Characterization of immunomodulating agents from Staphylococcus aureus for priming immunotherapy in triple-negative breast cancers

Immunotherapy, specifically immune checkpoint blockade (ICB), has revolutionized the treatment paradigm of triple-negative breast cancers (TNBCs). However, a subset of TNBCs devoid of tumor-infiltrating T cells (TILs) or PD-L1 expression generally has a poor response to immunotherapy. In this study, we aimed to sensitize TNBCs to ICB by harnessing the immunomodulating potential of S. aureus, a breast-resident bacterium. We show that intratumoral injection of spent culture media from S. aureus recruits TILs and suppresses tumor growth in a preclinical TNBC model. We further demonstrate that α-hemolysin (HLA), an S. aureus-produced molecule, increases the levels of CD8+ T cells and PD-L1 expression in tumors, delays tumor growth, and triggers tumor necrosis. Mechanistically, while tumor cells treated with HLA display Gasdermin E (GSDME) cleavage and a cellular phenotype resembling pyroptosis, splenic T cells incubated with HLA lead to selective expansion of CD8+ T cells. Notably, intratumoral HLA injection prior to ICB augments the therapeutic efficacy compared to ICB alone. This study uncovers novel immunomodulatory properties of HLA and suggests that intratumoral administration of HLA could be a potential priming strategy to expand the population of TNBC patients who may respond to ICB.

Distinct metabolic profiles associated with autism spectrum disorder versus cancer in individuals with germline PTEN mutations

PTEN hamartoma tumor syndrome (PHTS), caused by germline PTEN mutations, has been associated with organ-specific cancers and autism spectrum disorder (ASD) and/or developmental delay (DD). Predicting precise clinical phenotypes in any one PHTS individual remains impossible. We conducted an untargeted metabolomics study on an age- and sex-matched series of PHTS individuals with ASD/DD, cancer, or both phenotypes. Using agnostic metabolomic-analyses from patient-derived lymphoblastoid cells and their spent media, we found 52 differentially abundant individual metabolites, 69 cell/media metabolite ratios, and 327 pair-wise metabotype (shared metabolic phenotype) ratios clearly distinguishing PHTS individuals based on phenotype. Network analysis based on significant metabolites pointed to hubs converging on PTEN-related insulin, MAPK, AMPK, and mTOR signaling cascades. Internal cross-validation of significant metabolites showed optimal overall accuracy in distinguishing PHTS individuals with ASD/DD versus those with cancer. Such metabolomic markers may enable more accurate risk predictions and prevention in individual PHTS patients at highest risk.

Cross-level analysis of molecular and neurobehavioral function in a prospective series of patients with germline heterozygous PTEN mutations with and without autism

Background

PTEN is a well-established risk gene for autism spectrum disorder (ASD). Yet, little is known about how PTEN mutations and associated molecular processes influence neurobehavioral function in mutation carriers with (PTEN-ASD) and without ASD (PTEN no-ASD). The primary aim of the present study was to examine group differences in peripheral blood-derived PTEN pathway protein levels between PTEN-ASD, PTEN no-ASD, and idiopathic macrocephalic ASD patients (macro-ASD). Secondarily, associations between protein levels and neurobehavioral functions were examined in the full cohort.

Methods

Patients were recruited at four tertiary medical centers. Peripheral blood-derived protein levels from canonical PTEN pathways (PI3K/AKT and MAPK/ERK) were analyzed using Western blot analyses blinded to genotype and ASD status. Neurobehavioral measures included standardized assessments of global cognitive ability and multiple neurobehavioral domains. Analysis of variance models examined group differences in demographic, neurobehavioral, and protein measures. Bivariate correlations, structural models, and statistical learning procedures estimated associations between molecular and neurobehavioral variables. To complement patient data, Western blots for downstream proteins were generated to evaluate canonical PTEN pathways in the PTEN-m3m4 mouse model.

Results

Participants included 61 patients (25 PTEN-ASD, 16 PTEN no-ASD, and 20 macro-ASD). Decreased PTEN and S6 were observed in both PTEN mutation groups. Reductions in MnSOD and increases in P-S6 were observed in ASD groups. Elevated neural P-AKT/AKT and P-S6/S6 from PTEN murine models parallel our patient observations. Patient PTEN and AKT levels were independently associated with global cognitive ability, and p27 expression was associated with frontal sub-cortical functions. As a group, molecular measures added significant predictive value to several neurobehavioral domains over and above PTEN mutation status.

