Axl and MerTK regulate synovial inflammation and are modulated by IL-6 inhibition in rheumatoid arthritis

The TAM tyrosine kinases, Axl and MerTK, play an important role in rheumatoid arthritis (RA). Here, using a unique synovial tissue bioresource of patients with RA matched for disease stage and treatment exposure, we assessed how Axl and MerTK relate to synovial histopathology and disease activity, and their topographical expression and longitudinal modulation by targeted treatments. We show that in treatment-naive patients, high AXL levels are associated with pauci-immune histology and low disease activity and inversely correlate with the expression levels of pro-inflammatory genes. We define the location of Axl/MerTK in rheumatoid synovium using immunohistochemistry/fluorescence and digital spatial profiling and show that Axl is preferentially expressed in the lining layer. Moreover, its ectodomain, released in the synovial fluid, is associated with synovial histopathology. We also show that Toll-like-receptor 4-stimulated synovial fibroblasts from patients with RA modulate MerTK shedding by macrophages. Lastly, Axl/MerTK synovial expression is influenced by disease stage and therapeutic intervention, notably by IL-6 inhibition. These findings suggest that Axl/MerTK are a dynamic axis modulated by synovial cellular features, disease stage and treatment.

Tamoxifen-predictive value of gene expression signatures in premenopausal breast cancer: data from the randomized SBII:2 trial

BACKGROUND

Gene expression (GEX) signatures in breast cancer provide prognostic information, but little is known about their predictive value for tamoxifen treatment. We examined the tamoxifen-predictive value and prognostic effects of different GEX signatures in premenopausal women with early breast cancer.

METHODS

RNA from formalin-fixed paraffin-embedded tumor tissue from premenopausal women randomized between two years of tamoxifen treatment and no systemic treatment was extracted and successfully subjected to GEX profiling (n = 437, NanoString Breast Cancer 360™ panel). The median follow-up periods for a recurrence-free interval (RFi) and overall survival (OS) were 28 and 33 years, respectively. Associations between GEX signatures and tamoxifen effect were assessed in patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+ /HER2-) tumors using Kaplan-Meier estimates and Cox regression. The prognostic effects of GEX signatures were studied in the entire cohort. False discovery rate adjustments (q-values) were applied to account for multiple hypothesis testing.

RESULTS

In patients with ER+/HER2- tumors, FOXA1 expression below the median was associated with an improved effect of tamoxifen after 10 years with regard to RFi (hazard ratio [HR]FOXA1(high) = 1.04, 95% CI = 0.61-1.76, HRFOXA1(low) = 0.30, 95% CI = 0.14-0.67, qinteraction = 0.0013), and a resembling trend was observed for AR (HRAR(high) = 1.15, 95% CI = 0.60-2.20, HRAR(low) = 0.42, 95% CI = 0.24-0.75, qinteraction = 0.87). Similar patterns were observed for OS. Tamoxifen was in the same subgroup most beneficial for RFi in patients with low ESR1 expression (HRRFi ESR1(high) = 0.76, 95% CI = 0.43-1.35, HRRFi, ESR1(low) = 0.56, 95% CI = 0.29-1.06, qinteraction = 0.37). Irrespective of molecular subtype, higher levels of ESR1, Mast cells, and PGR on a continuous scale were correlated with improved 10 years RFi (HRESR1 = 0.80, 95% CI = 0.69-0.92, q = 0.005; HRMast cells = 0.74, 95% CI = 0.65-0.85, q < 0.0001; and HRPGR = 0.78, 95% CI = 0.68-0.89, q = 0.002). For BC proliferation and Hypoxia, higher scores associated with worse outcomes (HRBCproliferation = 1.54, 95% CI = 1.33-1.79, q < 0.0001; HRHypoxia = 1.38, 95% CI = 1.20-1.58, q < 0.0001). The results were similar for OS.

CONCLUSIONS

Expression of FOXA1 is a promising predictive biomarker for tamoxifen effect in ER+/HER2- premenopausal breast cancer. In addition, each of the signatures BC proliferation, Hypoxia, Mast cells, and the GEX of AR, ESR1, and PGR had prognostic value, also after adjusting for established prognostic factors. Trial registration This trial was retrospectively registered in the ISRCTN database the 6th of December 2019, trial ID: https://clinicaltrials.gov/ct2/show/ISRCTN12474687 .

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression toward severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.

Neoadjuvant enoblituzumab in localized prostate cancer: a single-arm, phase 2 trial

B7 homolog 3 (B7-H3; CD276), a tumor-associated antigen and possible immune checkpoint, is highly expressed in prostate cancer (PCa) and is associated with early recurrence and metastasis. Enoblituzumab is a humanized, Fc-engineered, B7-H3-targeting antibody that mediates antibody-dependent cellular cytotoxicity. In this phase 2, biomarker-rich neoadjuvant trial, 32 biological males with operable intermediate to high-risk localized PCa were enrolled to evaluate the safety, anti-tumor activity and immunogenicity of enoblituzumab when given before prostatectomy. The coprimary outcomes were safety and undetectable prostate-specific antigen (PSA) level (PSA0) 1 year postprostatectomy, and the aim was to obtain an estimate of PSA0 with reasonable precision. The primary safety endpoint was met with no notable unexpected surgical or medical complications, or surgical delay. Overall, 12% of patients experienced grade 3 adverse events and no grade 4 events occurred. The coprimary endpoint of the PSA0 rate 1 year postprostatectomy was 66% (95% confidence interval 47-81%). The use of B7-H3-targeted immunotherapy in PCa is feasible and generally safe and preliminary data suggest potential clinical activity. The present study validates B7-H3 as a rational target for therapy development in PCa with larger studies planned. The ClinicalTrials.gov identifier is NCT02923180.

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression towards severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.

Modulation of BCL-2 in both T Cells and Tumor Cells to Enhance Chimeric Antigen Receptor T cell Immunotherapy against Cancer

Chimeric Antigen Receptor T-cell (CART) immunotherapy led to unprecedented responses in patients with refractory/relapsed B-cell non-Hodgkin lymphoma (NHL); nevertheless, two-thirds of patients fail this treatment. Resistance to apoptosis is a key feature of cancer cells that associates with treatment failure. In 87 NHL patients treated with anti-CD19 CART, we found that chromosomal alteration of BCL-2, a critical anti-apoptotic regulator, in lymphoma cells was associated with reduced survival. Therefore, we combined CART19 with the FDA-approved BCL-2-inhibitor, venetoclax, and demonstrated in vivo synergy in venetoclax-sensitive NHL. However, higher venetoclax doses for venetoclax-resistant lymphomas resulted in CART toxicity. To overcome this limitation, we developed venetoclax-resistant CART by overexpressing mutated BCL-2(F104L) which is not recognized by venetoclax. Notably, BCL-2(F104L)-CART19 synergized with venetoclax in multiple lymphoma xenograft models. Furthermore, we uncovered that BCL-2 overexpression in T cells per se enhanced CART anti-tumor activity in preclinical models and in patients by prolonging CART persistence.

