Biology subjects

Tran, T. T. P.

Publications and source records attributed to Tran, T. T. P..

5 recordsLinked to original sources

bioRxiv2025

Identification of molecular pathways involved in the anti-liver cancer activity of madecassic acid

Natural products are a time-tested source of medicinal compounds, and there is huge interest in discovery of new drugs from plant sources. However, in many cases the effects are not as well understood, strong, or selective, as would be hoped. An example of this is madecassic acid (MA), which has promising activity against liver cancer, activity which can be improved through chemical modifications, although a molecular understanding of its mechanism of action is unknown. In this report we have used chemical proteomics to identify the proteins with which madecassic interacts in liver cancer cells, and used RNAseq to support those findings, as well as showing more precisely how chemical modifications can focus and amplify MA activity. Our results show that madecassic acid interacts with a number of proteins relating to metabolism, nucleic acid processing, and protein folding, which have been previously identified as linked to liver cancer. This provides a route from phenotypic- to target based-drug discovery and develop new potential treatments for a globally challenging disease.

pharmacology and toxicology↗

bioRxiv2025

Regioselectively Acetylated Silybin Derivatives and their Cytotoxic Activity in Liver Cancer Cells

O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=48 SRC="FIGDIR/small/638106v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@13744c8org.highwire.dtl.DTLVardef@184bb9borg.highwire.dtl.DTLVardef@138f442org.highwire.dtl.DTLVardef@2c45ca_HPS_FORMAT_FIGEXP M_FIG C_FIG Natural products continue to serve as a valuable source of starting points for therapeutic agents. Six silybin derivatives have been synthesized and tested in vitro for their cytotoxic effect on the human hepatocellular carcinoma line HepG2 using the MTT assay. Results indicate that the 3,5,7,20,23-penta-O-acetyl-2,3-dehydrosilybin possesses a stronger cytotoxic effect than that of the parent silybin by a factor of 12. This compound was further evaluated for its cytotoxic activity on Hep3B, Huh7, and Huh7R hepatocellular carcinoma cell lines, giving similar potencies, arresting the cell cycle at S phase and causing apoptosis. These results illustrate the potential of silybin derivatives as therapeutics against liver cancer.

pharmacology and toxicology↗

bioRxiv2021

Adenovirus-α-defensin complexes induce NLRP3-associated maturation of human phagocytes via TLR4 engagement

Intramuscular delivery of human adenovirus (HAdV)-based vaccines leads to rapid recruitment of neutrophils, which then release antimicrobial peptides/proteins (AMPs). How these AMPs influence vaccine efficacy over the subsequent 24 hr is poorly understood. In this study, we asked if human neutrophil protein 1 (HNP-1), an -defensin that influences the direct and indirect innate immune responses to a range of pathogens, impacts the innate response of human phagocytes to three HAdV species/types (HAdV-C5, -D26, -B35). We show that HNP-1 binds to the capsids, redirects HAdV-C5, -D26, -B35 to Toll-like receptor 4 (TLR4), which leads to internalization, an NLRP3-mediated inflammasome response, and IL-1{beta} release. Surprisingly, IL-1{beta} release was not associated with notable disruption of plasma membrane integrity. These data further our understanding of HAdV innate immunogenicity and may provide pathways to extend HAdV-based vaccines efficacy.

immunology↗

bioRxiv2020

Lactoferrin retargets adenoviruses to TLR4 to induce an abortive NLRP3-associated pyroptotic response in human dendritic cells

Despite decades of investigations, we still poorly grasp the immunogenicity of human adenovirus (HAdV)-based vaccines in humans. In this study, we explored the role of lactoferrin, which belong to the alarmin subset of antimicrobial peptides that provide immediate direct and indirect activity against a range of pathogens following a breach in tissue homeostasis. Lactoferrin is a globular, iron-sequestering, glycoprotein that can increase HAdV infection and maturation of antigen-presenting cells. However, the mechanism by which HAdV-lactoferrin complexes induce maturation is unknown. We show that lactoferrin redirects HAdVs from species B, C, and D to toll-like receptor 4 (TLR4) complexes on human mononuclear phagocyte. TLR4-mediated internalization induces an abortive NLRP3-associated pyroptotic response inducing pro-inflammatory cytokine release and disrupting plasma membrane integrity without cell death. These data impact our understanding of the immunogenicity of HAdV-based vaccines and may provide ways to increase their efficacy.

immunology↗

bioRxiv2018

Humoral immune response to adenovirus induce tolerogenic bystander dendritic cells that promote generation of regulatory T cells

Following repeated encounters with adenoviruses most of us develop robust humoral and cellular immune responses that are thought to act together to combat ongoing and subsequent infections. Yet in spite of robust immune responses, adenoviruses establish subclinical persistent infections that can last for decades. While adenovirus persistence pose minimal risk in B-cell compromised individuals, if T-cell immunity is severely compromised, reactivation of latent adenoviruses can be life threatening. This dichotomy led us to ask how anti-adenovirus antibodies influence adenovirus-specific T-cell immunity. Using primary human blood cells, transcriptome and secretome profiling, and pharmacological, biochemical, genetic, molecular, and cell biological approaches, we initially found that healthy adults harbor adenovirus-specific regulatory T cells (Tregs). As peripherally induced Tregs are generated by tolerogenic dendritic cells (DCs), we then addressed how tolerogenic DCs could be created. Here, we demonstrate that DCs that take up immunoglobulin-complexed (IC)-adenoviruses create an environment that causes bystander DCs to become tolerogenic. These adenovirus antigen-loaded tolerogenic DCs can drive naive T cells to mature into adenovirus-specific Tregs. Our results may provide ways to improve antiviral therapy and/or pre-screening high-risk individuals undergoing immunosuppression.\n\nAuthor summaryWhile numerous studies have addressed the cellular and humoral response to primary virus encounters, relatively little is known about the interplay between persistent infections, neutralizing antibodies, antigen-presenting cells, and the T-cell response. Our studies suggests that if adenovirus-antibody complexes are taken up by professional antigen-presenting cells (dendritic cells), the DCs generate an environment that causes bystander dendritic cells to become tolerogenic. These tolerogenic dendritic cells favors the creation of adenovirus-specific regulatory T cells. While this pathway likely favors pathogen survival, there may be advantages for the host also.

microbiology↗