IL-2-mediated hepatotoxicity: knowledge gap identification based on the irAOP concept

Drug-induced hepatotoxicity constitutes a major reason for non-approval and post-marketing withdrawal of pharmaceuticals. In many cases, preclinical models lack predictive capacity for hepatic damage in humans. A vital concern is the integration of immune system effects in preclinical safety assessment. The immune-related Adverse Outcome Pathway (irAOP) approach, which is applied within the Immune Safety Avatar (imSAVAR) consortium, presents a novel method to understand and predict immune-mediated adverse events elicited by pharmaceuticals and thus targets this issue. It aims to dissect the molecular mechanisms involved and identify key players in drug-induced side effects. As irAOPs are still in their infancy, there is a need for a model irAOP to validate the suitability of this tool. For this purpose, we developed a hepatotoxicity-based model irAOP for recombinant human IL-2 (aldesleukin). Besides producing durable therapeutic responses against renal cell carcinoma and metastatic melanoma, the boosted immune activation upon IL-2 treatment elicits liver damage. The availability of extensive data regarding IL-2 allows both the generation of a comprehensive putative irAOP and to validate the predictability of the irAOP with clinical data. Moreover, IL-2, as one of the first cancer immunotherapeutics on the market, is a blueprint for various biological and novel treatment regimens that are under investigation today. This review provides a guideline for further irAOP-directed research in immune-mediated hepatotoxicity.

Fine tuning of the innate and adaptive immune responses by Interleukin-2

Novel immunotherapies for cancer and other diseases aim to trigger the immune system to produce durable responses, while overcoming the immunosuppression that may contribute to disease severity, and in parallel considering immunosafety aspects. Interleukin-2 (IL-2) was one of the first cytokines that the FDA approved as a cancer-targeting immunotherapy. However, in the past years, IL-2 immunotherapy is not actively offered to patients, due to limited efficacy, when compared to other novel immunotherapies, and the associated severe adverse events. In order to design improved in vitro and in vivo models, able to predict the efficacy and safety of novel IL-2 alternatives, it is important to delineate the mechanistic immunological events triggered by IL-2. Particularly, in this review we will discuss the effects IL-2 has with the bridging cell type of the innate and adaptive immune responses, dendritic cells. The pathways involved in the regulation of IL-2 by dendritic cells and T-cells in cancer and autoimmune disease will also be explored.

Exploring Spatial Heterogeneity of Immune Cells in Nasopharyngeal Cancer

Nasopharyngeal cancer (NPC) is a malignant tumor. In a recent publication, we described the presence and distribution of CD8⁺ T cells in NPC and used the information to identify 'inflamed', 'immune-excluded', and 'desert' immune phenotypes, where 'inflamed' and 'immune-excluded' NPCs were correlated with CD8 T cell infiltration and survival. Arguably, more detailed and, in particular, spatially resolved data are required for patient stratification and for the identification of new treatment targets. In this study, we investigate the phenotype of CD45⁺ leukocytes in the previously analyzed NPC samples by applying multiplexed tissue analysis to assess the spatial distribution of cell types and to quantify selected biomarkers. A total of 47 specified regions-of-interest (ROIs) were generated based on CD45, CD8, and PanCK morphological staining. Using the GeoMx^® Digital Spatial Profiler (DSP), 49 target proteins were digitally quantified from the selected ROIs of a tissue microarray consisting of 30 unique NPC biopsies. Protein targets associated with B cells (CD20), NK cells (CD56), macrophages (CD68), and regulatory T cells (PD-1, FOXP3) were most differentially expressed in CD45⁺ segments within 'immune-rich cancer cell islet' regions of the tumor (cf. 'surrounding stromal leukocyte' regions). In contrast, markers associated with suppressive populations of myeloid cells (CD163, B7-H3, VISTA) and T cells (CD4, LAG3, Tim-3) were expressed at a higher level in CD45⁺ segments in the 'surrounding stromal leukocyte' regions (cf. 'immune-rich cancer cell islet' regions). When comparing the three phenotypes, the 'inflamed' profile (cf. 'immune-excluded' and 'desert') exhibited higher expression of markers associated with B cells, NK cells, macrophages, and myeloid cells. Myeloid markers were highly expressed in the 'immune-excluded' phenotype. Granulocyte markers and immune-regulatory markers were higher in the 'desert' profile (cf. 'inflamed' and 'immune-excluded'). In conclusion, this study describes the spatial heterogeneity of the immune microenvironment in NPC and highlights immune-related biomarkers in immune phenotypes, which may aid in the stratification of patients for therapeutic purposes.

