Expert consensus on the monitoring and treatment of sepsis-induced immunosuppression.

Emerged evidence has indicated that immunosuppression is involved in the occurrence and development of sepsis. To provide clinical practice recommendations on the immune function in sepsis, an expert consensus focusing on the monitoring and treatment of sepsis-induced immunosuppression was developed. Literature related to the immune monitoring and treatment of sepsis were retrieved from PubMed, Web of Science, and Chinese National Knowledge Infrastructure to design items and expert opinions were collected through an online questionnaire. Then, the Delphi method was used to form consensus opinions, and RAND appropriateness method was developed to provide consistency evaluation and recommendation levels for consensus opinions. This consensus achieved satisfactory results through two rounds of questionnaire survey, with 2 statements rated as perfect consistency, 13 as very good consistency, and 9 as good consistency. After summarizing the results, a total of 14 strong recommended opinions, 8 weak recommended opinions and 2 non-recommended opinions were produced. Finally, a face-to-face discussion of the consensus opinions was performed through an online meeting, and all judges unanimously agreed on the content of this consensus. In summary, this expert consensus provides a preliminary guidance for the monitoring and treatment of immunosuppression in patients with sepsis.

The relevance of liquid biopsy in surgical oncology: The application of perioperative circulating nucleic acid dynamics in improving patient outcomes.

BACKGROUND: Liquid biopsy is gaining increasing clinical utility in the management of cancer patients. The main components of a liquid biopsy are circulating nucleic acids, circulating tumour cells and extracellular vesicles such as exosomes. Circulating nucleic acids including cell free DNA (cfDNA) and circulating tumour DNA (ctDNA) in particular have been the focus of recent attention as they have demonstrated excellent potential in cancer screening, provision of prognostic information and in genomic profiling of a tumour without the need for repeated tissue biopsies. The aim of this review was to explore the current evidence in relation to the use of liquid biopsy in the perioperative setting and identify ways in which liquid biopsy may be applied in the future. METHODS: This narrative review is based on a comprehensive literature search up to the 1st of June 2020 for papers relevant to the application of liquid biopsy in surgical oncology, focusing particularly on the perioperative period. RESULTS: Recent evidence has demonstrated that perioperative liquid biopsy can accurately stratify patients' risk of recurrence compared to conventional biomarkers. Attention to the perioperative dynamics of liquid biopsy components can potentially provide new understanding of the complex relationship between surgery and cancer outcome. In addition, careful evaluation of liquid biopsy components in the perioperative window may provide important diagnostic and therapeutic information for cancer patients. CONCLUSION: The rapidly evolving concept of the liquid biopsy has the potential to become the cornerstone for decision making around surveillance and adjuvant therapies the era of personalised medicine.

Two-phase releasing immune-stimulating composite orchestrates protection against microbial infections.

Sepsis, a syndrome of acute organ dysfunction induced by various infections, could lead to a very high mortality in hospitals despite the development of advanced medical technologies. Herein, a type of two-phase releasing immune-stimulating composite is developed by mixing alginate (ALG) with muramyl dipeptide (MDP) and the nanoparticle formulation of monophosphoryl lipid A (MPLA), the latter two are immunomodulatory agents with different release rates from the formed ALG hydrogel. The obtained two phase-releasing composite could provide instantaneous sepsis protection by the rapid release of MDP to enhance the phagocytic and bactericidal function of macrophages. Later on, such composite could further offer long-term sepsis protection by the sustained release of MPLA to continuously activate the immune system, via up-regulating the production of various pro-inflammatory cytokines, promoting the polarization of macrophages, and increasing the percent of natural killer (NK) cells in the lesion after sepsis challenge. Mice survived from sepsis challenge after such treatment could resist a second infection. Notably, treatment with our composite could increase the mouse survival rate in a cecal ligation and puncture (CLP) induced polymicrobial sepsis model. This work provides an easy-translatable immune-stimulating formulation for effective protection against sepsis under various triggering causes. Our strategy may be promising for long-term broad prevention against various infections, and could potentially be used to protect medical workers under a new pandemic before a reliable vaccine is available.

