Immune-related Response Research Articles

The Role of Head Associated Lymphoid Tissues in Infectious Bronchitis Virus

Infectious bronchitis virus (IBV) replicates primarily in the epithelial tissues of the respiratory tract, particularly the trachea. However, little is known about IBV replication and immune responses in relation to head-associated lymphoid tissue (HALT), such as the Harderian gland (HG) and choanal cleft, as well as respiratory (turbinate) tissues. Furthermore, few studies have looked into the role of the HG, choanal cleft, pharyngeal tissues, and turbinate in innate, cellular, and mucosal immune responses of commercial broiler chickens and laying hens infected with IBV, compared to the studies about the effects on the trachea. This review article overviewed the role of avian HALT, conjunctival-associated lymphoid tissue (CALT), concerning the anatomical, physiological, and immune responses to infectious bronchitis disease in chickens. The HG, choanal cleft, and turbinate in innate, mucosal, and cellular immune responses play a significant role in avian protection through virulent or attenuated vaccines of IBVs. The IBV viruses could not reach the trachea in chickens vaccinated with IBV vaccine due to the inhibition of viruses by HALT and respiratory tissues by innate, mucosal, and cellular immunity. It can be concluded that other than the trachea, the HALT and respiratory tissues play an important role in the infectivity and immune induction against IBVs due to their proximity to the upper air passages. Keywords: Avian immunity, Chicken, Harderian gland, Infectious bronchitis, Turbinate

Abstract P3-06-10: Immune-related adverse events (irAEs) and pathological complete response (pCR) rates in patients receiving neoadjuvant chemotherapy (CHT) and pembrolizumab (PEM) for early triple-negative breast cancer (eTNBC)

Abstract Background and Significance: Recently, the addition of the immune checkpoint-inhibitor PEM to CHT was shown to increase pCR rates and invasive event-free survival in the Keynote-522 (KN522) trial. Several irAEs are known to occur during use of PEM in various cancer entities. In our multicenter analysis we aimed to identify real-world occurrence rates of irAES and pCR rates in women receiving PEM and CHT, analogously to KN522, for eTNBC treatment. Methods: All patients receiving CHT + PEM for eTNBC treatment at participating centers were followed prospectively and monitored for occurrence of irAEs and neoadjuvant treatment outcome as defined by pCR from October 2020 until data cut-off on September 15th 2022. Only patients who underwent surgery for their primary tumor before data cut-off were included. Results: A total number of 22 patients with available pCR outcomes were included. All patients were female. Median age was 51 years (range 25-72). Mean tumor size at baseline was 29mm (range 10-75). 41% (9/22) of patients exhibited nodal involvement according to baseline radiological findings. Median MIB-1/Ki67 expression at biopsy was 70%. Patients received a median of 8 (range 1-8) neoadjuvant cycles of PEM and exhibited a median duration of CHT of 24 weeks (range 4-24). Neoadjuvant PEM was discontinued in 32% (7/22) of patients. Discontinuation of neoadjuvant treatment before week 18 occurred in 22,7% (5/22) of patients. We report irAE rates of any kind and all grades of 50% (11/22) and of grade 3-4 in 9% of patients (2/22). Steroids were administered in 7/11 patients experiencing irAEs (64%). 8 irAEs occurred during the neoadjuvant treatment phase, 3 during postneoadjuvant treatment with PEM. No grade 5 toxicity was observed. irAEs observed were hypothyroidism (n=3, all grade 2), arthritis (n=3, all grade 2), myocarditis (n=2, one grade 3/one grade 4), and single cases of hepatitis (grade 2), nephritis (grade 3) and pneumonitis (grade 1). 18% (4/22) of patients underwent mastectomy and 36% (8/22) of patients underwent axillary dissection. Lastly, upon definitive surgery of the primary tumor, we observed pCR in 50% (11/22) of cases. Patients who completed >18 weeks of neoadjuvant therapy exhibited a pCR rate of 59% (10/17), whilst patients who completed ≤18 weeks of neoadjuvant therapy reached pCR in 20% of cases (1/5). Conclusion: We report real-world prospective data about irAE as well as pCR rates during eTNBC treatment with PEM and CHT. irAEs occurred in similar rates as observed in KN522, although numerically higher for irAEs of all grades. The pCR rate within our cohort was numerically lower than reported for KN522, most probably due to a low pCR rate observed for 5 of 22 patients included in this analysis who completed ≤18 weeks of neoadjuvant treatment. Looking at our data, we hypothesize that clinical benefit from combination therapy of PEM and CHT depends on reaching an adequate duration of >18 weeks of neoadjuvant treatment. Citation Format: Maximilian Marhold, Simon Udovica, Kerstin Wimmer, Zsuzsanna Bago-Horvath, Tim Robinson, Florian Fitzal, Kathrin Strasser-Weippl, Rupert Bartsch. Immune-related adverse events (irAEs) and pathological complete response (pCR) rates in patients receiving neoadjuvant chemotherapy (CHT) and pembrolizumab (PEM) for early triple-negative breast cancer (eTNBC) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-06-10.

