Characterization of natural killer and cytotoxic T-cell immune infiltrates in pancreatic ductal adenocarcinoma

BACKGROUND AND OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with poor response to systemic therapies, including immunotherapy. Given the immunotherapeutic potential of natural killer (NK) cells, we evaluated intratumoral NK cell infiltrates along with cytotoxic T cells in PDAC to determine their association with patient outcomes.

METHODS

We analyzed tumors from 93 PDAC patients treated from 2012 to 2020. Predictor variables included tumor-infiltrating lymphocytes (TILs), T-cell markers (CD3, CD8, CD45RO), NK marker (NKp46), and NK inhibitory marker (major histocompatibility complex class I [MHC-I]) by immunohistochemistry. Primary outcome variables were recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Mean TILs, CD3, and NKp46 scores were 1.3 ± 0.63, 20.6 ± 17.5, and 3.1 ± 3.9, respectively. Higher expression of CD3 and CD8 was associated with higher OS, whereas NK cell infiltration was not associated with either RFS or OS. There was a tight positive correlation between MHC-I expression and all T-cell markers, but not with NKp46.

CONCLUSIONS

Overall NK cell infiltrates were low in PDAC and did not predict clinical outcomes, whereas T-cell infiltrates did. Further characterization of the immune infiltrate in PDAC, including inhibitory signals and suppressive cell types, may yield better biomarkers of prognosis and immune targeting in this refractory disease.

Intratumoral NKp46+ natural killer cells are spatially distanced from T and MHC-I+ cells with prognostic implications in soft tissue sarcoma

Introduction

Soft tissue sarcomas (STS) are rare, heterogenous malignancies with an unmet need for novel immunotherapies. Tumor infiltrating lymphocytes (TILs) have been linked with favorable outcomes in STS patients, though the contribution of natural killer (NK) cells and spatial relationships of TILs with MHC-I expressing cells lacks detailed characterization.

Experimental design

Using archived and prospectively collected specimens, we evaluated intratumoral NK cells by immunohistochemistry (IHC), flow cytometry, and immunofluorescence (IF). We assessed spatial localization of NK and T cells by multiplex IF, analyzing the effects of MHC-I expression status on NK and T cell clustering.

Results

Both intratumoral NKp46 and CD56dim expression were associated with significantly improved overall survival (P=0.05), while higher infiltrates of CD56bright NK cells predicted a worse prognosis (P=0.05). The presence of intratumoral NK cells was inversely proportional to CD3+ T cells. Spatial analyses showed NK cells preferentially clustering close to other NK cells with sparse CD3+ T and CD8+ T cells in range (P<0.0001). Additionally, CD3+ T and CD8+ T cells showed significantly greater co-localization with MHC-I+ cells, compared to NK cells (P<0.0001). After neoadjuvant radiotherapy, there was greater CD8 clustering, while after neoadjuvant chemotherapy, there was overall lower TIL clustering.

Conclusion

Intratumoral NK cells are prognostic in STS and localize closer to MHC-I- cells than T cells. Although both NK and T cells are associated with improved survival in STS, their differential distribution in the TME based on MHC-I expression status may serve as a biomarker for improved immunotherapy treatment selection.

Human soft tissue sarcomas harbor an intratumoral viral microbiome which is linked with natural killer cell infiltrate and prognosis

BACKGROUND

Groundbreaking studies have linked the gut microbiome with immune homeostasis and antitumor immune responses. Mounting evidence has also demonstrated an intratumoral microbiome, including in soft tissue sarcomas (STS), although detailed characterization of the STS intratumoral microbiome is limited. We sought to characterize the intratumoral microbiome in patients with STS undergoing preoperative radiotherapy and surgery, hypothesizing the presence of a distinct intratumoral microbiome with potentially clinically significant microbial signatures.

METHODS

We prospectively obtained tumor and stool samples from adult patients with non-metastatic STS using a strict sterile collection protocol to minimize contamination. Metagenomic classification was used to estimate abundance using genus and species taxonomic levels across all classified organisms, and data were analyzed with respect to clinicopathologic factors.