B7 homolog 3 aggravates brain injury in a murine model of Streptococcus pneumoniae-induced meningitis.

Despite the application of antibiotics, Streptococcus pneumoniae (SP)-induced meningitis continues to be a life-threatening disease with a high fatality rate and an elevated risk of serious neurological sequelae, particularly in developing countries. In this study, the contribution of the co-stimulatory molecule B7 homolog 3 (B7-H3) to the pathogenesis of experimental SP-induced meningitis was investigated. Mice were challenged with the intracerebroventricular injection of serotype 3 SP with or without B7-H3. The clinical status of mice with SP-induced meningitis was examined by body weight loss and spontaneous motor activity with neurological scoring. Coronal brain sections were analyzed by counting Nissl-positive neurons and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells. Protein expression of neuron-specific enolase (NSE) and S100B in brain tissues was examined with immunohistochemical staining. All experiments were performed in a randomized and blinded setting. By the intracerebroventricular injection of SP suspension, a murine model of pneumococcal meningitis was successfully established. In this SP-induced meningitis model, B7-H3 deteriorated the clinical status, as manifested by a decreased neurological score and increased body weight loss. Following the B7-H3 challenge, the number of Nissl-positive cells decreased and TUNEL-stained positive cells increased in the brain tissues of mice with SP meningitis, which demonstrates the enhancement of neuronal necrosis and apoptosis, respectively. Protein expression of NSE was decreased, while that of S100B was increased. These in vivo findings indicate that B7-H3 aggravates brain injury during the pathological process of experimental SP-induced meningitis.

The emerging role of microRNA in regulation of endotoxin tolerance.

Endotoxin tolerance is a phenomenon where cells show reduced responsiveness toward repeated endotoxin stimulation. Regulation of tolerance occurs at multiple levels of the cell signaling cascade, and many of these levels are potentially regulated by miRNA, which are a class of small RNA that bind to mRNA to down-regulate gene expression at the post-transcriptional level. Roles have been identified for miR-146a, miR-221, miR-579, miR-125b, miR-155, let-7e, and miR-98 in regulating the TLR4 signaling pathway during the development of endotoxin tolerance at receptor, signaling pathway, and gene transcription and translational levels. miRNA represent exciting, new potential targets in attempts to exogenously modulate development of endotoxin tolerance.

[Study on the nuclear translocation mechanism in the inhibition of nuclear factor-ΚB activation in bacterial lipoprotein-tolerant THP-1 cells].

OBJECTIVE: To approach the nuclear factor-ΚB (NF-ΚB) nuclear translocation mechanism in bacterial lipoprotein (BLP) tolerance. METHODS: Human monocytic THP-1 cells were first pretreated with 10, 100, 1 000 ng/ml BLP for 20 hours to induce BLP tolerance. Then THP-1 cells without BLP pretreatment (control group) or with BLP pretreatment (tolerance group) were stimulated with 0, 10, 100, 1 000 ng/ml BLP again for 6 hours. The tumor necrosis factor-α (TNF-α) content in culture medium was measured by enzyme linked immunosorbent assay (ELISA) in order to determine the most suitable BLP pretreatment and stimulation concentration. Western blotting was used to detect the protein level, nuclear translocation and phosphorylation of NF-ΚB p50 and p65 in the cells of control and tolerance groups treated with respective conditions for 0, 0.5, 1, 2 and 6 hours. RESULTS: In control group BLP stimulation (10, 100, 1 000 ng/ml) could induce THP-1 activation and TNF-α production (pg/ml: 184.86±32.51, 3 215.88±167.09, 6 042.96±245.37) in a dose-dependent manner. In tolerance group, 100 ng/ml BLP pretreatment resulted in almost complete inhibition of TNF-α production as induced by 101 000 ng/ml BLP stimulation. Therefore, 100 ng/ml BLP pretreatment and 1 000 ng/ml stimulation were selected for following cell treatment. Western blotting analysis showed that there was an increase of p50 protein level in BLP-tolerant cells comparing with control group (0 hour: 542.9±15.6 vs. 272.8±13.2, 0.5 hour: 558.0±16.9 vs. 236.4±11.8, 1 hour: 524.7±17.5 vs. 211.6±9.8, 2 hours: 584.9±15.6 vs. 222.4±12.3, all P<0.01), whereas the p65 protein level was similar between the two groups. BLP stimulation also induced the nuclear translocation of p50 and p65 in control group (1-hour p50: 344.2±13.6 vs. 79.0±5.2, p65: 78.4±4.5 vs. 0, both P<0.05), but not in tolerance group. In addition, the phosphorylation of p65 at serine 536 was induced after BLP stimulation in control THP-1 cells (0.5 hour: 0.67±0.08 vs. 0.04±0.01, 1 hour: 0.71±0.11 vs. 0.04±0.01, both P<0.05), but this change was not detected in BLP-tolerant cells. CONCLUSION: It was found that in BLP-tolerant cells, the expression of inhibitory subunit p50 was increased and the nuclear translocation and phosphorylation of p65 with trans-activation ability was inhibited. These changes are likely responsible for the reduced gene expression of NF-ΚB dependent genes in BLP-tolerant cells.