Radiomics-guided checkpoint inhibitor immunotherapy for precision medicine in cancer: A review for clinicians.

Immunotherapy using immune checkpoint inhibitors (ICIs) is a breakthrough in oncology development and has been applied to multiple solid tumors. However, unlike traditional cancer treatment approaches, immune checkpoint inhibitors (ICIs) initiate indirect cytotoxicity by generating inflammation, which causes enlargement of the lesion in some cases. Therefore, rather than declaring progressive disease (PD) immediately, confirmation upon follow-up radiological evaluation after four-eight weeks is suggested according to immune-related Response Evaluation Criteria in Solid Tumors (ir-RECIST). Given the difficulty for clinicians to immediately distinguish pseudoprogression from true disease progression, we need novel tools to assist in this field. Radiomics, an innovative data analysis technique that quantifies tumor characteristics through high-throughput extraction of quantitative features from images, can enable the detection of additional information from early imaging. This review will summarize the recent advances in radiomics concerning immunotherapy. Notably, we will discuss the potential of applying radiomics to differentiate pseudoprogression from PD to avoid condition exacerbation during confirmatory periods. We also review the applications of radiomics in hyperprogression, immune-related biomarkers, efficacy, and immune-related adverse events (irAEs). We found that radiomics has shown promising results in precision cancer immunotherapy with early detection in noninvasive ways.

A phase II trial of pembrolizumab combined with platinum-based chemotherapy as first-line systemic therapy in advanced penile cancer: HERCULES (LACOG 0218) trial.

TPS14 Background: Penile squamous cell carcinoma (PSCC) is an uncommon malignancy which accounts for 2,300 new cases and 400 deaths annually worldwide. However, in low-income countries from South America, Asia and Africa, incidence corresponds to 10-20% of all malignancies in men. Approximately 4% of PSCC patients present with metastatic disease at diagnosis. Also, even if diagnosed in early stages (localized disease), around 30% of patients will recur. No improvements have been achieved over the last three decades in platinum-based chemotherapy, which remains the standard-of-care; objective response rate (ORR), median progression-free survival (PFS) and overall survival (OS) are currently at 20-30%, 3-4 months and 7-15 months, respectively. HPV16 is the most important known risk factor for PSCC. Favorable results have been achieved with Pembrolizumab in other HPV-associated cancers, such as cervical and oropharyngeal cancer. HERCULES (LACOG 0218) aims to evaluate the efficacy of pembrolizumab combined with platinum-based chemotherapy as first-line treatment in advanced PSCC. Methods: HERCULES is a phase 2, single-arm, multicentric trial evaluating patients with histologically proven PSCC and metastatic disease (de novo or recurrent); or recurrent locally advanced disease not amenable to curative-intent therapy; or TanyN3M0 or T4NanyM0 (stage IV – AJCC 8th ed) not amenable to curative-intent therapy. Additional inclusion criteria were ECOG PS 0–1; measurable disease by RECIST 1.1; no prior systemic therapy for recurrent or metastatic disease (however, patients progressing after 12 months of neo/adjuvant chemotherapy completion are allowed). The primary endpoint is ORR up to week 24. Secondary endpoints are OS, PFS, clinical benefit rate, immune related response criteria, quality of life, safety, and predictive biomarkers of response/survival. Eligible subjects receive 5-FU 1000mg/m²/day IV D1-D4, cisplatin 70mg/m² or carboplatin AUC 5 IV D1 plus pembrolizumab 200mg IV D1 at each 3-week (Q3W) dosing cycle for 6 cycles, followed by Pembrolizumab 200mg IV Q3W maintenance. Patients without disease progression are allowed to continue pembrolizumab monotherapy until completing 34 cycles, disease progression or unacceptable toxicity, whichever comes first. Tumor evaluations are performed every 6 weeks until week 24. Sample size was calculated as 33 patients to detect an increase in ORR from 20% to 40% up to week 24 with 78.5% power and considering 10% drop-out. From Aug 2020 to Jul 2022, 33 patients were enrolled in 11 Brazilian research sites. Results are expected in 2023. NCT04224740. Clinical trial information: NCT04224740 .