RESULTS

Fifteen patients were enrolled. Most tumors were located at an extremity (67%) and were histologic grade 3 (87%). 40% were well-differentiated/dedifferentiated liposarcoma histology. With a median follow-up of 24 months, 4 (27%) patients developed metastases, and 3 (20%) died. Despite overwhelming human DNA (>99%) intratumorally, we detected a small but consistent proportion of bacterial DNA (0.02-0.03%) in all tumors, including Proteobacteria, Bacteroidetes, and Firmicutes, as well as viral species. In the tumor microenvironment, we observed a strong positive correlation between viral relative abundance and natural killer (NK) infiltration, and higher NK infiltration was associated with superior metastasis-free and overall survival by immunohistochemical, flow cytometry, and multiplex immunofluorescence analyses.

CONCLUSIONS

We prospectively demonstrate the presence of a distinct and measurable intratumoral microbiome in patients with STS at multiple time points. Our data suggest that the STS tumor microbiome has prognostic significance with viral relative abundance associated with NK infiltration and oncologic outcome. Additional studies are warranted to further assess the clinical impact of these findings.

Using the canine microbiome to bridge translation of cancer immunotherapy from pre-clinical murine models to human clinical trials

The microbiome has clearly been established as a cutting-edge field in tumor immunology and immunotherapy. Growing evidence supports the role of the microbiome in immune surveillance, self-tolerance, and response to immune checkpoint inhibitors such as anti PD-L1 and CTLA-4 blockade (1-6). Moreover, recent studies including those using fecal microbial transplantation (FMT) have demonstrated that response to checkpoint immunotherapies may be conferred or eliminated through gut microbiome modulation (7, 8). Consequently, studies evaluating microbiota-host immune and metabolic interactions remain an area of high impact research. While observations in murine models have highlighted the importance of the microbiome in response to therapy, we lack sufficient understanding of the exact mechanisms underlying these interactions. Furthermore, mouse and human gut microbiome composition may be too dissimilar for discovery of all relevant gut microbial biomarkers. Multiple cancers in dogs, including lymphoma, high grade gliomas, melanomas and osteosarcoma (OSA) closely resemble their human analogues, particularly in regard to metastasis, disease recurrence and response to treatment. Importantly, dogs with these spontaneous cancers also have intact immune systems, suggesting that microbiome analyses in these subjects may provide high yield information, especially in the setting of novel immunotherapy regimens which are currently expanding rapidly in canine comparative oncology (9, 10). Additionally, as onco-microbiotic therapies are developed to modify gut microbiomes for maximal responsiveness, large animal models with intact immune systems will be useful for trialing interventions and monitoring adverse events. Together, pre-clinical mechanistic studies and large animal trials can help fully unlock the potential of the microbiome as a diagnostic and therapeutic target in cancer.

Transcriptome Analysis of Tumor-Infiltrating Lymphocytes Identifies NK Cell Gene Signatures Associated With Lymphocyte Infiltration and Survival in Soft Tissue Sarcomas

Purpose

Clinical successes using current T-cell based immunotherapies have been limited in soft tissue sarcomas (STS), while pre-clinical studies have shown evidence of natural killer (NK) cell activity. Since tumor immune infiltration, especially tumor-infiltrating lymphocytes, is associated with improved survival in most solid tumors, we sought to evaluate the gene expression profile of tumor and blood NK and T cells, as well as tumor cells, with the goal of identifying potential novel immune targets in STS.

Experimental Design

Using fluorescence-activated cell sorting, we isolated blood and tumor-infiltrating CD3^-CD56⁺ NK and CD3⁺ T cells and CD45^- viable tumor cells from STS patients undergoing surgery. We then evaluated differential gene expression (DGE) of these purified populations with RNA sequencing analysis. To evaluate survival differences and validate primary DGE results, we also queried The Cancer Genome Atlas (TCGA) database to compare outcomes stratified by bulk gene expression.

