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List of significant gene symbols

SF1: IL-26 protein or mRNA expression in human cell lines and clinical samples; SF2: Single-cell profiling of CD4+ TH17 cells in TNBC patients; SF3: Confirmation of IL-26 knockdown in MDA-MB-231 cells; SF4: In vitro proliferation and in vivo metastasis of IL-26 knockdown MDA-MB-231 cells; SF5: Gene expression profiling of IL-26 knockdown MDA-MB-231 tumors; SF6: IL-26 knockdown in SUM159 and MDA-MB-468 cells and in vitro phenotyping; SF7: Western blot confirmation of IL-26 knock-in E0771 cells and IL-26 upregulation after growth in vivo; SF8: IL-26 knock-in E0771 tumors progress more rapidly than control in an immune competent setting; SF9: Stat3 activation by IL-26 is dependent on human IL10RB and IL20RA; SF10: DNA-bound IL-26 elicits inflammatory signaling in human and mouse immune cells; SF11: Confirmation of mouse neutrophil enrichment; SF12: Confirmation of Anti-Ly6G antibody depletion of mouse neutrophils; SF13: Inflammatory cytokine expression in MDA-MB-231 parental and MDA-MB-231 LM2 lung-metastatic subclone; SF14: CRISPR knockdown of IL-6, IL-8, and Cxcl1 in MDA-MB-231 LM2 CRISPR 3x cell lines/lung metastases and correlation of CRISPR 3x primary tumor volume with metastasis; SF15: IL-26 signature and Neutrophil enrichment score are significantly correlated in METABRIC dataset; SF16: T cell ELISPOT response to IL-26 vaccination in vivo.

Significant hits identified in CRISPR screen

CRISPR screen results

IL26 is a unique amphipathic member of the IL10 family of cytokines that participates in inflammatory signaling through a canonical receptor pathway. It also directly binds DNA to facilitate cellular transduction and intracellular inflammatory signaling. Although IL26 has almost no described role in cancer, our in vivo screen of inflammatory and cytokine pathway genes revealed IL26 to be one of the most significant inflammatory mediators of mammary engraftment and lung metastatic growth in triple-negative breast cancer (TNBC). Examination of human breast cancers demonstrated elevated IL26 transcripts in TNBC specimens, specifically in tumor cells as well as in Th17 CD4+ T cells within clinical TNBC specimens. IL26 did not have an autocrine effect on human TNBC cells, but rather its effect on engraftment and growth in vivo required neutrophils. IL26 enhanced mouse-derived DNA induction of inflammatory cytokines, which were collectively important for mammary and metastatic lung engraftment. To neutralize this effect, we developed a novel IL26 vaccine to stimulate antibody production and suppress IL26-enhanced engraftment in vivo, suggesting that targeting this inflammatory amplifier could be a unique means to control cancer-promoting inflammation in TNBC and other autoimmune diseases. Thus, we identified IL26 as a novel key modulator of TNBC metastasis and a potential therapeutic target in TNBC as well as other diseases reliant upon IL26-mediated inflammatory stimulation.Significance:These findings identify IL26 as a unique, clinically relevant, inflammatory amplifier that enhances TNBC engraftment and dissemination in association with neutrophils, which has potential as a therapeutic target.