Plasma Proteomic Variables Related to COVID-19 Severity: An Untargeted nLC-MS/MS Investigation.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection leads to a wide range of clinical manifestations and determines the need for personalized and precision medicine. To better understand the biological determinants of this heterogeneity, we explored the plasma proteome of 43 COVID-19 patients with different outcomes by an untargeted liquid chromatography-mass spectrometry approach. The comparison between asymptomatic or pauci-symptomatic subjects (MILDs), and hospitalised patients in need of oxygen support therapy (SEVEREs) highlighted 29 proteins emerged as differentially expressed: 12 overexpressed in MILDs and 17 in SEVEREs. Moreover, a supervised analysis based on a decision-tree recognised three proteins (Fetuin-A, Ig lambda-2chain-C-region, Vitronectin) that are able to robustly discriminate between the two classes independently from the infection stage. In silico functional annotation of the 29 deregulated proteins pinpointed several functions possibly related to the severity; no pathway was associated exclusively to MILDs, while several only to SEVEREs, and some associated to both MILDs and SEVEREs; SARS-CoV-2 signalling pathway was significantly enriched by proteins up-expressed in SEVEREs (SAA1/2, CRP, HP, LRG1) and in MILDs (GSN, HRG). In conclusion, our analysis could provide key information for 'proteomically' defining possible upstream mechanisms and mediators triggering or limiting the domino effect of the immune-related response and characterizing severe exacerbations.

Functional and molecular immune responses in Octopus vulgaris skin mucus and haemolymph under stressful conditions

The common octopus (Octopus vulgaris) is a cephalopod species with a high economic market value, hence one of the species in spotlight to be reared in aquaculture. The increasing importance of animal welfare has ethical considerations and also implications for improving quality standards. Unfortunately, defence mechanisms in cephalopods are largely unexplored and a comprehensive insight on cephalopod physiological and immune responses in relation to stress becomes particularly prominent. Therefore, the aim of the present study was to gather deeper insights on functional and molecular stress biomarkers in the common octopus. For this purpose, adult individuals were exposed to a stressful condition by limiting movements in the aquarium for 17 days. Innate immune parameters were assessed in skin mucus and plasma samples whereas the expression level of genes coding for antioxidant enzymes, related to immune functions, or involved in folding proteins was analysed in haemocytes at several sampling times. Our results indicated that most of the innate immune parameters measured (haemolytic, lysozyme, esterase, peroxidase, and protease activities) in skin mucus showed substantial variations at middle term of experiment (i.e., 11 days). After 11 days of movement limitations, the haemolytic and protease activities decreased in the octopus plasma. At the transcriptional level, lyz, hsp90 and ire1 gene expression values were particularly down-regulated while C1-like, prdx and sod transcripts showed up-regulation over an early stage (i.e., 5 days) in haemocytes from octopuses under stressful conditions. Moreover, C1-like, prdx and sod mRNA expression decreased at 11 and 17 days whereas lyz and hsp90 gene expression level augmented at 11 days in exposed octopus compared to unexposed specimens, with the subsequent increase at plasma and skin mucus level at long term. Overall, results from the present study showed potential functional and molecular biomarkers which could be of assistance in studies comprising stressful conditions in the common octopus. Moreover, biomarkers from skin mucus could also be considered as a low-invasive approach to assess and improve cephalopods welfare.

MicroRNAs induced by Listeria monocytogenes and their role in cells.

Listeria monocytogenes (Lm) causes abortions at high rates and threatens newborns' lives. Also, the elderly and immunocompromised individuals are particularly vulnerable neurologically. The bacterium exerts its pathogenesis intracellularly by manipulating cell organs. It manipulates nucleus elements, microRNAs (miRNAs), in order to increase survival and evade immunity. miRNAs are small non-coding RNAs that degrade gene expression post-transcriptionally. Any alteration to the expression of miRNAs affects various cascades in cells, especially immunity-related responses. Thus, utilizing miRNAs as a novel therapeutic agent not only restricts infection but enhances immunity reactions. This review provides an overview of miRNAs in listeriosis, their role in cells, and their prospects as therapy.

Phase 1b study of intravenous coxsackievirus A21 (V937) and ipilimumab for patients with metastatic uveal melanoma

PurposeNo standard of care therapy exists for patients with metastatic uveal melanoma who are not HLA-A2:01 positive. The phase 1b, open-label CLEVER study (NCT03408587) evaluated V937 in combination with ipilimumab in patients with uveal melanoma.MethodsAdults with advanced uveal melanoma and liver metastases received up to 8 cycles of intravenous V937 (1 × 109 TCID50 per infusion; infusions on days 1, 3, 5, and 8 [cycle 1], then every 3 weeks [Q3W] thereafter [cycles 2–8]) and 4 cycles of intravenous ipilimumab 3 mg/kg Q3W (beginning at cycle 1 day 8). The primary endpoint was safety. Secondary endpoints included objective response rate and progression-free survival (PFS) per immune-related Response Evaluation Criteria in Solid Tumors (irRECIST).ResultsEleven patients were enrolled (median age, 65.0 years) and received a median of 6 injections of V937 and 3.5 infusions of ipilimumab. The best overall response was stable disease in 3 patients and progressive disease in 8 patients. All patients exhibited progression per irRECIST, with a 9% irPFS rate at week 26. Ten patients had treatment-related AEs, the most frequent of which were diarrhea (55%), fatigue (45%), and myalgia (36%). Two grade 3 AEs (diarrhea, n = 2) were considered related to ipilimumab; neither was related to V937.ConclusionAlthough the combination of V937 with ipilimumab had a manageable safety profile, meaningful clinical benefit was not observed in patients with uveal melanoma and liver metastases.Trial registrationClinicalTrials.gov, NCT03408587 (January 24, 2018).

