A Pathologist's Guide to Non-clinical Safety Assessment of Adoptive Cell Therapy Products.

Through two decades of research and development, adoptive cell therapies (ACTs) have revolutionized treatment for hematologic malignancies. Many of the seven US Food and Drug Administration (FDA)-approved products are proven to be a curative last line of defense against said malignancies. The ACTs, known more commonly as chimeric antigen receptor (CAR) T-cells, utilize engineered lymphocytes to target and destroy cancer cells in a patient-specific, major histocompatibility complex (MHC)-independent manner, acting as "living drugs" that adapt to and surveil the body post-treatment.

TYRP1 directed CAR T cells control tumor progression in preclinical melanoma models.

Despite therapeutic efficacy observed with immune checkpoint blockade in advanced melanoma, many tumors do not respond to treatment, representing a need for new therapies. Here, we have generated chimeric antigen receptor (CAR) T cells targeting TYRP1, a melanoma differentiation antigen expressed on the surface of melanomas, including rare acral and uveal melanomas. TYRP1-targeted CAR T cells demonstrate antigen-specific activation and cytotoxic activity and against human melanomas independent of the MHC alleles and expression.

Innate immune signaling drives late cardiac toxicity following DNA-damaging cancer therapies.

Late cardiac toxicity is a potentially lethal complication of cancer therapy, yet the pathogenic mechanism remains largely unknown, and few treatment options exist. Here we report DNA-damaging agents such as radiation and anthracycline chemotherapies inducing delayed cardiac inflammation following therapy due to activation of cGAS- and STING-dependent type I interferon signaling. Genetic ablation of cGAS-STING signaling in mice inhibits DNA damage-induced cardiac inflammation, rescues late cardiac functional decline, and prevents death from cardiac events.

Radioimmunotherapy Targeting Delta-like Ligand 3 in Small Cell Lung Cancer Exhibits Antitumor Efficacy with Low Toxicity.

Purpose: Small cell lung cancer (SCLC) is an exceptionally lethal form of lung cancer with limited treatment options. Delta-like ligand 3 (DLL3) is an attractive therapeutic target as surface expression is almost exclusive to tumor cells.

Experimental Design: We radiolabeled the anti-DLL3 mAb SC16 with the therapeutic radioisotope, Lutetium-177.

Research-Relevant Conditions and Pathology of Laboratory Mice, Rats, Gerbils, Guinea Pigs, Hamsters, Naked Mole Rats, and Rabbits.

Animals are valuable resources in biomedical research in investigations of biological processes, disease pathogenesis, therapeutic interventions, safety, toxicity, and carcinogenicity. Interpretation of data from animals requires knowledge not only of the processes or diseases (pathophysiology) under study but also recognition of spontaneous conditions and background lesions (pathology) that can influence or confound the study results. Species, strain/stock, sex, age, anatomy, physiology, spontaneous diseases (noninfectious and infectious), and neoplasia impact experimental results and interpretation as well as animal welfare.

ImmunoPET of Ovarian and Pancreatic Cancer with AR9.6, a Novel MUC16-Targeted Therapeutic Antibody.

Purpose: Advances in our understanding of the contribution of aberrant glycosylation to the pro-oncogenic signaling and metastasis of tumor cells have reinvigorated the development of mucin-targeted therapies. Here, we validate the tumor-targeting ability of a novel monoclonal antibody (mAb), AR9.6, that binds MUC16 and abrogates downstream oncogenic signaling to confer a therapeutic response.

Influence of Fc Modifications and IgG Subclass on Biodistribution of Humanized Antibodies Targeting L1CAM.

Immuno-PET is a powerful tool to noninvasively characterize the in vivo biodistribution of engineered antibodies. L1 cell adhesion molecule-targeting humanized (HuE71) IgG and IgG antibodies bearing identical variable heavy- and light-chain sequences but different fragment crystallizable (Fc) portions were radiolabeled with Zr, and the in vivo biodistribution was studied in SKOV3 ovarian cancer xenografted nude mice. In addition to showing uptake in L1 cell adhesion molecule-expressing SKOV3 tumors, as does its parental counterpart HuE71 IgG, the afucosylated variant having enhanced Fc-receptor affinity showed high nonspecific uptake in lymph nodes.

Exclusion of Expert Contributors From Authorship Limits the Quality of Scientific Articles.