Upper airway microbiome transplantation for patients with chronic rhinosinusitis

BACKGROUND

Chronic or recurrent rhinosinusitis without polyps (CRSsNP) is characterized by a persistent inflammation of the sinonasal mucosa. The underlying cause is unclear but increasing interest has been directed toward changes in the sinonasal microbiome as a potential driver.

METHODS

Twenty-two patients diagnosed with CRSsNP were treated with antibiotics for 13 days, followed by 5 consecutive days of nasal microbiome transplants from healthy donors. Outcome measures were 22-item Sino-Nasal Outcome Test (SNOT-22) questionnaire, total nasal symptom score (TNSS), endoscopic grading, 16S ribosomal RNA (rRNA) next generation sequencing (microbiome analysis), and nasal lavage fluid analysis of inflammatory cytokines. Patients were examined at the start of the study and after antibiotic treatment as well as 10 days and 3 months after the transplant series.

RESULTS

At the end of the study, patients reported significantly reduced SNOT-22 scores and microbiome analysis showed significantly increased abundance and diversity. No significant change was observed for TNSS or endoscopic scoring.

CONCLUSION

Nasal microbiome transplants obtained from healthy individuals and administered as nasal lavages to patients with CRSsNP are feasible. The patients reported significant and lasting reduction of symptoms and these findings were associated with a lasting increase in abundance and diversity of the local bacterial flora. The observations, which need to be confirmed by randomized controlled trials, may constitute a new treatment avenue for these difficult to treat patients where antibiotics only provide short lasting symptom control.

Bispecific antibodies targeting CD40 and tumor-associated antigens promote cross-priming of T cells resulting in an antitumor response superior to monospecific antibodies

BACKGROUND

Indications with poor T-cell infiltration or deficiencies in T-cell priming and associated unresponsiveness to established immunotherapies represent an unmet medical need in oncology. CD40-targeting therapies designed to enhance antigen presentation, generate new tumor-specific T cells, and activate tumor-infiltrating myeloid cells to remodel the tumor microenvironment, represent a promising opportunity to meet this need. In this study, we present the first in vivo data supporting a role for tumor-associated antigen (TAA)-mediated uptake and cross-presentation of tumor antigens to enhance tumor-specific T-cell priming using CD40×TAA bispecific antibodies, a concept we named Neo-X-Prime.

METHODS

Bispecific antibodies targeting CD40 and either of two cell-surface expressed TAA, carcinoembryonic antigen-related cell adhesion molecule 5 (CEA) or epithelial cell adhesion molecule (EpCAM), were developed in a tetravalent format. TAA-conditional CD40 agonism, activation of tumor-infiltrating immune cells, antitumor efficacy and the role of delivery of tumor-derived material such as extracellular vesicles, tumor debris and exosomes by the CD40×TAA bispecific antibodies were demonstrated in vitro using primary human and murine cells and in vivo using human CD40 transgenic mice with different tumor models.

RESULTS

The results showed that the CD40×TAA bispecific antibodies induced TAA-conditional CD40 activation both in vitro and in vivo. Further, it was demonstrated in vitro that they induced clustering of tumor debris and CD40-expressing cells in a dose-dependent manner and superior T-cell priming when added to dendritic cells (DC), ovalbumin (OVA)-specific T cells and OVA-containing tumor debris or exosomes. The antitumor activity of the Neo-X-Prime bispecific antibodies was demonstrated to be significantly superior to the monospecific CD40 antibody, and the resulting T-cell dependent antitumor immunity was directed to tumor antigens other than the TAA used for targeting (EpCAM).

CONCLUSIONS

The data presented herein support the hypothesis that CD40×TAA bispecific antibodies can engage tumor-derived vesicles containing tumor neoantigens to myeloid cells such as DCs resulting in an improved DC-mediated cross-priming of tumor-specific CD8⁺ T cells. Thus, this principle may offer therapeutics strategies to enhance tumor-specific T-cell immunity and associated clinical benefit in indications characterized by poor T-cell infiltration or deficiencies in T-cell priming.

Nasal administration of a probiotic assemblage in allergic rhinitis: a placebo-controlled crossover experimental study

BACKGROUND

Topical probiotics have been suggested as a treatment option for allergic rhinitis, as they may skew the immune response towards a beneficial type-1 non-allergic profile. So far observations in man have exclusively involved oral intake. The aim of this study was to examine if a topical/nasal administration of a probiotic assemblage (PA) affects quality of life, symptoms, and signs of allergic rhinitis in a nasal allergen challenge (NAC) model.