Evaluation of humoral immune response in relation to COVID-19 severity over 1 year post-infection: critical cases higher humoral immune response than mild cases.

Coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2. We investigated the antibody response against SARS-CoV-2 until 1 year after symptom onset. We collected 314 serum samples from 97 patients with COVID-19. Antibody responses were tested using an indirect immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), and plaque reduction neutralization test (PRNT) to detect specific neutralizing antibodies. The positivity rates for neutralizing antibodies at a 1:10 titer cutoff were 58.1% at 1 week, 97.8% at 4 weeks, and 78% at 1 year after symptom onset (53.8% in asymptomatic patients and 89.3% in symptomatic patients). The IFA and anti-S1 ELISA IgG results significantly correlated with neutralizing antibody titers. Critical/fatal cases showed significantly higher antibody titers than the asymptomatic or mild-to-moderate illness groups. Nonetheless, the median number of days to the seroconversion of neutralizing antibodies was 10 and 15 in asymptomatic and symptomatic patients, respectively. The asymptomatic group had a significantly higher neutralizing potency index than the mild-to-severe illness groups. Neutralizing antibodies corresponded to earlier seroconversion but had a shorter presence in the asymptomatic group than in the symptomatic group and were still present 1 year after symptom onset in critical/fatal cases.

Weighted gene co-expression network analysis combined with machine learning validation to identify key hub biomarkers in colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies worldwide; however, the potentially possible molecular biological mechanism of CRC is still not completely comprehended. This study aimed to confirm candidate key hub genes involved in the growth and development of CRC and their connection with immune infiltration as well as the related pathways. Gene expression data were selected from the GEO dataset. Hub genes for CRC were identified on the basis of differential expression analysis, weighted gene co-expression network analysis (WGCNA), and LASSO regression. Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Gene Set Enrichment Analysis (GSEA) were applied to reveal possible functions of the differential genes. Single-sample GSEA (ssGSEA) was implemented to identify the relationship between immune cells infiltration and hub genes. Two hundred and sixty-two differentially expressed genes (DEGs) were identified. Three modules were acquired based on WGCNA, and the blue module presented the highest relevance with CRC. Ten hub genes (AQP8, B3GALT5, CDH3, CEMIP, CPM, FOXQ1, PLAC8, SCNN1B, SPINK5, and SST) were acquired with LASSO analysis as underlying biomarkers for CRC. Compared with normal tissues, CRC tissues presented significantly higher numbers of CD4 T cells, CD8 T cells, B cells, natural regulatory T (Treg) cells, and monocytes. The functional enrichment analyses demonstrated that hub genes were primarily enriched in metabolic process, inflammatory-related, and immune-related response. Ten hub genes were identified to be involved in the occurrence and development of CRC and may be deemed as novel biomarkers for clinical diagnosis and treatment.

Intratumoral oncolytic virus V937 plus ipilimumab in patients with advanced melanoma: the phase 1b MITCI study

BackgroundIntratumoral administration of V937, a bioselected, genetically unmodified coxsackievirus A21, has previously demonstrated antitumor activity in patients with advanced melanoma as monotherapy and in combination with the programmed cell death...

Infection Characteristics and Transcriptomics of African Swine Fever Virus in Bama Minipigs.

Animal experiments on African swine fever virus (ASFV) are vital to the study of ASFV; however, ASFV can only infect pigs, and animal experiments need to be performed in animal biosafety level 3 (ABSL-3) laboratories, meaning that many small ABSL-3 laboratories are unable to carry out in vivo ASFV experiments. Therefore, miniaturized experimental animals for ASFV infection are urgently needed. Here, we successfully isolated genotype II of ASFV SY-1 from wild boars and evaluated ASFV-infected Bama minipigs in a negative-pressure isolator of a small ABSL-3 laboratory. The pathological changes of ASFV-infected Bama minipigs were consistent with characteristic lesions of ASFV-infected domestic pigs and wild boars. All pigs died 5 to 14 days postinfection (dpi) through intramuscular injection. Viral genomic DNA from nasal, oral, and rectal swab samples was first detectable at 2 to 4 dpi. The common differentially expressed genes were clustered in the immune-related, metabolic, and inflammatory response pathways from the spleen and inguinal lymph node samples comparing infected to mock. In summary, these results demonstrated that the Bama minipig was an appropriate model for ASFV infection in small ABSL-3 laboratories that can accelerate the research of vaccines and antiviral drugs and uncover pathogenic mechanisms of ASFV infection. IMPORTANCE African swine fever virus (ASFV) can only infect pigs rather than other animals. However, the domestic pigs cannot be kept in small ABSL-3 laboratories for a long time due to the characteristics of rapid growth and large size, which hinder ASFV research, including research of vaccines, antiviral drugs, and mechanisms. In contrast, Bama minipigs have unique advantages consisting of low growth and small size. In the research, Bama minipigs were used to evaluate the characteristics of ASFV infection in small ABSL-3 laboratories. The pathological changes, viral shedding, and gene regulation were consistent with those of domestic pigs infected with ASFV. Therefore, Bama minipigs can be a suitable model for ASFV infection in small ABSL-3 laboratories.