Veterinary pathologists are key contributors to multidisciplinary biomedical research. However, they are occasionally excluded from authorship in published articles despite their substantial intellectual and data contributions. To better understand the potential origins and implications of this practice, we identified and analyzed 29 scientific publications where the contributing pathologist was excluded as an author.

Anti-ceramide single-chain variable fragment mitigates radiation GI syndrome mortality independent of DNA repair.

After 9/11, threat of nuclear attack on American urban centers prompted government agencies to develop medical radiation countermeasures to mitigate hematopoietic acute radiation syndrome (H-ARS) and higher-dose gastrointestinal acute radiation syndrome (GI-ARS) lethality. While repurposing leukemia drugs that enhance bone marrow repopulation successfully treats H-ARS in preclinical models, no mitigator potentially deliverable under mass casualty conditions preserves GI tract. Here, we report generation of an anti-ceramide 6B5 single-chain variable fragment (scFv) and show that s.

Alpha radioimmunotherapy using Ac-proteus-DOTA for solid tumors - safety at curative doses.

This is the initial report of an α-based pre-targeted radioimmunotherapy (PRIT) using Ac and its theranostic pair, In. We call our novel tumor-targeting DOTA-hapten PRIT system "proteus-DOTA" or "Pr." Herein we report the first results of radiochemistry development, radiopharmacology, and stoichiometry of tumor antigen binding, including the role of specific activity, anti-tumor efficacy, and normal tissue toxicity with the Pr-PRIT approach (as α-DOTA-PRIT).

Ethmoidal meningoencephalocele in a C57BL/6J mouse.

An otherwise healthy two-month-old female C57BL/6J mouse presented with a left-sided head tilt. Differential diagnoses included idiopathic necrotizing arteritis, bacterial otitis media/interna (, , , and ), encephalitis, an abscess, neoplasia, a congenital malformation and an accidental or iatrogenic head trauma. Magnetic resonance imaging (MRI) revealed a large space-occupying right olfactory lobe intra-axial lesion with severe secondary left-sided subfalcine herniation.

Senolytic CAR T cells reverse senescence-associated pathologies.

Cellular senescence is characterized by stable cell-cycle arrest and a secretory program that modulates the tissue microenvironment. Physiologically, senescence serves as a tumour-suppressive mechanism that prevents the expansion of premalignant cells and has a beneficial role in wound-healing responses. Pathologically, the aberrant accumulation of senescent cells generates an inflammatory milieu that leads to chronic tissue damage and contributes to diseases such as liver and lung fibrosis, atherosclerosis, diabetes and osteoarthritis.

Outbreaks of Typhlocolitis Caused by Hypervirulent Group ST1 in Highly Immunocompromised Strains of Mice.

is an enteric pathogen that can cause significant clinical disease in both humans and animals. However, clinical disease arises most commonly after treatment with broad-spectrum antibiotics. The organism's ability to cause naturally occurring disease in mice is rare, and little is known about its clinical significance in highly immunocompromised mice.

Radiopharmacologic screening of antibodies to the unshed ectodomain of MUC16 in ovarian cancer identifies a lead candidate for clinical translation.

Introduction: Despite its limitations, CA125 remains the most widely used biomarker for the diagnosis and treatment monitoring of ovarian cancer. Targeting the unshed portion of serum biomarkers such as CA125/MUC16 may afford more specific imaging and targeting of MUC16-positive tumors in High Grade Serous Ovarian Cancer (HGSOC) patients.

Methods: Six monoclonal antibodies raised against the 58 amino acid sequence between the extracellular cleavage site and the transmembrane region of MUC16 were radiolabeled with [Zr]Zr.

ALS/FTD mutant CHCHD10 mice reveal a tissue-specific toxic gain-of-function and mitochondrial stress response.

Mutations in coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10), a mitochondrial protein of unknown function, cause a disease spectrum with clinical features of motor neuron disease, dementia, myopathy and cardiomyopathy. To investigate the pathogenic mechanisms of CHCHD10, we generated mutant knock-in mice harboring the mouse-equivalent of a disease-associated human S59L mutation, S55L in the endogenous mouse gene. CHCHD10 mice develop progressive motor deficits, myopathy, cardiomyopathy and accelerated mortality.

The APMAP interactome reveals new modulators of APP processing and beta-amyloid production that are altered in Alzheimer's disease.