Rituximab versus tocilizumab in rheumatoid arthritis: synovial biopsy-based biomarker analysis of the phase 4 R4RA randomized trial

Patients with rheumatoid arthritis (RA) receive highly targeted biologic therapies without previous knowledge of target expression levels in the diseased tissue. Approximately 40% of patients do not respond to individual biologic therapies and 5-20% are refractory to all. In a biopsy-based, precision-medicine, randomized clinical trial in RA (R4RA; n = 164), patients with low/absent synovial B cell molecular signature had a lower response to rituximab (anti-CD20 monoclonal antibody) compared with that to tocilizumab (anti-IL6R monoclonal antibody) although the exact mechanisms of response/nonresponse remain to be established. Here, in-depth histological/molecular analyses of R4RA synovial biopsies identify humoral immune response gene signatures associated with response to rituximab and tocilizumab, and a stromal/fibroblast signature in patients refractory to all medications. Post-treatment changes in synovial gene expression and cell infiltration highlighted divergent effects of rituximab and tocilizumab relating to differing response/nonresponse mechanisms. Using ten-by-tenfold nested cross-validation, we developed machine learning algorithms predictive of response to rituximab (area under the curve (AUC) = 0.74), tocilizumab (AUC = 0.68) and, notably, multidrug resistance (AUC = 0.69). This study supports the notion that disease endotypes, driven by diverse molecular pathology pathways in the diseased tissue, determine diverse clinical and treatment-response phenotypes. It also highlights the importance of integration of molecular pathology signatures into clinical algorithms to optimize the future use of existing medications and inform the development of new drugs for refractory patients.

Phase 1 trial of cyclosporine for hospitalized patients with COVID-19

BACKGROUND

Coronavirus Disease 2019 (COVID-19) remains a global health emergency with limited treatment options, lagging vaccine rates, and inadequate healthcare resources in the face of an ongoing calamity. The disease is characterized by immune dysregulation and cytokine storm. Cyclosporine A (CSA) is a calcineurin inhibitor that modulates cytokine production and may have direct antiviral properties against coronaviruses.

METHODS

To test whether a short course of CSA was safe in COVID-19 patients, we treated 10 hospitalized, oxygen requiring, non-critically ill patients with CSA (starting dose of 9mg/kg/day). We evaluated patients for clinical response and adverse events and measured serum cytokines and chemokines associated with COVID-19 hyper-inflammation and conducted gene-expression analyses.

RESULTS

Five subjects experienced adverse events, none were serious; transaminitis was most common. No subject required intensive care unit (ICU)-level care and all patients were discharged alive. CSA treatment was associated with significant reductions in serum cytokines and chemokines important in COVID-19 hyper-inflammation, including CXCL10. Following CSA administration, we also observed a significant reduction in type I interferon gene expression signatures and other transcriptional profiles associated with exacerbated hyper-inflammation in the peripheral blood cells of these patients.

CONCLUSIONS

Short courses of CSA appear safe and feasible in COVID-19 patients requiring oxygen and may be a useful adjunct in resource-limited health care settings.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov (IND#149997, ClinicalTrials.gov identifier: NCT04412785).

FUNDING

This study was internally funded by the Center for Cellular Immunotherapies.

PAM50 subtyping and ROR score add long-term prognostic information in premenopausal breast cancer patients

PAM50 intrinsic subtyping and risk of recurrence (ROR) score are approved for risk profiling in postmenopausal women. We aimed to examine their long-term prognostic value in terms of breast cancer-free interval (BCFi) and overall survival (OS) (n = 437) in premenopausal women randomised to 2 years of tamoxifen versus no systemic treatment irrespective of hormone-receptor status. Intrinsic subtyping added independent prognostic information in patients with oestrogen receptor-positive/human epidermal growth factor 2-negative tumours for BCFi and OS after maximum follow-up (overall P-value 0.02 and 0.006, respectively) and those with high versus low ROR had worse prognosis (maximum follow-up: hazard ratio (HR)_BCFi: 1.70, P = 0.04). The prognostic information by ROR was similar regarding OS and in multivariable analysis. These results support that PAM50 subtyping and ROR score provide long-term prognostic information in premenopausal women. Moreover, tamoxifen reduced the incidence of breast cancer events only in patients with Luminal A_PAM50 tumours (0–10 years: HR_{BCFi(Luminal A)}: 0.41, HR_{BCFi(Luminal B)}: 1.19, P_interaction = 0.02).

Trial registration: This trial is registered in the ISRCTN database, trial ID: ISRCTN12474687.

Abstract P2-07-13: High-dimensional, single-cell analysis and transcriptional profiling reveal novel correlatives of response to PARP inhibition plus PD-1 blockade in triple-negative breast cancer

Background: TOPACIO was a phase I/II study evaluating the PARP inhibitor (PARPi) niraparib in combination with the anti-PD-1 antibody pembrolizumab in patients with locally advanced and metastatic triple-negative breast cancer (TNBC, n=55) and ovarian cancer irrespective of BRCA mutation status. In the efficacy-evaluable population (n=47) the objective response rate (ORR) was 21% and disease control rate (DCR) 49%. Although activity was greater in patients with BRCA mutations (7/15, ORR=47% and 12/15, DCR=80%), durable clinical benefit was seen in patients with wild-type BRCA tumors (3/27, ORR=11% and 9/27, DCR=33%). In a limited cohort of 20 patients with durable clinical benefit, there were 8 BRCA wildtype patients, four of whom had mutations in genes associated with the homologous recombination repair and other DNA damage repair pathways. Pre-treatment tissues were collected and evaluated for tumor PD-L1 status. Patients with PD-L1 positive tumors (28/47, 60%) had a higher response rate (9/28, ORR=32%) than those with PD-L1 negative tumors (1/13, ORR=8%; 6 tumors had unknown PD-L1 status). It remains unstudied whether the tumor’s gene expression profile or immune status in baseline biospecimens is predictive of treatment response. In this study we conducted exploratory biomarker analyses to test the hypothesis that gene expression patterns and immune status are associated with treatment response. Methods: Transcriptional profiling of baseline samples was performed using the BC360 (n=41) and PanCancer IO360 (n=42) panels (Nanostring) and multigene signatures were used to measure tumor and immune activities as well as relative immune cell abundance. Transcriptional analysis was paired with high-dimensional, single-cell cyclic immunofluorescence (CyCIF) of samples that had adequate tissue for analysis (n=19) to characterize the composition and topology of the immune microenvironment at single-cell resolution. Results: Nanostring transcriptional analysis revealed that PAM50 genes stratified tumor samples into 4 subgroups with distinct histology as determined by CyCIF. Each subgroup was capable of responding to niraparib plus pembrolizumab. Multiple genes involved in WNT signaling (WNT5B, TANKS1, TANKS2, PARP4, and NET02) were associated with favorable clinical responses. Low neuropilin and tolloid-like protein 2 (NETO2) gene expression was strongly correlated with favorable progression free survival (PFS; R=-0.61, p=0.0008, Spearman’s correlation), suggesting it may be a predictive biomarker of therapeutic response. Nanostring gene expression signatures for tumor inflammation, apoptosis, and inflammatory chemokines also distinguished responders from non-responders (p&lt;0.05). CyCIF analysis performed on whole tissue sections accounting for 2.97 million single cells revealed 43 distinct cell-states comprising the tumor microenvironment. PD1+CD4+ T cells were significantly correlated with extended PFS (R=0.65, p=0.006, Spearman’s correlation). However, PD1+CD4+ T cells were less abundant in patients who continue to respond to the therapy (2.7-fold reduced, p=0.004), suggesting two groups of responders. Conclusion: WNT signaling, NETO2 and PD1+CD4 T cells are candidate biomarkers for predicting response to niraparib plus pembrolizumab. Further studies are underway to characterize the biological underpinnings of these correlative findings.