Hemodynamic response to intestinal pH stimulation measured with spectroscopic video imaging

To investigate the relationship between the gut and skin (gut-skin axis), head skin hemodynamic responses to gut stimulation including the injection of acetic acid in nude mice were measured by spectroscopic video imaging, which was calculated using a modified Beer-Lambert formula. The relationship with blood proteins was also analyzed. The blood volume changes in three mice injected with acetic acid were highly reproducible in the mathematical model equation. Four proteins correlated with blood volume changes were all related to immunity. These results suggest that intestinal pH can alter the blood volume in the skin and induce immune-related responses.

Survival Prediction Optimization of Acute Myeloid Leukemia Based on T-Cell Function-Related Genes and Plasma Proteins

Current prognostic models of gene expression profiles for acute myeloid leukemia (AML) are inconsistent at predicting clinical outcomes for individual patients. None include data on T-cell function-related genes (TFGs). Here, we identified 218 candidate genes from the bone marrow mononuclear cells bulk RNA-seq matrix in the SYSUCC-1 cohort based on the immune ProcartaPlex panel. We then identified 83 genes as TFGs with a significant Spearman correlation to a T-cell subset fraction or PD-1/CTLA-4 MFI expression. Next, we interrogated data of RNA matrices from 1,611 persons with AML extracted from public databases arrayed in training and 3 cohorts. Using a random survival forest variable hunting algorithm we developed an 8 gene T-cell function-related signature which correlated with survival after adjusting for other prognostic co-variates. The final TFG signature was determined based on validation with the best predictive performance in the real world dataset using the formula: TFG risk scores = (-0.177 × expression of CD27) + (0.26 ×expression of IL2RA) -(0.19 × expression of CD96) - (0.098 × expression of TIMP1) + (0.19 × COL18A1 expression of COL18A1) - (0.017 × expression of HGF) - (0.196 × GDF15 expression of GDF15) - (0.161 × CLEC11A expression of CLEC11A). The model had robust predictive accuracy in the training and 4 external validation cohorts with 5-year areas under receiver-operator characteristic curve (AUROCs) of 0.67-0.76(Figure 1A-D). The signature was divided into high- and low-risk scores using optimum cutoff value. 5-year survivals in the 4 high-risk cohorts were 6-23% compared with 42-58% in the 3 low-risk cohorts (all p-values < 0.001). In multi-variable analyses a high-risk score independently predicted briefer survival with Hazard Ratios (HR) = 1.28-2.59 in the training and validation cohorts (all p-values < 0.05). Gene set enrichment analyses (GESA) indicated significant enrichment for genes involved in immune suppression pathways in the high-risk cohorts. Accuracy of gene identification was validated in a real world cohort of 88 subjects by determining cognate plasma protein concentrations of these genes (Figure 1E). To investigate TFG expression depending on cell type and function in the AML bone marrow microenvironment, we performed single-cell analysis of 36,477 cells from 16 subjects with de novo AML. Using a UMAP analysis, 36,477 bone marrow-derived cells were segregated into 10 populations according to the corresponding cell markers (Figure 1F). The expression profile of model TFGs showed that most of the genes, including CD96, TIMP1, HGF, CLEC11A, and IL2RA, were upregulated in leukaemia cells. In addition, CD27 and CD96 were highly upregulated in NK&T cells (Figure 1G-H). To further understand the role of IL2RA (the gene with the largest weight)-driven functional changes in leukaemia cells of AML patients, we divided all leukaemia cells into two groups according to the expression level of IL2RA (IL2RA high- and low-expression groups) and performed DEG (Differential gene) analysis (Figure 1I). The KEGG pathways enriched in the upregulated DEG were mainly specific to transcriptional dysregulation in cancer and associated with cancer progression and immune-related responses, including human T-cell leukaemia virus-1, Epstein-Barr virus (EBV) infection and tuberculosis pathways (Figure 1J). Finally, the TFG signature and ELN2017 risk cohorts were integrated to generate a model using a nomogram, which had an accurate predictive value for 1-, 3-, and 5-year survival (Figure 1K) and increased the AUROC value from 0.76 (0.72, 0.81) to 0.82 (0.78, 0.84; P < 0.001; Figure 1L). In summary, we developed a survival prediction score based on the expression of T-cell function related genes. Adding our score to the 2017 ELN risk score increased survival prediction accuracy. The combined nomogram may help physicians select appropriate therapies.Detection of plasma protein concentrations in peripheral blood may be a simple and effective method for predicting the survival outcome and prognosis of patients with AML. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Moyamoya disease emerging as an immune-related angiopathy.

