VAX014 Activates Tumor-Intrinsic STING and RIG-I to Promote the Development of Antitumor Immunity.

In situ immunization (ISI) has emerged as a promising approach to bolster early phases of the cancer immunity cycle through improved T cell priming. One class of ISI agents, oncolytic viruses (OVs), has demonstrated clinical activity, but overall benefit remains limited. Mounting evidence suggests that due to their inherent vulnerability to antiviral effects of type I interferon (IFN), OVs have limited activity in solid tumors expressing stimulator of interferon genes (STING) and/or retinoic acid-inducible gene I (RIG-I).

Quantitative target engagement of RIPK1 in human whole blood via the cellular thermal shift assay for potential pre-clinical and clinical applications.

The cellular thermal shift assay (CETSA®) is a target engagement method widely used for preclinical characterization of small molecule compounds. CETSA® has been used for semi-quantitative readouts in whole blood with PBMC isolation, and quantitative, plate-based readouts using cell lines. However, there has been no quantitative evaluation of CETSA® in unprocessed human whole blood, which is preferred for clinical applications.

The PTPN2/PTPN1 inhibitor ABBV-CLS-484 unleashes potent anti-tumour immunity.

Immune checkpoint blockade is effective for some patients with cancer, but most are refractory to current immunotherapies and new approaches are needed to overcome resistance. The protein tyrosine phosphatases PTPN2 and PTPN1 are central regulators of inflammation, and their genetic deletion in either tumour cells or immune cells promotes anti-tumour immunity. However, phosphatases are challenging drug targets; in particular, the active site has been considered undruggable.

VAX014, an Oncolytic Therapy, Reduces Adenomas and Modifies Colon Microenvironment in Mouse Model of CRC.

Colorectal cancer (CRC) remains the third most common form of cancer and, despite its reduced mortality, results in over 50,000 deaths annually, highlighting the need for novel therapeutic approaches. VAX014 is a novel clinical-stage, oncolytic bacterial minicell-based therapy shown to elicit protective antitumor immune responses in cancer, but it has not been fully evaluated in CRC. Here, VAX014 was demonstrated to induce oncolysis in CRC cell lines in vitro and was evaluated in vivo, both as a prophylactic (before spontaneous development of adenomatous polyps) and as a neoadjuvant treatment using the Fabp-CreXApc preclinical animal model of colon cancer.

Characterizing group and individual engagement in intergroup encounters between small groups of ring-tailed lemurs (Lemur catta) on St. Catherines Island, USA.

Primate species exhibit considerable variation in behavior and outcomes during intergroup encounters (IGEs). Social group characteristics, like group size, and individual traits, such as sex, rank, and reproductive status, within those groups can influence both IGE engagement and outcomes. To better understand the impact of group heterogeneity on IGEs, we must examine individual strategies to elucidate individual costs and benefits of engaging in these interactions.

Intravesical VAX014 Synergizes with PD-L1 Blockade to Enhance Local and Systemic Control of Bladder Cancer.

Emerging clinical evidence indicates that the combination of local administration of immunotherapy with systemic immune-checkpoint blockade targeting the PD-1/PD-L1 pathway improves response rates in select solid tumor indications; however, limited clinical experience with this approach exists in advanced bladder cancer patients. VAX014 is a novel bacterial minicell-based, integrin-targeted oncolytic agent undergoing clinical investigation for intravesical (IVE) treatment of nonmuscle-invasive bladder cancer. Here, we demonstrated that the antitumor activity of VAX014 following IVE administration was dependent upon CD4+ and CD8+ T cells in two syngeneic orthotopic bladder tumor models (MB49 and MBT-2).

Monitoring PD-1 Phosphorylation to Evaluate PD-1 Signaling during Antitumor Immune Responses.

PD-1 expression marks activated T cells susceptible to PD-1-mediated inhibition but not whether a PD-1-mediated signal is being delivered. Molecular predictors of response to PD-1 immune checkpoint blockade (ICB) are needed. We describe a monoclonal antibody (mAb) that detects PD-1 signaling through the detection of phosphorylation of the immunotyrosine switch motif (ITSM) in the intracellular tail of mouse and human PD-1 (phospho-PD-1).

