Autophagy induced by taurolidine protects against polymicrobial sepsis by promoting both host resistance and disease tolerance.

Sepsis, septic shock, and their sequelae are the leading causes of death in intensive care units, with limited therapeutic options. Disease resistance and tolerance are two evolutionarily conserved yet distinct defense strategies that protect the host against microbial infection. Here, we report that taurolidine administered at 6 h before septic challenge led to strong protection against polymicrobial sepsis by promoting both host resistance and disease tolerance characterized by accelerated bacterial clearance, ameliorated organ damage, and diminished vascular and gut permeability. Notably, taurolidine administered at 6 h after septic challenge also rescued mice from sepsis-associated lethality by enhancing disease tolerance to tissue and organ injury. Importantly, this in vivo protection afforded by taurolidine depends on an intact autophagy pathway, as taurolidine protected wild-type mice but was unable to rescue autophagy-deficient mice from microbial sepsis. In vitro, taurolidine induced light chain 3-associated phagocytosis in innate phagocytes and autophagy in vascular endothelium and gut epithelium, resulting in augmented bactericidal activity and enhanced cellular tolerance to endotoxin-induced damage in these cells. These results illustrate that taurolidine-induced autophagy augments both host resistance and disease tolerance to bacterial infection, thereby conferring protection against microbial sepsis.

An Early Neutrophil Recruitment into the Infectious Site Is Critical for Bacterial Lipoprotein Tolerance-Afforded Protection against Microbial Sepsis.

Bacterial lipoprotein (BLP)-induced tolerance represents an essential regulatory mechanism during bacterial infection and has been shown to protect against microbial sepsis. This protection is generally attributed to BLP-tolerized monocytes/macrophages characterized by hyporesponsiveness in producing inflammatory cytokines and, simultaneously, an augmented antimicrobial activity. However, the contribution of polymorphonuclear neutrophils (PMNs), another major player in innate immunity against bacterial infection, to BLP tolerance-afforded protection against microbial sepsis has not been identified. In this study, we report that induction of BLP tolerance protected mice against cecal ligation and puncture-induced polymicrobial sepsis, with significantly improved survival. Importantly, BLP tolerization via i.p. injection triggered an early PMN recruitment even before bacterial infection and promoted further PMN influx into the infectious site (i.e., the peritoneal cavity upon cecal ligation and puncture-associated septic challenge). Notably, this early PMN influx was mediated by BLP tolerization-induced PMN chemoattractant CXCL2-formed concentration gradient between the circulation and peritoneal cavity. Critically, blockage of PMN influx with the CXCR2 antagonist SB225002 abolished BLP tolerance-afforded protection and rendered BLP-tolerized mice more vulnerable to microbial infection with impaired bacterial clearance and increased overall mortality. Thus, our results highlight that an early recruitment of PMNs in the infectious site, as an important cellular mechanism, contributes to BLP tolerance-afforded protection against microbial sepsis.

Antagonism of Integrin CD11b Affords Protection against Endotoxin Shock and Polymicrobial Sepsis via Attenuation of HMGB1 Nucleocytoplasmic Translocation and Extracellular Release.

High mobility group box 1 (HMGB1), a chromatin-binding nuclear protein, plays a critical role in sepsis by acting as a key "late-phase" inflammatory mediator. Integrin CD11b is essential for inflammatory cell activation and migration, thus mediating inflammatory responses. However, it is unclear whether CD11b participates in the development of sepsis. In this study, we report that CD11b contributes to LPS-induced endotoxin shock and microbial sepsis, as antagonism of CD11b with the CD11b blocking Ab or CD11b inhibitor Gu-4 protects mice against LPS- and microbial sepsis-related lethality, which is associated with significantly diminished serum HMGB1 levels. Consistent with this, CD11b-deficient mice were more resistant to microbial sepsis with a much lower serum HMGB1 level compared with wild-type mice. Pharmacological blockage and genetic knockdown/knockout of CD11b in murine macrophages hampered LPS-stimulated HMGB1 nucleocytoplasmic translocation and extracellular release. Furthermore, silencing CD11b interrupted the interaction of HMGB1 with either a nuclear export factor chromosome region maintenance 1 or classical protein kinase C and inhibited classical protein kinase C-induced HMGB1 phosphorylation, the potential underlying mechanism(s) responsible for CD11b blockage-induced suppression of HMGB1 nucleocytoplasmic translocation and subsequent extracellular release. Thus, our results highlight that CD11b contributes to the development of sepsis, predominantly by facilitating nucleocytoplasmic translocation and active release of HMGB1.

