Intratumoral STING agonist reverses immune evasion in PD-(L)1-refractory Merkel cell carcinoma: mechanistic insights from detailed biomarker analyses.

Background: Antibodies blocking programmed death (PD)-1 or its ligand (PD-L1) have revolutionized cancer care, but many patients do not experience durable benefits. Novel treatments to stimulate antitumor immunity are needed in the PD-(L)1 refractory setting. The stimulator of interferon genes (STING) protein, an innate sensor of cytoplasmic DNA, is a promising target with several agonists in development.

Merkel cell carcinoma refractory to anti-PD(L)1: utility of adding ipilimumab for salvage therapy.

Merkel cell carcinoma (MCC) incidence has risen to approximately 3,000 cases annually in the USA. Although anti-programmed cell death (ligand) 1 (PD-(L)1) agents are now the first-line treatment for advanced MCC, approximately 50% of such patients do not persistently benefit. In PD-(L)1-refractory cases, ipilimumab (anti-cytotoxic T lymphocyte antigen-4) is often added; however, the extent of the clinical benefit of this combination is controversial.

Preclinical Ultra-High Dose Rate (FLASH) Proton Radiation Therapy System for Small Animal Studies.

Purpose: Animal studies with ultrahigh dose-rate radiation therapy (FLASH, >40 Gy/s) preferentially spare normal tissues without sacrificing antitumor efficacy compared with conventional dose-rate radiation therapy (CONV). At the University of Washington, we developed a cyclotron-generated preclinical scattered proton beam with FLASH dose rates. We present the technical details of our FLASH radiation system and preliminary biologic results from whole pelvis radiation.

Postoperative Radiation Therapy Is Indicated for "Low-Risk" Pathologic Stage I Merkel Cell Carcinoma of the Head and Neck Region but Not for Other Locations.

Purpose: The role of postoperative radiation therapy (PORT) in early stage Merkel cell carcinoma (MCC) is controversial. We analyzed the role of PORT in preventing local recurrences (LR) among patients with low-risk, pathologic stage I MCC based on the location of the primary tumors: head/neck (HN) versus non-HN sites.

Methods And Materials: One hundred forty-seven patients with MCC were identified that had "low risk" disease (pathologic T1 primary tumor, negative microscopic margins, negative pathologic node status, no immunosuppression or prior systemic therapy).

Increased risk of recurrence and disease-specific death following delayed postoperative radiation for Merkel cell carcinoma.

Background: Merkel cell carcinoma (MCC) is often treated with surgery and postoperative radiation therapy (PORT). The optimal time to initiate PORT (Time-to-PORT [ttPORT]) is unknown.

Purpose: We assessed if delays in ttPORT were associated with inferior outcomes.

Radiation therapy for low- and high-risk perineural invasion in head and neck cutaneous squamous cell carcinoma: Clinical outcomes and patterns of failure.

Background: Perineural invasion (PNI) in head and neck squamous cell carcinoma (HNSCC) portends poor prognosis. Extent of treatment of nerve pathways with varying degrees of PNI and patterns of failure following elective neural radiotherapy (RT) remain unclear.

Methods: Retrospective review of HNSCC patients with high-risk (clinical/gross, large-nerve, extensive) or low-risk (microscopic/focal) PNI who underwent curative-intent treatment from 2010 to 2021.

The Evolving Treatment Landscape of Merkel Cell Carcinoma.

Merkel cell carcinoma (MCC) has a high risk of recurrence and requires unique treatment relative to other skin cancers. The patient population is generally older, with comorbidities. Multidisciplinary and personalized care is therefore paramount, based on patient preferences regarding risks and benefits.

Neoadjuvant Therapy Induces a Potent Immune Response to Sarcoma, Dominated by Myeloid and B Cells.

Purpose: To characterize changes in the soft-tissue sarcoma (STS) tumor immune microenvironment induced by standard neoadjuvant therapy with the goal of informing neoadjuvant immunotherapy trial design.

Experimental Design: Paired pre- and postneoadjuvant therapy specimens were retrospectively identified for 32 patients with STSs and analyzed by three modalities: multiplexed IHC, NanoString, and RNA sequencing with ImmunoPrism analysis.

Results: All 32 patients, representing a variety of STS histologic subtypes, received neoadjuvant radiotherapy and 21 (66%) received chemotherapy prior to radiotherapy.

