Sepsis inhibits tumor growth in mice with cancer through Toll-like receptor 4-associated enhanced Natural Killer cell activity

When inflammatory stressors dramatically change, disease phenotypes may transform between autoimmune hematopoietic failure and myeloid neoplasms

Aplastic anemia (AA) and hypoplastic myelodysplastic syndrome are paradigms of autoimmune hematopoietic failure (AHF). Myelodysplastic syndrome and acute myeloid leukemia are unequivocal myeloid neoplasms (MNs). Currently, AA is also known to be a clonal hematological disease. Genetic aberrations typically observed in MNs are detected in approximately one-third of AA patients. In AA patients harboring MN-related genetic aberrations, a poor response to immunosuppressive therapy (IST) and an increased risk of transformation to MNs occurring either naturally or after IST are predicted. Approximately 10%-15% of patients with severe AA transform the disease phenotype to MNs following IST, and in some patients, leukemic transformation emerges during or shortly after IST. Phenotypic transformations between AHF and MNs can occur reciprocally. A fraction of advanced MN patients experience an aplastic crisis during which leukemic blasts are repressed. The switch that shapes the disease phenotype is a change in the strength of extramedullary inflammation. Both AHF and MNs have an immune-active bone marrow (BM) environment (BME). In AHF patients, an inflamed BME can be evoked by infiltrated immune cells targeting neoplastic molecules, which contributes to the BM-specific autoimmune impairment. Autoimmune responses in AHF may represent an antileukemic mechanism, and inflammatory stressors strengthen antileukemic immunity, at least in a significant proportion of patients who have MN-related genetic aberrations. During active inflammatory episodes, normal and leukemic hematopoieses are suppressed, which leads to the occurrence of aplastic cytopenia and leukemic cell regression. The successful treatment of underlying infections mitigates inflammatory stress-related antileukemic activities and promotes the penetration of leukemic hematopoiesis. The effect of IST is similar to that of treating underlying infections. Investigating inflammatory stress-powered antileukemic immunity is highly important in theoretical studies and clinical practice, especially given the wide application of immune-activating agents and immune checkpoint inhibitors in the treatment of hematological neoplasms.

The Calm after the Storm: Implications of Sepsis Immunoparalysis on Host Immunity

The immunological hallmarks of sepsis include the inflammation-mediated cytokine storm, apoptosis-driven lymphopenia, and prolonged immunoparalysis. Although early clinical efforts were focused on increasing the survival of patients through the first phase, studies are now shifting attention to the long-term effects of sepsis on immune fitness in survivors. In particular, the most pertinent task is deciphering how the immune system becomes suppressed, leading to increased incidence of secondary infections. In this review, we introduce the contribution of numerical changes and functional reprogramming within innate (NK cells, dendritic cells) and adaptive (T cells, B cells) immune cells on the chronic immune dysregulation in the septic murine and human host. We briefly discuss how prior immunological experience in murine models impacts sepsis severity, immune dysfunction, and clinical relevance. Finally, we dive into how comorbidities, specifically autoimmunity and cancer, can influence host susceptibility to sepsis and the associated immune dysfunction.

Plants against cancer: the immune-boosting herbal microbiome: not of the plant, but in the plant. Basic concepts, introduction, and future resource for vaccine adjuvant discovery