Hypertonic Saline Attenuates the Pro-metastatic Effects of LPS by Reducing Tumor Cell Migration, Proliferation and MMP-9 Expression.

BACKGROUND: Lipopolysaccharide (LPS) promotes tumor metastases. The aim of this study was to determine the ability of a hypertonic environment to attenuate the pro metastatic properties of LPS both in vitro, and in vivo. METHODS: LPS stimulated, and unstimulated, 4T1 tumor cells were cultured in either an isotonic or hypertonic environment. The effect on invasion, migration, pro-matellomatrixproteinase 9 (proMMP-9) expression, proliferation, and microscopic cell structure was assessed. Lung metastases were induced in C57 mice with systemic hypertonicity in unstimulated and stimulated mice. The metastatic burden was assessed by estimation of lung/body weight ratio, pleural nodules and clonogenic assay. RESULTS: In vitro, a hypertonic environment reduced proMMP-9 expression (0.012 versus 1.16, P < 0.001) invasion (0.06 versus 0.119, P = 0.005), tumor cell proliferation (0.035 versus 0.041, P = 0.001), while inducing structural changes to tumor cells reducing overall cell volume. In vivo, the induction of transient systemic hypertonicity reduced metastatic burden as demonstrated by reduced lung nodules (4 versus 8, P = 0.004) and colonies on clonogenic assay (12 versus 43, P = 0.04). CONCLUSION: The in vitro exposure of tumor cells to a hypertonic environment reduces tumor cell migration and proliferation. Transient systemic hypertonicity can reduce the metastatic burden following intra-operative exposure to LPS in vivo.

[The influence of over expression of interleukin-1 receptor-associated kinase 1 on bacterial lipoprotein-induced tolerance].

OBJECTIVE: To investigate Toll-like receptor 2 (TLR2) and interleukin-1 receptor-associated kinase 1 (IRAK-1) in bacterial lipoprotein (BLP) tolerance. METHODS: Western blotting was used to confirm the over expression of TLR2 and IRAK-1 in human embryo kidney 293 (HEK293) cells. Plasmids for dual luciferase reporter gene with nuclear factor-KappaB promoter (pNF-KappaB-Luc) or CMV promoter (phRL-CMV internal control vector) were used to detect the NF-KappaB activation and the induction of BLP tolerance in HEK-TLR2 cells. RESULTS: BLP stimulation resulted in dose-dependent NF-KappaB activation in HEK293 cells stably expressing TLR2. And BLP pretreatment could reduce NF-KappaB activation and induce BLP tolerance in HEK-TLR2 cells. The NF-KappaB activation was 0.329+/-0.010 and 0.168+/-0.010 in BLP-activated and BLP-tolerant HEK-TLR2 cells, respectively. After transfection with 0.02 microg IRAK-1 plasmid, NF-KappaB activation in the two groups was 0.493+/-0.010 and 0.427+/-0.035, respectively (both P<0.01). So over expression of IRAK-1 could increase NF-KappaB activation in a dose-dependent manner. CONCLUSION: These results demonstrated that over expression of IRAK-1 could reverse BLP tolerance, whereas over expression of TLR2 failed to prevent the induction of BLP tolerance. Therefore reduced IRAK-1 protein expression is an important mechanism in the development of BLP-induced tolerance, suggesting that it could be a potentially important target for future therapeutic strategies in bacterial infection and sepsis.