The adipocyte plasma membrane-associated protein APMAP is expressed in the brain where it associates with γ-secretase, a protease responsible for the generation of the amyloid-β peptides (Aβ) implicated in the pathogenesis of Alzheimer's disease (AD). In this study, behavioral investigations revealed spatial learning and memory deficiencies in our newly generated mouse line lacking the protein APMAP. In a mouse model of AD, the constitutive deletion of APMAP worsened the spatial memory phenotype and led to increased Aβ production and deposition into senile plaques.

Context-dependent roles of MDMX (MDM4) and MDM2 in breast cancer proliferation and circulating tumor cells.

Introduction: Many human breast cancers overexpress the E3 ubiquitin ligase MDM2 and its homolog MDMX. Expression of MDM2 and MDMX occurs in estrogen receptor α-positive (ERα) breast cancer and triple-negative breast cancer (TNBC). There are p53-independent influences of MDM2 and MDMX, and 80% of TNBC express mutant p53 (mtp53).

Theranostic pretargeted radioimmunotherapy of internalizing solid tumor antigens in human tumor xenografts in mice: Curative treatment of HER2-positive breast carcinoma.

In recent reports, we have shown that optimized pretargeted radioimmunotherapy (PRIT) based on molecularly engineered antibody conjugates and Lu-DOTA chelate (DOTA-PRIT) can be used to cure mice bearing human solid tumor xenografts using antitumor antibodies to minimally internalizing membrane antigens, GPA33 (colon) and GD2 (neuroblastoma). However, many solid tumor membrane antigens are internalized after antibody binding and it is generally believed that internalizing tumor membrane antigens are not suitable targets for PRIT. In this study, we tested the hypothesis that DOTA-PRIT can be performed successfully to target HER2, an internalizing membrane antigen widely expressed in breast, ovarian, and gastroesophageal junction cancers.

CAR T cell-induced cytokine release syndrome is mediated by macrophages and abated by IL-1 blockade.

Chimeric antigen receptor (CAR) therapy targeting CD19 is an effective treatment for refractory B cell malignancies, especially acute lymphoblastic leukemia (ALL) . Although a majority of patients will achieve a complete response following a single infusion of CD19-targeted CAR-modified T cells (CD19 CAR T cells), the broad applicability of this treatment is hampered by severe cytokine release syndrome (CRS), which is characterized by fever, hypotension and respiratory insufficiency associated with elevated serum cytokines, including interleukin-6 (IL-6). CRS usually occurs within days of T cell infusion at the peak of CAR T cell expansion.

GKAP Acts as a Genetic Modulator of NMDAR Signaling to Govern Invasive Tumor Growth.

Genetic linkage analysis previously suggested that GKAP, a scaffold protein of the N-methyl-D-aspartate receptor (NMDAR), was a potential modifier of invasion in a mouse model of pancreatic neuroendocrine tumor (PanNET). Here, we establish that GKAP governs invasive growth and treatment response to NMDAR inhibitors of PanNET via its pivotal role in regulating NMDAR pathway activity. Combining genetic knockdown of GKAP and pharmacological inhibition of NMDAR, we implicate as downstream effectors FMRP and HSF1, which along with GKAP demonstrably support invasiveness of PanNET and pancreatic ductal adenocarcinoma cancer cells.

Neutrophils and Snail Orchestrate the Establishment of a Pro-tumor Microenvironment in Lung Cancer.

Understanding the immune compartment of tumors facilitates the development of revolutionary new therapies. We used a Kras(G12D)-driven mouse model of lung cancer to establish an immune signature and identified a contribution of Gr1 neutrophils to disease progression. Depletion experiments showed that Gr1 cells (1) favor tumor growth, (2) reduce T cell homing and prevent successful anti-PD1 immunotherapy, and (3) alter angiogenesis, leading to hypoxia and sustained Snail expression in lung cancer cells.

Larval Echinococcus multilocularis infection reduces dextran sulphate sodium-induced colitis in mice by attenuating T helper type 1/type 17-mediated immune reactions.

The tumour-like growth of larval Echinococcus multilocularis tissue (causing alveolar echinococcosis, AE) is directly linked to the nature/orientation of the periparasitic host immune-mediated processes. Parasite-mediated immune suppression is a hallmark triggering infection outcome in both chronic human and murine AE. So far, little is known about secondary systemic immune effects of this pathogen on other concomitant diseases, e.