Limitations

Sample sizes were small, precluding within-group analyses. Protein and neurobehavioral data were limited to a single evaluation. A small number of patients were excluded with invalid protein data, and cognitively impaired patients had missing data on some assessments.

Conclusions

Several canonical PTEN pathway molecules appear to influence the presence of ASD and modify neurobehavioral function in PTEN mutation patients. Protein assays of the PTEN pathway may be useful for predicting neurobehavioral outcomes in PTEN patients. Future longitudinal analyses are needed to replicate these findings and evaluate within-group relationships between protein and neurobehavioral measures.

Trial registration

ClinicalTrials.gov Identifier NCT02461446

Distinct Alterations in Tricarboxylic Acid Cycle Metabolites Associate with Cancer and Autism Phenotypes in Cowden Syndrome and Bannayan-Riley-Ruvalcaba Syndrome

Germline heterozygous PTEN mutations cause subsets of Cowden syndrome (CS) and Bannayan-Riley-Ruvalcaba syndrome (BRRS); these subsets are characterized by high risks of breast, thyroid, and other cancers and, in one subset, autism spectrum disorder (ASD). Up to 10% of individuals with PTEN^MUT CS, CS-like syndrome, or BRRS have germline SDHx (succinate dehydrogenase, mitochondrial complex II) variants, which modify cancer risk. PTEN contributes to metabolic reprogramming; this is a well-established role in a cancer context. Relatedly, SDH sits at the crossroad of the electron transport chain and tricarboxylic acid (TCA) cycle, two central bioenergetic pathways. Intriguingly, PTEN^MUT and SDH^MUT individuals have reduced SDH catalytic activity, resulting in succinate accumulation; this indicates a common genotype-independent biochemical alteration. Here, we conducted a TCA targeted metabolomics study on 511 individuals with CS, CS-like syndrome, or BRRS with various genotypes (PTEN or SDHx, mutant or wild type [WT]) and phenotypes (cancer or ASD) and a series of 187 population controls. We found consistent TCA cycle metabolite alterations in cases with various genotypes and phenotypes compared to controls, and we found unique correlations of individual metabolites with particular genotype-phenotype combinations. Notably, increased isocitrate (p = 1.2 × 10⁻³), but reduced citrate (p = 5.0 × 10⁻⁴), were found to be associated with breast cancer in individuals with PTEN^MUT/SDHx^WT. Conversely, increased lactate was associated with neurodevelopmental disorders regardless of genotype (p = 9.7 × 10⁻³); this finding was replicated in an independent validation series (n = 171) enriched for idiopathic ASD (PTEN^WT, p = 5.6 × 10⁻⁴). Importantly, we identified fumarate (p = 1.9 × 10⁻²) as a pertinent metabolite, distinguishing individuals who develop ASD from those who develop cancer. Our observations suggest that TCA cycle metabolite alterations are germane to the pathobiology of PTEN-related CS and BRRS, as well as genotype-independent ASD, with implications for potential biomarker and/or therapeutic value.

Mutual Regulation of TLR/NLR and CEACAM1 in the Intestinal Microvasculature: Implications for IBD Pathogenesis and Therapy

BACKGROUND

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) displays multiple activities, among which pathogen binding and angiogenesis are particularly prominent. These same functions are also exerted by Toll- and NOD-like receptors (TLRs and NLRs), which are critical mediators of innate immune responses. We investigated whether a functional inter-relationship exists between CEACAM1 and TLRs and NLRs and its potential impact on induction of intestinal angiogenesis.

METHODS

This hypothesis was tested using human intestinal microvascular endothelial cells, a unique cell population exposed to microbial products under physiological and pathological conditions.

RESULTS

The results show that activation of TLR2/4, TLR4, NOD1, and NOD2 by specific bacterial ligands selectively and differentially upregulates the levels of cellular and soluble CEACAM1 produced by intestinal microvascular endothelial cells. The results also show that CEACAM1 regulates the migration, transmigration, and tube formation of these endothelial cells and mediates vessel sprouting induced by specific TLR and NLR bacterial ligands. Combined, these results demonstrate a close and reciprocal regulatory interaction between CEACAM1 and bacterial products in mediating multiple functions essential to new vessel formation in the gut mucosa.

CONCLUSIONS

A coordinated and reciprocal interaction of CEACAM1 and microbiota-derived factors is necessary to optimize angiogenesis in the gut mucosa. This suggests that a coordination of endogenous and exogenous innate immune responses is necessary to promote intestinal angiogenesis under physiological and inflammatory conditions such as inflammatory bowel disease.