VISTA is an activating receptor in human monocytes.

As indicated by its name, V-domain Ig suppressor of T cell activation (VISTA) is thought to serve primarily as an inhibitory protein that limits immune responses. VISTA antibodies can dampen the effects of several concomitantly elicited activation signals, including TCR and TLR activation, but it is currently unclear if VISTA agonism could singly affect immune cell biology. In this study, we discovered two novel VISTA antibodies and characterized their effects on human peripheral blood mononuclear cells by scRNA/CITE-seq.

A new method for discovering EMAST sequences in animal models of cancer.

Elevated Microsatellite Alterations at Selected Tetranucleotide repeats (EMAST) occur in up to 60% of colorectal cancers and may associate with aggressive and advanced disease in patients. Although EMAST occurs in many cancer types, current understanding is limited due to the lack of an animal model. Reported here is the design and implementation of an algorithm for detecting EMAST repeats in mice.

New adenovirus-based vaccine vectors targeting Pfs25 elicit antibodies that inhibit Plasmodium falciparum transmission.

Background: An effective malaria transmission-blocking vaccine (TBV) would be a major advance in the current efforts to eliminate and, ultimately, eradicate malaria. Antibodies against Plasmodium falciparum surface protein, Pfs25, are known to block parasite development in the mosquito vector. However, in initial clinical trials the limited immunogenicity of recombinant Pfs25 protein-in-adjuvant vaccines has been a challenge.

PD-L1 on tumor cells is sufficient for immune evasion in immunogenic tumors and inhibits CD8 T cell cytotoxicity.

It is unclear whether PD-L1 on tumor cells is sufficient for tumor immune evasion or simply correlates with an inflamed tumor microenvironment. We used three mouse tumor models sensitive to PD-1 blockade to evaluate the significance of PD-L1 on tumor versus nontumor cells. PD-L1 on nontumor cells is critical for inhibiting antitumor immunity in B16 melanoma and a genetically engineered melanoma.

A Single Intravesical Instillation of VAX014 Inhibits Orthotopic Superficial Bladder Tumor Implantation to Increase Survival.

Background/aim: VAX014 minicells (VAX014) have been previously characterized as an integrin-specific oncolytic biotherapeutic agent. The present study was designed to evaluate the potential of VAX014 as an immediate post-operative intravesical adjuvant therapy in the treatment of non-muscle invasive bladder cancer (NMIBC).

Materials And Methods: The ability of VAX014 to kill a panel of dissociated urothelial carcinoma cell lines was tested in vitro.

Decreased Anti-Tumor Cytotoxic Immunity among Microsatellite-Stable Colon Cancers from African Americans.

Colorectal cancer is a leading cause of cancer related deaths in the U.S., with African-Americans having higher incidence and mortality rates than Caucasian-Americans.

Influence of race on microsatellite instability and CD8+ T cell infiltration in colon cancer.

African American patients with colorectal cancer show higher mortality than their Caucasian counterparts. Biology might play a partial role, and prior studies suggest a higher prevalence for microsatellite instability (MSI) among cancers from African Americans, albeit patients with MSI cancers have improved survival over patients with non-MSI cancers, counter to the outcome observed for African American patients. CD8+ T cell infiltration of colon cancer is postively correlated with MSI tumors, and is also related to improved outcome.

Expression differences between African American and Caucasian prostate cancer tissue reveals that stroma is the site of aggressive changes.

In prostate cancer, race/ethnicity is the highest risk factor after adjusting for age. African Americans have more aggressive tumors at every clinical stage of the disease, resulting in poorer prognosis and increased mortality. A major barrier to identifying crucial gene activity differences is heterogeneity, including tissue composition variation intrinsic to the histology of prostate cancer.

Alpha-synuclein induces lysosomal rupture and cathepsin dependent reactive oxygen species following endocytosis.

α-synuclein dysregulation is a critical aspect of Parkinson's disease pathology. Recent studies have observed that α-synuclein aggregates are cytotoxic to cells in culture and that this toxicity can be spread between cells. However, the molecular mechanisms governing this cytotoxicity and spread are poorly characterized.

