The impact of yeast-encapsulated orange oil in Aedes aegypti oviposition

The yeast-encapsulated orange oil (YEOO) is a novel larvicide under development against vector mosquitoes. Despite its efficiency against Aedes aegypti (L.) in small scale experiments, its applicability in vector control can be influenced by other effects on mosquito behaviour or physiology. For this reason, the impact of YEOO particles in mosquito oviposition was evaluated in laboratory and semi-field conditions. Oviposition assays with one gravid Aedes aegypti female were carried under laboratory and semi-field conditions with natural light and temperature fluctuation. For all ovitraps, the number of eggs was manually counted in the wooden paddle and in the solution of each ovitrap. The proportion of eggs between substrates (wooden paddle and solution) varied between conditions, with females in laboratory presenting a lower preference to lay eggs in paddles when compared with studies in semi-field. This behaviour shifts in laboratory can create challenges to extrapolate results from laboratory to the field. Here, studies in both conditions indicate a similar impact of YEOO particles in Aedes aegypti oviposition. The potential treatment concentration of YEOO particles presents a strong repellent/deterrent effect (-0.559 > OAI > -0.760) within the initial 72h of application when compared with water, and weak repellent/deterrent signal (OAI = -0.220) when compared against inactivated yeast. Control ovitraps with water were more positive for egg presence than treated ovitraps, while ovitraps with YEOO particles and inactivated yeast present similar number of positive ovitraps. It is possible that the repellent/deterrent action is partially driven by the delivery system, since most times Citrus sinensis EO oviposition repellent/deterrent signal is weak, and it seem influenced by solvent/delivery used. However, it is unclear how the yeast wall that protect/surrounds the orange oil will negatively affect oviposition since live yeast are normally consider an attractant for mosquito oviposition.

Interventions about physical activity and diet and their impact on adolescent and young adult cancer survivors: a Prisma systematic review

PURPOSE

Over the past few decades, the incidence of cancer among adolescents and young adults (AYA) has been increasing. The impact of behaviors, such as physical activity (PA) and nutrition, on disease progression, prognosis, and overall health and quality of life for AYA cancer survivors is of significant importance. This systematic review aims to evaluate the effectiveness of PA and diet interventions for AYA cancer survivors and to critically evaluate existing literature, gaps, and limitations.

METHODS

A search of literature was conducted in PubMed, Science Direct, Scopus, and Google Scholar following the PRISMA guidelines. Twenty-two studies were included from online databases from 2012 to 2022, 13 of which were randomized controlled trials.

RESULTS

Most interventions were related to PA, with only four studies including nutrition or Diet interventions. The interventions were generally feasible and acceptable to AYA cancer survivors, and digitally based PA interventions were commonly used. PA interventions mainly comprised aerobic and resistance training and were individualized. Overall, this review found various PA and diet interventions for AYA cancer survivors that were feasible and well-accepted, but gaps in knowledge and design still exist.

CONCLUSIONS

This systematic review underscores the importance of conducting more research on diet interventions for YCS. PROSPERO REGISTRATION: https://www.crd.york.ac.uk/prospero/#aboutregpage.

Facts and Hopes on Biomarkers for Successful Early Clinical Immunotherapy Trials: Innovative Patient Enrichment Strategies

Despite the clinical validation and unequivocal benefit to patients, the development of cancer immunotherapies is facing some key challenges and the attrition rate in early phases of development remains high. Identifying the appropriate patient population that would benefit most from the drug is on the critical path for successful clinical development. We believe that a systematic implementation of patient enrichment strategies early in the drug development process and trial design, is the basis for an innovative, more efficient, and leaner clinical development to achieve earlier a clear proof of concept or proof of failure. In this position article, we will describe and propose key considerations for the implementation of patient enrichment strategies as an opportunity to provide decision-enabling data earlier in the drug development process. We introduce an innovative multidimensional tool for immuno-oncology drug development that focuses on facilitating the identification and prioritization of enrichment-relevant biomarkers, based on the drug mechanism of action. To illustrate its utility, we discuss patient enrichment examples and use a case in the field of cancer immunotherapy, together with technical and regulatory considerations. Overall, we propose to implement fit for purpose enrichment strategies for all investigational drugs as early as possible in the development process. We believe that this will increase the success rate of immuno-oncology clinical trials, and eventually bring new and better medicines to patients faster.

An Efficient Edge Computing-Enabled Network for Used Cooking Oil Collection

In Portugal, more than 98% of domestic cooking oil is disposed of improperly every day. This avoids recycling/reconverting into another energy. Is also may become a potential harmful contaminant of soil and water. Driven by the utility of recycled cooking oil, and leveraging the exponential growth of ubiquitous computing approaches, we propose an IoT smart solution for domestic used cooking oil (UCO) collection bins. We call this approach SWAN, which stands for Smart Waste Accumulation Network. It is deployed and evaluated in Portugal. It consists of a countrywide network of collection bin units, available in public areas. Two metrics are considered to evaluate the system's success: (i) user engagement, and (ii) used cooking oil collection efficiency. The presented system should (i) perform under scenarios of temporary communication network failures, and (ii) be scalable to accommodate an ever-growing number of installed collection units. Thus, we choose a disruptive approach from the traditional cloud computing paradigm. It relies on edge node infrastructure to process, store, and act upon the locally collected data. The communication appears as a delay-tolerant task, i.e., an edge computing solution. We conduct a comparative analysis revealing the benefits of the edge computing enabled collection bin vs. a cloud computing solution. The studied period considers four years of collected data. An exponential increase in the amount of used cooking oil collected is identified, with the developed solution being responsible for surpassing the national collection totals of previous years. During the same period, we also improved the collection process as we were able to more accurately estimate the optimal collection and system's maintenance intervals.

Epigenetic MLH1 silencing concurs with mismatch repair deficiency in sporadic, naturally occurring colorectal cancer in rhesus macaques

BACKGROUND

Naturally occurring colorectal cancers (CRC) in rhesus macaques share many features with their human counterparts and are useful models for cancer immunotherapy; but mechanistic data are lacking regarding the comparative molecular pathogenesis of these cancers.

METHODS

We conducted state-of-the-art imaging including CT and PET, clinical assessments, and pathological review of 24 rhesus macaques with naturally occurring CRC. Additionally, we molecularly characterized these tumors utilizing immunohistochemistry (IHC), microsatellite instability assays, DNAseq, transcriptomics, and developed a DNA methylation-specific qPCR assay for MLH1, CACNA1G, CDKN2A, CRABP1, and NEUROG1, human markers for CpG island methylator phenotype (CIMP). We furthermore employed Monte-Carlo simulations to in-silico model alterations in DNA topology in transcription-factor binding site-rich promoter regions upon experimentally demonstrated DNA methylation.

RESULTS

Similar cancer histology, progression patterns, and co-morbidities could be observed in rhesus as reported for human CRC patients. IHC identified loss of MLH1 and PMS2 in all cases, with functional microsatellite instability. DNA sequencing revealed the close genetic relatedness to human CRCs, including a similar mutational signature, chromosomal instability, and functionally-relevant mutations affecting KRAS (G12D), TP53 (R175H, R273*), APC, AMER1, ALK, and ARID1A. Interestingly, MLH1 mutations were rarely identified on a somatic or germline level. Transcriptomics not only corroborated the similarities of rhesus and human CRCs, but also demonstrated the significant downregulation of MLH1 but not MSH2, MSH6, or PMS2 in rhesus CRCs. Methylation-specific qPCR suggested CIMP-positivity in 9/16 rhesus CRCs, but all 16/16 exhibited significant MLH1 promoter hypermethylation. DNA hypermethylation was modelled to affect DNA topology, particularly propeller twist and roll profiles. Modelling the DNA topology of a transcription factor binding motif (TFAP2A) in the MLH1 promoter that overlapped with a methylation-specific probe, we observed significant differences in DNA topology upon experimentally shown DNA methylation. This suggests a role of transcription factor binding interference in epigenetic silencing of MLH1 in rhesus CRCs.

CONCLUSIONS

These data indicate that epigenetic silencing suppresses MLH1 transcription, induces the loss of MLH1 protein, abrogates mismatch repair, and drives genomic instability in naturally occurring CRC in rhesus macaques. We consider this spontaneous, uninduced CRC in immunocompetent, treatment-naïve rhesus macaques to be a uniquely informative model for human CRC.

Tumor beta2-microglobulin and HLA-A expression is increased by immunotherapy and can predict response to CIT in association with other biomarkers

Background

Downregulation of MHC class I expression and/or defects in the antigen presentation pathways are commonly reported in human cancers. Numerous studies previously have explored extensively the molecular mechanisms that underlie HLA-class I and Beta2-Microglobulin (B2M) downregulation. However, the techniques presently available to detect expression of MHC class I proteins lack the robustness, specificity and sensitivity needed for systematic integration and analysis in clinical trials. Furthermore, the dynamics of HLA-class I and B2M expression have not been comprehensively studied as a potential biomarker for immunotherapy.