The presence of microorganism communities (MOCs) comprised of bacteria, fungi, archaea, algae, protozoa, viruses, and the like, are ubiquitous in all living tissue, including plant and animal. MOCs play a significant role in establishing innate and acquired immunity, thereby influencing susceptibility and resistance to disease. This understanding has fostered substantial advancements in several fields such as agriculture, food science/safety, and the development of vaccines/adjuvants, which rely on administering inactivated-attenuated MOC pathogens. Historical evidence dating back to the 1800s, including reports by Drs Busch, Coley, and Fehleisen, suggested that acute febrile infection in response to "specific microbes" could trigger spontaneous tumor remission in humans. This discovery led to the purposeful administration of the same attenuated strains, known as "Coley's toxin," marking the onset of the first microbial (pathogen) associated molecular pattern (MAMPs or PAMPs)-based tumor immunotherapy, used clinically for over four decades. Today, these same MAMPS are consumed orally by billions of consumers around the globe, through "specific" mediums (immune boosting "herbal supplements") as carriers of highly concentrated MOCs accrued in roots, barks, hulls, sea algae, and seeds. The American Herbal Products Association (AHPA) mandates microbial reduction in botanical product processing but does not necessitate the removal of dead MAMP laden microbial debris, which we ingest. Moreover, while existing research has focused on the immune-modulating role of plant phytochemicals, the actual immune-boosting properties might instead reside solely in the plant's MOC MAMP laden biomass. This assertion is logical, considering that antigenic immune-provoking epitopes, not phytochemicals, are known to stimulate immune response. This review explores a neglected area of research regarding the immune-boosting effects of the herbal microbiome - a presence which is indirectly corroborated by various peripheral fields of study and poses a fundamental question: Given that food safety focuses on the elimination of harmful pathogens and crop science acknowledges the existence of plant microbiomes, what precisely are the immune effects of ingesting MAMPs of diverse structural composition and concentration, and where are these distributed in our botanicals? We will discuss the topic of concentrated edible MAMPs as acid and thermally stable motifs found in specific herbs and how these would activate cognate pattern recognition receptors (PPRs) in the upper gut-associated lymphoid tissue (GALT), including Peyer's patches and the lamina propria, to boost antibody titers, CD8+ and CD4+ T cells, NK activity, hematopoiesis, and facilitating M2 to M1 macrophage phenotype transition in a similar manner as vaccines. This new knowledge could pave the way for developing bioreactor-grown/heat-inactivated MOC therapies to boost human immunity against infections and improve tumor surveillance.

Cancer and sepsis

Sepsis is one of the leading causes of death worldwide. While mortality is high regardless of inciting infection or comorbidities, mortality in patients with cancer and sepsis is significantly higher than mortality in patients with sepsis without cancer. Cancer patients are also significantly more likely to develop sepsis than the general population. The mechanisms underlying increased mortality in cancer and sepsis patients are multifactorial. Cancer treatment alters the host immune response and can increase susceptibility to infection. Preclinical data also suggests that cancer, in and of itself, increases mortality from sepsis with dysregulation of the adaptive immune system playing a key role. Further, preclinical data demonstrate that sepsis can alter subsequent tumor growth while tumoral immunity impacts survival from sepsis. Checkpoint inhibition is a well-accepted treatment for many types of cancer, and there is increasing evidence suggesting this may be a useful strategy in sepsis as well. However, preclinical studies of checkpoint inhibition in cancer and sepsis demonstrate results that could not have been predicted by examining either variable in isolation. As sepsis management transitions from a 'one size fits all' model to a more individualized approach, understanding the mechanistic impact of cancer on outcomes from sepsis represents an important strategy towards delivering on the promise of precision medicine in the intensive care unit.

Multi-Omics Endotypes in ICU Sepsis-Induced Immunosuppression

It is evident that the admission of some patients with sepsis and septic shock to hospitals is occurring late in their illness, which has contributed to the increase in poor outcomes and high fatalities worldwide across age groups. The current diagnostic and monitoring procedure relies on an inaccurate and often delayed identification by the clinician, who then decides the treatment upon interaction with the patient. Initiation of sepsis is accompanied by immune system paralysis following "cytokine storm". The unique immunological response of each patient is important to define in terms of subtyping for therapy. The immune system becomes activated in sepsis to produce interleukins, and endothelial cells express higher levels of adhesion molecules. The proportions of circulating immune cells change, reducing regulatory cells and increasing memory cells and killer cells, having long-term effects on the phenotype of CD8 T cells, HLA-DR, and dysregulation of microRNA. The current narrative review seeks to highlight the potential application of multi-omics data integration and immunological profiling at the single-cell level to define endotypes in sepsis and septic shock. The review will consider the parallels and immunoregulatory axis between cancer and immunosuppression, sepsis-induced cardiomyopathy, and endothelial damage. Second, the added value of transcriptomic-driven endotypes will be assessed through inferring regulatory interactions in recent clinical trials and studies reporting gene modular features that inform continuous metrics measuring clinical response in ICU, which can support the use of immunomodulating agents.