RandomiSed clinical trial assessing Use of an anti-inflammatoRy aGent in attenUating peri-operatiVe inflAmmatioN in non-meTastatic colon cancer - the S.U.R.G.U.V.A.N.T. trial.

BACKGROUND: Peri-operative inflammation has been extensively highlighted in cancer patients as detrimental. Treatment strategies to improve survival for cancer patients through targeting peri-operative inflammation have yet to be devised. METHODS: We conducted a multi-centre, randomised controlled clinical trial using Taurolidine in non-metastatic colon cancer patients. Patients were randomly assigned to receive Taurolidine or a placebo. The primary endpoint for the study was the mean difference in day 1 IL-6 levels. Secondary clinical endpoints included rates of post-operative infections and tumor recurrence. RESULTS: A total of 293 patients were screened for trial inclusion. Sixty patients were randomised. Twenty-eight patients were randomised to placebo and 32 patients to Taurolidine. IL-6 levels were equivalent on day 1 post-operatively in both groups. However, IL-6 levels were significantly attenuated over the 7 day study period in the Taurolidine group compared to placebo (p = 0.04). In addition, IL-6 levels were significantly lower at day 7 in the Taurolidine group (p = 0.04). There were 2 recurrences in the placebo group at 2 years and 1 in the Taurolidine group. The median time to recurrence was 19 months in the Placebo group and 38 months in the Taurolidine group (p = 0.27). Surgical site infection was reduced in the Taurolidine treated group (p = 0.09). CONCLUSION: Peri-operative use of Taurolidine significantly attenuated circulating IL-6 levels in the initial 7 day post-operative period in a safe manner. Future studies are required to establish the impact of IL-6 attenuation on survival outcomes in colon cancer. TRIAL REGISTRATION: The trial was registered with EudraCT (year = 2008, registration number = 005570-12 ) and ISRCTN (year = 2008, registration number = 77,829,558 ).

Inefficient antimicrobial functions of innate phagocytes render infant mice more susceptible to bacterial infection.

Neonates and infants, due to the immaturity in their adaptive immunity, are thought to depend largely on the innate immune system for protection against bacterial infection. However, the innate immunity-mediated antimicrobial response in neonates and infants is incompletely characterized. Here, we report that infant mice were more susceptible to microbial sepsis than adult mice, with significantly reduced bacterial clearance from the circulation and visceral organs. Infant PMNs exhibited less constitutive expression of the chemokine receptor CXCR2, and bacterial infection caused further reduction of PMN CXCR2 in infant mice compared with adult mice. This correlates with diminished in vitro chemotaxis of infant PMNs toward the chemoattractant CXCL2 and impaired in vivo recruitment of infant PMNs into the infectious site. Furthermore, consistent with the reduced antimicrobial response in vivo, infant macrophages displayed an impaired bactericidal activity with a defect in phagosome maturation after ingestion of either gram-positive or gram-negative bacteria. Thus, infant mice exhibit an increased vulnerability to microbial infection with delayed bacterial clearance, which is associated with the inefficiency in their innate phagocyte-associated antimicrobial functions characterized by defects in PMN recruitment and macrophage phagosome maturation during microbial sepsis.