Methods

Using novel, validated, immunohistochemistry (IHC)-based methods for quantifying B2M and HLA-A in tumor samples from diverse cancer types, we have determined loss of B2M and HLA-A proteins in 336 archived, primary specimens and 329 biopsies from metastatic patients collected during Roche-sponsored Phase 1 clinical trials investigating novel immunotherapy candidates as monotherapy or in combination with CPI.

Results

Up to 56% of cases with B2M or HLA-A loss were noted in the investigated tumor types. The frequency of loss was dependent on indication and stage of disease and revealed heterogeneous expression patterns across patients. B2M and HLA-A loss was increased in metastatic lesions compared to primary tumors, indicating selection of MHC class I low clones in metastatic and refractory tumor cells. High on-treatment B2M expression correlated with successful clinical outcome (RECIST), while high baseline B2M did not. A treatment-induced increase of B2M expression was noted in most of the patients with low B2M levels at baseline. The triple biomarker combination of B2M, CD8 and PDL1 strongly improved response prediction to cancer immunotherapy.

Conclusion

Our results indicate that B2M and HLA-A loss occurs frequently in tumors and is reversed in most instances following immunotherapy which supports the conclusion that MHC class I loss is not the dominant resistance mechanism to CPI treatment. This investigation reveals a highly dynamic expression of HLA-A and B2M in tumors affected by indication, metastatic status, immunophenotype and immunotherapy treatment. Baseline expression levels of B2M on tumors may be of utility as a constituent of a biomarker panel used for selecting patients for immunotherapy clinical trials.

A Composite Decision Rule of CD8+ T-cell Density in Tumor Biopsies Predicts Efficacy in Early-stage, Immunotherapy Trials

PURPOSE

To examine whether CD8+ T-cell numbers in paired tumor biopsies in early-stage clinical trials can be used as an early indicator of clinical benefit for cancer immunotherapies.

EXPERIMENTAL DESIGN

Paraffin sections of tumor biopsies were stained immunohistochemically for CD8+ T cells, which were digitally enumerated. The tumor biopsies were from cancer patients in early-phase trials testing novel immunotherapeutic agents. Paired biopsies taken before the start of treatment and on-treatment were compared. A total of 155 patients were used as the training set and an additional 221 patients were used as the validation set.

RESULTS

Using the Cox proportional hazard model, a ≥0.9- increase in fold change (FC) on a ln scale in CD8+ T cells (corresponding to a 2.5-fold increase on the linear scale), from baseline, demonstrated a greater association with prolonged progression-free survival and allowed improved differentiation between groups above and below the threshold. Similarly, a ≥6.2 threshold in geometric mean of the on-treatment density (OTD) of T cells, which approximately corresponds to 500 cells/mm2, correlated with longer PFS. The combination of both criteria (FC and OTD) provided the best discrimination between clinically nonactive and active compounds.

CONCLUSIONS

We propose that a composite score of CD8+ T-cell density in paired biopsies taken before and on-treatment may be a new biomarker to inform on clinical outcomes in early immunotherapy clinical trials.

Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World

Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites.

Stimulus representations in visual cortex shaped by spatial attention and microsaccades

Microsaccades (MSs) are commonly associated with spatially directed attention, but how they affect visual processing is still not clear. We studied MSs in a task in which the animal was randomly cued to attend to a target stimulus and ignore distractors, and it was rewarded for detecting a color change in the target. We found that the enhancement of firing rates normally found with attention to a cued stimulus was delayed until the first MS directed towards that stimulus. Once that MS occurred, attention to the target was engaged and there were persistent effects of attention on firing rates for the remainder of the trial. These effects were found in the superficial and deep layers of V4 as well as the lateral pulvinar and IT cortex. Although the tuning curves of V4 cells do not change depending on the locus of spatial attention, we found pronounced effects of MS direction on stimulus representations that persisted for the length of the trial in V4. In intervals following a MS towards the target in the RF, stimulus decoding from population activity was substantially better than in intervals following a MS away from the target. Likewise, turning curves of cells were substantially sharper following a MS towards the target in the RF. This sharpening appeared to result from both a "refreshing" of the initial transient sensory response to stimulus onset, and a magnification of the effects of attention in this condition. MSs to the target also enhanced the neuronal response to the behaviorally relevant target color change and led to faster reaction times. These results thus reveal a major link between spatial attention, object processing and its coordination with eye movements.

Spontaneous, naturally occurring cancers in non-human primates as a translational model for cancer immunotherapy

The complexity of cancer immunotherapy (CIT) demands reliable preclinical models to successfully translate study findings to the clinics. Non-human primates (NHPs; here referring to rhesus and cynomolgus macaques) share broad similarities with humans including physiology, genetic homology, and importantly also immune cell populations, immune regulatory mechanisms, and protein targets for CIT. Furthermore, NHP naturally develop cancers such as colorectal and breast cancer with an incidence, pathology, and age pattern comparable to humans. Thus, these tumor-bearing monkeys (TBMs) have the potential to bridge the experimental gap between early preclinical cancer models and patients with human cancer.This review presents our current knowledge of NHP immunology, the incidence and features of naturally-occurring cancers in NHP, and recent TBM trials investigating CIT to provide a scientific rationale for this unique model for human cancer.

Should orthognathic surgery be performed in growing patients? A scoping review

The aim of this study was to determine whether the benefits of orthognathic surgery in a growing individual outweigh its risks. A scoping review was performed according to the PRISMA-ScR guideline. A bibliographic search from MEDLINE, Cochrane Library and LILACS was conducted until February 1, 2022. Scientific publications which reported orthognathic surgery in individuals under 18 years of age were considered. Inclusion criteria were performed according to PICOS model: do individuals with dentofacial deformity submitted to orthognathic surgery with an immature skeleton other than waiting growth cessation have overall benefits over any possible pos-operative consequences? Predictor of interest was growth status and outcome variables were positive benefits or negative consequences related to orthognathic surgery. Two reviewers screened records independently, and any disagreement between them was resolved by a third reviewer. Eligible studies were compiled into an extraction data form and were verified for validity and reliability. Risk of bias between studies was carried out using Review Manager. A total of 15 articles were included in this scoping review, comprising retrospective studies (9), case reports (3), and surveys (3). The topics covered varied from assessment of the functional needs, role, quality of life after orthognathic surgery, impact on growth, relation with temporomandibular joint surgical treatments, minimal referral age for surgery by orthodontists and complex cranio-maxillofacial deformities. Due to the heterogeneity of the articles, it was not possible to perform a meta-analysis. Within the limitations of the study it seems that the existing evidence seems favorable towards the intervention, improving quality of life in growing individuals, even at the risk of a second surgery.

Abstract A021: Clinical and molecular characterization of naturally-occurring colorectal cancer in rhesus macaques reveals mismatch repair deficiency driven by epigenetic silencing of MLH1

Naturally occurring colorectal cancers (CRC) in rhesus macaques share many features with their human counterparts and emerge at similar life stages as in human patients, but the carcinogenesis and molecular background remain elusive, limiting the value of the model for human disease and cancer therapy. In order to better understand this naturally occurring model, we established a diagnostic and staging pipeline including imaging (18F-FDG PET, plain and contrast-enhanced CT), histopathology, and clinical assessments. We observed cancer symptoms and co-morbidities in our cohort (n=16, all Indian-origin, 11 females, mean age at arrival 20.2y) such as hypoalbuminemia, fecal occult blood, and microcytic anemia, as frequently described in human CRC patients. Pathologically, all cancers were right-sided, involving the proximal colon and/or ileocecocolic junction, and most were densely fibrotic, restricting the colonic lumen. Most cancers appeared with glandular morphology and some (18.8%) had mucinous components. Immunohistochemistry revealed loss of MLH1 and PMS2 in 100% of investigated CRCs, indicating mismatch repair deficiency which furthermore resulted in microsatellite instability (PCR & fragment analysis). Whole exome sequencing revealed the close genetic relatedness to human CRCs, particularly exemplified by mutations affecting KRAS (37.5%, e.g., p.G12D), APC (31.3%), TP53 (18.8%, e.g. p.R175H), ARID1A (56.3%), and ALK (43.8%), as similarly annotated in the human COSMIC database. Nonetheless, somatic mutations do not explain the loss of MLH1 in the entire CRC cohort. Transcriptomics on the other hand revealed the transcriptional suppression of MLH1 but not MSH2, MSH6, or PMS2 in rhesus CRC in comparison to adjacent healthy colon. Moreover, comparison of differentially expressed gene sets of rhesus CRC with a human annotated database (IPA) confirmed the disease similarities observed clinically, genetically, and histopathologically. Subsequently, we investigated DNA methylation of the promoter region of MLH1 and retranslated markers for the CpG island methylator phenotype (CIMP) as described in human CRC. While only 56.3% of CRCs were considered CIMP positive (≥3/5 markers hypermethylated), 100% of investigated CRCs exhibited MLH1 promoter hypermethylation. As a result, epigenetic silencing is suggested to suppress MLH1 transcription, cause the loss of MLH1 protein, and drive mismatch repair deficiency and genomic instability in naturally occurring CRC in rhesus macaques. We therefore consider spontaneous, uninduced CRC in rhesus macaques, their treatment-naïve nature, and their unaltered immune competence an outstanding model for human disease and in particular for human cancer immunotherapy.