Moyamoya disease (MMD) is a rare cerebrovascular disorder with unknown etiology. MMD is characterized by progressive narrowing of arteries of the brain and the formation of a compensatory network of fragile vessels. Genetic studies have identified RNF213, also known as mysterin, as a susceptibility gene for MMD, but the low penetrance in genetically susceptible individuals suggests that a second hit is necessary to trigger disease onset. Recently, several molecular studies uncovered RNF213 as a key antimicrobial protein with important functions in the immune system. In addition, an increasing number of clinical reports describe the development of moyamoya angiopathy (MMA) associated with infection or autoimmune disorders. Together, this growing body of molecular and clinical evidence points towards immune-related responses as second hits to trigger MMD onset.

Tumor response assessment on imaging following immunotherapy.

In recent years, various systemic immunotherapies have been developed for cancer treatment, such as monoclonal antibodies (mABs) directed against immune checkpoints (immune checkpoint inhibitors, ICIs), oncolytic viruses, cytokines, cancer vaccines, and adoptive cell transfer. While being estimated to be eligible in 38.5% of patients with metastatic solid or hematological tumors, ICIs, in particular, demonstrate durable disease control across many oncologic diseases (e.g., in melanoma, lung, bladder, renal, head, and neck cancers) and overall survival benefits. Due to their unique mechanisms of action based on T-cell activation, response to immunotherapies is characterized by different patterns, such as progression prior to treatment response (pseudoprogression), hyperprogression, and dissociated responses following treatment. Because these features are not encountered in the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), which is the standard for response assessment in oncology, new criteria were defined for immunotherapies. The most important changes in these new morphologic criteria are, firstly, the requirement for confirmatory imaging examinations in case of progression, and secondly, the appearance of new lesions is not necessarily considered a progressive disease. Until today, five morphologic (immune-related response criteria (irRC), immune-related RECIST (irRECIST), immune RECIST (iRECIST), immune-modified RECIST (imRECIST), and intra-tumoral RECIST (itRECIST)) criteria have been developed to accurately assess changes in target lesion sizes, taking into account the specific response patterns after immunotherapy. In addition to morphologic response criteria, 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG-PET/CT) is a promising option for metabolic response assessment and four metabolic criteria are used (PET/CT Criteria for Early Prediction of Response to Immune Checkpoint Inhibitor Therapy (PECRIT), PET Response Evaluation Criteria for Immunotherapy (PERCIMT), immunotherapy-modified PET Response Criteria in Solid Tumors (imPERCIST5), and immune PERCIST (iPERCIST)). Besides, there is evidence that parameters on 18F-FDG-PET/CT, such as the standardized uptake value (SUV)max and several radiotracers, e.g., directed against PD-L1, may be potential imaging biomarkers of response. Moreover, the emerge of human intratumoral immunotherapy (HIT-IT), characterized by the direct injection of immunostimulatory agents into a tumor lesion, has given new importance to imaging assessment. This article reviews the specific imaging patterns of tumor response and progression and available imaging response criteria following immunotherapy.

Predictors of Response to Salvage High-Dose plus Low-Dose Radiation in Checkpoint-Inhibitor Resistant Patients