B7-H3 participates in the development of experimental pneumococcal meningitis by augmentation of the inflammatory response via a TLR2-dependent mechanism.

In addition to a well-documented role in regulating T cell-mediated immune responses, B7-H3, a newly discovered member of the B7 superfamily, has been recently identified as a costimulator in the innate immunity-mediated inflammatory response. In this study, we further report that B7-H3 participates in the development of pneumococcal meningitis in a murine model. Exogenous administration of B7-H3 strongly amplified the inflammatory response, exacerbated blood-brain barrier disruption, and aggravated the clinical disease status in Streptococcus pneumoniae-infected C3H/HeN wild-type mice. Consistent with the in vivo findings, B7-H3 substantially augmented proinflammatory cytokine and chemokine production, upregulated NF-κB p65 and MAPK p38 phosphorylation, and enhanced the nuclear transactivation of NF-κB p65 at both TNF-α and IL-6 promoters in S. pneumoniae-stimulated primary murine microglia cells. These B7-H3-associated in vitro and in vivo effects appeared to be dependent on TLR2 signaling, as B7-H3 almost completely lost its amplifying actions in both TLR2-deficient microglial cells and TLR2-deficient mice. Furthermore, administration of the anti-B7-H3 mAb (MIH35) attenuated the inflammatory response and ameliorated blood-brain barrier disruption in S. pneumoniae-infected wild-type mice. Collectively, our results indicate that B7-H3 plays a contributory role in the development of S. pneumoniae infection-induced bacterial meningitis.

Risk Stratification Tools to Aid Decisions on Adjuvant Chemotherapy Usage in Resected Soft Tissue Sarcomas: A Ten-Year Review of an Irish Sarcoma Center Experience.

Background: Soft tissue sarcoma (STS) is comprised of approximately 80 subtypes, with an incidence of 4 - 5 per 100,000 annually in Europe. The National Comprehensive Cancer Network (NCCN) guidelines recommend consideration of neoadjuvant/adjuvant chemotherapy in tumors at high risk of recurrence based on the American Joint Committee on Cancer (AJCC) staging. Alternatively, the Sarculator is a risk prediction tool that has identified a threshold of risk, above which chemotherapy may provide an overall survival (OS) benefit. Using this nomogram, patients with a 10-year predicted OS < 60% are classified as high risk and should be considered for chemotherapy. The aim of this study was to assess the prognostic accuracy of these two risk prediction methods in an Irish population. Methods: All newly diagnosed patients with resected STS discussed in the STS tumor board in Cork University Hospital between January 2012 and December 2021 were identified. Clinicopathological data were collected. Risk assessment using AJCC and Sarculator nomogram was performed on all patients with an extremity/trunk sarcoma. The OS was calculated including Kaplan-Meier method for time to event analysis. Results: In total, 200 STS patients were reviewed, of whom 134 had truncal or extremity tumors. Sarculator score was calculated for 60 of these (well differentiated liposarcomas, desmoid tumors and dermatofibrosarcoma protuberans were excluded). Using the Sarculator nomogram to calculate 10-year predicted OS, 19 patients were categorized as high risk and 41 were categorized as low risk. Using AJCC staging, 25 patients were categorized as high risk and 35 as low risk. The 5-year OS rate in the Sarculator high-risk group was 60.2%, compared with 87.1% in the low-risk group (P = 0.009). The 5-year OS rate in the AJCC high-risk group was 67.6%, compared with 86.3% in the low-risk group (P = 0.083). Conclusions: Our cohort is representative of the broad histological subtypes expected. In our population, Sarculator score results correlate with international outcomes and higher scores were associated with increased mortality. The Sarculator was more predictive of clinical outcome than AJCC staging, and its use would lower the proportion of patients being considered for adjuvant chemotherapy thereby sparing toxicity, which is important in the setting of uncertain clinical benefit.

Laparotomy and laparoscopy diversely affect macrophage-associated antimicrobial activity in a murine model.