Citation Format: Simon Deycmar, Brendan Johnson, Karina Ray, David Caudell Caudell, John Olson, Greg Dugan, W. Shane Sills, Declan Ryan, Christopher Whitlow, Kiran K. Solingapuram Sai, Betsy Ferguson, Benjamin Bimber, Cassandra Cullin, Brandy Dozier, Emily Romero, Francois Villinger, Armando Burgos, Jeff Chou, Bruno Gomes, Michael Hettich, Maurizio Ceppi, Jehad Charo, J. Mark Cline. Clinical and molecular characterization of naturally-occurring colorectal cancer in rhesus macaques reveals mismatch repair deficiency driven by epigenetic silencing of MLH1 [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr A021.

What do future public health doctors know about the One Health concept in Portugal?

Background

The One Health (OH) approach brings together a transdisciplinary collaboration between human, animal, and environmental health, to tackle emerging zoonotic diseases, antimicrobial resistance, and food safety. Therefore, incorporating of OH principles in the education of health care providers is fundamental.

Methods

To assess OH knowledge, attitudes and practices (KAP), an anonymous, multiple-choice, online self-administered survey was sent to 1st year Portuguese Public Health Medical Residents (PPHMR), during an online congress targeted to them. A descriptive analysis was performed.

Results

A 50.0% response rate was obtained out of the 42 PPHMR attendees. Only 33.3% were familiar with OH concept; 57,1% had heard of it but were not aware of its meaning, and 9.5% had never heard of it. Concerningly, 9,5% believed zoonosis were diseases transmitted between animals and 42.9% considered that “antimicrobial resistance” is applied to antibiotics only. Regarding major zoonosis, etiologic agents were not recognized for Cryptosporidiosis (47.6%), Echinococcosis (42.9%), Toxoplasmosis and Leptospirosis (38.1%), Dermatophytosis (33.3%), Rabies (28.6%), Borreliosis/Brucellosis (23.8%). Half (52.4%) were unaware of the transmission route of Brucellosis/Dermatophytosis, followed by Leptospirosis (38.1%), Toxoplasmosis (28.6%) and Borreliosis/Rabies (23.8%). Remarkably, all participants showed willingness to be informed on OH issues and agreed that prevention and speed of intervention would be higher with greater collaboration between health technicians. About education towards OH throughout their medical curricula, 61.9% classified it as low, 23.8% as absent, 14.3% as sufficient and none classified it as adequate or very adequate.

Conclusions

This is the first study assessing KAP regarding the OH concept among PPHMR. Results highlight the need to bring OH to the Portuguese medical schools’ agenda to better prepare the next generation of PPHMR to the emerging health crisis.

Key messages

• Despite the interest shown by 1st year Portuguese Public Health Medical Residents concerning One Health, a general lack of knowledge on the topic was found.

• The majority qualified as insufficient their training on this subject, highlighting the need for medical schools to improve education and raise awareness regarding this transdisciplinary approach.

Structure and expression of Rhodnius prolixus GH18 chitinases and chitinase-like proteins: Characterization of the physiological role of RpCht7, a gene from subgroup VIII, in vector fitness and reproduction

Chitinases are enzymes responsible for the hydrolysis of glycosidic linkages within chitin chains. In insects, chitinases are typically members of the multigenic glycoside hydrolase family 18 (GH18). They participate in the relocation of chitin during development and molt, and in digestion in detritivores and predatory insects, and they control the peritrophic membrane thickness. Chitin metabolism is a promising target for developing vector control strategies, and knowledge of the roles of chitinases may reveal new targets and illuminate unique aspects of their physiology and interaction with microorganisms. Rhodnius prolixus is an important vector of Chagas disease, which is caused by the parasite Trypanosoma cruzi. In this study, we performed annotation and structural characterization of nine chitinase and chitinase-like protein genes in the R. prolixus genome. The roles of their corresponding transcripts were studied in more depth; their physiological roles were studied through RNAi silencing. Phylogenetic analysis of coding sequences showed that these genes belong to different subfamilies of GH18 chitinases already described in other insects. The expression patterns of these genes in different tissues and developmental stages were initially characterized using RT-PCR. RNAi screening showed silencing of the gene family members with very different efficiencies. Based on the knockdown results and the general lack of information about subgroup VIII of GH18, the RpCht7 gene was chosen for phenotype analysis. RpCht7 knockdown doubled the mortality in starving fifth-instar nymphs compared to dsGFP-injected controls. However, it did not alter blood intake, diuresis, digestion, molting rate, molting defects, sexual ratio, percentage of hatching, or average hatching time. Nevertheless, female oviposition was reduced by 53% in RpCht7-silenced insects, and differences in oviposition occurred within 14–20 days after a saturating blood meal. These results suggest that RpCht7 may be involved in the reproductive physiology and vector fitness of R. prolixus.

Abstract 1325: Naturally occurring colorectal cancer in nonhuman primates used to study human immunotherapeutic agents confirms a link between DNA methylation and mismatch repair deficiency

Background Non-human primates (NHP) such as rhesus macaques with naturally occurring cancers are a proposed model for translational cancer immunotherapy (CIT) research and have generated relevant proof-of-mechanism evidence for 3 different CIT agents. NHP spontaneously develop cancers with progression patterns, histology, and clinical symptoms similar to humans. Gene suppression by DNA hypermethylation in the promoter region is the major characteristics of the CpG-island-methylator-phenotype (CIMP) described in human CRC patients but information in rhesus macaques is scarce. To further validate these animals as translational models for CIT, we conducted a deep molecular characterization of NHP colorectal cancers and established novel qPCR panels to assess DNA methylation of marker genes published for humans.

Methods Our cohort (n=16) consisted of Indian-origin rhesus macaques (Macaca mulatta) with naturally occurring CRC (n=16, female=11). Clinical examination, imaging (contrast-enhanced CT, FDG-PET) and biopsy to confirm cancer histology were performed. Molecular characterization was done by IHC for CRC-associated mismatch repair proteins MLH1, MSH2, MSH6, and PMS2 and by PCR/electrophoresis for microsatellite instability. Ultimately, we designed DNA methylation- and rhesus-specific qPCR probes (Methylight) targeting corresponding regions as published in human patients, including CACNA1G, CDKN2A, CRABP1, MLH1, and NEUROG1 as parts of the CIMP panel and BMP3, NDRG4, and SEPTIN9 as probed for human CRC-screening.

Results MLH1 deficiency by IHC, in conjunction with PMS2 absence, is observed in all NHP CRC cases, clearly exceeding frequencies reported in human CRCs (ranging from 2-15%). Moreover, we have documented microsatellite instable cases in some NHP CRCs, analog to human CRCs. DNA methylation of the MLH1 promoter region was significantly elevated in CRCs (100% of CRCs >2-fold, p<0.0001) compared to healthy colon. We hypothesized that this elevation would suppress MLH1 mRNA expression. This hypothesis of epigenetic suppression is corroborated by both qPCR and RNA sequencing which demonstrate significantly downregulated levels of MLH1 mRNA. DNA methylation of the other markers is less consistent but revealed CIMP positive and CIMP negative cases in our NHP CRC cohort.

Conclusions Transcriptional suppression of MLH1 by promoter hypermethylation is a major and widespread driver of genetic instability and carcinogenesis in rhesus macaque colorectal cancer. Differential DNA methylation in the promoter regions as observed in NHP CRCs can provide a screening target for liquid biopsies. This work highlights the possible translatability of naturally occurring NHP cancers for human cancer immunotherapy research and can be further explored in future tumor-bearing monkey trials.

Citation Format: Simon Deycmar, Brendan Johnson, Declan Ryan, Shane Sills, David Caudell, Greg Dugan, George Schaaf, Christopher Whitlow, Kiran Kumar Solingapuram Sai, Betsy Ferguson, Benjamin Bimber, Karina Ray, Cassandra Cullin, Brandy Dozier, Armando Burgos, Michael Hettich, Bruno Gomes, Jehad Charo, Maurizio Ceppi, Mark Cline. Naturally occurring colorectal cancer in nonhuman primates used to study human immunotherapeutic agents confirms a link between DNA methylation and mismatch repair deficiency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1325.