METHODS

In a placebo-controlled and crossover design, 24 patients with seasonal allergic rhinitis were subjected to topical/nasal administration with a PA of Lactobacillus rhamnosus SP1, Lactobacillus paracasei 101/37, and Lactococcus lactis L1A for three weeks. The last week of each treatment period was combined with a NAC-series. Efficacy variables were "Mini-Rhinoconjunctivitis Quality of Life Questionnaire" (Mini-RQLQ), "Total Nasal Symptom Score" (TNSS), "Peak Nasal Inspiratory Flow" (PNIF), and "Fractional Exhaled Nitric Oxide" (FeNO). In addition, to assess whether or not the PA produced any pro-inflammatory effect per se, soluble analytes were monitored in nasal lavage fluids. Finally, bacterial cultures, sampled using swabs from the middle nasal meatus, were assessed for presence of the PA by MALDI-TOF analysis.

RESULTS

Administration of the PA did not produce any nasal symptoms (cf. placebo). An innate response was discerned within the PA-run (cf. baseline), but no change in nasal lavage fluid levels of cytokines/mediators were observed cf. placebo except for IL-17/IL-17A (a minor increase in the PA run). Administration of the PA did neither affect Mini-RQLQ, TNSS, PNIF, nor FeNO. No evidence of persistent colonization was observed.

CONCLUSION

Topical/nasal administration of a PA comprising Lactobacillus rhamnosus SP1, Lactobacillus paracasei 101/37, Lactococcus lactis L1A, while likely evoking a minor innate immune response yet being safe, does not affect quality of life, symptoms, or signs of allergic rhinitis.

Tonsillar Cancer with High CD8+ T-Cell Infiltration Features Increased Levels of Dendritic Cells and Transcriptional Regulation Associated with an Inflamed Tumor Microenvironment

Human papillomavirus (HPV) is the main causal agent of tonsillar cancer (TC) and HPV+ TC has a favorable prognosis compared to HPV- disease. In this study, we examined aspects of the tumor microenvironment of TC, focusing on T-cells, dendritic cells (DC), and macrophages. Fresh biopsies of TC and the contralateral healthy tonsil (HT) were obtained from 20 patients, analyzed by multiparameter flow cytometry, and assessed against a detailed HPV-status. Additionally, RNA-sequencing data from 38 TC samples available in the public database, The Cancer Genome Atlas (TCGA), were explored, focusing on the same leukocyte populations. HPV+ TC featured increased levels of CD8+ T-cells and antigen-presenting cells (cf. HPV- TC and HT, respectively). In HPV+ TC, CD8+ T-cell frequencies correlated to DC levels independently of tumor stage, HPV 16 copy number, and E7 oncogene expression as well as frequencies of other leukocytes. Similarly, RNA sequencing data were explored by dividing the HPV+ TCs according to predefined CD8+ T-cell scores in silico. Higher levels of genes expressed by antigen-presenting cells and effector T-cells, such as immune checkpoints and cytokines, were detected in the CD8HIGH HPV+ TC samples (cf. CD8LOW HPV+ TC). In conclusion, CD8HIGH HPV+ TC displays a unique inflammatory profile associated with increased effector T-cell functions and the presence of antigen-presenting cells in the tumor microenvironment. Further studies are warranted to assess if this information can be used on an individual basis to aid in prognosis and treatment decisions.

Immune delineation of laryngeal papilloma reveals enhanced neutrophil associated gene profile

Laryngeal papilloma (LP) is a rare benign disease, caused by recurrent multisite papillomas that are referred to as recurrent respiratory papillomatosis (RRP). RRP is caused primarily by two types of human papillomavirus (HPV): HPV6 and HPV11. The immune dysregulation within the microenvironment of the lesions has been shown to likely play a role in the development of RRP. The present study aimed at analyzing the transcriptional profile of immune response genes and cancer-related genes in the LP microenvironment. We used the NanoString^® nCounter^® analysis system to study expression of 730 genes among seven paired samples of LP and healthy laryngeal (HL) tissue. qRT-PCR and flow cytometric analysis was performed to confirm identified transcripts and follow-up scores of infiltrating immune cells, respectively. In total, 113 differentially expressed transcripts were detected of which 37 showed increased expression levels and 76 decreased expression levels in the LP samples compared to the HL samples (fold change ≥ 2). Transcripts with increased expression levels included S100As (A7, A8, and A12), CEACAM1, neutrophil activation associated cytokines (IL8), chemokines (CXCL6), and IL receptors, e.g., IL4R. Transcripts with decreased expression in LP were associated with innate and adaptive immunity. Overall, HPV6 and 11 were present in 67% and 33% of the patients, respectively. There was a significant increase in neutrophils and a significant decrease in CD8⁺ T cells in LP. LP samples display an immune profile characterized by enhanced expression of neutrophilic markers and significantly reduced T cell-associated markers.