Citation Format: Jennifer L Guerriero, Gregory J Baker, Jia-Ren Lin, Yu-An Chen, Ricardo Pastorello, Tuulia Vallius, Janae Davis, Clarence Yapp, Sarah E Church, Eric Miller, Anniina Färkkilä, Shaveta Vinayak, Melinda L Telli, Giulia Fulci, Alan D'Andrea, Geoffrey I Shapiro, Sara M Tolaney, Sandro Santagata, Peter K Sorger, Elizabeth A Mittendorf. High-dimensional, single-cell analysis and transcriptional profiling reveal novel correlatives of response to PARP inhibition plus PD-1 blockade in triple-negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-07-13.

Abstract P1-05-02: Intratumor molecular tumor heterogeneity in low ER-expressing primary breast tumors

Background: Change in estrogen receptor (ER) status between primary breast cancer and distant recurrence are seen in the clinic in up to 15-20% of patients. This is difficult to reconcile with the current understanding of breast cancer molecular subtypes, the large-scale molecular differences between ER-positive (ER+) and ER-negative (ER-) cancers suggest different cellular origins, luminal versus basal breast epithelium, respectively. A potential explanation for ER status switch is the presence of mixed molecular subtypes at diagnosis. ER+ cancers with less than 100% positivity may be composed by both luminal and basal-like cancer cells, and a recurrence might arise from one subtype that survived adjuvant therapy. The goal of this study was to test if molecular subtype heterogeneity exists at diagnosis in less than 100% ER+ breast cancer using the NanoString GeoMx™ platform. Methods: GeoMx™ is a highly multiplexed assay that quantifies RNA expression from spatially discrete regions of interest (ROIs) within formalin fixed paraffin embedded (FFPE) tissue sections. We identified 4 cancers with 30-40% ER-positivity on routine immunohistochemistry (IHC) staining (clone SP1). Eight ROIs per case were selected to represent both ER-high and -low regions of the section using ER IHC (clone 1D5). Invasive tumor cells were defined as PanCK positive cells. 1,825 mRNA species were measured separately in each ROI. mRNA expression results (unique molecular index [UMI] counts) were quantile normalized and differential expression analyses for all genes, ESR1, ER-regulated gene set, and PAM50 gene set were performed between ROIs within the same cancer. We also assessed PAM50 subtypes of each cases on bulk RNA using NanoString BC360 panel. Results: Three of the 4 cases had heterogenous ER IHC (1D5) staining; the fourth case was uniformly ER-negative during ROI selection. For this last case, ROIs were selected based on PanCK staining from different locations in the cancer. Bulk PAM50 subtyping indicated 1 basal-like, 2 HER2-enriched (HER2-E), and 1 luminal (lum)A cancer. We also attempted ROI-level subtyping; however, Pearson correlations to the nearest centroid were low (&lt;0.5) for all ROIs, possibly due to low expression of PAM50 genes or to the exploratory methodology used. There was substantial within cancer, between ROI, expression heterogeneity for many genes including ESR1 and sensitivity to endocrine therapy (SET) index genes. Conclusions: ER- and ER+ cells are intermixed which makes defining low and high ER regions challenging. We observed region to region variation in ESR1 and SET index gene expression. ROI-level PAM50 subtyping was unstable. The novel NanoString GeoMx™ DSP technology can be used to study intratumor molecular heterogeneity in regions of interest on FFPE breast cancer tissue sections. We found substantial region-to-region gene expression differences within tissue sections.

Case ID1234ER IHC SP130%40%40%30%ER IHC 1D50%40%40%30%Bulk PAM50 SubtypeBasalHER2-ELumAHER2-EESR1 UMI average (range across ROIs)28.45 (22.4-34.6)64.9 (18.8-173)179.9 (114-245)34.8 (25.1-45.4)SET Index (genes positively correlated with ESR1) UMI average (range across ROIs)41.5 (39.1-44.8)120.1 (86.9-182.9)94.9 (72.9-118.4)143.5 (124.9-150.3)SET Index (genes negatively correlated with ESR1) UMI average (range across ROIs)57.6 (45-75.3)43.4 (38.8-52.6)33.7 (31.8-36.7)44.8 (41.4-50.6)

Citation Format: Julia Foldi, Emily Reisenbichler, Liuliu Pan, Krsitina Sorg, Sarah E. Church, Lajos Pusztai. Intratumor molecular tumor heterogeneity in low ER-expressing primary breast tumors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-05-02.

The tumor immune microenvironment of primary and metastatic HER2- positive breast cancers utilizing gene expression and spatial proteomic profiling

BACKGROUND

The characterization of the immune component of the tumor microenvironment (TME) of human epidermal growth factor receptor 2 positive (HER2+) breast cancer has been limited. Molecular and spatial characterization of HER2+ TME of primary, recurrent, and metastatic breast tumors has the potential to identify immune mediated mechanisms and biomarker targets that could be used to guide selection of therapies.

METHODS

We examined 15 specimens from eight patients with HER2+ breast cancer: 10 primary breast tumors (PBT), two soft tissue, one lung, and two brain metastases (BM). Using molecular profiling by bulk gene expression TME signatures, including the Tumor Inflammation Signature (TIS) and PAM50 subtyping, as well as spatial characterization of immune hot, warm, and cold regions in the stroma and tumor epithelium using 64 protein targets on the GeoMx Digital Spatial Profiler.

RESULTS

PBT had higher infiltration of immune cells relative to metastatic sites and higher protein and gene expression of immune activation markers when compared to metastatic sites. TIS scores were lower in metastases, particularly in BM. BM also had less immune infiltration overall, but in the stromal compartment with the highest density of immune infiltration had similar levels of T cells that were less activated than PBT stromal regions suggesting immune exclusion in the tumor epithelium.

CONCLUSIONS

Our findings show stromal and tumor localized immune cells in the TME are more active in primary versus metastatic disease. This suggests patients with early HER2+ breast cancer could have more benefit from immune-targeting therapies than patients with advanced disease.

Best Practices for Spatial Profiling for Breast Cancer Research with the GeoMx® Digital Spatial Profiler

Breast cancer is a heterogenous disease with variability in tumor cells and in the surrounding tumor microenvironment (TME). Understanding the molecular diversity in breast cancer is critical for improving prediction of therapeutic response and prognostication. High-plex spatial profiling of tumors enables characterization of heterogeneity in the breast TME, which can holistically illuminate the biology of tumor growth, dissemination and, ultimately, response to therapy. The GeoMx Digital Spatial Profiler (DSP) enables researchers to spatially resolve and quantify proteins and RNA transcripts from tissue sections. The platform is compatible with both formalin-fixed paraffin-embedded and frozen tissues. RNA profiling was developed at the whole transcriptome level for human and mouse samples and protein profiling of 100-plex for human samples. Tissue can be optically segmented for analysis of regions of interest or cell populations to study biology-directed tissue characterization. The GeoMx Breast Cancer Consortium (GBCC) is composed of breast cancer researchers who are developing innovative approaches for spatial profiling to accelerate biomarker discovery. Here, the GBCC presents best practices for GeoMx profiling to promote the collection of high-quality data, optimization of data analysis and integration of datasets to advance collaboration and meta-analyses. Although the capabilities of the platform are presented in the context of breast cancer research, they can be generalized to a variety of other tumor types that are characterized by high heterogeneity.