Abstract 2780: Loss of tumor HLA-A and B2M expression and association with biomarkers and clinical outcome

Loss of MHC-I and/or Beta 2 microglobulin (B2M) expression is regarded as a frequent resistance mechanism to immunotherapies. Indeed, downregulation of MHC-I expression and/or defects in the pathways of antigen presentation machinery are commonly reported in human cancers. Despite many reports published, available tools lack the robustness, specificity and sensitivity needed for systematic integration and analysis in clinical trials. In order to explore loss of antigen presentation as one of the major resistance mechanisms to checkpoint inhibitor (CPI) therapy treatment and to enable identification of patients with tumors harboring antigen presentation defects, we have developed immunohistochemistry (IHC)-based robust prototype assays to quantify HLA-A and B2M proteins in patient tissue samples. We have determined the prevalence of loss of HLA-A and B2M in banked primary tumor blocks as well as in 329 tumor metastatic biopsies collected during Roche-sponsored Phase 1 clinical trials investigating novel immunotherapies as single agents or in combination with CPI. Below are the key findings and preliminary interpretations:We confirm a significant prevalence of HLA-A and B2M loss (up to 65%) depending on indication, revealing heterogeneous expression patterns across patients and indications.We describe an increase of HLA-A and B2M loss from primary to metastatic lesions, which may reflect a selection of MHC-I-low/negative clones in spreading cancer cells (and maybe lines of therapies).We show that high on-treatment B2M expression is positively associated with clinical outcome (RECIST), while high baseline B2M expression only shows a trend (but no statistical significance) towards positive association with response. If the former (on-treatment expression) could be seen as a consequence of the drug effect (induction of inflammation, IFN-signaling and subsequent induction of MHC-I expression), the latter (baseline expression) would have been the foundation for enriching patient populations based on MHC-I expression. Based on these data, the absence of strong correlation between baseline expression and response does not support a cross-CIT enrichment approach at this stage.We see a treatment-induced increase of MHC-I expression in most of the patients. Preliminary conclusions could be that 1/MHC-I loss can be rescued in most of the cases we analyzed (few hard losses), 2/Since we only see few responders, MHC-I loss is not the dominant resistance mechanism or the drug(s) did not induce a strong-enough MHC-I expression to rescue it.This investigation reveals a highly dynamic expression of HLA-A and B2M in tumors affected by key variables such as indication, metastatic status, immunophenotype and immunotherapy treatment. We plan to explore MHC-I expression in larger cohorts of CPI-treated patients in order to confirm and broaden our preliminary findings.

Citation Format: Bernhard Reis, Sebastian Dziadek, Jan Attig, Nico Graefe, Astrid Heller, Natascha Rieder, Bruno Gomes. Loss of tumor HLA-A and B2M expression and association with biomarkers and clinical outcome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2780.

T-Cell Heterogeneity in Baseline Tumor Samples: Implications for Early Clinical Trial Design and Analysis

Background

In early stage clinical trials, changes to levels of tumor infiltrating lymphocytes (TILs) in the tumor microenvironment (TME) are critical biomarkers of the mechanism of action of novel immunotherapies. However, baseline heterogeneity of tumor samples, both between and within patients, and the resultant impact on the validity of clinical trial data is not well defined. Here we identify and quantify the impact of baseline variables on the heterogeneity of FoxP3+ and proliferating CD8+ T-cells levels (MKi67+CD8A+) in the TME both between and within patients for the purpose of informing clinical trial design and analysis.

Methods

We compared levels of FoxP3+ and MKi67+CD8+ cell densities (counts/mm2) from >1000 baseline tumor samples from clinical trials and commercially available sources. Using multivariate hierarchical regression techniques, we investigated whether inter-person heterogeneity of activated or regulatory T-cells could be attributed to baseline characteristics including demographics, indication, lesion type, tissue of excision, biopsy method, prior cancer treatment, and tissue type i.e., "fresh" or "archival" status. We also sought to characterize within-patient heterogeneity by lesion type and tissue type.

Results

Prior cancer treatment with hormone therapy or chemotherapy that induces immunogenic cell death may alter the TME. Archival tissue is an unreliable substitute for fresh tissue for determining baseline TIL levels. Baseline and on treatment biopsies should be matched by lesion type to avoid bias.

11 Molecular characterization of naturally occurring colorectal and breast cancer in non-human primates to model human immunotherapeutic agents

Background

Non-human primates (NHP) with naturally occurring cancers (also called tumor-bearing monkeys or TBM) are a proposed model for translational cancer immunotherapy (CIT) research.1 TBM spontaneously develop cancers with progression patterns similar to humans, potentially bridging the gap between preclinical models and cancers in patients. Interventional CIT trials recently conducted in colorectal (CRC) and breast cancer (BC)-bearing NHP, have generated relevant proof-of-mechanism evidence for three different CIT agents.1–3 To further validate these animals as translational models for CIT, we conducted a deep molecular characterization of tumors at baseline and reverse translated biomarker assays employed in human patients.

Methods

Our cohort (n=19) consisted of Indian-origin rhesus macaques (Macaca mulatta) with naturally occurring CRC (n=14, female=9, male=5) and BC (n=5, female=5). Clinical examination, imaging (contrast-enhanced CT, PET) and biopsy to confirm cancer histology were performed. Molecular characterization was done by IHC for CRC-associated mismatch repair (MMR) proteins MLH1, MSH2, MSH6, and PMS2 and BC markers ER, PR, and HER2. We assessed microsatellite instability (MSI) by PCR and electrophoresis, and for selected cases somatic tumor mutations and tumor mutational burden (TMB) by whole exome sequencing.

Results

Deficiency in MMR proteins determines eligibility for PD-1 blockade therapy, is observed in approximately 15% of human CRCs, and surprisingly in 100% (14/14) of our NHP CRCs. The absence of MLH1 (14/14), MSH2 (1/14), MSH6 (0/14) and PMS2 (14/14) observed in NHP CRCs clearly exceeds the frequencies reported in human CRCs ranging from 2–15% for each individual MMR protein.4 5 Moreover, we have documented MSI cases in some NHP CRCs, as described in human CRCs. We sequenced 3 CRCs and observed mutations in KRAS (G12D & A59T), WNT7A (V238M), IDH2 (R362Q), AKT3 (R388H), and TMB of 4.27, 22.95, and 29.3 mut/Mbp. Regarding breast, we found hormone receptor positive (Luminal A), HER2 positive, and TNBC, as in human BC patients. Sequencing of 2 BCs revealed mutations in PTEN (G251V), TGFBR2 (L162P), and ERBB4 (R1250Q), and TMB of 2.32 and 17.22 mut/Mbp.

Conclusions

NHP cancers can be similarly characterized as human cancers, both macroscopically and molecularly. In this study we demonstrated an overrepresentation of MMR deficiency in NHP CRCs. Receptor expression in NHP BCs revealed similar subtypes as in human BCs. Cancer-associated mutations described in humans are also evident in TBM. This work highlights the possible translatability of naturally occurring NHP cancers for human cancer immunotherapy research, and can be further explored in future TBM trials.

References

Ceppi M, Hettich M, Teichgraeber V, Driessen W, Tuerck D, et al. Tumor-bearing non-human primates: an unrivaled model for translational cancer immunology research. Proceedings: AACR Annual Meeting 2020.

Claus C, Ferrara C, Xu W, Sam J, Lang S, Uhlenbrock F, et al. Tumor-targeted 4-1BB agonists for combination with T cell bispecific antibodies as off-the-shelf therapy. Sci Transl Med 2019;11(496).

Waldhauer I, Gonzalez-Nicolini V, Freimoser-Grundschober A, Nayak TK, Fahrni L, et al. Simlukasfusp alfa (FAP-IL2v) immunocytokine is a versatile combination partner for cancer immunotherapy. MAbs 2021;13(1).

Parc Y, Gueroult S, Mourra N, Serfaty L, Flejou J-F, Tiret E, Parc R. Prognostic significance of microsatellite instability determined by immunohistochemical staining of MSH2 and MLH1 in sporadic T3N0M0 colon cancer. Gut 2004;53.

Chen L, Chen G, Zheng X, Chen Y. Expression status of four mismatch repair proteins in patients with colorectal cancer: clinical significance in 1238 cases. Int J Clin Exp Pathol 2019;12(10).

Ethics Approval

Wake Forest University is accredited by the Association for the Assessment and Accreditation of Laboratory Animal Care, International (AAALAC) and registered with the United States Department of Agriculture (USDA) to conduct research in laboratory animals. The protocols and any subsequent amendments are reviewed and approved by the Wake Forest Institutional Animal Care and Use Committee (IACUC) and in compliance with the U.S. Animal Welfare Act, the Guide for the Care and Use of Laboratory Animals, the Office of Laboratory Animal Welfare, and public health service regulations.

527 Digital spatial profiling of paired tumor biopsies reveals indoleamine 2,3-dioxygenase (IDO)1 as a potential resistance mechanism for a tumor-targeted 4–1BB agonist in patients with solid tumors

Background

We previously described the capacity of RO7122290 (RO) - a FAP-targeted 4-1BB bispecific antibody - to induce CD8+ T cell infiltration and activation in the tumor (Moreno V. et al, SITC 2020). Aiming to compare pharmacodynamic (PD) changes in tumor nests and stroma, paired tumor biopsies from patients treated with RO (Part A) and RO + atezolizumab (Part B) were analysed by digital spatial profiling (DSP, Nanostring).