Results

Sorted intra-tumoral CD3⁺ T cells showed significant upregulation of established activating (CD137) and inhibitory genes (TIM-3) compared to circulating T cells. In contrast, intra-tumoral NK cells did not exhibit upregulation of canonical cytotoxic genes (IFNG, GZMB), but rather significant DGE in mitogen signaling (DUSP4) and metabolic function (SMPD3, SLC7A5). Tumors with higher NK and T cell infiltration exhibited significantly increased expression of the pro-inflammatory receptor TLR4 in sorted CD45^- tumor cells. TCGA analysis revealed that tumors with high TLR4 expression (P = 0.03) and low expression of STMN1 involved in microtubule polymerization (P < 0.001) were associated with significantly improved survival.

Conclusions

Unlike T cells, which demonstrate significant DGE consistent with upregulation of both activating and inhibiting receptors in tumor-infiltrating subsets, NK cells appear to have more stable gene expression between blood and tumor subsets, with alterations restricted primarily to metabolic pathways. Increased immune cell infiltration and improved survival were positively correlated with TLR4 expression and inversely correlated with STMN1 expression within tumors, suggesting possible novel therapeutic targets for immunotherapy in STS.

Characterization of the Tumor Immune Microenvironment in Soft Tissue Sarcoma Patients Undergoing Surgery

Tumor infiltrating lymphocytes (TILs) have been shown to predict survival in soft tissue sarcomas (STS), but the specific contribution of natural killer (NK) and CD8+ T cells to outcomes is undefined. Therefore, we sought to characterize the extent of NK and CD8+ T cell infiltration in STS.

Prospectively, we evaluated 15 patients using fresh tumor from surgery for flow cytometric analysis. Retrospectively, we evaluated archived tumor tissue from 90 STS patients by immunohistochemistry (IHC) for CD3, CD8, CD45RO, NKp46, TIGIT, MHC-I, and p53. We analyzed metastasis-free survival (MFS) and overall survival (OS) by Kaplan-Meier method and log-rank test.

By flow cytometry, we observed significant variability in CD45+ leukocytes in the STS TME (mean 29±24% of total live cells) with low percentages of tumor-infiltrating CD3-CD56+ NK cells (1.7±1.9% of total live cells and 5.3±3.0% of live CD45+ cells) and CD8+ T cells (1.6±1.6% of total live cells and 29.6±30.5% of live CD45+ cells). By IHC, NK and T cell infiltrates were low (median H score 0, range 0–66.5 and 2.7, range 0–110, respectively). We confirmed a positive correlation between CD8+ T cell infiltration and significantly improved OS (P&lt;0.05) and a trend for improved MFS. We also observed a trend for improved OS among patients with higher NKp46 scores (P=0.07). MHC-I expression positively correlated with both T and NK cell infiltration (P&lt;0.05), whereas TIGIT expression positively correlated with T cell infiltration (P&lt;0.05), but not NK infiltration.

Infiltration of NK and CD8+ T cells is overall low in STS patients undergoing surgery but associated with superior OS. Further characterization of the immune infiltrate in STS may yield better biomarkers of prognosis and immune targeting.

Supported by the following grants: NIH/NCI 1R03CA252793 NIH/NCI T32 CA251007-01

Natural Killer and T Cell Infiltration in Canine Osteosarcoma: Clinical Implications and Translational Relevance

Metastatic osteosarcoma has a bleak prognosis in both humans and dogs, and there have been minimal therapeutic advances in recent decades to improve outcomes. Naturally occurring osteosarcoma in dogs is shown to be a highly suitable model for human osteosarcoma, and limited data suggest the similarities between species extend into immune responses to cancer. Studies show that immune infiltrates in canine osteosarcoma resemble those of human osteosarcoma, and the analysis of tumor immune constituents as predictors of therapeutic response is a promising direction for future research. Additionally, clinical studies in dogs have piloted the use of NK transfer to treat osteosarcoma and can serve as valuable precursors to clinical trials in humans. Cytotoxic lymphocytes in dogs and humans with osteosarcoma have increased activation and exhaustion markers within tumors compared with blood. Accordingly, NK and T cells have complex interactions among cancer cells and other immune cells, which can lead to changes in pathways that work both for and against the tumor. Studies focused on NK and T cell interactions within the tumor microenvironment can open the door to targeted therapies, such as checkpoint inhibitors. Specifically, PD-1/PD-L1 checkpoint expression is conserved across tumors in both species, but further characterization of PD-L1 in canine osteosarcoma is needed to assess its prognostic significance compared with humans. Ultimately, a comparative understanding of T and NK cells in the osteosarcoma tumor microenvironment in both dogs and humans can be a platform for translational studies that improve outcomes in both dogs and humans with this frequently aggressive disease.