Immune landscapes predict chemotherapy resistance and immunotherapy response in acute myeloid leukemia

Acute myeloid leukemia (AML) is a molecularly and clinically heterogeneous hematological malignancy. Although immunotherapy may be an attractive modality to exploit in patients with AML, the ability to predict the groups of patients and the types of cancer that will respond to immune targeting remains limited. This study dissected the complexity of the immune architecture of AML at high resolution and assessed its influence on therapeutic response. Using 442 primary bone marrow samples from three independent cohorts of children and adults with AML, we defined immune-infiltrated and immune-depleted disease classes and revealed critical differences in immune gene expression across age groups and molecular disease subtypes. Interferon (IFN)-γ-related mRNA profiles were predictive for both chemotherapy resistance and response of primary refractory/relapsed AML to flotetuzumab immunotherapy. Our compendium of microenvironmental gene and protein profiles provides insights into the immuno-biology of AML and could inform the delivery of personalized immunotherapies to IFN-γ-dominant AML subtypes.

Flotetuzumab as salvage immunotherapy for refractory acute myeloid leukemia

Approximately 50% of acute myeloid leukemia (AML) patients do not respond to induction therapy (primary induction failure [PIF]) or relapse after <6 months (early relapse [ER]). We have recently shown an association between an immune-infiltrated tumor microenvironment (TME) and resistance to cytarabine-based chemotherapy but responsiveness to flotetuzumab, a bispecific DART antibody-based molecule to CD3ε and CD123. This paper reports the results of a multicenter, open-label, phase 1/2 study of flotetuzumab in 88 adults with relapsed/refractory AML: 42 in a dose-finding segment and 46 at the recommended phase 2 dose (RP2D) of 500 ng/kg per day. The most frequent adverse events were infusion-related reactions (IRRs)/cytokine release syndrome (CRS), largely grade 1-2. Stepwise dosing during week 1, pretreatment dexamethasone, prompt use of tocilizumab, and temporary dose reductions/interruptions successfully prevented severe IRR/CRS. Clinical benefit accrued to PIF/ER patients showing an immune-infiltrated TME. Among 30 PIF/ER patients treated at the RP2D, the complete remission (CR)/CR with partial hematological recovery (CRh) rate was 26.7%, with an overall response rate (CR/CRh/CR with incomplete hematological recovery) of 30.0%. In PIF/ER patients who achieved CR/CRh, median overall survival was 10.2 months (range, 1.87-27.27), with 6- and 12-month survival rates of 75% (95% confidence interval [CI], 0.450-1.05) and 50% (95% CI, 0.154-0.846). Bone marrow transcriptomic analysis showed that a parsimonious 10-gene signature predicted CRs to flotetuzumab (area under the receiver operating characteristic curve = 0.904 vs 0.672 for the European LeukemiaNet classifier). Flotetuzumab represents an innovative experimental approach associated with acceptable safety and encouraging evidence of activity in PIF/ER patients. This trial was registered at www.clinicaltrials.gov as #NCT02152956.

Abstract 6679: Immunophenotypic and transcriptome analyses of CT26 and 4T1 murine tumor models following anti-CTLA-4 treatment

Model selection for evaluation of immuno-oncology agents is often aided by both response to therapy and changes in immune cell subsets following treatment. To identify underlying factors that influence differences in therapeutic response, CT26 colorectal and 4T1-Luc (4T1) breast tumor models, which are immunologically warm and cold, respectively, were treated with anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4). Flow cytometry and transcriptome analysis were used to describe treatment-related changes in immune cell infiltrate, TIL activation status, cytokine/granzyme B production, and overall changes in gene expression. Response to anti-CTLA-4 therapy was distinct between these models. Tumor growth inhibition was observed in CT26 (74%), but not 4T1. In CT26, CD8+ and NK T cell infiltration increased, while M2 macrophages decreased. In 4T1 tumors, only increased NKT cell infiltration was noted after treatment, and no demonstrable changes were observed in any other cell type or activation marker. Several pharmacodynamic changes in immune cell activation were observed in CT26. Notably, CT26-derived CD4+, CD8+, and NK T cell subsets had increased IFNγ production (70%, 25%, and 17%, respectively, versus control). An increase in polyfunctional T cells producing both IFNγ and TNFα was also noted for CT26 and was correlated with slower tumor growth. Granzyme B was reduced and CD107a was increased in CT26-derived NK T cells, suggesting functionally active T cells. This was also supported by upregulation of genes in the cytotoxicity, antigen presentation, and NFkappaB pathways.

Following CT26 treatment with anti-CTLA-4, transcriptome analysis with the nCounter® Mouse PanCancer IO 360 Panel (NanoString) showed an 8-10 fold induction of several T cell-related genes as well as an 8-14 fold induction of several chemokines and their receptors. These data complement the flow cytometry data and support stimulation of T cell activation and recruitment to CT26 tumors following anti-CTLA-4 treatment. In contrast, analysis of 4T1 tumors indicated only a 2 to 3-fold induction of CCL4, CCL11, and Granzyme A after treatment. Interestingly, genes in the matrix remodeling pathway were upregulated in 4T1 tumors upon anti-CTLA-4 treatment.

In summary, CT26 tumors were responsive to anti-CTLA-4 treatment, showing increased polyfunctional T cell recruitment, NK T cell activity, and reduced M2 macrophage infiltration, as well as marked upregulation of several genes involved in T cell recruitment and activation in tumor. In contrast, 4T1 tumors did not display any remarkable response to therapy, changes to TIL infiltrates, and only limited changes to gene expression with treatment. Collectively, these results suggest tumor profiles following treatment can provide insight into potential targets of interest and are important for preclinical model selection.

Citation Format: Sheri R. Barnes, David Draper, Sarah E. Church, Maryland Rosenfeld Franklin. Immunophenotypic and transcriptome analyses of CT26 and 4T1 murine tumor models following anti-CTLA-4 treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6679.