Genome-wide analysis of DNA methylation and gene expression defines molecular characteristics of Crohn's disease-associated fibrosis

BACKGROUND

Fibrosis of the intestine is a common and poorly understood complication of Crohn's disease (CD) characterized by excessive deposition of extracellular matrix and accompanied by narrowing and obstruction of the gut lumen. Defining the molecular characteristics of this fibrotic disorder is a vital step in the development of specific prediction, prevention, and treatment strategies. Previous epigenetic studies indicate that alterations in DNA methylation could explain the mechanism by which mesenchymal cells adopt the requisite pro-fibrotic phenotype that promotes fibrosis progression. However, to date, genome-wide analysis of the DNA methylome of any type of human fibrosis is lacking. We employed an unbiased approach using deep sequencing to define the DNA methylome and transcriptome of purified fibrotic human intestinal fibroblasts (HIF) from the colons of patients with fibrostenotic CD.

RESULTS

When compared with normal fibroblasts, we found that the majority of differential DNA methylation was within introns and intergenic regions and not associated with CpG islands. Only a low percentage occurred in the promoters and exons of genes. Integration of the DNA methylome and transcriptome identified regions in three genes that inversely correlated with gene expression: wingless-type mouse mammary tumor virus integration site family, member 2B (WNT2B) and two eicosanoid synthesis pathway enzymes (prostacyclin synthase and prostaglandin D2 synthase). These findings were independently validated by RT-PCR and bisulfite sequencing. Network analysis of the data also identified candidate molecular interactions relevant to fibrosis pathology.

CONCLUSIONS

Our definition of a genome-wide fibrosis-specific DNA methylome provides new gene networks and epigenetic states by which to understand mechanisms of pathological gene expression that lead to fibrosis. Our data also provide a basis for development of new fibrosis-specific therapies, as genes dysregulated in fibrotic Crohn's disease, following functional validation, can serve as new therapeutic targets.

Chromosome-associated protein D3 promotes bacterial clearance in human intestinal epithelial cells by repressing expression of amino acid transporters

BACKGROUND & AIMS

Defects in colonic epithelial barrier defenses are associated with ulcerative colitis (UC). The proteins that regulate bacterial clearance in the colonic epithelium have not been completely identified. The Drosophila chromosome-associated protein D3 (dCAP-D3) regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium.

METHODS

Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing small hairpin RNAs against CAP-D3. We used immunoblot assays to measure levels of CAP-D3 in colonic epithelial cells from patients with UC and healthy individuals (controls). RNA sequencing identified genes activated by CAP-D3. We analyzed the roles of CAP-D3 target genes in bacterial clearance using gentamycin protection and immunofluorescence assays and studies with pharmacologic inhibitors.

RESULTS

CAP-D3 expression was reduced in colonic epithelial cells from patients with active UC. Reduced CAP-D3 expression decreased autophagy and impaired intracellular bacterial clearance by HT-29 and Caco-2 colonic epithelial cells. Lower levels of CAP-D3 increased transcription of genes encoding SLC7A5 and SLC3A2, the products of which heterodimerize to form an amino acid transporter in HT-29 cells after bacterial infection; levels of SLC7A5-SLC3A2 were increased in tissues from patients with UC compared with controls. Reduced CAP-D3 in HT-29 cells resulted in earlier recruitment of SLC7A5 to Salmonella-containing vacuoles, increased activity of mTORC1, and increased survival of bacteria. Inhibition of SLC7A5-SLC3A2 or mTORC1 activity rescued the bacterial clearance defects of CAP-D3-deficient cells.

CONCLUSIONS

CAP-D3 down-regulates transcription of genes that encode amino acid transporters (SLC7A5 and SLC3A2) to promote bacterial autophagy by colon epithelial cells. Levels of CAP-D3 protein are reduced in patients with active UC; strategies to increase its levels might restore mucosal homeostasis to patients with active UC.