Surgical and oncologic outcomes following arterial resection and reconstruction for advanced solid tumors

BACKGROUND AND OBJECTIVES

Although arterial involvement for advanced tumors is rare, vascular resection may be indicated to achieve complete tumor resection. Given the potential morbidity of this approach, we sought to evaluate perioperative outcomes, vascular graft patency, and survival among patients undergoing tumor excision with en bloc arterial resection and reconstruction.

METHODS

From 2010 to 2020, we identified nine patients with tumors encasing or extensively abutting major arterial structures for whom en bloc arterial resection and reconstruction was performed.

RESULTS

Mean age was 53 ± 20 years, and 89% were females. Diagnoses were primary sarcomas (5), recurrent gynecologic carcinomas (3), and benign retroperitoneal fibrosis (1). Tumors involved the infrarenal aorta (2), iliac arteries (6), and superficial femoral artery (1). Three patients (33%) had severe perioperative morbidity (Grade III + ) with no mortality. At a median follow-up of 23 months, eight patients (89%) had primary graft patency, and five patients (56%) had no evidence of disease.

CONCLUSIONS

Arterial resection and reconstruction as part of the multimodality treatment of regionally advanced tumors is associated with acceptable short- and long-term outcomes, including excellent graft patency. In appropriately selected patients, involvement of major arterial structures should not be viewed as a contraindication to attempted curative surgery.

Gene expression analysis of sarcoma-infiltrating NK cells identifies signatures correlating with favorable prognosis and potential new targets for augmenting NK function

Success of current T-cell based immunotherapies in soft tissue sarcomas (STS) is limited while pre-clinical and clinical studies have shown evidence of NK activity in STS. To investigate the effects of the tumor microenvironment (TME) on tumor-infiltrating NK cell gene expression, we isolated circulating and tumor-infiltrating NK and CD3 T cells from sarcoma patients undergoing surgery (N=4) and performed RNA sequencing analysis. Comparing Differential Gene Expression (DGE) of flow-sorted intra-tumoral NK cells to circulating NK cells, we identified upregulation of genes involved in mitogen signaling inhibition (DUSP4) and metabolic function (SMPD3, SLC7A5), but not of genes typically associated with cytotoxic function (e.g. IFNG, GZMB). In contrast, intra-tumoral T cells showed significant upregulation of both activating (CD137) and inhibitory genes (TIM-3) compared to circulating T cells. We then queried the TCGA STS dataset and stratified cases into “NK Activating TME” and “NK Suppressing TME” based on the CIBERSORT NK signature analysis program (based on high or low proportion of activated NK cells, respectively). Patients with NK Activating TME had significantly improved survival compared to NK Suppressive TME (log-rank p = 0.03). DGE identified unique tumor-associated gene ontology between NK activated versus suppressive subsets with upregulation of the retinoic acid pathway. Unlike T cells which demonstrate significant DGE between circulating and tumor-infiltrating subsets, NK cells appear to have similar gene expression between blood and tumor. Therefore, although NK cells appear to be prognostic in STS, their anti-tumor effects may be dictated by systemic rather than local factors.

Fetal endoscopic tracheal occlusion reduces pulmonary hypertension in severe congenital diaphragmatic hernia

OBJECTIVE

Fetal endoscopic tracheal occlusion (FETO) is associated with increased perinatal survival and reduced need for extracorporeal membrane oxygenation (ECMO) in fetuses with severe congenital diaphragmatic hernia (CDH). This study evaluates the impact of FETO on the resolution of pulmonary hypertension (PH) in fetuses with isolated CDH.