Abstract CT035: TP53 abnormalities correlate with immune infiltration and are associated with response to flotetuzumab, an investigational immunotherapy, in acute myeloid leukemia

Background: Acute myeloid leukemia (AML) is a molecularly and clinically heterogeneous disease. TP53 mutations and 17p (TP53) deletions occur in 37-46% of AML cases with adverse risk cytogenetics and are associated with primary induction failure (PIF), high risk of relapse and dismal prognosis. Herein, we aimed to determine whether TP53 abnormalities identify a patient subgroup that may benefit from immunotherapy approaches. Patients and Methods: We used the following transcriptomic data sets and patient cohorts (C) for in silico and wet-lab analyses: 1) The Cancer Genome Atlas (TCGA; 162 adult AML patients, 13 with TP53 mutations); 2) Beat AML Master Trial (281 adult AML patients, 17 with TP53 mutations); 3) HOVON (618 adult AML patients, 14 with TP53 mutations); 4) 24 diagnostic bone marrow (BM) samples from patients with TP53-wild-type AML (Bologna series); 5) 36 diagnostic BM samples from patients with TP53-mutated AML (Studien Allianz Leukämie [SAL] series); 6) 30 BM samples from patients with relapsed/refractory (R/R) AML (10 cases with TP53 mutations and/or 17p deletion) that received immunotherapy with flotetuzumab, a CD123×CD3 bispecific DART molecule (NCT02152956). Microenvironmental immune gene expression profiles (wet-lab cohorts, C4 and C5) were analyzed using the Pan-Cancer IO 360 Panel (NanoString Technologies, Seattle, WA). Immune cell type-specific and biological activity signature scores were computed as recently published (JITC 2017; 5: 18). Results: Compared with TCGA-AML cases (C1) with favorable-risk and intermediate-risk molecular features, all patients with TP53 mutations showed high levels of immune infiltration, including genes associated with adaptive immune responses and an interferon (IFN)-γ-dominant tumor microenvironment (TME), and a higher tumor mutational burden (14 versus 10 mutations on average in patients with TP53-mutated and TP53-wild-type AML, respectively; p=0.02). Similarly, 16 out of 17 (94%) TP53-mutated Beat AML cases (C2) expressed high levels of IFN signaling molecules, CD8 and markers of cytotoxicity (GZMB). Compared with patients with TP53-wild-type AML (C4), primary BM samples from patients with TP53-mutated AML (C5) showed higher levels of CD8A, markers of cellular senescence (EOMES, KLRD1, HRAS), IFN-γ-inducible genes (IRF1) and negative immune checkpoints including LAG3, IDO1, PDL1 and VSIR (VISTA). Interestingly, 10 patients with R/R AML (C6) had TP53 abnormalities and 5 of 6 patients evaluated for immune gene profiles had an immune-infiltrated TME. In patients with TP53 abnormalities, the overall response rate (ORR) was 40% to flotetuzumab (2 patients with CR, 1 patient with CRh, and 1 patient with morphologic leukemia-free state). The overall decrease of BM blasts averaged 42%. Stable disease was observed in 3 patients. Median overall survival (OS) was 3.5 months (range 1.25-21.25), which favorably compares with survival estimates for TP53-mutated cases with PIF in large AML series, such as HOVON (C3; median OS=1.16 months). Conclusions: This study provides evidence for a correlation between IFN-γ-dominant immune subtypes of AML and TP53 abnormalities. The ORR seen in this patient subgroup encourages further study of this immunotherapeutic approach.

Citation Format: Jayakumar Vadakekolathu, Catherine Lai, Stephen Reeder, Sarah E. Church, Tressa Hood, John Muth, Heidi Altmann, Marilena Ciciarello, Antonio Curti, Peter J. Valk, Bob Löwenberg, Martin Bornhäuser, John F. DiPersio, Jan K. Davidson-Moncada, Sergio Rutella. TP53 abnormalities correlate with immune infiltration and are associated with response to flotetuzumab, an investigational immunotherapy, in acute myeloid leukemia [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT035.

Multiplex digital spatial profiling of proteins and RNA in fixed tissue

Digital Spatial Profiling (DSP) is a method for highly multiplex spatial profiling of proteins or RNAs suitable for use on formalin-fixed, paraffin-embedded (FFPE) samples. The approach relies on (1) multiplexed readout of proteins or RNAs using oligonucleotide tags; (2) oligonucleotide tags attached to affinity reagents (antibodies or RNA probes) through a photocleavable (PC) linker; and (3) photocleaving light projected onto the tissue sample to release PC oligonucleotides in any spatial pattern across a region of interest (ROI) covering 1 to ~5,000 cells. DSP is capable of single-cell sensitivity within an ROI using the antibody readout, with RNA detection feasible down to ~600 individual mRNA transcripts. We show spatial profiling of up to 44 proteins and 96 genes (928 RNA probes) in lymphoid, colorectal tumor and autoimmune tissues by using the nCounter system and 1,412 genes (4,998 RNA probes) by using next-generation sequencing (NGS). DSP may be used to profile not only proteins and RNAs in biobanked samples but also immune markers in patient samples, with potential prognostic and predictive potential for clinical decision-making.

Abstract 5006: Comprehensive gene expression analysis of the tumor microenvironment in patients with advanced cancer treated with a personalized neoantigen vaccine, NEO-PV-01, in combination with anti-PD1

Background: Neoantigens arise from DNA mutations in cancer cells and are important targets for T cell mediated anti-tumor immunity. NEO-PV-01 is a personal neoantigen vaccine of up to 20 peptides designed based on a patient’s neoantigen and HLA profile that is directed at inducing tumor-specific T cell responses to neoantigens. Here we report comprehensive immune-related gene expression analysis of longitudinal tumor biopsies from patients with metastatic melanoma, bladder, and non-small cell lung cancer treated on our NT-001 trial with NEO-PV-01 + adjuvant in combination with nivolumab (NCT02897765) to correlate with clinical outcomes.

Methods: Tumor biopsies from all three tumor types were collected i) prior to treatment, ii) after 12 weeks of nivolumab monotherapy and iii) after completion of NEO-PV-01 vaccination. Targeted gene expression analysis on RNA extracted from FFPE blocks was performed using the NanoString™ nCounter platform. A custom set of 800 genes included markers for immune cell populations, cytolytic markers, immune activation and suppression, and the tumor microenvironment. Gene signatures of key immune features were calculated after normalization with housekeeping genes and used for subsequent analysis.

Results: Changes in the immune cell populations and the tumor microenvironment were detected after treatment with nivolumab and NEO-PV-01. Increases in various immune cell subsets, including T cells and B cells, as well as an increase in cytolytic phenotype were observed in tumor biopsies following treatment. Moreover, changes in the tumor microenvironment, consistent with the absence of tumor by histologic evaluation, were detected in many of the post-vaccination biopsies. In addition, these observations were consistent with data from peripheral blood that demonstrated durable de novo neoantigen-specific immune responses after vaccination. Additional exploratory analyses of the data demonstrate differential gene expression in patients’ tumors that align with tumor responses to therapy.

Conclusion: Treatment with nivolumab and NEO-PV-01 leads to changes in the tumor microenvironment that are consistent with cell types and phenotypes that could contribute to an anti-tumor response.

Citation Format: Meghan E. Bushway, Ying Sonia Ting, Rana H. Besada, Tracey E. Sciuto, Jasmina Prabhakara, Julian Scherer, Kristen N. Balogh, April Lamb, Jennifer A. Kaplan, Lisa D. Cleary, Melissa A. Moles, Sarah E. Church, Yuqi Ren, Xing Ren, Richard B. Gaynor, Matthew J. Goldstein, Les H. Brail, Joel Greshock, Lakshmi Srinivasan. Comprehensive gene expression analysis of the tumor microenvironment in patients with advanced cancer treated with a personalized neoantigen vaccine, NEO-PV-01, in combination with anti-PD1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5006.