IL26 is a unique amphipathic member of the IL10 family of cytokines that participates in inflammatory signaling through a canonical receptor pathway. It also directly binds DNA to facilitate cellular transduction and intracellular inflammatory signaling. Although IL26 has almost no described role in cancer, our in vivo screen of inflammatory and cytokine pathway genes revealed IL26 to be one of the most significant inflammatory mediators of mammary engraftment and lung metastatic growth in triple-negative breast cancer (TNBC). Examination of human breast cancers demonstrated elevated IL26 transcripts in TNBC specimens, specifically in tumor cells as well as in Th17 CD4+ T cells within clinical TNBC specimens. IL26 did not have an autocrine effect on human TNBC cells, but rather its effect on engraftment and growth in vivo required neutrophils. IL26 enhanced mouse-derived DNA induction of inflammatory cytokines, which were collectively important for mammary and metastatic lung engraftment. To neutralize this effect, we developed a novel IL26 vaccine to stimulate antibody production and suppress IL26-enhanced engraftment in vivo, suggesting that targeting this inflammatory amplifier could be a unique means to control cancer-promoting inflammation in TNBC and other autoimmune diseases. Thus, we identified IL26 as a novel key modulator of TNBC metastasis and a potential therapeutic target in TNBC as well as other diseases reliant upon IL26-mediated inflammatory stimulation. Significance: These findings identify IL26 as a unique, clinically relevant, inflammatory amplifier that enhances TNBC engraftment and dissemination in association with neutrophils, which has potential as a therapeutic target.

Background: Androgen receptor (AR) signaling has been the central target for standard-of-care prostate cancer therapies, although de novo resistance to these therapies occurs in many metastatic prostate cancer patients within 2-3 years. Resistance to AR targeting agents most often develops through overexpression of AR and expression of truncated, constitutively active RNA splice variants of AR. While clinical use of PD-1/PD-L1 immune checkpoint blockade has failed to demonstrate clinical success in treating resistance prostate cancers, the slower progression of prostate cancer provides an opportunity for immune targeted interventions. Cancer specific vaccines have the potential to enable and enhance tumor specific immune responses by stimulating and directing T cell immunity to important oncologic targets. We hypothesized that a cancer vaccine designed to induce a T cell response against cells expressing high levels of AR would result in an anti-tumor effect and potentially prevent or delay the development of therapeutic resistance. Methods: To evaluate AR and AR variants as potential immunological targets, we produced adenoviral vaccines against AR (Ad-AR) or AR splice variant 7 (Ad-AR-V7). We vaccinated naïve mice and examined AR and AR variant specific immunity in peptide restimulation. We further tested our vaccines in prophylactic and therapeutic regimens using multiple subcutaneous syngeneic tumor models (including prostate tumor lines, such as TrampC2) which were engineered to express AR or AR-V7. Results: Adenoviral vaccines targeting AR or AR-V7 produced robust T-cell responses against the N-terminal domain of AR. Notably, vaccination with both Ad-AR or Ad-AR-V7 induced significant anti-tumor immune responses, inducing complete tumor clearance against tumors expressing AR-V7 and allowing for long-term survival in the majority of vaccinated mice. Conclusions: These data demonstrate the potential of AR and AR splice variants as immunologic targets of prostate cancer vaccines, which elicit AR specific T cell immunity and produce anti-tumor responses in prostate cancers. Citation Format: Robert D. Marek, Junping Wei, Tao Wang, Xiao-Yi Yang, Gangjun Lei, Zachary C. Hartman. Vaccination against androgen receptor splice variant induces anti-tumor adaptive immune responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 683.