BACKGROUND: Surgical intervention-related trauma contributes largely to the development of postoperative immunosuppression, with reduced resistance to secondary bacterial infection. This study compared the impact of laparotomy versus laparoscopy on macrophage-associated bactericidal ability and examined whether laparotomy renders the host more susceptible to microbial infection. RESULTS: BALB/c mice were randomized into control, laparotomy, and laparoscopy groups. Laparotomy, but not laparoscopy, significantly downregulated CR3 expression on macrophages, diminished macrophage-induced uptake and phagocytosis of E. coli and S. aureus, and impaired macrophage-mediated intracellular bacterial killing. Consistent with this, mice that underwent laparotomy displayed substantially higher bacterial counts in the blood and visceral organs as well as a significantly enhanced mortality rate following bacterial infection, whereas mice subjected to laparoscopy did not show any defects in their bacterial clearance. CONCLUSION: Laparotomy has an adverse effect on host innate immunity against microbial infection by impairing macrophage-mediated phagocytosis and killing of the invaded bacteria. By contrast, laparoscopy appears to preserve macrophage-associated bactericidal ability, thus alleviating the development of postoperative immunosuppression.

Silencing of TLR4 increases tumor progression and lung metastasis in a murine model of breast cancer.

BACKGROUND: Toll-like receptor 4 (TLR4) is a member of a family of pattern recognition receptors that are involved in the host defense against microbial infection. Little research has investigated the link between TLR4 and cancer. We thus addressed the effect of TLR4 in both the host immune system and cancer cells with regard to its effect on breast cancer progression and metastasis. METHODS: Adult female Balb/c mice aged 6-8 weeks were divided into three groups. In group 1, 15 each wild-type and TLR4(-/-) mice were inoculated with 4T1 cells; in group 2, wild-type mice were inoculated with 4T1 cells (n = 15), 4T1 cells transduced with TLR4 lentivirus (n = 15) or with control lentivirus (n = 15); and in group 3, 15 TLR4(-/-) mice were inoculated with 4T1 cells transduced with TLR4 lentivirus. Flank tumor volume was measured with calipers during weeks 2-5. Animals were then humanely killed and the number of macroscopic lung nodules counted. RESULTS: There was a significant increase in tumor volume in weeks 2, 3 and 4 after inoculation of TLR4(-/-) mice with 4T1 cells compared with wild-type mice (p < 0.05). The number of metastatic lung nodules was significantly higher in TLR4(-/-) mice (p < 0.05), and survival of tumor-bearing TLR4(-/-) mice was substantially reduced compared with wild-type mice (p = 0.004). Knockdown of TLR4 from the 4T1 cells led to a relative reduction in lung metastasis, although it did not reach statistical significance. CONCLUSIONS: TLR4 exerts both a defensive role at the host level and a negative role at the cancer cell level in this murine metastatic breast tumor model. Further evaluation of the role of TLR4 in breast cancer is warranted.

Bacterial superantigens enhance the in vitro proinflammatory response and in vivo lethality of the TLR2 agonist bacterial lipoprotein.

Bacterial superantigens are Gram-positive exotoxins that induce proinflammatory cytokine release in vitro, cause lethal shock in vivo, and can be detected in the bloodstream of critically ill patients. They also have a powerful priming effect on the TLR4 agonist LPS. The aim of this study was to investigate the relationship between superantigens and the TLR2 agonist bacterial lipoprotein (BLP). Priming of human monocytes or PBMCs with superantigens significantly enhanced proinflammatory cytokine TNF-α and IL-6 release in response to BLP stimulation. The priming effect of superantigens could be blocked by inhibiting p38 MAPK during the priming phase as opposed to NF-κB or ERK inhibition. This was consistent with higher expression of the phosphorylated p38 after superantigen priming and BLP or LPS stimulation. C57BL/6 mice with superantigen priming (10 µg/mouse) when challenged with BLP (600 µg/mouse) exhibited substantially higher mortality (100%) compared with mice without superantigen priming (zero). Mice given superantigen alone did not demonstrate any signs of illness. Mice challenged with both superantigen and BLP had significantly higher levels of serum TNF-α and IL-6 compared with those of mice challenged with either agent alone. Depletion of the monocyte/macrophage subpopulation significantly reduced the mortality rate from 100 to 20% in superantigen-primed, BLP-challenged C57BL/6 mice, with a 5- to 10-fold decrease in serum TNF-α and IL-6. Our results demonstrate that bacterial superantigens enhance the in vitro proinflammatory cytokine release and in vivo lethality of BLP. This novel finding may help to explain the massive proinflammatory cytokine release seen in superantigen-mediated septic shock.