Methods

Seven paired (baseline and on-treatment) FFPE tumor tissue biopsies (three from Part A, four from Part B) obtained from an ongoing Phase 1/1b trial (EUDRACT 2017-003961-83) were assessed for mRNA and protein expression. Biopsies were taken from six different tumor types at different RO doses. Up to twelve Regions of Interest (ROIs) were collected per slide and the morphology markers PanCK, CD8, CD3 and DAPI were applied. The ROIs were further annotated in tumor nests and stroma segments based on PanCK staining. The immune-oncology 58-plex protein and 78-plex mRNA expression panels (Nanostring) were used to profile all samples. Data were normalized according to Nanostring guidelines and filtered based on relevance (absolute log2 fold change > 1) and significance (FDR < 0.05, p-value).

Results

The level of CD8+ T cell infiltration measured by spatial profiling correlated with the level measured by IHC, in both tumor nests and stroma. The activation markers 4-1BB and PD-1 were upregulated, confirming the PD effect already measured by mRNA sequencing. We also identified novel protein markers - CD40, PD-L1 and IDO1 - being upregulated after treatment. Spatial regulation differed among the markers with 4-1BB, PD-1 and CD40 upregulated only in the stroma, PD-L1 and IDO1 upregulated in the tumor nests and in the stroma. IDO1 induction is particularly relevant, since this protein is known to attenuate 4-1BB-mediated effector responses. Conventional IHC analysis performed on 14 paired biopsies confirmed IDO1 being upregulated in 11 out of 14 cases and revealed dendritic cells, macrophages and stromal cells to express IDO1. Importantly, IDO1 upregulation was observed in both Part A (3 out of 3) and Part B (8 out of 11).

Conclusions

Spatial profiling allowed us to identify key markers that are spatially regulated after treatment and to gain new insights on the MoA of RO. The induction of IDO1 by RO confirms the dual immunoregulatory nature of 4-1BB signaling and highlights IDO1 as a potential resistance mechanism for RO in the clinical setting, both as single agent and in combination with atezolizumab.

Trial Registration

EUDRACT Number:

2017-003961-83; Protocol Number: BP40087

References

Moreno V. et al, Pharmacodynamic assessment of a novel FAP-targeted 4–1BB agonist, administered as single agent and in combination with atezolizumab to patients with advanced solid tumors, Nov 1 2020, Journal for ImmunoTherapy of Cancer, presented at SITC 2020

Engaging local health research communities to enhance long-term capacity building in Brazil

The '2019 Research Capacity Network (REDe) workshop series' was an initiative led by Brazil-based REDe coordinators and The Global Health Network (TGHN) in partnership with Brazilian researchers interested in arboviruses. This workshop initiative has provided crucial training to the local research community offering transferable skills to effectively respond to health emergencies, with an impact beyond arboviral diseases, as evidenced by further activities undertaken during the COVID-19 pandemic. The success of this approach resulted from several factors, especially the workshops' local leadership and the combination of in-person training with online sharing of the resources generated in the local language. Analytics data from REDe online platform evidenced the wider reach of the shared resources to a larger audience than the workshop attendees. Importantly, the impact of this approach extends beyond the workshop series per se, with workshop participants afforded access to wider training, career development and collaborative opportunities through REDe and TGHN platforms. In addition, this initiative design resulted in the development of new collaborations between the workshop leaders and other local researchers, who have been jointly writing research projects and applying for grants. As a result, REDe has become a highly dynamic community of practice for health researchers in the region, strengthening the research culture and improving connectivity. Here, we describe the design and implementation of this initiative and demonstrate the value of integrating local expertise, and a practical workshop series format with digital dissemination of research resources and training materials to generate a vibrant and robust community of practice.

Static lung storage at 10°C maintains mitochondrial health and preserves donor organ function

[Figure: see text].

Biomarker Technologies to Support Early Clinical Immuno-oncology Development: Advances and Interpretation

Today, there is a huge effort to develop cancer immunotherapeutics capable of combating cancer cells as well as the biological environment in which they can grow, adapt, and survive. For such treatments to benefit more patients, there is a great need to dissect the complex interplays between tumor cells and the host's immune system. Monitoring mechanisms of resistance to immunotherapeutics can delineate the evolution of key players capable of driving an efficacious antitumor immune response. In doing so, simultaneous and systematic interrogation of multiple biomarkers beyond single biomarker approaches needs to be undertaken. Zooming into cell-to-cell interactions using technological advancements with unprecedented cellular resolution such as single-cell spatial transcriptomics, advanced tissue histology approaches, and new molecular immune profiling tools promises to provide a unique level of molecular granularity of the tumor environment and may support better decision-making during drug development. This review will focus on how such technological tools are applied in clinical settings, to inform the underlying tumor-immune biology of patients and offer a deeper understanding of cancer immune responsiveness to immuno-oncology treatments.

Sarcoidosis with Rare Extrapulmonary Involvement

Sarcoidosis is a systemic granulomatous disease in which medullary involvement is a rare extrapulmonary manifestation. We present the case of a 37-year-old man with right abdominal and dorso-lumbar pain lasting for months. Computerized tomography showed renal microlithiasis and retroperitoneal, hilar and mediastinal adenopathies. Laboratory results showed an elevated erythrocyte sedimentation rate, IgG, β2-microgobulin and angiotensin-conversion enzyme, serum calcium in the upper limit and hypercalciuria. There was a slight elevation of the CD4/CD8 ratio in bronchoalveolar lavage, without lymphocytic alveolitis. An endobronchial ganglion biopsy was inconclusive. A positron emission tomography scan demonstrated supra and infra-diaphragmatic, splenic and medullary involvement, suggesting lymphoproliferative disease (LPD). A bone marrow biopsy (BMB) revealed sarcoid-like epithelioid cell granulomas, excluding LPD. Sarcoidosis was assumed and corticosteroids were started. Although cytopenias were not present, the extensive ganglion, splenic and medullary involvement made LPD exclusion imperative, while BMB allowed for a definitive diagnosis.

LEARNING POINTS

Sarcoidosis is a multisystemic granulomatous disease in which medullary involvement is a rare extrapulmonary manifestation.Bone marrow biopsy is rarely performed based on serial blood counts, which may be associated with underdiagnosis.FDG-PET cannot reliably distinguish between sarcoidosis and lymphoproliferative disease as the cause of extensive ganglion, splenic and bone marrow involvement, and so a high index of clinical suspicion is required.

Determination of Optical Properties and Photodynamic Threshold of Lung Tissue for Treatment Planning of In Vivo Lung Perfusion Assisted Photodynamic Therapy

BACKGROUND

Isolated lung metastases in sarcoma and colorectal cancer patients are inadequately treated with current standard therapies. In Vivo Lung Perfusion, a novel platform, could overcome limitations to photodynamic therapy treatment volumes by using low cellular perfusate, removing blood, theoretically allowing greater light penetration. To develop personalized photodynamic therapy protocols requires in silico light propagation simulations based on optical properties and maximal permissible photodynamic threshold dose of lung tissue. This study presents quantification of optical properties for two perfusates and the photodynamic threshold for 5-ALA and Chlorin e6.

METHODS

Porcine and human lungs were placed on Ex Vivo Lung Perfusion, and perfused with acellular solution or blood. Isotropic diffusers were placed within bronchi and on lung surface for light transmission measurements, from which absorption and light scattering properties were calculated at multiple wavelengths. Separately, pigs were injected with 5-ALA or Chlorin e6, and lung tissue was irradiated at increasing doses. Resultant lesion sizes were measured by CT and histology to quantify the photodynamic threshold.

RESULTS

Low cellular perfusate reduced the tissue absorption coefficient significantly, increasing penetration depth of light by 3.3 mm and treatment volumes 3-fold. The photodynamic threshold for lung exposed to 5-ALA was consistent with other malignancies. Chlorin e6 levels were undetectable in lung tissue and did not demonstrate photodynamic-induced necrosis.

CONCLUSIONS

Light penetration with low cellular perfusate is significantly greater and could enable treatments for diffuse disease. This data aids photodynamic treatment planning and will guide clinical translation of photodynamic therapy protocols in the lung, especially during lung perfusion.

High larvicidal efficacy of yeast-encapsulated orange oil against Aedes aegypti strains from Brazil

Background

Botanical substances such as essential oils (EOs) have demonstrated insecticidal properties and are a valid option for vector control. However, free EOs are unreliable as mosquito larvicides due their easy degradation by environmental exposure to ultraviolet light and higher temperatures. Here, we assessed the efficacy of a mosquito larvicide based on orange oil in a yeast-based delivery system against Aedes aegypti strains with different resistance status towards chemical neurotoxic insecticides. This larvicide preparation was physicochemically characterized in a previous report.