Can surgery for cancer accelerate the progression of secondary tumors within residual minimal disease at both local and systemic levels?

BACKGROUND: Surgical removal remains the principal treatment modality in the management of lung cancer. Our aim is to characterize the effects of tumor removal on subsequent tumor recurrence at both local and systemic levels. METHODS: C57/BL6 mice [10/group] underwent a mammary fat pad inoculation of 3LL cells [5 x 10(5)/animal] and were divided into two groups. Group 1 served as control while mice in group 2 were further subdivided into groups 2A and 2B. After 2 weeks, all mice in 2A were killed, and primary tumors and lungs were excised. At 2 weeks, primary tumors were excised completely for all mice in group 2B. These mice were then recovered and recurrent tumor growth evaluated for a further 2 weeks. Four weeks from the onset of the study, all remaining primary tumors and lungs were excised from groups 1 and 2. RESULTS: After 4 weeks undisturbed growth, primary tumors in group 1 reached a mean size of 2.85 +/- 0.33 cm. After 2 weeks growth, primary tumors in groups 2A and 2B were comparable at 1.36 +/- 0.44 m and 1.53 +/- 0.29 cm, respectively. Two weeks after primary tumor excision, recurrent tumors in group 2B had reached a mean size of 2.65 +/- 0.74 cm. Moreover, for several animals, recurrent tumors rapidly reached similar volumes to that of primary tumors in group 1. Primary tumors were typically encapsulated and nonadherent. In contrast, recurrent tumors were locally invasive and adherent to chest wall and wound. Interestingly, pulmonary metastatic burden was increased in group 2B relative to group 1. Histologic examination revealed increased mitosis in recurrent tumors when compared with primary tumors. CONCLUSIONS: Tumor removal is followed by accelerated growth of locally recurrent tumors and metastases. Moreover, recurrent tumors are more locally invasive than primary tumors. These findings strongly indicate that resection may be followed by tumor progression in residual disease.

Surgically induced accelerated local and distant tumor growth is significantly attenuated by selective COX-2 inhibition.

BACKGROUND: Even after apparently curative resection, lung cancer recurrence continues to lead to high mortality levels. The aim of this study was to assess the effects of cyclooxygenase-2 (COX-2) inhibitor on local and systemic recurrent tumor growth. METHODS: C57BL/6 mice underwent mammary fat pad inoculation with 3LL cells. After two weeks growth, flank tumors were resected completely and followed for recurrent tumor growth. Postresection mice were randomized to receive placebo alone (group 1) or the selective COX-2 inhibitor, rofecoxib (group 2), daily for two weeks by tube feeding. Recurrent tumor growth kinetics were compared for both groups. Two weeks following primary tumor excision animals were sacrificed, after which lungs were resected and pulmonary metastatic burden was assessed using the lung-body weight ratio. Apoptotic and mitotic indices were established for recurrent tumors and lungs, using hematoxylin and eosin histology. RESULTS: Two weeks postexcision of the primary tumor, recurrent tumors in the placebo group were significantly greater than the treatment group (p = 0.002). While primary tumors were typically encapsulated and not adherent, recurrent tumors in the placebo group were invasive, adherent to the chest wall and the overlying wound. In contrast, recurrent tumors in the treatment group were nonadherent to the chest wall. Moreover, postoperative pulmonary metastatic burden was significantly reduced in treated animals. Histologic examination revealed increased apoptosis as well as an increase in the apoptosis-mitosis ratio in treated animals. CONCLUSIONS: Primary tumor excision was associated with accelerated local and systemic tumor recurrence. However, these effects were significantly attenuated using selective COX-2 inhibition. The COX-2-inhibition was associated with increased levels of apoptosis. These findings endorse a role for COX-2 inhibition in the secondary prevention of lung cancer recurrence at both local and systemic levels.