Increased susceptibility of ST2-deficient mice to polymicrobial sepsis is associated with an impaired bactericidal function.

ST2, a member of the Toll/IL-1R superfamily, negatively regulates both TLR2 and TLR4 signaling. In this study, we report that ST2-deficient mice were more susceptible to polymicrobial sepsis than their wild-type littermates, with increased production of proinflammatory cytokines. Bacterial clearance from the circulation and visceral organs following polymicrobial infection was markedly impaired in ST2-deficient mice. This was associated with substantially reduced uptake, phagocytosis, and intracellular killing of both Gram-positive and Gram-negative bacteria by ST2-deficient phagocytes. Consistent with a reduced antimicrobial response, phagocytes lacking ST2 displayed a defect in bactericidal activity in response to bacterial challenges with severely impaired phagosome maturation and NOX2 function. Thus, ST2-deficient mice exhibit an increased susceptibility to polymicrobial infection with impaired bacterial clearance, which is associated with defects in phagosome maturation and NOX2-derived production of reactive oxygen species characterized in ST2-deficient phagocytes.

Metabolomic Pathway Activity with Genomic Single-Nucleotide Polymorphisms Associated with Colorectal Cancer Recurrence and 5-Year Overall Survival.

PURPOSE: Metabolomic analysis in colorectal cancer (CRC) is an emerging research area with both prognostic and therapeutic targeting potential. We aimed to identify metabolomic pathway activity prognostic for CRC recurrence and overall survival and cross-reference such metabolomic data with prognostic genomic single-nucleotide polymorphisms (SNPs). METHODS: A systematic search of PubMed, Embase and Cochrane Library was performed for studies reporting prognostic metabolomic pathway activity in CRC in keeping with PRISMA guidelines. The QUADOMICS tool was used to assess study quality. MetaboAnalyst software (version4.0) was used to map metabolites that were associated with recurrence and survival in CRC to recognise metabolic pathways and identify genomic SNPs associated with CRC prognosis, referencing the following databases: Human Metabolome Database (HMDB), the Small Molecule Pathway Database (SMPDB), PubChem and Kyoto Encyclopaedia of Genes and Genomes (KEGG) Pathway Database. RESULTS: Nine studies met the inclusion criteria, reporting on 1117 patients. Increased metabolic activity in the urea cycle (p = 0.002, FDR = 0.198), ammonia recycling (p = 0.004, FDR = 0.359) and glycine and serine metabolism (p = 0.004, FDR = 0.374) was prognostic of CRC recurrence. Increased activity in aspartate metabolism (p < 0.001, FDR = 0.079) and ammonia recycling (p = 0.004, FDR = 0.345) was prognostic of survival. Eight resulting SNPs were prognostic for CRC recurrence (rs2194980, rs1392880, rs2567397, rs715, rs169712, rs2300701, rs313408, rs7018169) and three for survival (rs2194980, rs169712, rs12106698) of which two overlapped with recurrence (rs2194980, rs169712). CONCLUSIONS: With a caveat on study heterogeneity, specific metabolites and metabolic pathway activity appear evident in the setting of poor prognostic colorectal cancers and such metabolic signatures are associated with specific genomic SNPs.