Toward a comprehensive view of cancer immune responsiveness: a synopsis from the SITC workshop

Tumor immunology has changed the landscape of cancer treatment. Yet, not all patients benefit as cancer immune responsiveness (CIR) remains a limitation in a considerable proportion of cases. The multifactorial determinants of CIR include the genetic makeup of the patient, the genomic instability central to cancer development, the evolutionary emergence of cancer phenotypes under the influence of immune editing, and external modifiers such as demographics, environment, treatment potency, co-morbidities and cancer-independent alterations including immune homeostasis and polymorphisms in the major and minor histocompatibility molecules, cytokines, and chemokines. Based on the premise that cancer is fundamentally a disorder of the genes arising within a cell biologic process, whose deviations from normality determine the rules of engagement with the host's response, the Society for Immunotherapy of Cancer (SITC) convened a task force of experts from various disciplines including, immunology, oncology, biophysics, structural biology, molecular and cellular biology, genetics, and bioinformatics to address the complexity of CIR from a holistic view. The task force was launched by a workshop held in San Francisco on May 14-15, 2018 aimed at two preeminent goals: 1) to identify the fundamental questions related to CIR and 2) to create an interactive community of experts that could guide scientific and research priorities by forming a logical progression supported by multiple perspectives to uncover mechanisms of CIR. This workshop was a first step toward a second meeting where the focus would be to address the actionability of some of the questions identified by working groups. In this event, five working groups aimed at defining a path to test hypotheses according to their relevance to human cancer and identifying experimental models closest to human biology, which include: 1) Germline-Genetic, 2) Somatic-Genetic and 3) Genomic-Transcriptional contributions to CIR, 4) Determinant(s) of Immunogenic Cell Death that modulate CIR, and 5) Experimental Models that best represent CIR and its conversion to an immune responsive state. This manuscript summarizes the contributions from each group and should be considered as a first milestone in the path toward a more contemporary understanding of CIR. We appreciate that this effort is far from comprehensive and that other relevant aspects related to CIR such as the microbiome, the individual's recombined T cell and B cell receptors, and the metabolic status of cancer and immune cells were not fully included. These and other important factors will be included in future activities of the taskforce. The taskforce will focus on prioritization and specific actionable approach to answer the identified questions and implementing the collaborations in the follow-up workshop, which will be held in Houston on September 4-5, 2019.

The Link between the Multiverse of Immune Microenvironments in Metastases and the Survival of Colorectal Cancer Patients

Treatment of metastatic colorectal cancer is based upon the assumption that metastases are homogeneous within a patient. We quantified immune cell types of 603 whole-slide metastases and primary colorectal tumors from 222 patients. Primary lesions, and synchronous and metachronous metastases, had a heterogeneous immune infiltrate and mutational diversity. Small metastases had frequently a low Immunoscore and T and B cell score, while a high Immunoscore was associated with a lower number of metastases. Anti-epidermal growth factor receptor treatment modified immune gene expression and significantly increased T cell densities in the metastasis core. The predictive accuracy of the Immunoscore from a single biopsy was superior to the one of programmed cell death ligand 1 (PD-L1). The immune phenotype of the least-infiltrated metastasis had a stronger association with patient outcome than other metastases.

Dissecting the Immune Landscape of Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a molecularly heterogeneous hematological malignancy with variable response to treatment. Recurring cytogenetic abnormalities and molecular lesions identify AML patient subgroups with different survival probabilities; however, 50⁻70% of AML cases harbor either normal or risk-indeterminate karyotypes. The discovery of better biomarkers of clinical success and failure is therefore necessary to inform tailored therapeutic decisions. Harnessing the immune system against cancer with programmed death-1 (PD-1)-directed immune checkpoint blockade (ICB) and other immunotherapy agents is an effective therapeutic option for several advanced malignancies. However, durable responses have been observed in only a minority of patients, highlighting the need to gain insights into the molecular features that predict response and to also develop more effective and rational combination therapies that address mechanisms of immune evasion and resistance. We will review the state of knowledge of the immune landscape of AML and identify the broad opportunity to further explore this incompletely characterized space. Multiplexed, spatially-resolved immunohistochemistry, flow cytometry/mass cytometry, proteomic and transcriptomic approaches are advancing our understanding of the complexity of AML-immune interactions and are expected to support the design and expedite the delivery of personalized immunotherapy clinical trials.

International validation of the consensus Immunoscore for the classification of colon cancer: a prognostic and accuracy study

BACKGROUND

The estimation of risk of recurrence for patients with colon carcinoma must be improved. A robust immune score quantification is needed to introduce immune parameters into cancer classification. The aim of the study was to assess the prognostic value of total tumour-infiltrating T-cell counts and cytotoxic tumour-infiltrating T-cells counts with the consensus Immunoscore assay in patients with stage I-III colon cancer.

METHODS

An international consortium of 14 centres in 13 countries, led by the Society for Immunotherapy of Cancer, assessed the Immunoscore assay in patients with TNM stage I-III colon cancer. Patients were randomly assigned to a training set, an internal validation set, or an external validation set. Paraffin sections of the colon tumour and invasive margin from each patient were processed by immunohistochemistry, and the densities of CD3+ and cytotoxic CD8+ T cells in the tumour and in the invasive margin were quantified by digital pathology. An Immunoscore for each patient was derived from the mean of four density percentiles. The primary endpoint was to evaluate the prognostic value of the Immunoscore for time to recurrence, defined as time from surgery to disease recurrence. Stratified multivariable Cox models were used to assess the associations between Immunoscore and outcomes, adjusting for potential confounders. Harrell's C-statistics was used to assess model performance.

FINDINGS

Tissue samples from 3539 patients were processed, and samples from 2681 patients were included in the analyses after quality controls (700 patients in the training set, 636 patients in the internal validation set, and 1345 patients in the external validation set). The Immunoscore assay showed a high level of reproducibility between observers and centres (r=0·97 for colon tumour; r=0·97 for invasive margin; p<0·0001). In the training set, patients with a high Immunoscore had the lowest risk of recurrence at 5 years (14 [8%] patients with a high Immunoscore vs 65 (19%) patients with an intermediate Immunoscore vs 51 (32%) patients with a low Immunoscore; hazard ratio [HR] for high vs low Immunoscore 0·20, 95% CI 0·10-0·38; p<0·0001). The findings were confirmed in the two validation sets (n=1981). In the stratified Cox multivariable analysis, the Immunoscore association with time to recurrence was independent of patient age, sex, T stage, N stage, microsatellite instability, and existing prognostic factors (p<0·0001). Of 1434 patients with stage II cancer, the difference in risk of recurrence at 5 years was significant (HR for high vs low Immunoscore 0·33, 95% CI 0·21-0·52; p<0·0001), including in Cox multivariable analysis (p<0·0001). Immunoscore had the highest relative contribution to the risk of all clinical parameters, including the American Joint Committee on Cancer and Union for International Cancer Control TNM classification system.

INTERPRETATION

The Immunoscore provides a reliable estimate of the risk of recurrence in patients with colon cancer. These results support the implementation of the consensus Immunoscore as a new component of a TNM-Immune classification of cancer.

FUNDING

French National Institute of Health and Medical Research, the LabEx Immuno-oncology, the Transcan ERAnet Immunoscore European project, Association pour la Recherche contre le Cancer, CARPEM, AP-HP, Institut National du Cancer, Italian Association for Cancer Research, national grants and the Society for Immunotherapy of Cancer.