858 A bispecific antibody targeting CD40 and EpCAM induces superior anti-tumor effects compared to the combination of the monospecific antibodies

Background

Alligator has developed a new concept, Neo-X’, to enable antigen presenting cells to efficiently enhance priming of neoantigen-specific T cells, which may be the missing aspect in tumors that lack T cell infiltration. We hypothesize that binding of the CD40 x EpCAM bsAb (4224) to CD40 on DCs and EpCAM on tumor exosomes or tumor debris leads to i) activation of the DC, ii) uptake of the tumor material, iii) cross-presentation of tumor-derived neoantigen (present in exosomes or debris) and iiii) priming of tumor neoantigen-specific T cells, resulting in an increased quantity and/or quality of the tumor-targeting T cell pool. CD40 crosslinking by engagement with a tumor antigen on a tumor cell is required to achieve a functional agonistic effect, and subsequent DC activation will therefore only be achieved in the presence of tumor antigens.

Methods

4224 evaluated in vitro using human monocyte-derived DC, co-cultured with cells expressing EpCAM. In addition the functional effects were evaluated using tumor cell lines and B-cell lines expressing CD40. In vivo, the anti-tumor efficacy of the CD40 x EpCAM bsAb was determined in human CD40 transgenic mice bearing MB49 bladder carcinoma tumors transfected with human EpCAM or controls.

Results

In vitro, we have demonstrated that the CD40 x EpCAM bsAb induces tumor target dependent activation of dendritic cells, as analyzed by flow cytometry measuring HLA-DR and CD86 expression on the DC and by measuring IL-12p40 levels in the supernatant. Further, the ability of bsAbs within the Neo-X’ concept to mediate co-localization of tumor debris and CD40 expressing antigen presenting cells depends on the receptor density of the tumor target. In vivo, 4224 displayed a potent, EpCAM-dependent anti-tumor effect with significantly reduced tumor growth and improved survival compared to an equivalent dose of the combination of the monospecific CD40 Ab and EpCAM targeting antibody. The tumor-localizing property of 4224 also shows potential for improved safety compared to CD40 monospecific antibodies. A biodistribution analysis demonstrated that the bispecific 4224 in the RUBY-format displayed similar half-life as the monospecific CD40 mAb in mice.

Conclusions

In conclusion, the Neo-X’ concept, by targeting CD40 and a tumor specific antigen, has the potential to mediate an expansion of the tumor-specific T cell repertoire, resulting in increased T cell infiltration and potent anti-tumor effects.

Prostate cancer cells enhance interleukin-15-mediated expansion of NK cells

OBJECTIVES

To identify cytokines that can activate and expand NK cells in the presence of prostate cancer cells in order to determine whether these agents may be useful in future intra-tumoural administration in pre-clinical and clinical prostate cancer trials.

MATERIALS AND METHODS

Lymphocytes isolated from normal donor blood were set up in co-cultures with either cancer or non-cancerous prostate cell lines, together with each of the cytokines interleukin (IL)-2, IL-12, IL-15, interferon (IFN)-γ or IL-21 for a period of 7 days. Then, expansion of NK cells, NKT cells and CD8 T cells was measured by flow cytometry and compared with the expansion of the same cells in the absence of prostate cells. The cytotoxic activity of NK cells, as measured by perforin and tumour cell killing, was also assessed. NK cell receptors and their corresponding ligands on prostate tumour cells were analysed to determine whether any of these were modulated by co-culture. The role of the tumour-secreted heat shock proteins HSP90 and HSP70 in the expansion of NK cells in the co-cultures was also investigated because of their effects on NK and CD8 T-cell activation.

RESULTS

We showed that, among a panel of cytokines known to cause NK cell activation and expansion, only IL-15 could actively induce expansion of NK, NKT and CD8 T cells in the presence of prostate cancer cell lines. Furthermore, the expansion of NK cells was far greater (up to 50% greater) in the presence of the cancer cells (LNCaP, PC3) than when lymphocytes were incubated alone. In contrast, non-cancerous cell lines (PNT2 and WPMY-1) did not exert any expansion of NK cells. The cytolytic activity of the NK cells, as measured by perforin, CD107a and killing of tumour cells, was also greatest in co-cultures with IL-15. Examination of NK cell receptors shows that NKG2D is upregulated to a greater degree in the presence of prostate cancer cells, compared with the upregulation with IL-15 in lymphocytes alone. However, blocking of NKG2D does not inhibit the enhanced expansion of NK cells in the presence of tumour cells.