<h3>Purpose/Objective(s)</h3> Patients (pts) with immune checkpoint inhibitor (ICI)-resistant advanced cancer have poor outcomes and limited alternative treatment options. High-dose radiation therapy (HD-RT) can augment local and systemic ICI effects and lead to tumor regression outside of the treatment field (abscopal effect). Low-dose RT (LD-RT) to secondary sites may further enhance responses by modulating the stroma and facilitating immune cell infiltration. Prior studies suggest that high BED regimens may better stimulate antitumor immune responses than lower BED regimens. We explored BED and baseline pt factors as predictors of response to salvage HD-RT plus LD-RT in a <i>post hoc</i> analysis of an ongoing phase II trial. <h3>Materials/Methods</h3> We included 56 (of 60) enrolled pts with follow up imaging in our analysis. All had metastatic solid tumors that progressed on ICI. Study treatment consisted of HD-RT to 1-2 sites plus LD-RT to 1+ additional sites. HD-RT regimens included conventional RT, comprised of 20-60 Gy in 4-5 fractions (fx), or stereotactic body RT (SBRT), comprised of 27-36 Gy in 3 fx, 50 Gy in 4 fx, or 60-70 Gy in 10 fx. LD-RT consisted of 1-10 Gy total doses given in 0.5-2 Gy fxs, with 7 Gy/5 fx being the most frequent. We evaluated relationships between pt responses (disease control at 4mo post-RT, DC; overall objective response, OR; time-to-progression, TTP) and patient- and treatment-related factors with logistic and Cox proportional hazard models. PFS and response outcomes were then assessed after stratifying by HD-RT BED₁₀ (BED>100 vs BED<100). <h3>Results</h3> Of 56 pts, 20 received HD-RT with BED >100 (range 106-119) and 36 with BED <100 (range 28-96). DC (SD or PR/CR per immune related response criteria, irRC) was achieved in 28/54 pts (52%; 2 pts not evaluable for response). OR (PR/CR) occurred in 15/54 pts (28%). On UVA, HD-RT BED₁₀ was predictive of both DC (OR 1.02, P = 0.03) and OR (OR 1.03, P = 0.008). Other factors, including age, gender, histology, fx count, baseline absolute lymphocyte count (bALC), and metastatic burden (MB) did not affect DC or OR. Stratifying by BED₁₀, median PFS was greater for the BED >100 cohort than BED <100 cohort (6.5mo vs 2.5mo, HR 0.43, P = 0.009), as were DCR (78% vs 39%, OR 5.5, P = 0.01) and ORR (OR 61% vs 11%, OR 12.6, P < 0.001). Cox multivariable analysis indicated that BED >100 (HR 0.27, P < 0.001), MB (HR 1.22, P = 0.001) and bALC (HR 0.43, P < 0.001) were independent predictors of TTP. However, when stratified by IO-class (PD1/PDL1 vs CTLA-4/combo) and histology (NSCLC vs other), only BED remained consistently significant. <h3>Conclusion</h3> Salvage HD-RT plus LD-RT is a unique therapeutic approach that can re-induce disease control after ICI progression. HD-RT regimens with a higher BED₁₀ – optimally >100 – will likely provide the greatest chance of treatment success with this strategy. Larger randomized trials are needed to further explore the role of salvage RT in ICI resistance.

Predictors of Systemic Responses Induced by Salvage Radiation after Progression on Immunotherapy

<h3>Purpose/Objective(s)</h3> Radiation can induce systemic immune responses and tumor regression outside of the treatment field, a phenomenon known as the abscopal effect. Salvage high dose radiation (HD-RT) may reinvigorate antitumor immunity and re-induce disease control in patients (pts) with advanced cancer who have progressed on immune checkpoint inhibition (ICI). Prior studies suggest that BED ≥ 100 is optimal for disease control and may produce superior antitumor immune responses than lower BED regimens. We explored BED and pt factors as predictors of response to salvage HD-RT in a <i>post hoc</i> analysis of an ongoing phase II immunoradiation trial. <h3>Materials/Methods</h3> We included 50 enrolled trial pts in our analysis. All had metastatic solid tumors that progressed on ICI. Study treatment consisted of HD-RT to 1-2 sites, leaving at least 1 site untreated to monitor for abscopal response. Regimens included conventional RT, comprised of 20-30 Gy in 5 fractions (fx) or 45-52.5 Gy in 15 fx, or stereotactic body RT (SBRT), comprised of 24 Gy in 3 fx, 50 Gy in 4 fx, or 63-70 Gy in 9-10 fx. We evaluated relationships between response (disease control at 4mo post-RT, DC; overall objective response, OR; abscopal response, AR; time-to-progression, TTP) and patient- and treatment-related factors with logistic regression and Cox proportional hazard models. PFS and response outcomes were then assessed after stratifying by HD-RT BED₁₀ (BED>100 vs BED<100). <h3>Results</h3> Systemic disease control rate (DCR; SD or PR/CR per immune related response criteria, irRC) was 45% (24/49 pts; 1 pt not evaluable for response). OR (PR/CR) were observed in 8/49 pts (16%). AR (lesion-level CR/PR) were observed in 14/49 pts (29%). On multivariable analysis, HD-RT BED₁₀ (OR 111.9 P = 0.001) and baseline absolute lymphocyte count (bALC; OR 5.4 P = 0.02) predicted probability of DC, while gender, age, metastatic burden (MB), and fx count did not. Of 50 pts, 18 received HD-RT with BED >100 (range 107-119) and 32 with BED <100 (range 28-96). Stratifying by BED, median PFS was greater for the BED >100 cohort than BED <100 (8mo vs 2mo HR 0.45 P = 0.003), and DCR was 83% for BED >100 vs 28% for BED <100 (RR 2.96 P < 0.001). Although not statistically significant, ORR was also greater in BED >100 vs BED <100 (24% vs 12.5% P = 0.4), as was ARR (41% vs 22% P = 0.2). On Cox multivariable analysis, BED >100 (HR 0.27 P < 0.001), MB (HR 1.22 P < 0.001), and bALC (HR 0.43 P < 0.001) were independent predictors of TTP. Adjusting for IO class (PD1/PDL1 vs CTLA-4/combo) and histology (NSCLC vs other), each of these factors remained significant. <h3>Conclusion</h3> Salvage HD-RT after systemic progression on ICI may be a valid treatment option that is most likely to benefit pts with lower disease burden and stable ALC. RT regimens utilizing SBRT with BED₁₀ >100 will likely provide improved outcomes compared to lower BED regimens. Larger trials are indicated to validate optimal regimens and cohorts for this strategy.

