Browsing by Author "Tung, Chun-Yu"
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Item Actin at stereocilia tips is regulated by mechanotransduction and ADF/cofilin(Elsevier, 2021-03) McGrath, Jamis; Tung, Chun-Yu; Liao, Xiayi; Belyantseva, Inna A.; Roy, Pallabi; Chakraborty, Oisorjo; Li, Jinan; Berbari, Nicolas F.; Faaborg-Andersen, Christian C.; Barzik, Melanie; Bird, Jonathan E.; Zhao, Bo; Balakrishnan, Lata; Friedman, Thomas B.; Perrin, Benjamin J.; Biology, School of ScienceStereocilia on auditory sensory cells are actin-based protrusions that mechanotransduce sound into an electrical signal. These stereocilia are arranged into a bundle with three rows of increasing length to form a staircase-like morphology that is required for hearing. Stereocilia in the shorter rows, but not the tallest row, are mechanotransducing because they have force-sensitive channels localized at their tips. The onset of mechanotransduction during mouse postnatal development refines stereocilia length and width. However, it is unclear how actin is differentially regulated between stereocilia in the tallest row of the bundle and the shorter, mechanotransducing rows. Here, we show actin turnover is increased at the tips of mechanotransducing stereocilia during bundle maturation. Correspondingly, from birth to postnatal day 6, these stereocilia had increasing amounts of available actin barbed ends, where monomers can be added or lost readily, as compared with the non-mechanotransducing stereocilia in the tallest row. The increase in available barbed ends depended on both mechanotransduction and MYO15 or EPS8, which are required for the normal specification and elongation of the tallest row of stereocilia. We also found that loss of the F-actin-severing proteins ADF and cofilin-1 decreased barbed end availability at stereocilia tips. These proteins enriched at mechanotransducing stereocilia tips, and their localization was perturbed by the loss of mechanotransduction, MYO15, or EPS8. Finally, stereocilia lengths and widths were dysregulated in Adf and Cfl1 mutants. Together, these data show that actin is remodeled, likely by a severing mechanism, in response to mechanotransduction.Item Activation of Dendritic Cell Function by Soypeptide Lunasin as a Novel Vaccine Adjuvant(Office of the Vice Chancellor for Research, 2015-04-17) Simmons, Sharena J.; Tung, Chun-Yu; Chang, Hua-ChenThe innate immune system is the first line of defense against intruding pathogens. Dendritic cells (DCs) act as messengers between the adaptive and innate immune system, which process and present antigens to mature T helper cells (CD4+T), and Cytotoxic T cells (CD8+T). The addition of an appropriate adjuvant that activates the innate immunity is essential to subsequent development of the adaptive immunity specific to the vaccine antigens. Thus, any innovation capable of improving the immune responses may lead to a more efficacious vaccine. We recently identified a novel immune modulator using a naturally occurring seed peptide called lunasin. Lunasin was originally isolated from soybeans, and it is a small peptide containing 43 amino acids. Our studies had revealed stimulatory effects of lunasin on innate immune cells by regulating expression of a number of genes that are important for immune responses. The objective was to define the effectiveness of lunasin as an adjuvant that enhances immune responses. Immunization of mice with ovalbumin (OVA) and lunasin inhibited the growth of OVA-expressing A20 B-lymphomas, which was correlated with OVA-specific CD8+ T cells. Increased levels of anti-OVA IgG were also observed in mice immunized with OVA and lunasin. These results suggest that lunasin may function as a vaccine adjuvant by promoting DC maturation, which in turn enhances the development of protective immune responses to the vaccine antigens.Item Activation of Dendritic Cells by Soypeptide Lunasin: Implication in Vaccine Adjuvant(Office of the Vice Chancellor for Research, 2014-04-11) Flores, Sarah; Dong, Melissa; Tung, Chun-Yu; Chang, Hua-ChenAdjuvants enhance the immunogenicity of vaccines and improve the immune responses. Although many adjuvants are currently used in research, FDA approved aluminum salt (Alum) remains the most often used in human vaccines. Alum is known to promote the Th2 immune response and enhance antibody