CONCLUSIONS

Among a panel of NK cell-activating cytokines, IL-15 was the only cytokine that could stimulate expansion of NK cells in the presence of prostate cancer cells; therefore IL-15 may be a good candidate for novel future intra-tumoural therapy of the disease.

Bloodstream infection due to extended-spectrum beta-lactamase (ESBL)-positive K. pneumoniae and E. coli: an analysis of the disease burden in a large cohort

PURPOSE

The burden of extended-spectrum beta-lactamase (ESBL)-positive Enterobacteriaceae (ESBL-E) is growing worldwide. We aimed to determine the financial disease burden attributable to ESBL-positive species in cases of bloodstream infection (BSI) due to K. pneumoniae and E. coli.

METHODS

We conducted a cohort study on patients with BSI due to K. pneumoniae or E. coli between 2008 and 2011 in our institution. Data were collected on true hospital costs, length of stay (LOS), basic demographic parameters, underlying diseases as Charlson comorbidity index (CCI) and ESBL positivity of the pathogens. Multivariable regression analysis on hospital costs and length of stay was performed.

RESULTS

Overall we found 1,851 consecutive cases of ESBL-E BSI, 352 (19.0%) cases of K. pneumoniae BSI and 1,499 (81.0%) cases of E. coli BSI. Sixty-six of E. coli BSI (18.8%) and 178 of K. pneumoniae BSI (11.9%) cases were due to ESBL-positive isolates, respectively (p = 0.001). 830 (44.8%) cases were hospital-onset, 215 (61.1%) of the K. pneumoniae and 615 (41.0%) of the E. coli cases (p < 0.001). In-hospital mortality was overall 19.8, 25.0% in K. pneumoniae cases and 18.5% in E. coli cases (p = 0.006). Increased hospital costs and length of stay were significantly associated to BSI with ESBL-positive K. pneumoniae.

CONCLUSION

In contrast to BSI due to ESBL-positive E. coli, cases of ESBL-positive K. pneumoniae BSI were associated with significantly increased costs and length of stay. Infection prevention measures should differentiate between both pathogens.

The effect of red cell shape on the measurement of red cell volume. A proposed method for the comparative assessment of this effect among various haematology analysers

Shape changes of abnormally deformed red cells in aperture impedance haematology analysers are known to affect MCV, MCHC and haematocrit estimation. However, different counters vary in the manifestation of this effect. We performed a comparative study among five analysers. Three of them are based on impedance without hydrodynamic focusing (Coulter STKR, Cell-Dyn3000 Abbott and K-1000 Sysmex). The other two use hydrodynamic focusing, either with impedance (NE-8000 Sysmex) or two angle laser scatter (H*1 Bayer). A novel method of analysis was applied. Two hundred and three specimens with abnormal red cells and 50 normal specimens (according to ICSH criteria) were assayed. In all samples the PCV was estimated by the reference method without correction for trapped plasma. A true MCHC value was estimated from the mean haemoglobin value and the PCV. The shape effect was assessed by three linear regressions: 1) haematocrit deviations from PCV (corrected for any calibration bias) versus true MCHC; 2) analyser MCHC vs. true MCHC; 3) MCV vs. MCH. The regressions for the analysers with hydrodynamic focusing indicated no significant shape effect. Aperture impedance analysers without focusing varied in their behaviour. The Coulter STKR and the Cell-Dyn3000 both showed strong correlation of haematocrit deviations with true MCHC, poor MCHC correlations and linear MCV-MCH regressions. The K-1000 showed minor indications of such an effect. We conclude that comparative studies are needed to quantitate red cell shape effect errors among various impedance analysers.

Staphylococci from the feces of different animal species: biotypes of Staphylococcus aureus strains of sheep and goat origin

Staphylococcus aureus was found in 96% of the rectal swabs from 133 sheep and in 80% of the swabs from 125 goats. Seventy-seven percent of the isolates from both hosts exhibited the fibrinolytic and growth characteristics of human biotype A on human plasma and crystal violet agar, respectively, but 99% of these isolates resembled S. aureus of animal origin in their other properties. Only 21% of the sheep and 24% of the goat isolates were clearly identifiable as human biotype A and animal biotypes B and C.