The epithelial danger signal IL-1α is a potent activator of fibroblasts and reactivator of intestinal inflammation

Intestinal epithelial cell (IEC) death is typical of inflammatory bowel disease (IBD). We investigated: i) whether IEC-released necrotic cell products (proinflammatory mediators) amplify mucosal inflammation, ii) the capacity of necrotic cell lysates from HT29 cells or human IECs to induce human intestinal fibroblasts' (HIF) production of IL-6 and IL-8, and iii) whether IL-1α, released by injured colonocytes, exacerbated experimental IBD. Necrotic cell lysates potently induced HIF IL-6 and IL-8 production independent of Toll-like receptors 2 and 4, receptor for advanced glycation end-products, high-mobility group box 1, uric acid, IL-33, or inflammasome activation. IL-1α was the key IEC-derived necrotic cell product involved in HIF cytokine production. IL-1α-positive cells were identified in the epithelium in human IBD and dextran sulfate sodium (DSS)-induced colitis. IL-1α was detected in the stool of colitic mice before IL-1β. IL-1α enemas reactivated inflammation after DSS colitis recovery, induced IL-1 receptor expression in subepithelial fibroblasts, and activated de novo inflammation even in mice without overt colitis, after the administration of low-dose DSS. IL-1α amplifies gut inflammation by inducing cytokine production by mesenchymal cells. IL-1α-mediated IEC-fibroblast interaction may be involved in amplifying and perpetuating inflammation, even without obvious intestinal damage. IL-1α may be a target for treating early IBD or preventing the reactivation of IBD.

Cytokine-induced chromatin modifications of the type I collagen alpha 2 gene during intestinal endothelial-to-mesenchymal transition

BACKGROUND

Fibrosis of the intestine is currently an irreversible complication of inflammatory bowel disease; yet, little is understood of the underlying pathogenesis and antifibrotic strategies remain elusive. To develop effective therapies, knowledge of the mechanism of transcription and excessive deposition of type I collagen, a hallmark of fibrosis, is needed. We have shown previously that endothelial-to-mesenchymal transition (EndoMT) contributes to the pool of intestinal fibrotic cells and that a cytokine cocktail (interleukin 1-β, tumor necrosis factor α, and transforming growth factor β) induces collagen I alpha 2 (COL1A2) mRNA and protein.

METHODS

Chromatin immunoprecipitation assays on pure cultures of human intestinal mucosal endothelial cells undergoing EndoMT were performed with antibodies to specific histone modifications and RNA polymerase II. Reverse transcriptase-PCR was used to quantify the levels of Col1A2 and endothelial-specific von Willebrand factor (vWF) mRNA.

RESULTS

We showed that cytokines induce selective chromatin modifications (histone 4 hyperacetylation, and hypermethylation of histone 3) and phosphorylated RNA polymerase II at the COL1A2 promoter. Hypoacetylated and hypomethylated histone 3 was detected on the repressed vWF gene. Prolonged exposure to cytokines (16 days) retained hyperacetylation of select lysines in H4 on the COL1A2 promoter. Removal of cytokines after 16 days and continued culture for 10 days showed persistent hyperacetylation at lysine 16 in histone H4.

CONCLUSIONS

This is the first study to show that COL1A2 gene expression is associated with cytokine-induced, temporally ordered, and persistent chromatin modifications and suggests that these are important determinants of gene expression in EndoMT and intestinal fibrosis.

Germline mutations and variants in the succinate dehydrogenase genes in Cowden and Cowden-like syndromes

Individuals with PTEN mutations have Cowden syndrome (CS), associated with breast, thyroid, and endometrial neoplasias. Many more patients with features of CS, not meeting diagnostic criteria (termed CS-like), are evaluated by clinicians for CS-related cancer risk. Germline mutations in succinate dehydrogenase subunits SDHB-D cause pheochromocytoma-paraganglioma syndrome. One to five percent of SDHB/SDHD mutation carriers have renal cell or papillary thyroid carcinomas, which are also CS-related features. SDHB-D may be candidate susceptibility genes for some PTEN mutation-negative individuals with CS-like cancers. To address this hypothesis, germline SDHB-D mutation analysis in 375 PTEN mutation-negative CS/CS-like individuals was performed, followed by functional analysis of identified SDH mutations/variants. Of 375 PTEN mutation-negative CS/CS-like individuals, 74 (20%) had increased manganese superoxide dismutase (MnSOD) expression, a manifestation of mitochondrial dysfunction. Among these, 10 (13.5%) had germline mutations/variants in SDHB (n = 3) or SDHD (7), not found in 700 controls (p < 0.001). Compared to PTEN mutation-positive CS/CS-like individuals, those with SDH mutations/variants were enriched for carcinomas of the female breast (6/9 SDH versus 30/107 PTEN, p < 0.001), thyroid (5/10 versus 15/106, p < 0.001), and kidney (2/10 versus 4/230, p = 0.026). In the absence of PTEN alteration, CS/CS-like-related SDH mutations/variants show increased phosphorylation of AKT and/or MAPK, downstream manifestations of PTEN dysfunction. Germline SDH mutations/variants occur in a subset of PTEN mutation-negative CS/CS-like individuals and are associated with increased frequencies of breast, thyroid, and renal cancers beyond those conferred by germline PTEN mutations. SDH testing should be considered for germline PTEN mutation-negative CS/CS-like individuals, especially in the setting of breast, thyroid, and/or renal cancers.