The tumor microenvironment and Immunoscore are critical determinants of dissemination to distant metastasis

Although distant metastases account for most of the deaths in cancer patients, fundamental questions regarding mechanisms that promote or inhibit metastasis remain unanswered. We show the impact of mutations, genomic instability, lymphatic and blood vascularization, and the immune contexture of the tumor microenvironment on synchronous metastases in large cohorts of colorectal cancer patients. We observed large genetic heterogeneity among primary tumors, but no major differences in chromosomal instability or key cancer-associated mutations. Similar patterns of cancer-related gene expression levels were observed between patients. No cancer-associated genes or pathways were associated with M stage. Instead, mutations of FBXW7 were associated with the absence of metastasis and correlated with increased expression of T cell proliferation and antigen presentation functions. Analyzing the tumor microenvironment, we observed two hallmarks of the metastatic process: decreased presence of lymphatic vessels and reduced immune cytotoxicity. These events could be the initiating factors driving both synchronous and metachronous metastases. Our data demonstrate the protective impact of the Immunoscore, a cytotoxic immune signature, and increased marginal lymphatic vessels, against the generation of distant metastases, regardless of genomic instability.

Integrative Analyses of Colorectal Cancer Show Immunoscore Is a Stronger Predictor of Patient Survival Than Microsatellite Instability

Microsatellite instability in colorectal cancer predicts favorable outcomes. However, the mechanistic relationship between microsatellite instability, tumor-infiltrating immune cells, Immunoscore, and their impact on patient survival remains to be elucidated. We found significant differences in mutational patterns, chromosomal instability, and gene expression that correlated with patient microsatellite instability status. A prominent immune gene expression was observed in microsatellite-instable (MSI) tumors, as well as in a subgroup of microsatellite-stable (MSS) tumors. MSI tumors had increased frameshift mutations, showed genetic evidence of immunoediting, had higher densities of Th1, effector-memory T cells, in situ proliferating T cells, and inhibitory PD1-PDL1 cells, had high Immunoscores, and were infiltrated with mutation-specific cytotoxic T cells. Multivariate analysis revealed that Immunoscore was superior to microsatellite instability in predicting patients' disease-specific recurrence and survival. These findings indicate that assessment of the immune status via Immunoscore provides a potent indicator of tumor recurrence beyond microsatellite-instability staging that could be an important guide for immunotherapy strategies.

Tumor Microenvironment and Immunotherapy: The Whole Picture Is Better Than a Glimpse

Predicting cancer patients' response to therapy is essential for curing disease and improving quality of life. Garraway and colleagues demonstrate that the frequency and number of neoantigens, non-synonymous mutations, and adaptive immune genes, but not the assessment of individual recurrent neoantigens or mutations, predicts patient responses to immunotherapy.

Tumor-specific CD4+ T cells maintain effector and memory tumor-specific CD8+ T cells

Immunotherapies that augment antitumor T cells have had recent success for treating patients with cancer. Here we examined whether tumor-specific CD4(+) T cells enhance CD8(+) T-cell adoptive immunotherapy in a lymphopenic environment. Our model employed physiological doses of tyrosinase-related protein 1-specific CD4(+) transgenic T cells-CD4(+) T cells and pmel-CD8(+) T cells that when transferred individually were subtherapeutic; however, when transferred together provided significant (p ≤ 0.001) therapeutic efficacy. Therapeutic efficacy correlated with increased numbers of effector and memory CD8(+) T cells with tumor-specific cytokine expression. When combined with CD4(+) T cells, transfer of total (naïve and effector) or effector CD8(+) T cells were highly effective, suggesting CD4(+) T cells can help mediate therapeutic effects by maintaining function of activated CD8(+) T cells. In addition, CD4(+) T cells had a pronounced effect in the early posttransfer period, as their elimination within the first 3 days significantly (p < 0.001) reduced therapeutic efficacy. The CD8(+) T cells recovered from mice treated with both CD8(+) and CD4(+) T cells had decreased expression of PD-1 and PD-1-blockade enhanced the therapeutic efficacy of pmel-CD8 alone, suggesting that CD4(+) T cells help reduce CD8(+) T-cell exhaustion. These data support combining immunotherapies that elicit both tumor-specific CD4(+) and CD8(+) T cells for treatment of patients with cancer.

Note: cryogenic microstripline-on-Kapton microwave interconnects

Simple broadband microwave interconnects are needed for increasing the size of focal plane heterodyne radiometer arrays. We have measured loss and crosstalk for arrays of microstrip transmission lines in flex circuit technology at 297 and 77 K, finding good performance to at least 20 GHz. The dielectric constant of Kapton substrates changes very little from 297 to 77 K, and the electrical loss drops. The small cross-sectional area of metal in a printed circuit structure yields overall thermal conductivities similar to stainless steel coaxial cable. Operationally, the main performance tradeoffs are between crosstalk and thermal conductivity. We tested a patterned ground plane to reduce heat flux.

Multiple vaccinations: friend or foe

Few immunotherapists would accept the concept of a single vaccination inducing a therapeutic anticancer immune response in a patient with advanced cancer. But what is the evidence to support the "more-is-better" approach of multiple vaccinations? Because we are unaware of trials comparing the effect of a single vaccine versus multiple vaccinations on patient outcome, we considered that an anticancer immune response might provide a surrogate measure of the effectiveness of vaccination strategies. Because few large trials include immunologic monitoring, the majority of information is gleaned from smaller trials in which an evaluation of immune responses to vaccine or tumor, before and at 1 or more times following the first vaccine, was performed. In some studies, there is convincing evidence that repeated administration of a specific vaccine can augment the immune response to antigens contained in the vaccine. In other settings, multiple vaccinations can significantly reduce the immune response to 1 or more targets. Results from 3 large adjuvant vaccine studies support the potential detrimental effect of multiple vaccinations as clinical outcomes in the control arms were significantly better than that for treatment groups. Recent research has provided insights into mechanisms that are likely responsible for the reduced responses in the studies noted above, but supporting evidence from clinical specimens is generally lacking. Interpretation of these results is further complicated by the possibility that the dominant immune response may evolve to recognize epitopes not present in the vaccine. Nonetheless, the Food and Drug Administration approval of the first therapeutic cancer vaccine and recent developments from preclinical models and clinical trials provide a substantial basis for optimism and a critical evaluation of cancer vaccine strategies.

Bioavailability of metals in stream food webs and hazards to brook trout (Salvelinus fontinalis) in the upper Animas River watershed, Colorado

The water quality, habitats, and biota of streams in the upper Animas River watershed of Colorado, USA, are affected by metal contamination associated with acid drainage. We determined metal concentrations in components of the food web of the Animas River and its tributaries-periphyton (aufwuchs), benthic invertebrates, and livers of brook trout (Salvelinus fontinalis)-and evaluated pathways of metal exposure and hazards of metal toxicity to stream biota. Concentrations of the toxic metals cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in periphyton, benthic invertebrates, and trout livers from one or more sites in the upper Animas River were significantly greater than those from reference sites. Periphyton from sites downstream from mixing zones of acid and neutral waters had elevated concentrations of aluminum (Al) and iron (Fe) reflecting deposition of colloidal Fe and Al oxides, and reduced algal biomass. Metal concentrations in benthic invertebrates reflected differences in feeding habits and body size among taxa, with greatest concentrations of Zn, Cu, and Cd in the small mayfly Rhithrogena, which feeds on periphyton, and greatest concentrations of Pb in the small stonefly Zapada, a detritivore. Concentrations of Zn and Pb decreased across each trophic linkage, whereas concentrations of Cu and Cd were similar across several trophic levels, suggesting that Cu and Cd were more efficiently transferred via dietary exposure. Concentrations of Cu in invertebrates and trout livers were more closely associated with impacts on trout populations and invertebrate communities than were concentrations of Zn, Cd, or Pb. Copper concentrations in livers of brook trout from the upper Animas River were substantially greater than background concentrations and approached levels associated with reduced brook trout populations in field studies and with toxic effects on other salmonids in laboratory studies. These results indicate that bioaccumulation and transfer of metals in stream food webs are significant components of metal exposure for stream biota of the upper Animas River watershed and suggest that chronic toxicity of Cu is an important factor limiting the distribution and abundance of brook trout populations in the watershed.