Impact of the COVID-19 pandemic on cancer care in Ireland - Perspectives from a COVID-19 and Cancer Working Group.

Upon the COVID-19 pandemic onset in Ireland, cancer service disruptions occurred due to prioritisation of COVID-19 related care, redeployment of staff, initial pausing of screening, diagnostic, medical and surgical oncology procedures, staff shortages due to COVID-19 infection and impacts on the physical and mental health of cancer healthcare workers. This was coupled with reluctance among people with symptoms suspicious for cancer to attend for clinical evaluation, due to concerns of contracting the virus. This was further compounded by a cyber-attack on national health service IT systems on May 14th 2021. The Irish Cancer Society, a national cancer charity with a role in advocacy, research and patient supports, convened a multi-disciplinary stakeholder group (COVID-19 and Cancer Working Group) to reflect on and understand the impact of the pandemic on cancer patients and services in Ireland, and discuss potential mitigation strategies. Perspectives on experiences were gathered across domains including timeliness of data acquisition and its conversion into intelligence, and the resourcing of cancer care to address cancer service impacts. The group highlighted aspects for future research to understand the long-term pandemic impact on cancer outcomes, while also highlighting potential strategies to support cancer services, build resilience and address delayed diagnosis. Additional measures include the need for cancer workforce recruitment and retention, increased mental health supports for both patients and oncology professionals, improvements to public health messaging, a near real-time multimodal national cancer database, and robust digital and physical infrastructure to mitigate impacts of the current pandemic and future challenges to cancer care systems.

Bacterial lipoprotein-induced tolerance is reversed by overexpression of IRAK-1.

Tolerance to bacterial cell wall components including bacterial lipoprotein (BLP) represents an essential regulatory mechanism during bacterial infection. Reduced Toll-like receptor 2 (TLR2) and IL-1 receptor-associated kinase 1 (IRAK-1) expression is a characteristic of the downregulated TLR signaling pathway observed in BLP-tolerised cells. In this study, we attempted to clarify whether TLR2 and/or IRAK-1 are the key molecules responsible for BLP-induced tolerance. Transfection of HEK293 cells and THP-1 cells with the plasmid encoding TLR2 affected neither BLP tolerisation-induced NF-κB deactivation nor BLP tolerisation-attenuated pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) production, indicating that BLP tolerance develops despite overexpression of TLR2 in these cells. In contrast, overexpression of IRAK-1 reversed BLP-induced tolerance, as transfection of IRAK-1 expressing vector resulted in a dose-dependent NF-κB activation and TNF-α release in BLP-tolerised cells. Furthermore, BLP-tolerised cells exhibited markedly repressed NF-κB p65 phosphorylation and impaired binding of p65 to several pro-inflammatory cytokine gene promoters including TNF-α and interleukin-6 (IL-6). Overexpression of IRAK-1 restored the nuclear transactivation of p65 at both TNF-α and IL-6 promoters. These results indicate a crucial role for IRAK-1 in BLP-induced tolerance, and suggest IRAK-1 as a potential target for manipulation of the TLR-mediated inflammatory response during microbial sepsis.

ST2 negatively regulates TLR2 signaling, but is not required for bacterial lipoprotein-induced tolerance.

