancreatitis-associated ascitic fluid ±SB203580 or caspase-3 inhibitor-II. Mitochondrial membrane integrity was determined by DiOC6 staining. Apoptosis was measured by TUNEL staining and flow cytometry after dual labeling with Annexin-V/7-AAD. Data are mean ± SEM of triplicates. Pancreatitis-associated ascitic fluid increased serum AST, ALT, LDH, and apoptotic cells in the mouse liver (all P < 0.03 vs. sham). In CCL-13 cells, pancreatitis-associated ascitic fluid induced a time and dose-dependent increase in apoptosis, in addition to p38-MAPK phosphorylation (P = 0.02 vs. control), caspase-3 cleavage (P < 0.03 vs. control) and decreased DiOC6 mitochondrial staining (P < 0.01 vs. control). Both caspase-3 inhibitor-II and SB203580 decreased apoptosis, but the former had no effect on DiOC6 staining. Pancreatitis-associated ascitic fluid induces liver injury and hepatocyte apoptosis by activating p38-MAPK and caspase-3 dependent pro-apoptotic pathways. ( J Gastrointest Surg 2003;7:200–208.) [Copyright &y& Elsevier]

Linked Article: Hampras et al. Br J Dermatol 2019; 180:1449–1458 [ABSTRACT FROM AUTHOR]

Summary: Approximately three million non‐melanoma skin cancers (NMSCs) are diagnosed worldwide each year, although this number is likely an underestimate given that these cancers are not always recorded in cancer registries. Studies have suggested that skin (cutaneous) infections with human papillomaviruses (HPV) and polyomaviruses (HPyV) may play a role in the development of some NMSC types. Suppression of the immune system is also a risk factor for NMSC. This study, from the U.S.A, aimed to understand the relationship between T‐regulatory (Treg) cells, cells which suppress immune response, and cutaneous viral infections. Blood, skin swabs and eyebrow hairs were collected from 352 patients who underwent skin cancer screening and did not have cancer detected. The researchers examined whether the skin swabs (SSW) and eyebrow hairs (EBH) contained genetic material (DNA) corresponding to 98 cutaneous HPV types (including beta HPV and gamma HPV) and 5 HPyV types. The blood samples were analyzed to determine proportions of different types of Treg cell populations in circulation (in the blood). The researchers found no association between total percent of circulating Treg cells and beta HPV or HPyV infection. However, two types of Treg cells were found at lower levels in those that had gamma HPV infection in their EBH and/or SSW. Those two types were CLA+ Treg cells (known to travel to the skin) and effector CD27‐CD45RA‐FOXP3+CD4+ Treg cells (known to become active when exposed to a foreign viral infection). The study results suggest that gamma HPV infection may stimulate Treg cells to move from circulation into the skin tissues. Linked Article: Hampras et al. Br J Dermatol 2019; 180:1449–1458 [ABSTRACT FROM AUTHOR]