Hydroxyapatite nanoparticles promote TLR4 agonist-mediated anti-tumor immunity through synergically enhanced macrophage polarization

Macrophages represent the most prevalent immune cells in the tumor micro-environment, making them an appealing target for tumor immunotherapy. One of our previous studies showed that hydroxyapatite nanoparticles (HANPs) enhanced Toll-like receptor 4 (TLR4) signal transduction in macrophages. This study was proposed to investigate how HANPs manipulated the phenotype and function of macrophage against 4T1 tumors in the presence or absence of MPLA, a low toxic Toll-like receptor 4 (TLR4) agonist. The results demonstrated that the addition of HANPs to MPLA significantly promoted cytokine secretion and macrophage polarization toward a tumoricidal M1 phenotype. Further, the resulting supernatant from HANPs/MPLA co-stimulated macrophages enhanced 4T1 tumor cells apoptosis compared to that from macrophages treated with a single component or PBS control. In particular, we found HANPs elicited immunogenic cell death (ICD) indicated by the increased expression of "danger signals", including HMGB1, CRT and ATP in 4T1 cells. Subsequently, the ICD derivatives-containing supernatant from HANPs-treated 4T1 cells activated macrophage and shifted the phenotype of the cells toward M1 type. Moreover, in a tumor-bearing mice model, HANPs and MPLA synergistically delayed tumor growth compared to PBS control, which was positively associated with the promoted macrophage polarization and ICD induction. Therefore, our findings demonstrated a potential platform to modulate the function of macrophages, and shed a new insight into the mechanism involving the immunomodulatory effect of HANPs for tumor therapy. STATEMENT OF SIGNIFICANCE: Polarizing macrophage toward tumoricidal phenotype by harnessing Toll-like receptor (TLR) agonists has been proven effective for tumor immunotherapy. However, the immunomodulatory potency of TLR agonists is limited due to immune suppression or tolerance associated with TLR activation in immune cells. Herein, we introduced hydroxyapatite nanoparticles (HANPs) to MPLA, a TLR4 agonist. The results demonstrated that the addition of HANPs to MPLA promoted macrophage shift toward tumoricidal M1 phenotype, supported a "hot" tumor transformation, and delayed 4T1 tumor growth. Moreover, we found that HANPs elicited immunogenic cell death that produced "danger" signals from cancer cells thereby further facilitated macrophage polarization. This work is significant to direct the rational design of HANPs coupled with or without TLR agonists for tumor immunotherapy.

Association between haemorrhagic fever with renal syndrome and cancers

OBJECTIVES

To investigate the risk of haematologic and solid organ malignancies in patients with haemorrhagic fever with renal syndrome (HFRS) compared with the general population.

METHODS

This propensity-score-matched cohort study was conducted using data collected from the Korean national health insurance service (NHIS) between January 2003 and December 2017. The HFRS cohort included 5888 newly diagnosed cases of HFRS, and 412,804 general participants from the NHIS database were included as the control cohort. The incidence rate of malignancies was assessed and compared between the HFRS and control cohorts.

RESULTS

There were 64 cases of haematologic malignancy in 236,286 person-years of observation, and 1245 cases of solid organ cancer in 209,333 person-years. The risks of haematologic malignancy and solid organ cancer were significantly higher in the HFRS cohort [adjusted hazards ratio (aHR) 4.10, 95% confidence interval (CI) 2.36-7.14] than the control cohort [aHR 2.97, 95% CI 2.60-3.38). In subgroup analysis, the HFRS cohort was associated with high hazard ratios for leukaemia and non-Hodgkin lymphoma. The HFRS cohort also had increased aHRs for all types of solid organ cancer.