Integrated clinical service for sexual assault victims in a genitourinary setting

BACKGROUND

Reported sexual assault is increasing, and the diverse immediate and longer term needs of the victim are usually met by exposure to a number of healthcare professionals often in different locations, involving delays and travel, increasing the trauma for the victim.

OBJECTIVES

To set up a centre to address the immediate and longer term needs of the sexual assault victim and review issues arising during the development of the service.

METHODS

Description of setting up the service in the genitourinary medicine department of Kings College Hospital, south London, and the aspects of care offered.

RESULTS

The number of victims referred by police increased from 15 in 1992 to 58 in 1996. In 1996, 55 female and three male victims were seen. 23 different police stations brought victims for examination; mean age of the victim was 27 years (range 14-60), median time between assault and examination was 22 hours (range 3 hours-3 months); 23% had genital injuries, 59% had other physical injury, and 11% needed further hospital care. 71% accepted screening for sexually transmitted infection (STI), 21% had an STI diagnosed, 16% of the women required emergency contraception, 26% received prophylactic antibiotics, and 58% saw a health adviser. 70% had a follow up appointment arranged of which 50% attended.

CONCLUSION

The high uptake of STI screening, emergency contraception, health adviser consultation, and follow up supports the concept of a comprehensive integrated system to meet the disparate needs of the victim while still obtaining the necessary forensic evidence. The wide catchment area of service users indicates gaps in services available for the assault victim. Earlier genitourinary involvement after sexual assault is becoming increasingly pertinent in relation to HIV prophylaxis.

Examination of New Zealand's endemic Wiseana nucleopolyhedrovirus by analysis of the viral polyhedrin gene

Insects of the genus Wiseana (Lepidoptera: Hepialidae) are major agricultural pests in New Zealand. Singly enveloped nucleopolyhedroviruses (SNPVs) isolated from three of the seven described Wiseana species have potential as biological control agents. As part of an effort to characterise the Wiseana SNPV genome the polyhedrin gene was cloned and the nucleotide sequence determined. The gene sequence was used, in conjunction with morphological and restriction endonuclease analysis, to compare isolates from different sites and species of Wiseana. Heterogeneity was detected within a single site, as well as between SNPV from separate Wiseana species. The extent of divergence between the nucleotide sequences was small enough, however, to consider three SNPVs from W. signata, W. cervinata and W. umbraculata as different strains of a single SNPV species. This improves the likely practicability of developing a single viral agent to control this pest complex. In addition, the virus polyhedrin gene sequence was used to estimate the phylogenetic relatedness of a W. signata SNPV to 16 other NPV from diverse insect genera. These comparisons suggest the Wiseana SNPV was unique within the Baculoviridae, but was more closely related to the group II NPVs.

Behavioral effects of felbamate in childhood epileptic encephalopathy (Lennox-Gastaut syndrome)

The behavioral effects of felbamate were assessed in 20 persons, (ages 2 to 19 years) who were participating in a compassionate plea protocol for children with Lennox-Gastaut syndrome. Parents completed a questionnaire concerning aspects of behavioral change once all medications were in a constant regimen. Significant improvements were suggested in social functioning, intellectual functioning, motor functioning, attention and concentration, alertness, initiative, variability in performance, and memory. There was a tendency for these effects to reverse when the drug was discontinued.

Acute challenge ERP as a prognostic of stimulant therapy outcome in attention-deficit hyperactivity disorder

Thirty-five children were tested with an auditory oddball P300 paradigm both before and 2 hr after a single-dose trial of methylphenidate (MPH). A prediction of the long-term benefit of medication was then made based on the magnitude of the acute changes in P3b amplitude. Those with postdrug amplitude increases of at least 30% were predicted to respond favorably to stimulants. All children were followed-up at 6 months. The original MPH Challenge Test predictions (based on acute post drug P3b amplitude changes) were then compared with the clinicians' evaluations of outcome. The MPH challenge classification accurately predicted outcome in 81% of cases.