Activation of TLR signaling is critical for host innate immunity against bacterial infection. Previous studies reported that the ST2 receptor, a member of the Toll/IL-1 receptor superfamily, functions as a negative regulator of TLR4 signaling and maintains LPS tolerance. However, it is undetermined whether ST2 negatively regulates TLR2 signaling and furthermore, whether a TLR2 agonist, bacterial lipoprotein (BLP)-induced tolerance is dependent on ST2. In this study, we show that BLP stimulation-induced production of proinflammatory cytokines and immunocomplex formation of TLR2-MyD88 and MyD88-IL-1R-associated kinase (IRAK) were significantly enhanced in ST2-deficient macrophages compared with those in wild-type controls. Furthermore, overexpression of ST2 dose-dependently attenuated BLP-induced NF-kappaB activation, suggesting a negative regulatory role of ST2 in TLR2 signaling. A moderate but significantly attenuated production of TNF-alpha and IL-6 on a second BLP stimulation was observed in BLP-pretreated, ST2-deficient macrophages, which is associated with substantially reduced IRAK-1 protein expression and downregulated TLR2-MyD88 and MyD88-IRAK immunocomplex formation. ST2-deficient mice, when pretreated with a nonlethal dose of BLP, benefitted from an improved survival against a subsequent lethal BLP challenge, indicating BLP tolerance develops in the absence of the ST2 receptor. Taken together, our results demonstrate that ST2 acts as a negative regulator of TLR2 signaling, but is not required for BLP-induced tolerance.

B7-H3 augments the inflammatory response and is associated with human sepsis.

B7-H3, a new member of the B7 superfamily, acts as both a T cell costimulator and coinhibitor, and thus plays a key role in the regulation of T cell-mediated immune responses. However, it is unclear whether B7-H3 is involved in the innate immune monocyte/macrophage-mediated inflammatory response. In this paper, we show that, although B7-H3 alone failed to stimulate proinflammatory cytokine release from murine macrophages, it strongly augmented both LPS- and bacterial lipoprotein-induced NF-kappaB activation and inflammatory response. This occurred in both a TLR4- and TLR2-dependent manner. Blockage of B7-H3 in vivo attenuated LPS-induced proinflammatory cytokine release and endotoxic shock-related lethality. Furthermore, we found that patients diagnosed with sepsis, in contrast to healthy individuals, exhibited significant levels of raised plasma soluble B7-H3 (sB7-H3) and that this level correlated with the clinical outcome and levels of plasma TNF-alpha and IL-6. In addition, a putative receptor for B7-H3 was detected on monocytes and peritoneal macrophages from septic patients but not on monocytes from healthy donors. Stimulation of human monocytes with LPS and inflammatory cytokines led to a substantial release of sB7-H3. Taken together, our data indicate that significantly elevated plasma sB7-H3 in septic patients may predict a poor outcome. Furthermore, we demonstrate that B7-H3 functions as a costimulator of innate immunity by augmenting proinflammatory cytokine release from bacterial cell wall product-stimulated monocytes/macrophages and may contribute positively to the development of sepsis.

Induction of Trained Immunity Protects Neonatal Mice Against Microbial Sepsis by Boosting Both the Inflammatory Response and Antimicrobial Activity.

Background: Neonates are susceptible to a wide range of microbial infection and at a high risk to develop severe sepsis and septic shock. Emerged evidence has shown that induction of trained immunity triggers a much stronger inflammatory response in adult monocytes/macrophages, thereby conferring protection against microbial infection. Methods: This study was carried out to examine whether trained immunity is inducible and exerts its protection against microbial sepsis in neonates. Results: Induction of trained immunity by Bacillus Calmette-Guerin (BCG) plus bacterial lipoprotein (BLP) protected neonatal mice against cecal slurry peritonitis-induced polymicrobial sepsis, and this protection is associated with elevated circulating inflammatory cytokines, increased neutrophil recruitment, and accelerated bacterial clearance. In vitro stimulation of neonatal murine macrophages with BCG+BLP augmented both inflammatory response and antimicrobial activity. Notably, BCG+BLP stimulation resulted in epigenetic remodeling characterized by histone modifications with enhanced H3K4me3, H3K27Ac, and suppressed H3K9me3 at the promoters of the targeted inflammatory and antimicrobial genes. Critically, BCG+BLP stimulation led to a shift in cellular metabolism with increased glycolysis, which is the prerequisite for subsequent BCG+BLP-triggered epigenetic reprogramming and augmented inflammatory response and antimicrobial capacity. Conclusion: These results illustrate that BCG+BLP induces trained immunity in neonates, thereby protecting against microbial infection by boosting both inflammatory and antimicrobial responses.