CONCLUSIONS

Patients with HFRS are at increased risk of both haematologic and solid organ malignancies compared with the general population, and this increased proportionally over time. Careful monitoring for malignancy after the onset of HFRS may be necessary.

Inflammation and cancer: paradoxical roles in tumorigenesis and implications in immunotherapies

Chronic inflammation caused by persistent infections and metabolic disorders is thought to contribute to the increased cancer risk and the accelerated cancer progression. Oppositely, acute inflammation induced by bacteria-based vaccines or that is occurring after cancer selectively inhibits cancer progression and metastasis. However, the interaction between inflammation and cancer may be more complex than the current explanations for the relationship between chronic and acute inflammation and cancer. In this review, we described the impact of inflammation on cancer on the basis of three perspectives, including inflammation with different durations (chronic and acute inflammation), different scopes (systemic and local inflammation) and different occurrence sequences (inflammation occurring after and before cancer). In addition, we also introduced bacteria/virus-based cancer immunotherapies. We perceive that inflammation may be a double-edged sword with cancer-promoting and cancer-suppressing functions in certain cases. We expect to further improve the understanding of the relationship between inflammation and cancer and provide a theoretical basis for further research on their complex interaction.

Down-regulation of lncRNA SNHG5 relieves sepsis-induced acute kidney injury by regulating the miR-374a-3p/TLR4/NF-κB pathway

Sepsis is an acute systemic infectious disease engendered by infectious factors, which can cause the dysfunction of multiple organs, including acute kidney injury (AKI). Recently, more and more researchers are focussing on long noncoding RNA (lncRNA) that is closely associated with the development and progression of various diseases; however, the role and mechanism of lncRNA in sepsis-induced AKI are not fully understood. Here, we found a significant increase in the expression of lncRNA small nuclear RNA host gene 5 (SNHG5) in the serum of patients with sepsis than healthy controls. Similar results were obtained from mouse model of sepsis. Further investigations revealed that knockdown of SNHG5 improves the viability and reduces the rate of apoptosis and the generation of inflammatory cytokines in HK-2 and TCMK-1 cells treated with lipopolysaccharide. Mechanistically, we showed that SNHG5 can combine with microRNA-374a-3p (miR-374a-3p), which inhibits nuclear factor-κB (NF-κB) activity by targeting TLR4. In conclusion, our results demonstrate that SNHG5 may regulate sepsis-induced AKI via the miR-374a-3p/TLR4/NF-κB pathway, therefore providing a new insight into the treatment of this disease.

Inducible MyD88/CD40 synergizes with IL-15 to enhance antitumor efficacy of CAR-NK cells

Natural killer (NK) cells expressing chimeric antigen receptors (CARs) are a promising anticancer immunotherapy, leveraging both innate NK cell antitumor activity and target-specific cytotoxicity. Inducible MyD88/CD40 (iMC) is a potent, rimiducid-regulated protein switch that has been deployed previously as a T-cell activator to enhance proliferation and persistence of CAR-modified T cells. In this study, iMC was extended to CAR-NK cells to enhance their growth and augment cytotoxicity against tumor cells. iMC-activated NK cells substantially increased cytokine and chemokine secretion and displayed higher levels of perforin and granzyme B degranulation. In addition, iMC activation could be coupled with ectopic interleukin-15 (IL-15) to further enhance NK cell proliferation. When coexpressed with a target-specific CAR (CD123 or BCMA), this IL-15/iMC system showed further augmented antitumor activity through enhanced CAR-NK cell expansion and cytolytic activity. To protect against potential toxicity from engineered NK cells, an orthogonal rapamycin-regulated Caspase-9 (iRC9) was included in a 4-gene, dual-switch platform. After infusion of dual-switch NK cells, pharmacologic iRC9 dimerization led to rapid elimination of a majority of expanded transduced NK cells. Thus, CAR-NK cells utilizing dual molecular switches provide an innovative and effective approach to cancer immunotherapy with controlled specificity, efficacy, and safety.