production, but is less efficient on eliciting Th1 and CTL cellular responses. Thus, it is prudent to improve the effectiveness of current adjuvants or to develop a novel alternative adjuvant. We have recently identified lunasin, a seed peptide from soybeans, as a novel immune modulator. The objective is to define the effectiveness of lunasin peptide as an adjuvant that can enhance the protective immunity of vaccines. Our studies have revealed stimulatory effects of lunasin on dendritic cells (DCs) by regulating expression of a number of genes that are important for immune responses. Lunasin-treated human conventional DCs (cDCs) not only expressed elevated levels of co-stimulatory molecules (CD86) but also exhibited up-regulation of chemokines (CCL2, CCL3, CCL4) and cytokine (IL-1β). To determine the function of lunasin-treated cDCs, these cells were co-cultured with allogeneic human peripheral blood CD4+ T cells for 7 days in the mixed lymphocyte reaction. Lunasin-treated cDCs induced almost 2-fold higher proliferation of allogeneic CD4+ T cells when comparing with a sham treatment. To verify the in vivo effects, lunasin was administered into mice. Increased CD86 expression was found in cDCs from spleens of mice treated with lunasin. Furthermore, mice vaccinated with lunasin-adjuvanted ovalbumin (OVA) had reduced tumor growth following challenging with OVA-expressing A20 B-lymphoma cells. Taken together, our data suggest that lunasin may act as a vaccine adjuvant by targeting DCs to enhance and modulate the immune responses to antigens.Item Activation of Natural Killer Cell by Lunasin and Cytokine(Office of the Vice Chancellor for Research, 2014-04-11) Kyazike, Sharifah; Lewis, David; Tung, Chun-Yu; Han, Ling; Chang, Hua-ChenCancer immunotherapy is one of the emerging therapeutic strategies to harness the immune system to eradicate chemotherapy-resistant cancerous cells. NK cells can recognize and eliminate cancer cells before adaptive immunity is developed. Human NK cells can be divided into 2 major subsets based on their surface expression of CD56. NK cells with CD56 bright populations are major cytokine producers, while NK cells expressing CD56 dim have higher lytic activity. Due to the role of NK cells in cancer surveillance, any approach to enhance their activity may augment cancer treatment. We have recently shown that soypeptide Lunasin is a novel immune modulating agent that, together with cytokines, enhances IFN- γ and Granzyme B expression by NK cells. This synergism augments the natural cytotoxicity of NK cells against various tumors in vitro as well as in the xenograft model. The objective of this study is to evaluate the effects of Lunasin on antibody-dependent cellular cytotoxicity (ADCC) activity of NK cells against Rituximab-coated human B-lymphoma Raji cells. We also evaluated the expression of several markers involved in NK-mediated tumorcidal activity using flow cytometry. Together, these results suggest that Lunasin could enhance the efficacy of NK cell-based immunotherapy for cancer.Item Characterization of TRPV4-mediated signaling pathways in an optimized human choroid plexus epithelial cell line(APS, 2022-12) Hulme, Louise; Hochstetler, Alexandra; Schwerk, Christian; Schroten, Horst; Ishikawa, Hiroshi; Tung, Chun-Yu; Perrin, Benjamin; Blazer-Yost, Bonnie; Biology, School of ScienceThe objectives of these studies were twofold: 1) to characterize the human choroid plexus papilloma (HIBCPP) cell line as a model of the blood-cerebrospinal fluid barrier (BCSFB) via morphology, tightness, and polarization of transporters in choroid plexus epithelia (CPe), and 2) to utilize Ussing-style electrophysiology to elucidate signaling pathways associated with the activation of the transient receptor potential vanilloid 4 (TRPV4) channel involved in cerebrospinal fluid (CSF) secretion. RT-PCR was implemented to determine gene expression of cell fate markers, junctional complex proteins, and transporters of interest. Scanning electron microscopy and confocal three-dimensional renderings of cultures grown on permeable supports were utilized to delineate the morphology of the brush border, junctional complexes, and polarization of key transporters. Electrophysiology was used to understand and explore TRPV4-mediated signaling in the HIBCPP cell line, considering both short-circuit