Evaluation of the Cytotoxic Effects of the Novel Antineoplastic Agent 1,4,5-Oxathiazinane-4,4-dioxide on Triple Negative Breast Cancer Cells.

BACKGROUND/AIM: Adjuvant therapeutic options are limited for triple negative breast cancer (TNBC). Thus, we evaluated the cytotoxic effects of the newly synthesized antineoplastic agent 1,4,5-Oxathiazinane-4,4-dioxide (OTD) on TNBC cells as a potential cancer therapeutic strategy. MATERIALS AND METHODS: TNBC primary BT-20 and metastatic MDA-MB-231 cell lines were treated with increasing concentrations of OTD for various time periods to assess cell viability. Cell necrosis, apoptosis, necroptosis, autophagy, and ROS generation were evaluated using assay kits or specific inhibitors. RESULTS: Treatment with OTD resulted in a dose- and time-dependent cell death of TNBC BT-20 and MDA-MB-231 cells. OTD also dose-dependently arrested TNBC cell proliferation. Notably, treatment with OTD induced both necrosis and apoptosis of TNBC cells, while the pan-caspase inhibitor Z-VAD-FMK partially attenuated OTD-induced cell death. Importantly, abrogated OTD-induced cell death was observed in the presence of the ROS scavenger N-acetylcysteine (NAC), whereas enhanced OTD-induced cell death was observed after the addition of the glutathione synthesis inhibitor BSO, indicating OTD-induced killing of TNBC cells via a reactive oxygen species-dependent mechanism. CONCLUSION: OTD is strongly cytotoxic to both primary and metastatic TNBC cells, possibly by inducing multiple cell death pathways.

Surgical injury enhances the expression of genes that mediate breast cancer metastasis to the lung.

OBJECTIVE: This study was conducted to test the hypothesis that surgery induces changes at the expression level of genes implicated in metastasis, thus leading to accelerated postoperative metastatic tumor growth. SUMMARY BACKGROUND DATA: Surgical resection of the primary tumor is a necessary and effective treatment for breast cancer patients. However, studies from both animals and humans have shown that surgery potentiates the growth of minimal residual neoplastic disease. METHODS: : Female BALB/c mice were inoculated with metastatic murine mammary adenocarcinoma 4T1-green fluorescent protein (GFP) cells in the mammary fat pad (3 × 105/mouse), and divided into a surgery group (n = 12) in which the flank tumor was completely resected after 21 day growth and a control (no surgery) group (n = 12). Metastatic tumor burden was assessed by both macroscopic metastatic nodule count and clonogenic assay. Mitotic and apoptotic indices were established using a combination of hematoxylin-eosin histology and Ki-67 immunohistochemistry. Green fluorescent protein (GFP) expressing tumor cells were isolated using FACS sorting, and RNA was extracted. The RT² Profiler PCR Array mouse Cancer Pathway Finder was used to determine and compare the mRNA levels of 84 genes involved in metastasis in both groups. RESULTS: Excision of the primary tumor was associated with increased systemic metastatic burden (P = 0.001). Postoperative metastases exhibited increased proliferation (P = 0.001), but no reduction in apoptosis. The quantitative real-time polymerase chain reaction array data indicate that surgery significantly upregulated the expression of Itgb3, Egfr, Hgf, Igf1, Pdgfb, Tnfα, Vegfa, Vegfc, and MMP9 genes, and led to the down regulation of Cdkn2a, Cdh1, and Syk genes. Increased expression of ITGB3 and MMP9 was further confirmed at the protein level by Western blot. CONCLUSIONS: Removal of the primary tumor led to a progressive phenotype of lung metastases that exhibited upregulation of genes involved in adhesion, invasion, and angiogenesis.