Intersection of Two Checkpoints: Could Inhibiting the DNA Damage Response Checkpoint Rescue Immune Checkpoint-Refractory Cancer?

Metastatic cancers resistant to immunotherapy require novel management strategies. DNA damage response (DDR) proteins, including ATR (ataxia telangiectasia and Rad3-related), ATM (ataxia telangiectasia mutated) and DNA-PK (DNA-dependent protein kinase), have been promising therapeutic targets for decades. Specific, potent DDR inhibitors (DDRi) recently entered clinical trials.

Radiation and Modulation of the Tumor Immune Microenvironment in Non-Small Cell Lung Cancer.

Immune checkpoint inhibitors are approved for a variety of indications for locally advanced and metastatic non-small cell lung cancer (NSCLC), and trials are ongoing in the early-stage setting. There is an unmet need to understand which patients may derive benefit from immunotherapies and how to harness combined modality therapies to improve overall response rates and durability. Here, we review studies from the bench-to-bedside to examine the role of radiation therapy (RT) on the tumor immune microenvironment in NSCLC with an eye toward augmenting antitumor immunity.

Postoperative, Single-Fraction Radiation Therapy in Merkel Cell Carcinoma of the Head and Neck.

Purpose: Conventionally fractionated, postoperative radiation therapy (cPORT; 50 Gy in 25 fractions) is considered for patients with Merkel cell carcinoma (MCC) to improve locoregional control. However, cPORT is associated with acute toxicity, especially in the head and neck (H&N) region, and requires daily treatments over several weeks. We previously reported high rates of durable local control with minimal toxicity using 8-Gy single-fraction radiation therapy (SFRT) in the metastatic setting.

Combined Intranasal Nanoemulsion and RIG-I Activating RNA Adjuvants Enhance Mucosal, Humoral, and Cellular Immunity to Influenza Virus.

Current influenza virus vaccines are focused on humoral immunity and are limited by the short duration of protection, narrow cross-strain efficacy, and suboptimal immunogenicity. Here, we combined two chemically and biologically distinct adjuvants, an oil-in-water nanoemulsion (NE) and RNA-based agonists of RIG-I, to determine whether the diverse mechanisms of these adjuvants could lead to improved immunogenicity and breadth of protection against the influenza virus. NE activates TLRs, stimulates immunogenic apoptosis, and enhances cellular antigen uptake, leading to a balanced T1/T2/T17 response when administered intranasally.

Oncolytic Newcastle disease virus expressing a checkpoint inhibitor as a radioenhancing agent for murine melanoma.

Background: Monoclonal antibodies (mAbs) targeting negative regulators, or checkpoint molecules (e.g. PD1/PD-L1 & CTLA4), of anti-tumoural T cells have demonstrated clinical efficacy in treating several neoplastic diseases.

2D kV orthogonal imaging with fiducial markers is more precise for daily image guided alignments than soft-tissue cone beam computed tomography for prostate radiation therapy.

Purpose: The hypothesis is that 2-dimensional kV orthogonal imaging with fiducial markers (kV-FM) and soft-tissue cone beam computed tomography (ST-CBCT) are equally reproducible for daily positional alignments for image guided (IG) intensity modulated radiation therapy (IMRT) for prostate cancer.

Methods And Materials: Ten patients undergoing definitive treatment for prostate cancer with IG-IMRT were imaged daily with kV-FM and ST-CBCT. For each acquired kV and CBCT image, offline alignments to the digitally reconstructed radiograph or planning CT, respectively, were made twice by the same physician to assess intraobserver test-retest reproducibility.

Synthetic Toll-Like Receptor 4 (TLR4) and TLR7 Ligands Work Additively via MyD88 To Induce Protective Antiviral Immunity in Mice.

We previously demonstrated that the combination of synthetic small-molecule Toll-like receptor 4 (TLR4) and TLR7 ligands is a potent adjuvant for recombinant influenza virus hemagglutinin, inducing rapid and sustained immunity that is protective against influenza viruses in homologous, heterologous, and heterosubtypic murine challenge models. Combining the TLR4 and TLR7 ligands balances Th1 and Th2-type immune responses for long-lived cellular and neutralizing humoral immunity against the viral hemagglutinin. Here, we demonstrate that the protective response induced in mice by this combined adjuvant is dependent upon TLR4 and TLR7 signaling via myeloid differentiation primary response gene 88 (MyD88), indicating that the adjuvants function via their known receptors, with negligible off-target effects, to induce protective immunity.