METHODS

We reviewed retrospectively the medical records of all fetuses evaluated for CDH between January 2004 and July 2017 at a single institution. Fetuses with additional major structural or chromosomal abnormalities were excluded. CDH cases were classified retrospectively into mild, moderate and severe groups based on prenatal magnetic resonance imaging indices (observed-to-expected total fetal lung volume and percentage of intrathoracic liver herniation). Presence of PH was determined based on postnatal echocardiograms. Logistic regression analyses were performed to evaluate the relationship between FETO and resolution of PH by 1 year of age while controlling for side of the CDH, use of ECMO, gestational age at diagnosis, gestational age at delivery, fetal gender, sildenafil use at discharge and CDH severity. Resolution of PH by 1 year of age was compared between a cohort of fetuses with severe CDH that underwent FETO and a cohort that did not have the procedure (non-FETO). A subanalysis was performed restricting the analysis to isolated left CDH. Parametric and non-parametric tests were used for comparisons.

RESULTS

Of 257 CDH cases evaluated, 72% (n = 184) had no major structural or chromosomal anomalies of which 58% (n = 107) met the study inclusion criteria. The FETO cohort consisted of 19 CDH cases and the non-FETO cohort (n = 88) consisted of 31 (35%) mild, 32 (36%) moderate and 25 (28%) severe CDH cases. All infants with severe CDH, regardless of whether they underwent FETO, had evidence of neonatal PH. FETO (OR, 3.57; 95% CI, 1.05-12.10; P = 0.041) and ECMO (OR, 5.01; 95% CI, 2.10-11.96; P < 0.001) were independent predictors of resolution of PH by 1 year of age. A higher proportion of infants with severe CDH that underwent FETO had resolution of PH by 1 year after birth compared with infants with severe CDH in the non-FETO cohort (69% (11/16) vs 28% (7/25); P = 0.017). Similar results were observed when the analysis was restricted to cases with left-sided CDH (PH resolution in 69% (11/16) vs 28% (5/18); P = 0.032).

CONCLUSION

In infants with severe CDH, FETO and ECMO are independently associated with increased resolution of PH by 1 year of age. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

A prospective randomized evaluation of three schedules of mesna administration in patients receiving an ifosfamide-containing chemotherapy regimen: sustained efficiency and simplified administration

Chemotherapy with oxazaphosphorines, such as ifosfamide, is often limited by unacceptable urotoxicity. Without uroprotection hemorrhagic cystitis becomes dose-limiting. Mesna, a thiol compound, is a drug able to bind the toxic metabolites, forming nontoxic compounds in the urine. A total of 122 patients were enrolled in this study and 228 chemotherapy cycles with an ifosfamide-containing regimen were performed (225 evaluable). Mesna was given at the same total dose as the ifosfamide in all arms. On arm A, mesna was given i. v. in equal doses 15 min before and 4 h and 8 h following the ifosfamide dose. On arm B, mesna was given in three equivalent doses 15 min before (i.v.) and 4 h (i.v.) and 8 h (p.o., double dose) following ifosfamide. On arm C, mesna was given i.v. in two equal doses given 15 min before and 4 h following. The incidence of urotoxicity was very low (lower than 15%) in the three arms, 0% in A, 1.36% in B and 2.70% in C. All three arms were equally efficient. Schedule C was considered superior to the others, since it was equally effective, simpler and more convenient.

[Nutritional assessment of children 0 to 5 years old cared for by the municipal network of urban health of the southern region of Brazil, 1988]

An epidemiological survey was undertaken to fulfil one of the conditions required for the establishment of the Nutritional Surveillance System, on the basis of data from 1988. In this survey an anthropometric examination was employed for the purpose of discovering the prevalence and the kinds of protein energy malnutrition among children under five years of age who had been assisted at Health Centers of the Municipal Health Department of Curitiba, Paraná (Brazil). Of a sample population of 4,213 children it was found (by the Gòmez criterion) that 28.1% had malnutrition 3.6% of this percentage being of second or third degree. By the use of the Seoane-Latham criterion as modified by Batista Filho, 19.7% of the children presented some kind of malnutrition. The distribution of the sample in centiles showed that it contained an excess of children in the first centiles after 6 th months of age as compared with the reference population. This excess was more evident in the 12 to 24-months age group.