current (Isc) and conductance responses. HIBCPP cells grown under optimized culture conditions exhibited minimal multilayering, developed an intermediate resistance monolayer, retained differentiation properties, and expressed, and correctly localized, junctional proteins and native transporters. We found that activation of TRPV4 resulted in a robust, multiphasic change in electrogenic ion flux and increase in conductance accompanied by substantial fluid secretion. This response appears to be modulated by a number of different effectors, implicating phospholipase C (PLC), protein kinase C (PKC), and phosphoinositide 3-kinase (PI3K) in TRPV4-mediated ion flux. The HIBCPP cell line is a representative model of the human BCSFB, which can be utilized for studies of transporter function, intracellular signaling, and regulation of CSF production.Item Effects of Soy Peptide on Dendritic Cells(Office of the Vice Chancellor for Research, 2013-04-05) Shipman, Kaylee; Tung, Chun-Yu; Han, Ling; Patel, Amy; Corn, Caleb; Chang, Hua-ChenInnate immunity is mediated by effector cells, including NK cells, dendritic cells (DCs), macrophages, and polymorphonuclear phagocytes, which can respond immediately after activation through receptors encoded by germ-line genes. Innate immune responses represent the first line of defense in immunosurveillance. Interventions that enhance the functions of innate immunity will be an important armamentarium to human health. We recently exploited a natural dietary soy peptide called lunasin to improve the immune functions. The hypothesis was that lunasin peptide has stimulatory effects on immune cells. To test this hypothesis, human peripheral blood mononuclear cells (PBMCs) of healthy donors were stimulated with or without lunasin. We found that lunasin is capable of stimulating DCs to up-regulate chemokines (CCL2, CCL3, and CCL4), cytokines (TNFα and IFNα), and co-stimulatory molecules (CD80, CD86). In addition, lunasin-treated DCs can provide NK with required signals for activation. Taken together, our results support the immunomodulatory activity of soy peptide on DCs, which leads to enhancement of innate immunity.Item Enhancement of Cancer Immunotherapy Using Immune Modulating Peptides(Office of the Vice Chancellor for Research, 2013-04-05) Chang, Hua-Chen; Han, Ling; Lewis, David; Tung, Chun-Yu; Srinivasan, Mythily; Robertson, Michael J.; Yeh, Wu-KuangImmune Peptide Therapeutics (IPT) LLC, an Indiana-based small business and its research partner Indiana University previously identified a novel property of lunasin as a distinct class of immune modulating agent that enhances anti-tumor immunity, which may promote disease-free survival by limiting tumor progression, and thus prolong lives of cancer patients. Lunasin, a synthetic 43-amino acid peptide, was originally isolated from soybeans. Our studies have demonstrated that lunasin exerts robust synergistic effects with cytokines on augmenting IFNγ and granzyme B expression by Natural Killer (NK) cells, which is associated with increased tumoricidal activity of NK cells. In addition, this combination regimen is capable of rescuing IFNγ production ex vivo by NK cells from chemotherapy-treated Non-Hodgkin’s Lymphoma (NHL) patients who are immunocompromised with acquired immune deficiency. The long-term goal is to develop an efficacious immunotherapy which will impact the treatment and improve the clinical outcomes for NHL patients. The dose-response study indicates the optimum concentration of lunasin is at the range of μM, which would undermine its use in clinical studies. To enhance the medicinal value lunasin must be optimized for in vitro and in vivo efficacy. The objective is to develop a second generation of lunasin, which will increase its potency to improve the performance. In this study we have implemented several strategies to design and modify the prototype. The newly developed peptide called IPT.103 has 15 amino acids that are in the D-isoform configuration. Activity of IPT.103 has been tested in vitro with EC50 of 0.78 μM as compared to 4.54 μM for lunasin. IPT.103 also has in vivo activity on enhancing the serum levels of IFNγ production using a mouse model. Taken together, we have developed a peptide derivative (IPT.103) that deviates from its parental type lunasin to increase intellectual merit for