Biology subjects

Esser-Kahn, A. P.

Publications and source records attributed to Esser-Kahn, A. P..

6 recordsLinked to original sources

bioRxiv2024

Intranasal immunization with CPAF combined with cyclic-di-AMP induces a memory CD4 T cell response and reduces bacterial burden following intravaginal infection with Chlamydia muridarum

Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection globally, and a vaccine is urgently needed to stop transmission and disease. Chlamydial Protease Activity Factor (CPAF) is an immunoprevalent and immunodominant antigen for CD4 T cells and B cells, which makes it a strong vaccine candidate. Due to the tolerogenic nature of the female genital tract (FGT) and its lack of secondary lymphoid tissue, effective induction of protective cell-mediated immunity will likely require potent and safe mucosal adjuvants. To address this need, we produced CPAF in a cell-free protein synthesis platform and adjuvanted it with the TLR9-agonist CpG1826, STING (stimulator of interferon genes) agonist cyclic-di-AMP (CDA), and/or the squalene oil-in-water nanoemulsion, AddaS03. We determined that intranasal immunization with CPAF plus CDA was well tolerated in female mice, induced CD4 T cells that produced IL-17A or IFN{gamma}, significantly reduced bacterial shedding, and shortened the duration of infection in mice intravaginally challenged with Chlamydia muridarum. These data demonstrate the potential for CDA as a mucosal adjuvant for vaccines against Chlamydia genital tract infection.

immunology↗

bioRxiv2024

β-glucan induced trained immunity enhances antibody levels in a vaccination model in mice

Trained immunity improves disease resistance by strengthening our first line of defense, the innate immune system. Innate immune cells, predominantly macrophages, are epigenetically and metabolically rewired by {beta}-glucan, a fungal cell wall component, to induce trained immunity. These trained macrophages exhibit increased co-stimulatory marker expression and altered cytokine production. Signaling changes from antigen-presenting cells, including macrophages, polarize T-cell responses. Recent work has shown that trained immunity can generally enhance protection against infection, and some work has shown increased protection with specific vaccines. It has been hypothesized that the trained cells themselves potentially modulate adaptive immunity in the context of vaccines. However, the mechanistic link between trained immunity on subsequent vaccinations to enhance antibody levels has not yet been identified. We report that trained immunity induced by a single dose of {beta}-glucan increased antigen presentation in bone-marrow-derived macrophages (BMDMs) and CD4+ T cell proliferation in-vitro. Mice trained with a single dose of {beta}-glucan a week before vaccination elicited higher antigen-specific antibody levels than untrained mice. Further experiments validate that macrophages mediate this increase. This effect persisted even after vaccinations with 100 times less antigen in trained mice. We report {beta}-glucan training as a novel prophylactic method to enhance the effect of subsequent vaccines.

immunology↗

bioRxiv2024

Novel non-immunogenic trained immunity inducing small molecule with improved anti-tumor properties

Trained immunity refers to the non-specific innate immune memory response triggered by the epigenetic and metabolic rewiring of innate immune cells. A strengthened innate immune system significantly improves disease resistance. However, very few trained immunity-inducing molecules have been identified. Almost all molecules for training are primarily immunogenic and then subsequently induce training. Non-immunogenic molecules that induce training could be employed in therapies without the concern of adverse inflammatory reactions. We identified a small molecule, A1155463, that modulates cellular metabolism to induce trained immunity in macrophages in-vitro. We show that nanomolar concentrations of these compounds uniquely alter only cellular metabolism without leading to apoptosis. We further observed that these compounds could induce training in an in-vivo model in mice. A1155463 training improved anti-tumor resistance to B16.F10 melanoma cells. The effect was enhanced upon combination with checkpoint therapy. In summary, we report the discovery of a novel trained immunity-inducing small molecule with enhanced anti-tumor properties.

immunology↗

bioRxiv2023

Data-driven discovery of innate immunomodulators via machine learning-guided high throughput screening

The innate immune response is vital for the success of prophylactic vaccines and immunotherapies. Control of signaling in innate immune pathways can improve prophylactic vaccines by inhibiting unfavorable systemic inflammation and immunotherapies by enhancing immune stimulation. In this work, we developed a machine learning-enabled active learning pipeline to guide in vitro experimental screening and discovery of small molecule immunomodulators that improve immune responses by altering the signaling activity of innate immune responses stimulated by traditional pattern recognition receptor agonists. Molecules were tested by in vitro high throughput screening (HTS) where we measured modulation of the nuclear factor{kappa} -light-chain-enhancer of activated B-cells (NF-{kappa}B) and the interferon regulatory factors (IRF) pathways. These data were used to train data-driven predictive models linking molecular structure to modulation of the NF-{kappa}B and IRF responses using deep representational learning, Gaussian process regression, and Bayesian optimization. By interleaving successive rounds of model training and in vitro HTS, we performed an active learning-guided traversal of a 139,998 molecule library. After sampling only[~] 2% of the library, we discovered viable molecules with unprecedented immunomodulatory capacity, including those capable of suppressing NF-{kappa}B activity by up to 15-fold, elevating NF-{kappa}B activity by up to 5-fold, and elevating IRF activity by up to 6-fold. We extracted chemical design rules identifying particular chemical fragments as principal drivers of specific immunomodulation behaviors. We validated the immunomodulatory effect of a subset of our top candidates by measuring cytokine release profiles. Of these, one molecule induced a 3-fold enhancement in IFN-{beta} production when delivered with a cyclic di-nucleotide stimulator of interferon genes (STING) agonist. In sum, our machine learning-enabled screening approach presents an efficient immunomodulator discovery pipeline that has furnished a library of novel small molecules with a strong capacity to enhance or suppress innate immune signaling pathways to shape and improve prophylactic vaccination and immunotherapies.

immunology↗

bioRxiv2018

Immune potentiator for increased safety and improved protection of vaccines by NF-kB modulation

Many modern vaccines include adjuvants that activate the immune system and provide an enhanced humoral or cellular response. Current approved adjuvants are unable to provide desired responses against some pathogens (e.g. HIV or dengue). Many new adjuvants have been developed and demonstrate promising results, but side effects from the inflammatory response induced by these adjuvants have resulted in limited FDA approvals. No adjuvants yet possess the capability to independently modulate inflammation and protection. Here we demonstrate a method to limit inflammation and side effects associated with vaccination while retaining the protective responses using a variety of promising adjuvants. To accomplish this, we combined a selective NF-kB inhibitor with the immune adjuvant. The resulting vaccines reduce systemic inflammation and boost antibody responses. In an influenza challenge model, we demonstrate that this approach enhances protection. This method is generalizable across a broad range of adjuvants and antigens. We anticipate these studies will lead to a novel approach to vaccine formulation design that may prove general across a wide range of adjuvants, enabling their greater use in the public realm.

immunology↗

bioRxiv2017

Light Guided In-vivo Activation of Innate Immune Cells with Photocaged TLR 2/6 Agonist

The complexity of the immune system creates challenges in exploring its importance and robustness. To date, there have been few techniques developed to manipulate individual components of the immune system in an in vivo environment. Here we show a light-based dendritic cell (DC) activation allowing spatial and temporal control of immune activation in vivo. Additionally, we show time dependent changes in RNA profiles of the draining lymph node, suggesting a change in cell profile following DC migration and indicating that the cells migrating have been activated towards antigen presentation.

immunology↗