Transient response in doped germanium photoconductors under very low background operation

Doped germanium photoconductors are the most sensitive detectors for astronomy in the wavelength range 40-240 µm. Under the extremely low background conditions encountered in cooled satellite instruments, these devices exhibit a number of transient effects, such as slow relaxation after a step change in illumination or bias, and spontaneous spiking at high signal levels. Such behavior can degrade the excellent instantaneous sensitivity of these detectors and create calibration uncertainties. These effects have been observed in the Ge:Be photoconductors and the stressed and unstressed Ge:Ga photoconductors in the Long Wavelength Spectrometer, one of the instruments on the Infrared Space Observatory. A systematic investigation of the transient response of the Long Wavelength Spectrometer detectors to a step change in illumination as a function of operating temperature, bias electric field, and illumination step size has been carried out to determine operating conditions that minimize the effects of this behavior. The transient effects appear to be due primarily to carrier sweep out, but they are not fully explained by existing models for transient response.

Airways obstruction and bronchiectasis: correlation with duration of symptoms and extent of bronchiectasis on computed tomography

Many patients with bronchiectasis have diffuse airways obstruction and this may be the dominant symptom. This study was performed to assess whether the severity of airway obstruction in these patients is related to duration of bronchiectatic symptoms or to the extent of bronchiectasis demonstrated by computed tomography (CT). Twenty-six patients were studied. The severity of airflow obstruction was measured by standard physiological testing and the extent of bronchiectasis demonstrated by CT was assessed using a scoring system. Correlation was measured by Kendall's rank correlation coefficient. A highly significant correlation between FEV1 and CT score was demonstrated and a significant correlation was also observed between FEV1 and duration of symptoms. A weak correlation was present between CT score and symptom duration.

Is resistance to ischaemic conduction failure induced by hypoxia?

Resistance to ischaemic conduction failure is a recognised but unexplained property of diabetic peripheral nerve. We have studied matched groups of control, diabetic, and non-diabetic hypoxic subjects (hypoxia: arterial oxygen tension less than or equal to 60 mm Hg (8 kPa) on at least one occasion and secondary to chronic lung disease). Similar resistance to ischaemia was seen in the hypoxic and diabetic groups compared with control subjects (p less than 0.001). The degree of resistance correlated with arterial oxygen tension at the time of testing (r = 0.72, p less than 0.01). In all individuals with acute exacerbations of hypoxia, the resistance to ischaemia was normalised with improvement of respiratory function (p less than 0.02). These results are compatible with the hypothesis that endoneurial hypoxia may be a factor in the pathogenesis of diabetic neuropathy.

X-ray structure study of thermotropic phases in isoacylphosphatidylcholine multibilayers

Structures of lamellar phases in aqueous dispersions of diisoacylphosphatidylcholines (17iPC and 20iPC) were determined by x-ray diffraction methods. In agreement with previous DSC studies, subgel, gel, and liquid crystal phases were observed in each homolog. The subgel Lc(c') phases of both homologs show significant two-dimensional long range order and can be described by rectangular lattices. The dimensions of the two rectangular unit cells differ in that the side chains are canted (approximately 33 degrees) in the 20iPC homolog, while in 17iPC the side chains are normal to the bilayer plane. The gel L beta phases of 17iPC (Tgg = 17-19.5 degrees C) and 20iPC (Tgg = 44 degrees C) are similar but not identical and are consistent with a distorted, pseudohexagonal lattice for the rotationally disordered side chains. The liquid crystal phases of 17iPC (Tgl = 28 degrees C) and 20iPC (Tgl = 52 degrees C) are structurally similar and are typical of lipids with fluid side chains. Significant but different changes occur in the long spacings at Tgg and Tgl for the two homologs. This implies that interfacial states (particularly in the subgel phases) differ in the two homologs below the liquid crystal phase transition temperature.

Chester porphyria: a clinical study of a new form of acute porphyria

Acute porphyria afflicts a large kindred in Chester that stems from a marriage in 1896 that has produced 200 descendants; this is the largest porphyric kindred to be identified in the United Kingdom. Six members aged 51 or under died from the condition over the past eight years. The diagnosis of porphyria was overlooked in some as the symptoms may mimic those of other acute illnesses, so that incomplete or incorrect death certificates have been issued. Psychosis, hypertension, and renal complications are particularly common. The porphyric members of the kindred show a previously undescribed hereditary disorder in which the characteristic enzymatic defects of acute intermittent porphyria and variegate porphyria coexist in the same subject. Acute porphyria is poorly understood by hospital and general practitioners, and this has caused anxiety in the kindred. A register of the kindred has been established, and families at risk should be offered biochemical screening, education, and genetic counselling.

Chester porphyria: biochemical studies of a new form of acute porphyria

A previously unrecognised form of acute porphyria has been identified in a large family in Chester, UK. Patients presented with attacks of neurovisceral dysfunction and none had experienced cutaneous photosensitivity. Biochemically, the excretion pattern of haem precursors varied between individuals; some had a pattern typical of acute intermittent porphyria, others showed that of variegate porphyria, and some had an intermediate pattern. Studies of the enzymes of haem biosynthesis in peripheral blood cells showed a dual enzyme deficiency, with reduced activity of both porphobilinogen deaminase, as seen in acute intermittent porphyria, and protoporphyrinogen oxidase, as seen in variegate porphyria. The genetic basis of this dual form of acute porphyria and its relation to the other acute porphyrias are not clear.

Structural properties of a monobrominated analog of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine

Hydrated multibilayers of 1-palmitoyl-2-monobromopalmitoyl-sn-glycero-3-phosphorylcholine (BrDPPC), where the 2-chain is brominated at either the C-9 or C-10 position, have been studied by low and wide angle X-ray diffraction methods. Oriented and unoriented samples were investigated. The long spacing was observed over the temperature interval -15 degrees C to 80 degrees C. A monotonic increase from approx. 50 A to approx. 62 A (28 wt. % H2O) occurred with decreasing temperature. The BrDPPC showed no evidence of a sharp gel-to-liquid crystal phase transition. Wide angle scattering showed a diffuse peak corresponding to (4.5 A)-1. Differential scanning calorimetry measurements for hydrated liposomes (50 wt. % H2O) also showed no evidence for a phase transition (-40 less than or equal to T less than or equal to 60 degrees C). These results suggest a low temperature amorphous (glass) state for the acyl side chains of BrDPPC. Monolayer film properties of monobrominated stearic acid also reflect a chain disordering effect occurring upon midchain substitution.