commercialization as well as support clinical application.Item GRXCR2 Regulates Taperin Localization Critical for Stereocilia Morphology and Hearing(Elsevier, 2018-10-30) Liu, Chang; Luo, Na; Tung, Chun-Yu; Perrin, Benjamin J.; Zhao, Bo; Otolaryngology -- Head and Neck Surgery, School of MedicineMutations in human GRXCR2, which encodes a protein of undetermined function, cause hearing loss by unknown mechanisms. We found that mouse GRXCR2 localizes to the base of the stereocilia, which are actin-based mechanosensing organelles in cochlear hair cells that convert sound-induced vibrations into electrical signals. The stereocilia base also contains taperin, another protein of unknown function required for human hearing. We show that taperin and GRXCR2 form a complex and that taperin is diffused throughout the stereocilia length in Grxcr2-deficient hair cells. Stereocilia lacking GRXCR2 are longer than normal and disorganized due to the mislocalization of taperin, which could modulate the actin cytoskeleton in stereocilia. Remarkably, reducing taperin expression levels could rescue the morphological defects of stereocilia and restore the hearing of Grxcr2-deficient mice. Thus, our findings suggest that GRXCR2 is critical for the morphogenesis of stereocilia and auditory perception by restricting taperin to the stereocilia base.Item Lunasin alleviates allergic airway inflammation while increases antigen-specific Tregs(PLoS, 2015-02-03) Yang, Xiaowei; Zhu, Jingjing; Tung, Chun-Yu; Gardiner, Gail; Wang, Qun; Chang, Hua-Chen; Zhou, Baohua; Department of Pediatrics, IU School of MedicineLunasin is a naturally occurring peptide isolated from soybeans and has been explored in cancer treatment. Lunasin inhibits NF-κB activation and thus pro-inflammatory cytokine and mediator production in macrophages. In this study we demonstrate that lunasin can effectively suppress allergic airway inflammation in two murine models of asthma. In an OVA+Alum sensitization model, intranasal lunasin treatment at the time of OVA challenges significantly reduced total cells counts in bronchoalveolar lavage (BAL) fluid and eosinophilia, peribronchiolar inflammatory infiltration, goblet cell metaplasia and airway IL-4 production. In an OVA+LPS intranasal sensitization model, lunasin treatment either at the time of sensitization or challenge has similar effects in suppress allergic airway inflammation including significantly reduced total cell and eosinophil counts in BAL fluid, inflammatory gene Fizz1 expression in the lung, and IL-4 production by OVA re-stimulated cells from mediastinal lymph nodes. We further show that intranasal instillation of OVA+lunasin significantly increases OVA-specific regulatory T cell (Treg) accumulation in the lung comparing to OVA only treatment. Taken together, our results suggest lunasin as an anti-inflammatory agent can be potentially used in asthma therapy or as an adjuvant to enhance the induction of antigen-specific Tregs and thus boost the efficacy of allergy immunotherapy.Item Mechanisms of Gene Regulation by Soy Peptide Lunasin in Innate Immune Cells(Office of the Vice Chancellor for Research, 2015-04-17) Casiano-Rivera, Félix M.; Tung, Chun-Yu; Chang, Hua-ChenLunasin is a seed peptide containing 43 amino acids, originally isolated from soybeans. Recently, a novel function of lunasin was discovered, as it acts as an immune modulating agent regulating gene expression of various innate immune cells. Lunasin strongly activated the expression of genes encoding for type I interferon and inflammatory cytokines. Nonetheless, the molecular mechanisms of lunasin’s gene regulation are relatively unknown. Our current hypothesis states that lunasin is able to induce activation of various transcription factors, resulting in gene expression in immune cells. Human dendritic cells (DCs) or monocytes were purified from peripheral blood mononuclear cells (PBMCs) in order to determine the activation of transcription factors. Phosphorylation of STAT1 and NF-ĸB (p65) were evident in cells treated with lunasin using flow cytometry and Western blotting. The results will ultimately lead to the signaling pathways involved in gene expression regulated by lunasin in innate immune cells. By defining the signaling pathway of lunasin, we can have a better understanding of its application in immune modulation.