Adenovirus type 5 rupture of lysosomes leads to cathepsin B-dependent mitochondrial stress and production of reactive oxygen species.

In response to viral infection, reactive oxygen species (ROS) mediate innate immune signaling or generate danger signals to activate immune cells. The mechanisms of virally induced ROS are poorly defined, however. We demonstrate that ROS are produced within minutes of adenovirus type 5 (Ad5) infection of macrophages and that oxidative stress supports Ad5-induced cytokine secretion.

Microsatellite instability, EMAST, and morphology associations with T cell infiltration in colorectal neoplasia.

Background And Objectives: Colorectal tumors are often observed with tumor infiltrating lymphocytes, presumably as a host-immune response, and patterns may segregate by types of genomic instability. Microsatellite unstable (MSI) colorectal cancers contain a pronounced lymphocyte reaction that can pathologically identify these tumors. Colorectal tumors with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) have not been examined for lymphocyte patterns.

Relationship of EMAST and microsatellite instability among patients with rectal cancer.

Background: Elevated microsatellite instability at selected tetranucleotide repeats (EMAST) is a genetic signature identified in 60% of sporadic colon cancers and may be linked with heterogeneous expression of the DNA mismatch repair (MMR) protein hMSH3. Unlike microsatellite instability-high (MSI-H) in which hypermethylation of hMLH1 occurs followed by multiple susceptible gene mutations, EMAST may be associated with inflammation and subsequent relaxation of MMR function with the biological consequences not known. We evaluated the prevalence of EMAST and MSI in a population-based cohort of rectal cancers, as EMAST has not been previously determined in rectal cancers.

Macrophages influence Salmonella host-specificity in vivo.

The generalist Salmonella enterica serovar Typhimurium causes disease in many animal species, but the closely related host-specific serovar Typhi only causes disease in humans. Typhi and Typhimurium share major virulence loci; hence it is not known exactly why Typhi does not cause disease in mice. We tested the hypothesis that macrophages contribute to Salmonella host-specificity in mice.

Comprehensive study of sansalvamide A derivatives and their structure-activity relationships against drug-resistant colon cancer cell lines.

We report an extensive structure-activity relationship (SAR) of 62 compounds active against two drug-resistant colon cancer cell lines. Our comprehensive evaluation of two generations of compounds utilizes SAR, NMR, and molecular modeling to evaluate the key 3D features of potent compounds. Of the seven most potent compounds reported here, five are second-generation, emphasizing our ability to incorporate potent features found in the first generation and utilize their structures to design potency into the second generation.

Identification of Sansalvamide a analog potent against pancreatic cancer cell lines.

Thirty-one Sansalvamide A peptide derivatives were synthesized. (3)H thymidine inhibition assays were performed using two pancreatic cancer cell lines (PL45 and BxPC-3). Six compounds possess 140-fold increased differential selectivity for cancer cell lines over normal cell lines (WS1, skin fiberblasts) and are 140 times more active against pancreatic cancer cell lines than compounds used clinically to treat these cancers (e.

Scaffold targeting drug-resistant colon cancers.

We have identified five derivatives of the natural product sansalvamide A that are potent against multiple drug-resistant colon cancer cell lines. These analogs share no structural homology to current colon cancer drugs, are cytotoxic at levels on par with existing drugs treating other cancers, and demonstrate selectivity for drug-resistant colon cancer cell lines over noncancerous cell lines. Thus, we have established sansalvamide A as a privileged structure for treating multiple drug-resistant colon cancers.

Immunization with non-replicating E. coli minicells delivering both protein antigen and DNA protects mice from lethal challenge with lymphocytic choriomeningitis virus.

In the midst of new investigations into the mechanisms of both delivery and protection of new vaccines and vaccine carriers, it has become clear that immunization with delivery mechanisms that do not involve living, replicating organisms are vastly preferred. In this report, non-replicating bacterial minicells simultaneously co-delivering the nucleoprotein (NP) of lymphocytic choriomeningitis virus (LCMV) and the corresponding DNA vaccine were tested for the ability to generate protective cellular immune responses in mice. It was found that good protection (89%) was achieved after intramuscular administration, moderate protection (31%) was achieved after intranasal administration, and less protection (7%) was achieved following gastric immunization.