Understanding and Managing Sepsis in Patients With Cancer in the Era of Antimicrobial Resistance

Sepsis is a frequent complication in immunosuppressed cancer patients and hematopoietic stem cell transplant recipients that is associated with high morbidity and mortality rates. The worldwide emergence of antimicrobial resistance is of special concern in this population because any delay in starting adequate empirical antibiotic therapy can lead to poor outcomes. In this review, we aim to address: (1) the mechanisms involved in the development of sepsis and septic shock in these patients; (2) the risk factors associated with a worse prognosis; (3) the impact of adequate initial empirical antibiotic therapy given the current era of widespread antimicrobial resistance; and (4) the optimal management of sepsis, including adequate and early source control of infection, optimized antibiotic use based on the pharmacokinetic and pharmacodynamics changes in these patients, and the role of the new available antibiotics.

Spontaneous Regression of Blastic Plasmacytoid Dendritic Cell Neoplasm Following Sepsis by Serratia marcescens: A Case Report and Literature Review

Spontaneous regression is rare in patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN). An 85-year-old man presented with pancytopenia and skin lesions, and the bone marrow exhibited 79.6% CD4+, CD56+, CD123+, and TCL-1+ abnormal cells, with a normal karyotype; he was thus diagnosed with BPDCN. While being followed without chemotherapy, he was admitted due to sepsis induced by Serratia marcescens, which was successfully treated with antibiotics. Notably, his blood cell counts improved, and the skin lesions disappeared. To our knowledge, this is the first reported case of spontaneous regression of BPDCN with a decrease in tumor cells in the bone marrow following sepsis.

Sepsis and Cancer: An Interplay of Friends and Foes

Sepsis and cancer share a number of pathophysiological features, and both result from the inability of the host's immune system to cope with the initial insult (tissue invasion by pathogens and malignant cell transformation, respectively). The common coexistence of both disorders and the profound related alterations in immune homeostasis raise the question of their mutual impact on each other's course. This translational review aims to discuss the interactions between cancer and sepsis supported by clinical data and the translation to experimental models. The dramatic improvement in cancer has come at a cost of increased risks of life-threatening infectious complications. Investigating the long-term outcomes of sepsis survivors has revealed an unexpected susceptibility to cancer long after discharge from the ICU. Nonetheless, it is noteworthy that an acute septic episode may harbor antitumoral properties under particular circumstances. Relevant double-hit animal models have provided clues to whether and how bacterial sepsis may impact malignant tumor growth. In sequential sepsis-then-cancer models, postseptic mice exhibited accelerated tumor growth. When using reverse cancer-then-sepsis models, bacterial sepsis applied to mice with cancer conversely resulted in inhibition or even regression of tumor growth. Experimental models thus highlight dual effects of sepsis on tumor growth, mostly depending on the sequence of insults, and allow deciphering the immune mechanisms and their relation with microorganisms.

Detection of immunogenic cell death and its relevance for cancer therapy

Chemotherapy, radiation therapy, as well as targeted anticancer agents can induce clinically relevant tumor-targeting immune responses, which critically rely on the antigenicity of malignant cells and their capacity to generate adjuvant signals. In particular, immunogenic cell death (ICD) is accompanied by the exposure and release of numerous damage-associated molecular patterns (DAMPs), which altogether confer a robust adjuvanticity to dying cancer cells, as they favor the recruitment and activation of antigen-presenting cells. ICD-associated DAMPs include surface-exposed calreticulin (CALR) as well as secreted ATP, annexin A1 (ANXA1), type I interferon, and high-mobility group box 1 (HMGB1). Additional hallmarks of ICD encompass the phosphorylation of eukaryotic translation initiation factor 2 subunit-α (EIF2S1, better known as eIF2α), the activation of autophagy, and a global arrest in transcription and translation. Here, we outline methodological approaches for measuring ICD markers in vitro and ex vivo for the discovery of next-generation antineoplastic agents, the development of personalized anticancer regimens, and the identification of optimal therapeutic combinations for the clinical management of cancer.