Atezolizumab and Stereotactic Body Radiation Therapy in Metastatic, Recurrent or Persistent Cervical Cancer: Interim Results from a Non-Randomized, Open-Label Phase II Multi-Institutional Study

<h3>Purpose/Objective(s)</h3> Inhibition of the anti-PD-1/PD-L1 axis has been approved in the metastatic, recurrent, or persistent settings for cervical cancer. Stereotactic body radiation therapy (SBRT) has a well-defined role in the management of oligometastatic disease. There may be potential synergy between stereotactic radiation and anti-PD-1/PD-L1 checkpoint inhibition in advanced cervical cancer. We hypothesize treatment with atezolizumab and SBRT will be well tolerated and may improve tumor control rates compared to atezolizumab alone in the management of metastatic, recurrent, or persistent cervical cancer. <h3>Materials/Methods</h3> The study is designed as a prospective, single arm, nonrandomized, open-label, phase II multi-institutional trial of SBRT with 24 Gy in 3 fractions to patients with ≥ 2 metastatic sites followed 1 week later by atezolizumab (1200 mg IV every 3 weeks) for patients with recurrent, persistent, or metastatic cervical cancer. The primary objective of the study is to evaluate the objective response rate by immune-related response evaluation criteria in solid tumors (irRECIST) criteria following SBRT and atezolizumab at the unirradiated target lesion. Secondary endpoints include progression free survival (PFS), overall survival (OS), and adverse events. Results of the pre-planned interim analysis are reported. Clinical trial information: NCT03614949. <h3>Results</h3> Between January 2019 and September 2021, a total of 13 patients were enrolled. The majority of patients had adenocarcinoma (n=9; 69%) with a median age of 50 (range: 36-69). Median number of lines of prior therapy was 2 (range: 1-5). Median follow-up is 18 months (range: 2.7-35.8 months). The median PFS was 4.5 months (95% CI: 3.87- Not reached) with a 6-month PFS of 46%. The median OS was 11 months (95% CI 7.77 – Not reached) with a 6-month OS of 84%. The overall response (irRECIST) was a partial response in 3 (23%) and stable disease in 4 (31%) patients. An objective response was observed in 2 patients meeting criteria to move to the stage II portion of the trial. Study therapy was well tolerated with no patients discontinuing therapy due to side effects. The most common grade ≥2 toxicities at least possibly attributed to study therapy included lymphopenia (n=4; 31%), fatigue (n=3; 23%), and hypothyroidism (n=2; 15%). <h3>Conclusion</h3> Atezolizumab and SBRT was well tolerated in the first stage of the phase II trial. Objective responses were noted in two patients meeting the pre-planned criteria to warrant opening of the second stage of the study.

The Characteristic Response of the Human Leukocyte Transcriptome to 60 Days of Bed Rest and to Reambulation.

We sought to isolate the microgravity effect of spaceflight from other space stressors by characterizing the leukocytes' transcriptome of participants to a 60-d bed rest study; an Earth model of microgravity. Twenty healthy men received a nutritional supplement or not and 10 blood samples were collected throughout three study phases: baseline data collection (BDC) (BDC-12, BDC-11), head-down tilt (HDT) bed rest (HDT1, HDT2, HDT30, HDT60), and reambulation (R1, R2, R12, R30). We measured gene expression through RNA sequencing of leukocytes, applied generalized linear models to assess differential expression followed by enrichment analysis to identify temporal changes (model 1) and to measure the impact of a nutritional supplement (model 2). Baseline transcriptomes included 14,624 protein-coding transcripts and showed both high intraindividual correlations (mean Kendall coefficient, 0.91 ± 0.04) and interindividual homogeneity (0.89 ± 0.03). We identified 2415 differentially expressed protein-coding transcripts grouping into six clusters (C1-C6). At phase transitions, clusters showed either a decrease-then-increase (C3 and C5) or an increase-then-decrease (C1, C2, C6) pattern. All six clusters converged toward average expression at HDT30 and HDT60. Gene ontology terms at baseline related to immune functions while in bed rest and reambulation related to sequestration of ions, immune response, cellular stress, and mineralization. The nutritional intervention had no effect. The temporal profiles of leukocytes' transcriptomes emphasized the dynamic nature of gene expression occurring during and after bed rest. Enriched biological processes among the differentially expressed genes included immune related and unrelated responses. The convergence toward no differential expression at days 30 and 60 of bed rest suggests a hypometabolic state. Current findings can guide future work on the complex responses and adaptation mechanisms to microgravity.