Synthetic Toll-like receptor 4 (TLR4) and TLR7 ligands as influenza virus vaccine adjuvants induce rapid, sustained, and broadly protective responses.

Unlabelled: Current vaccines against influenza virus infection rely on the induction of neutralizing antibodies targeting the globular head of the viral hemagglutinin (HA). Protection against seasonal antigenic drift or sporadic pandemic outbreaks requires further vaccine development to induce cross-protective humoral responses, potentially to the more conserved HA stalk region. Here, we present a novel viral vaccine adjuvant comprised of two synthetic ligands for Toll-like receptor 4 (TLR4) and TLR7.

Adjuvants and immunization strategies to induce influenza virus hemagglutinin stalk antibodies.

The global population remains vulnerable in the face of the next pandemic influenza virus outbreak, and reformulated vaccinations are administered annually to manage seasonal epidemics. Therefore, development of a new generation of vaccines is needed to generate broad and persistent immunity to influenza viruses. Here, we describe three adjuvants that enhance the induction of stalk-directed antibodies against heterologous and heterosubtypic influenza viruses when administered with chimeric HA proteins.

Guiding the immune response against influenza virus hemagglutinin toward the conserved stalk domain by hyperglycosylation of the globular head domain.

Influenza virus hemagglutinin consists of a highly variable and immunodominant head domain and a more conserved but immunosubdominant stalk domain. We introduced seven N-linked glycosylation sites in the hemagglutinin head domain to shield the immunodominant antigenic sites. The hyperglycosylated hemagglutinin enhanced stalk-directed seroreactivity while dampening the head response in immunized mice.

A small molecule multi-kinase inhibitor reduces influenza A virus replication by restricting viral RNA synthesis.

Currently available drugs against influenza virus target the viral neuraminidase or the M2 ion channel. The emergence of viral strains resistant to these drugs has been widely described; therefore, there is an urgent need for novel antiviral drugs. Targeting of host factors required for viral replication is an attractive option for circumventing the problem of drug resistance.

Induction of cross-reactive antibodies to novel H7N9 influenza virus by recombinant Newcastle disease virus expressing a North American lineage H7 subtype hemagglutinin.

Severe human disease caused by the emerging H7N9 influenza virus in China warrants a rapid response. Here, we present a recombinant Newcastle disease virus expressing a North American lineage H7 influenza virus hemagglutinin. Sera from immunized mice were cross-reactive to a broad range of H7 subtype viruses and inhibited hemagglutination by the novel H7 hemagglutinin.

Recombinant IgA is sufficient to prevent influenza virus transmission in guinea pigs.

A serum hemagglutination inhibition (HAI) titer of 40 or greater is thought to be associated with reduced influenza virus pathogenesis in humans and is often used as a correlate of protection in influenza vaccine studies. We have previously demonstrated that intramuscular vaccination of guinea pigs with inactivated influenza virus generates HAI titers greater than 300 but does not protect vaccinated animals from becoming infected with influenza virus by transmission from an infected cage mate. Only guinea pigs intranasally inoculated with a live influenza virus or a live attenuated virus vaccine, prior to challenge, were protected from transmission (A.

A majority of infectious Newcastle disease virus particles contain a single genome, while a minority contain multiple genomes.

Paramyxoviruses produce pleiomorphic particles containing variable amounts of genetic material that correlate with virion diameter by electron microscopy. However, the infectious nature of these particles is unknown, and functional genomes are indistinguishable from defective RNA. A quantitative approach to paramyxovirus packaging revealed a majority of infectious Newcastle disease viruses contain one functional genome.

The cargo-binding domain of transportin 3 is required for lentivirus nuclear import.

Lentiviruses, unlike the gammaretroviruses, are able to infect nondividing cells by transiting through nuclear pores to access the host genomic DNA. Several nuclear import and nuclear pore components have been implicated as playing a role in nuclear import, including transportin 3 (TNPO3), a member of the importin-β family of nuclear import proteins. We demonstrated that TNPO3 was required by several lentiviruses, with simian immunodeficiency virus mac239 (SIVmac239) and equine infectious anemia virus (EIAV) the most dependent and human immunodeficiency virus type 1 (HIV-1) and feline immunodeficiency virus (FIV) the least.