Methods

Larvae of four Ae. aegypti strains from different regions of Brazil and different resistance profiles for deltamethrin (pyrethroid) and temephos (organophosphate) were tested against yeast-encapsulated orange oil (YEOO) in laboratory conditions for measurement of LC₅₀ and LC₉₀ values. The same assays were performed with the Belo Horizonte strain under environmental conditions (natural light and temperature). The resistance profiles of these strains were compared to the Rockefeller reference strain in all conditions.

Results

YEOO was found to be a highly active larvicide (LC₅₀ < 50 mg/L) against all Ae. aegypti strains tested in both laboratory conditions (LC₅₀ = 8.1–24.7 mg/L) and environmental conditions with natural light and temperature fluctuation (LC₅₀ = 20.0–49.9 mg/L). Moreover, all strains were considered susceptible (RR < 5) to YEOO, considering resistance ratios calculated based on the Rockefeller strain. The resistance ratios were only higher than 2.5 for LC_90–95 of Belo Horizonte in the laboratory, probably due the higher heterogeneity associated with older egg papers (> 5 months).

Conclusion

YEOO demonstrates high larvicidal activity against Ae. aegypti strains with resistant phenotypes for deltamethrin (PY) and temephos (OP). This larvicidal activity suggests the potential for the development of YEOO as an alternative intervention to synthetic insecticides in integrated vector management programs, for populations with resistance to commonly used insecticides.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04733-2.

Characterization of the Temporal Pattern of Blood Protein Digestion in Rhodnius prolixus: First Description of Early and Late Gut Cathepsins

Rhodnius prolixus is one important vector for the parasite Trypanosoma cruzi in Latin America, where Chagas disease is a significant health issue. Although R. prolixus is a model for investigations of vector–parasite interaction and transmission, not much has been done recently to further comprehend its protein digestion. In this work, gut proteolysis was characterized using new fluorogenic substrates, including optimum pH, inhibition profiles, and tissue and temporal expression patterns. Each protease possessed a particular tissue prevalence and activity cycle after feeding. Cathepsin L had a higher activity in the posterior midgut lumen, being characterized by a plateau of high activities during several days in the intermediate phase of digestion. Cathepsin D showed high activity levels in the tissue homogenates and in the luminal content of the posterior midgut, with a single peak 5 days after blood feeding. Aminopeptidases are highly associated with the midgut wall, where the highest activity is located. Assays with proteinaceous substrates as casein, hemoglobin, and serum albumin revealed different activity profiles, with some evidence of biphasic temporal proteolytic patterns. Cathepsin D genes are preferentially expressed in the anterior midgut, while cathepsin L genes are mainly located in the posterior portion of the midgut, with specific sets of genes being differently expressed in the initial, intermediate, or late phases of blood digestion.

Significance Statement

This is the first description in a non-dipteran hematophagous species of a sequential protease secretion system based on midgut cathepsins instead of the most common insect digestive serine proteases (trypsins and chymotrypsins). The midgut of R. prolixus (Hemiptera) shows a different temporal expression of proteases in the initial, intermediate, and late stages of blood digestion. In this respect, a different timing in protease secretion may be an example of adaptative convergence in blood-sucking vectors from different orders. Expanding the knowledge about gut physiology in triatomine vectors may contribute to the development of new control strategies, aiming the blocking of parasite transmission.

Insecticide resistance selection and reversal in two strains of Aedes aegypti

Background: Laboratory reared mosquito colonies are essential tools to understand insecticide action. However, they differ considerably from wild populations and from each other depending on their origin and rearing conditions, which makes studying the effects of specific resistance mechanisms difficult. This paper describes our methods for establishing multiple resistant strains of Aedes aegypti from two colonies as a new resource for further research on metabolic and target site resistance. Methods: Two resistant colonies of Ae. aegypti, from Cayman and Recife, were selected through 10 generations of exposure to insecticides including permethrin, malathion and temephos, to yield eight strains with different profiles of resistance due to either target site or metabolic resistance. Resistance ratios for each insecticide were calculated for the selected and unselected strains. The frequency of kdr alleles (F1534C and V1016I) in the Cayman strains was determined using TaqMan assays. A comparative gene expression analysis among Recife strains was conducted using qPCR in larvae (CCae3A, CYP6N12, CYP6F3, CYP9M9) and adults (CCae3A, CYP6N12, CYP6BB2, CYP9J28a). Results: In the selected strain of Cayman, mortality against permethrin reduced almost to 0% and kdr became fixated by 5 generations. A similar phenotype was seen in the unselected homozygous resistant colony, whilst mortality in the susceptible homozygous colony rose to 82.9%. The Recife strains showed different responses between exposure to adulticide and larvicide, with detoxification genes in the temephos selected strain staying similar to the baseline, but a reduction in detoxification genes displayed in the other strains. Conclusions: These selected strains, with a range of insecticide resistance phenotypes and genotypes, will support further research on the effects of target-site and/or metabolic resistance mechanisms on various life-history traits, behaviours and vector competence of this important arbovirus vector.

Society for Immunotherapy of Cancer clinical and biomarkers data sharing resource document: Volume II-practical challenges

The development of strongly predictive validated biomarkers is essential for the field of immuno-oncology (IO) to advance. The highly complex, multifactorial data sets required to develop these biomarkers necessitate effective, responsible data-sharing efforts in order to maximize the scientific knowledge and utility gained from their collection. While the sharing of clinical- and safety-related trial data has already been streamlined to a large extent, the sharing of biomarker-aimed clinical trial derived data and data sets has been met with a number of hurdles that have impaired the progression of biomarkers from hypothesis to clinical use. These hurdles include technical challenges associated with the infrastructure, technology, workforce, and sustainability required for clinical biomarker data sharing. To provide guidance and assist in the navigation of these challenges, the Society for Immunotherapy of Cancer (SITC) Biomarkers Committee convened to outline the challenges that researchers currently face, both at the conceptual level (Volume I) and at the technical level (Volume II). The committee also suggests possible solutions to these problems in the form of professional standards and harmonized requirements for data sharing, assisting in continued progress toward effective, clinically relevant biomarkers in the IO setting.

Analysis of Spatial Organization of Suppressive Myeloid Cells and Effector T Cells in Colorectal Cancer-A Potential Tool for Discovering Prognostic Biomarkers in Clinical Research

The development and progression of solid tumors such as colorectal cancer (CRC) are known to be affected by the immune system and cell types such as T cells, natural killer (NK) cells, and natural killer T (NKT) cells are emerging as interesting targets for immunotherapy and clinical biomarker research. In addition, CD3⁺ and CD8⁺ T cell distribution in tumors has shown positive prognostic value in stage I–III CRC. Recent developments in digital computational pathology support not only classical cell density based tumor characterization, but also a more comprehensive analysis of the spatial cell organization in the tumor immune microenvironment (TiME). Leveraging that methodology in the current study, we tried to address the question of how the distribution of myeloid derived suppressor cells in TiME of primary CRC affects the function and location of cytotoxic T cells. We applied multicolored immunohistochemistry to identify monocytic (CD11b⁺CD14⁺) and granulocytic (CD11b⁺CD15⁺) myeloid cell populations together with proliferating and non-proliferating cytotoxic T cells (CD8⁺Ki67^+/–). Through automated object detection and image registration using HALO software (IndicaLabs), we applied dedicated spatial statistics to measure the extent of overlap between the areas occupied by myeloid and T cells. With this approach, we observed distinct spatial organizational patterns of immune cells in tumors obtained from 74 treatment-naive CRC patients. Detailed analysis of inter-cell distances and myeloid-T cell spatial overlap combined with integrated gene expression data allowed to stratify patients irrespective of their mismatch repair (MMR) status or consensus molecular subgroups (CMS) classification. In addition, generation of cell distance-derived gene signatures and their mapping to the TCGA data set revealed associations between spatial immune cell distribution in TiME and certain subsets of CD8⁺ and CD4⁺ T cells. The presented study sheds a new light on myeloid and T cell interactions in TiME in CRC patients. Our results show that CRC tumors present distinct distribution patterns of not only T effector cells but also tumor resident myeloid cells, thus stressing the necessity of more comprehensive characterization of TiME in order to better predict cancer prognosis. This research emphasizes the importance of a multimodal approach by combining computational pathology with its detailed spatial statistics and gene expression profiling. Finally, our study presents a novel approach to cancer patients’ characterization that can potentially be used to develop new immunotherapy strategies, not based on classical biomarkers related to CRC biology.