Background: Immune checkpoint blockade (ICB) antibodies have demonstrated that effective induction of T cell responses can elicit tumor regression of different metastatic cancers, although these responses are restricted to certain individuals with specific types of cancer. To enhance these responses, there has been renewed emphasis in developing different types of cancer-specific vaccines to stimulate and direct T cell and B cell immunity to important oncologic targets, such as the oncogene human epidermal growth factor receptor 2 (HER2), which is expressed in ~20% of breast cancers (BC). In our previous work we used a DNA plasmid vaccine targeting HER2, which utilized a lysosome-associated membrane protein 1 (LAMP) domain to traffic HER2 antigen to endolysosomal compartments. We demonstrated that this approach was more effective at eliciting antigen specific CD4+ and CD8+ T cell responses, and provided a significant but limited survival benefit in an endogenous mouse model of HER2+ BC compared to a HER2-wild type vaccine. Methods: In our current study, we explored the use of this modified antigen construct using different vaccine modalities, including DNA plasmid, adenoviral (Ad), modified vaccinia ankara (MVA), and self-replicating RNA vaccines to identify effective vaccine platforms to elicit HER2-specific immunity and anti-tumor immunity. Additionally, we have tested the combination of these modalities in homologous and heterologous vaccine boosting regimens to determine an optimal strategy to elicit anti-tumor immunity in vivo. Results: In our studies, plasmid and MVA vectors elicited suboptimal immune priming responses, in comparison to Ad and self-replicating RNA vectors that elicit significant HER2-specific T and B cell responses upon vaccination. While timing of boosting is critical, our results reflect that certain platforms (e.g., plasmid DNA vectors) are capable of homologous boosting capacity, while others (e.g., Ad vectors) elicit more robust T and B cell responses to capsid epitopes, limiting homologous boosting capacity for HER2-specific immunity. Significantly, using an endogenous model of metastatic HER2+ BC, we have found that heterologous vaccination with different HER2-LAMP targeted vectors can elicit significantly augmented HER2-specific T and B cell responses that translated into more effective anti-tumor immunity. This immunity proved capable of eliciting tumor regression in ~80% of vaccinated mice, compared to 0% using homologous HER2-WT plasmid vaccination, 30% using homologous HER2-LAMP plasmid vaccination, or 50% with HER2-WT heterologous vaccination. Conclusions: These data demonstrate the potential of utilizing heterologous vaccine platforms encoding LAMP-based endolysosomal trafficking vaccines to elicit HER2-specific immunity and effect anti-tumor responses. Citation Format: Robert D. Marek, Alan Chen, Renhuan Xu, Junping Wei, Tao Wang, Xiao Yang, Gangjun Lei, Teri Heiland, Zachary C. Hartman. Vaccination using different platforms encoding HER2-LAMP with heterologous boosting enhances adaptive HER2-specific immunity to enable potent anti-tumor responses [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 3564.

Longevity-associated neurological disorders have been observed across human and canine aging populations. Alzheimer’s disease (AD) and canine cognitive dysfunction syndrome (CDS) represent comparable diseases affecting both species as they age. Translational diagnostic and therapeutic research is needed for these incurable diseases. The amyloid β (Aβ) peptide family are AD-associated peptides with identical amino acid sequences between dogs and humans. Plasma Aβ42 concentration increases with age and decreases with AD in humans, and cerebrospinal fluid (CSF) concentration decreases in AD and correlates inversely with the amyloid load within the brain. Similarly, CSF Aβ42 concentrations decrease in dogs with CDS but there is limited and conflicting information on plasma Aβ42 concentrations in aging dogs and dogs with CDS. We measured plasma concentrations of Aβ42 and Aβ40 with an ultrasensitive single-molecule array assay (SIMOA) in a population of healthy aging dogs of different life stages (n = 36) and dogs affected with CDS (n = 11). In addition, the ratio of Aβ42/β40 was calculated. The mean plasma concentrations of Aβ42 and Aβ40 increased significantly with age (r2 = 0.27, p = 0.001; and r2 = 0.42, p < 0.001, respectively) and with life stage: puppy/junior group (0.43–2 years): 1.23 ± 0.95 and 38.26 ± 49.43 pg/mL; adult/mature group (2.1–9 years): 10.99 ± 5.45 and 131.05 ± 80.17 pg/mL; geriatric/senior group (9.3–14.5 years): 18.65 ± 16.65 and 192.88 ± 146.38 pg/mL, respectively. Concentrations of Aβ42 and Aβ40 in dogs with CDS (11.0–15.6 years) were significantly lower than age-matched healthy dogs at 11.61 ± 6.39 and 150.23 ± 98.2 pg/mL (p = 0.0048 and p = 0.001), respectively. Our findings suggest the dynamics of canine plasma amyloid concentrations are analogous to that found in aging humans with and without AD.