Society for Immunotherapy of Cancer clinical and biomarkers data sharing resource document: Volume I-conceptual challenges

The sharing of clinical trial data and biomarker data sets among the scientific community, whether the data originates from pharmaceutical companies or academic institutions, is of critical importance to enable the development of new and improved cancer immunotherapy modalities. Through data sharing, a better understanding of current therapies in terms of their efficacy, safety and biomarker data profiles can be achieved. However, the sharing of these data sets involves a number of stakeholder groups including patients, researchers, private industry, scientific journals and professional societies. Each of these stakeholder groups has differing interests in the use and sharing of clinical trial and biomarker data, and the conflicts caused by these differing interests represent significant obstacles to effective, widespread sharing of data. Thus, the Society for Immunotherapy of Cancer (SITC) Biomarkers Committee convened to identify the current barriers to biomarker data sharing in immuno-oncology (IO) and to help in establishing professional standards for the responsible sharing of clinical trial data. The conclusions of the committee are described in two position papers: Volume I-conceptual challenges and Volume II-practical challenges, the first of which is presented in this manuscript. Additionally, the committee suggests actions by key stakeholders in the field (including organizations and professional societies) as the best path forward, encouraging the cultural shift needed to ensure responsible data sharing in the IO research setting.

Abstract 6135: Tumor-bearing non-human primates: An unrivaled model for translational cancer immunology research

The translatability of mouse models for the clinical development of cancer immunotherapies remains limited because of substantial differences between the murine and the human immune systems, as well as dissimilarities in the tumor biology. Non-human primates (NHPs) display good homologies towards the human immune system, based on the development of vaccines to several human pathogens. Tumor-bearing monkeys (TBMs) are NHPs that spontaneously developed cancer with progression patterns similar to humans, potentially bridging the experimental gap between early preclinical models and cancer patients treated with immunotherapeutic agents.

TBMs are prevalently rhesus macaques (Macaca mulata) and the most common cancer types are of gastrointestinal, urogenital and endocrine origin. Rhesus macaques are genetically similar to humans and share many characteristics of aging. In both, humans and rhesus macaques, cancer incidence increases with age with the greatest incidence in those over 60 years of age and 20 years, respectively.

TBMs were recently employed to assess the tumor targeting and the pharmacodynamics of the FAP-expressing tumor stroma-targeted immunocytokine FAP-IL2v (Evers et al, AACR 2014, Abstract 2592) and costimulatory agonist FAP-4-1BBL (Claus et al, Science translational Medicine, 2019). In the latter study, we could show targeting of FAP-4-1BBL to FAP-expressing tumor stroma and lymph nodes in a colorectal cancer-bearing rhesus monkey. These data were the basis to investigate tumor targeting of FAP-4-1BBL in an on-going clinical imaging study.

In the present work, we validated further TBMs as translational models for cancer immunotherapy, by performing an imaging/biomarker study in animals exposed to a second FAP-targeted TNFRSF agonist. Two breast cancer-bearing rhesus monkeys (one triple-negative and one Luminal A) were first pre-immunized with a diphtheria/pertussis/tetanus (DTP) vaccine, and then exposed to a single injection of the TNFRSF agonist. In both animals, we could measure a strong systemic immune activation, induction of the TNFRSF agonist in T cells and also tumor regression. These observations validated the applied pre-immunization strategy to induce the TNFRSF protein expression, and confirmed the target to be pursued in the clinical setting.

In conclusion, we consider TBMs as valuable translational animal models to generate proof-of-mechanism evidence in small “signal-seeking” preclinical studies. Tumor targeting, biodistribution, peripheral and intra-tumoral pharmacodynamic activity, pharmacokinetics, immunogenicity, intra-tumoral metabolic activity and tumor regression can all be assessed in TBMs. Because of the similar tumor stroma biology shared between humans and rhesus macaques, TBMs are particularly well suited to test FAP-targeting agents. We anticipate that testing cancer immunotherapy compounds in TBMs could be of high predictability for clinical behavior.

Citation Format: Maurizio Ceppi, Michael Hettich, Volker Teichgräber, Wouter Driessen, Dietrich Tuerck, Estelle Marrer-Berger, Stefan Evers, Flavio Crameri, Bruno Gomes, Jürgen Bachl, Christian Klein, Christina Claus, Maria Amann, Oliver Krieter, Greg Dugan, David Caudell, Jason Grayson, Sai Kumar Solingapuram Kiran, Mark Cline. Tumor-bearing non-human primates: An unrivaled model for translational cancer immunology research [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 6135.

Abstract 2051: Precision immune phenotyping from primary tumor and metastatic lesions reveals novel insights into therapeutic intervention in cancer immunotherapy

A key question in cancer immunotherapy is the general immune status of the patient's tumor-microenvironment (TME) prior to therapy. A patient's underlying tumor immune-contexture may therefore a) guide the therapeutic intervention and b) help to identify potential resistance mechanisms to immunotherapies. The most commonly used classification of the patients' immune status is based on the CD8 tumor infiltrating lymphocytes (TIL) status referring to either “cold”- or “hot” tumors. Patients in early clinical development programs will mostly present with late metastatic disease and therefore the immune phenotypes from these lesions may more relevant to determine the actual tumor-immune contexture status than the currently used characterization based on the primary tumor type. In this study, we systematically analyzed the CD8 immune phenotype (CD8 IP) in 454 patients from various Phase 1 clinical trials using the commonly applied CD8 immnohistochemistry (IHC)-based classification into cold (CD8 deserts) and hot (CD8 excluded and inflamed) tumors and matched gene expression profiling. In total, we observed 116 inflamed, 95 excluded, and 243 desert phenotypes from 25 different indications. The main sources of tumor biopsy tissues were liver metastasis (N=151), lymph node (N=73) as well as lung (N=59). Overall, we identified a significant overrepresentation of the desert phenotype in liver metastasis (p=1e-05). In patients with metastatic disease, we compared the predominant CD8 IP in metastatic lesions to that of the primary tumor. The overall distribution for tumor types such as UBC, NSCLC or OvCa did not change, whereas PDAC, GC, and CRC revealed a significant change towards the desert phenotype for metastatic lesions. Beyond the predominant CD8 IP assessment via IHC, we characterized each CD8 subtype further using specific immune gene signatures. We could identify a reverse correlation of inflammatory and suppressive immune signatures along the CD8 phenotypes in metastatic lesions such as M2-like macrophages, MDSC, or Dendritic Cells. Further zooming into the desert phenotype, we were also able to show that liver metastasis have a more significant immunosuppressive tumor environment compared to other tumor biopsies. In summary, our data provide essential insights about the importance of the origin of the tissue biopsy to reduce impaired decision making based on the underlying tumor-immune contexture of cancer patients. Precision immune phenotyping beyond CD8 TIL infiltration is needed to identify specific resistance mechanisms to cancer immunotherapy and can be used for efficient patient enrichment and thus increase the probability of success for early clinical trials in immuno-oncology.

Citation Format: Andreas Roller, Claudia Ferreira, Laura Jarassier, Astrid Heller, Gabriele Dietmann, Konstanty Korski, Bruno Gomes, Michael A. Cannarile. Precision immune phenotyping from primary tumor and metastatic lesions reveals novel insights into therapeutic intervention in cancer immunotherapy [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 2051.

Insecticide resistance selection and reversal in two strains of Aedes aegypti

Background: Laboratory reared mosquito colonies are essential tools to understand insecticide action. However, they differ considerably from wild populations and from each other depending on their origin and rearing conditions, which makes studying the effects of specific resistance mechanisms difficult. This paper describes our methods for establishing multiple resistant strains of Aedes aegypti from two colonies as a new resource for further research on metabolic and target site resistance. Methods: Two resistant colonies of Ae. aegypti, from Cayman and Recife, were selected through 10 generations of exposure to insecticides including permethrin, malathion and temephos, to yield eight strains with different profiles of resistance due to either target site or metabolic resistance. Resistance ratios for each insecticide were calculated for the selected and unselected strains. The frequency of kdr alleles in the Cayman strains was determined using TaqMan assays. A comparative gene expression analysis among Recife strains was conducted using qPCR in larvae (CCae3A, CYP6N12, CYP6F3, CYP9M9) and adults (CCae3A, CYP6N12, CYP6BB2, CYP9J28a). Results: In the selected strain of Cayman, mortality against permethrin reduced almost to 0% and kdr became fixated by 5 generations. A similar phenotype was seen in the unselected homozygous resistant colony, whilst mortality in the susceptible homozygous colony rose to 82.9%. The Recife strains showed different responses between exposure to adulticide and larvicide, with detoxification genes in the temephos selected strain staying similar to the baseline, but a reduction in detoxification genes displayed in the other strains. Conclusions: These selected strains, with a range of insecticide resistance phenotypes and genotypes, will support further research on the effects of target-site and/or metabolic resistance mechanisms on various life-history traits, behaviours and vector competence of this important arbovirus vector.

Randomized, double-blind trial of F14512, a polyamine-vectorized anticancer drug, compared with etoposide phosphate, in dogs with naturally occurring lymphoma

Purpose: F14512 is an epipodophyllotoxin derivative from etoposide, combined with a spermine moiety introduced as a cell delivery vector. The objective of this study was to compare the safety and antitumor activity of F14512 and etoposide phosphate in dogs with spontaneous non-Hodgkin lymphoma (NHL) and to investigate the potential benefit of F14512 in P-glycoprotein (Pgp) overexpressing lymphomas.

Experimental Design: Forty-eight client-owned dogs with intermediate to high-grade NHL were enrolled into a randomized, double-blind trial of F14512 versus etoposide phosphate. Endpoints included safety and therapeutic efficacy.

Results: Twenty-five dogs were randomized to receive F14512 and 23 dogs to receive etoposide phosphate. All adverse events (AEs) were reversible, and no treatment-related death was reported. Hematologic AEs were more severe with F14512 and gastrointestinal AEs were more frequent with etoposide phosphate. F14512 exhibited similar response rate and progression-free survival (PFS) as etoposide phosphate in the global treated population. Subgroup analysis of dogs with Pgp-overexpressing NHL showed a significant improvement in PFS in dogs treated with F14512 compared with etoposide phosphate.

Conclusion: F14512 showed strong therapeutic efficacy against spontaneous NHL and exhibited a clinical benefice in Pgp-overexpressing lymphoma superior to etoposide phosphate. The results clearly justify the evaluation of F14512 in human clinical trials.

Yeast-encapsulated essential oils: a new perspective as an environmentally friendly larvicide

BACKGROUND

Effective mosquito control approaches incorporate both adult and larval stages. For the latter, physical, biological, and chemical control have been used with varying results. Successful control of larvae has been demonstrated using larvicides including insect growth regulators, e.g. the organophosphate temephos, as well as various entomopathogenic microbial species. However, a variety of health and environmental issues are associated with some of these. Laboratory trials of essential oils (EO) have established the larvicidal activity of these substances, but there are currently no commercially available EO-based larvicides. Here we report on the development of a new approach to mosquito larval control using a novel, yeast-based delivery system for EO.

METHODS

Food-grade orange oil (OO) was encapsulated into yeast cells following an established protocol. To prevent environmental contamination, a proprietary washing strategy was developed to remove excess EO that is adsorbed to the cell exterior during the encapsulation process. The OO-loaded yeast particles were then characterized for OO loading, and tested for efficacy against Aedes aegypti larvae.

RESULTS

The composition of encapsulated OO extracted from the yeast microparticles was demonstrated not to differ from that of un-encapsulated EO when analyzed by high performance liquid chromatography. After lyophilization, the oil in the larvicide comprised 26-30 percentage weight (wt%), and is consistent with the 60-65% reduction in weight observed after the drying process. Quantitative bioassays carried with Liverpool and Rockefeller Ae. aegypti strains in three different laboratories presented LD₅₀ of 5.1 (95% CI: 4.6-5.6) to 27.6 (95% CI: 26.4-28.8) mg/l, for L1 and L3/L4 mosquito larvae, respectively. LD₉₀ ranged between 18.9 (95% CI: 16.4-21.7) mg/l (L1 larvae) to 76.7 (95% CI: 69.7-84.3) mg/l (L3/L4 larvae).

CONCLUSIONS

The larvicide based on OO encapsulated in yeast was shown to be highly active (LD₅₀ < 50 mg/l) against all larval stages of Ae. aegypti. These results demonstrate its potential for incorporation in an integrated approach to larval source management of Ae. aegypti. This novel approach can enable development of affordable control strategies that may have significant impact on global health.

Abstract B048: A Promising Pathway in Immuno-oncology: CD73-Adenosine axis highlighted by quantitative mass spectrometry imaging

Introduction: The CD73-Adenosine (CD73-ADO) axis constitutes one of the most promising pathways in immuno-oncology. CD73 catalyzes the conversion of adenosine monophosphate (AMP) to ADO. CD73 is believed to play a role in mediating the inhibitory function of regulatory B and T cells. It is widely expressed and up-regulated in many cancerous tissues. The presence of extracellular ADO within tumor microenvironment has been described as an immunosuppressive halo surrounding the tumor, permeating the tumor microenvironment and preventing antitumor immunity. In this study, the endogenous level of AMP and ADO were analyzed by quantitative mass spectrometry imaging (QMSI) and LC-MS/MS in CT26 tumor mouse model. Clones with different CD73 expression levels were selected (low, medium & high), which mimed different CD73-inhibitors efficacies. Then, ADO metabolic pathway was targeted in order to highlight the tumor microenvironment response linked to a mimic immunotherapy effect. Methods: Undifferentiated colon carcinoma CT26 cell line was implanted into C57BL/6 mice. Then, tumors were harvested and frozen at -80°C until use. 1,5-diaminonaphthalene (1,5-DAN) and 2,5-dihydroxybenzoic acid (2,5-DHB) matrices mixed to internal standards were sprayed onto tumor sections of 10 µm thickness with the automatic TM Sprayer (HTX Technologies, LLC) prior analysis. Data acquisition was performed using 7T MALDI-FTICR (SolariX XR, Bruker Daltonics) and analyses were set at 120µm spatial resolution in full scan positive and negative modes. Acquired data were treated with MultimagingTM software (ImaBiotech). All quantitative results were confirmed by LC-MS/MS analysis. Histological and immunohistochemistry staining anti-CD73 were applied on adjacent section. Results: A validation of CT26 mouse model occurred since an increase of ADO/AMP ratio of 77% was relative to the high CD73 expression. In other words, CT26 mouse models with high CD73 expression showed higher ADO/AMP ratio (2.1) than CT26 medium (1.7) and low (1.6) clones. Then, as an immunosuppressive halo, the impact of ADO expression on tumor microenvironment was also characterized using MSI analysis. A large number of metabolites that are implicated in this pathway were highlighted (ADP, IMP, GMP, Guanosine, Inosine, Hypoxanthine, Xanthine, Uric acid…) and differences were also observed. Conclusion: The combination of all these data extended our understanding on the relative contribution of ADO signaling in suppressing antitumor immunity. Because the development of immunotherapies such as CD73 inhibitor requires a deep understanding of the interplay between the immune system and cancer cells in the tumor microenvironment, these immune/tumor metabolites and nutrients can now be followed by QMSI as biomarkers of response to treatment towards enhancing immunotherapies efficacy.

Citation Format: Lauranne Poncelet, Rima Ait-Belkacem, Bruno Gomes, Jonathan Stauber. A Promising Pathway in Immuno-oncology: CD73-Adenosine axis highlighted by quantitative mass spectrometry imaging [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B048. doi:10.1158/1535-7163.TARG-19-B048

Setting up a collaborative European human biological monitoring study on occupational exposure to hexavalent chromium

The EU human biomonitoring initiative, HBM4EU, aims to co-ordinate and advance human biomonitoring (HBM) across Europe. Within its remit, the project is gathering new, policy relevant, EU-wide data on occupational exposure to relevant priority chemicals and developing new approaches for occupational biomonitoring. In this manuscript, the hexavalent chromium [Cr(VI)] study design is presented as the first example of this HBM4EU approach. This study involves eight European countries and plans to recruit 400 workers performing Cr(VI) surface treatment e.g. electroplating or stainless steel welding activities. The aim is to collect new data on current occupational exposure to Cr(VI) in Europe and to test new methods for Cr biomonitoring, specifically the analysis of Cr(VI) in exhaled breath condensate (EBC) and Cr in red blood cells (RBC) in addition to traditional urinary total Cr analyses. Furthermore, exposure data will be complemented with early biological effects data, including genetic and epigenetic effects. Personal air samples and wipe samples are collected in parallel to help informing the biomonitoring results. We present standard operational procedures (SOPs) to support the harmonized methodologies for the collection of occupational hygiene and HBM samples in different countries.

Phylogeography and invasion history of Aedes aegypti, the Dengue and Zika mosquito vector in Cape Verde islands (West Africa)

Aedes-borne arboviruses have spread globally with outbreaks of vast impact on human populations and health systems. The West African archipelago of Cape Verde had its first outbreak of Dengue in 2009, at the time the largest recorded in Africa, and was one of the few African countries affected by the Zika virus epidemic. Aedes aegypti was the mosquito vector involved in both outbreaks. We performed a phylogeographic and population genetics study of A. aegypti in Cape Verde in order to infer the geographic origin and evolutionary history of this mosquito. These results are discussed with respect to the implications for vector control and prevention of future outbreaks. Mosquitoes captured before and after the Dengue outbreak on the islands of Santiago, Brava, and Fogo were analyzed with two mitochondrial genes COI and ND4, 14 microsatellite loci and five kdr mutations. Genetic variability was comparable to other African populations. Our results suggest that A. aegypti invaded Cape Verde at the beginning of the Holocene from West Africa. Given the historic importance of Cape Verde in the transatlantic trade of the 16th-17th centuries, a possible contribution to the genetic pool of the founding populations in the New World cannot be fully discarded. However, contemporary gene flow with the Americas is likely to be infrequent. No kdr mutations associated with pyrethroid resistance were detected. The implications for vector control and prevention of future outbreaks are discussed.