Biology subjects

Liou, G.-G.

Publications and source records attributed to Liou, G.-G..

4 recordsLinked to original sources

bioRxiv2023

Adjuvant Effects of Amphipathic Helical Peptides

Subunit vaccines are the focus of research in developing new vaccines against infectious diseases. Due to the low immunogenicity of recombinant proteins, adjuvants are required for the activation of humoral and cellular immunity against a protein antigen. In this study, we reported the identification of a novel pathway that can activate humoral immunity against a recombinant protein without inducing inflammatory responses. By fusing an amphipathic helical peptide to GFP, one can increases the immunogenicity of GFP by up to 1000 fold. This enhancement was correlated with the ability of amphipathic helical peptides to bind to cell membranes and cause lysosomal membrane permeabilization. We showed evidence that the amphipathic helical peptide may induce the delivery of antigen across the lysosomal membrane into cytosol. Amphipathic helical peptide fusion provided a new pathway for stimulating immune responses against recombinant proteins.

immunology↗

bioRxiv2022

A thermally stable protein nanoparticle that stimulates long lasting humoral immune response

Thermally stable vaccine platform is considered to be the missing piece of vaccine technology. In this article, we are reporting the development of a novel protein nanoparticle and evaluating its ability in withstanding extended high temperature incubation and stimulating long lasting humoral immune response. This protein nanoparticle is assembled from a fusion protein composed of an amphipathic helical peptide derived from M2 protein of H5N1 influenza virus (AH3) and a super folder green fluorescent protein(sfGFP). The proposed structure of this protein nanoparticle is modeled according to transmission electronic microscope (TEM) images of protein nanoparticle. From this proposed protein model, we have generated a mutant with two gain-of-function mutations that function synergistically on particle stability. Protein nanoparticle assembled from this gain-of-function mutant is able to remove a hydrophobic patch from the surface of protein nanoparticle. This gain-of-function mutant also contributes to higher thermostability of protein nanoparticle and stimulates long lasting humoral immune response after single immunization. This protein nanoparticle shows increasing particle stability in higher temperature and higher salt concentration. This novel protein nanoparticle may serve as a thermal-stable platform for vaccine development.

immunology↗

bioRxiv2020

A self-assembled protein nanoparticle serving as a one-shot vaccine carrier

In this paper, we are exploring the role of an amphipathic helical peptide in mediating the self-assembly of a fusion protein into a protein nanoparticle and the application of the nanoparticle as a one-shot vaccine carrier. Out of several candidates, an amphipathic helical peptide derived from M2 protein of type A influenza virus is found to stimulate high antigenicity when fused to a fluorescent protein genetically. This fusion protein was found to form protein nanoparticle spontaneously when expressed and purified protein stimulates long-lasting antibody responses in single immunization. Through modeling peptide structure and nanoparticle assembly, we have improved this vaccine carrier in complex stability. The revised vaccine carrier is able to stimulate constant antibody titer to a heterologous antigen for at least six months in single immunization. The immune response against a heterologous antigen can be boosted further by additional immunization in spite of high immune responses to carrier protein.

immunology↗

bioRxiv2020

Dynamin-2 regulates synaptic podosome maturation to facilitate neuromuscular junction development

Neuromuscular junctions (NMJs) govern rapid and efficient neuronal communication with muscle cells, which relies on the proper architecture of specialized postsynaptic compartments. However, the intrinsic mechanism in muscle cells contributing to elaborate NMJ development has been unclear. In this study, we reveal that the GTPase dynamin-2 (Dyn2), best-known for catalyzing synaptic vesicle endocytosis at the presynaptic membrane, is also involved in postsynaptic morphogenesis. We demonstrate that Dyn2 is enriched in the postsynaptic membrane of muscle cells and is involved in the maturation of neurotransmitter receptor clusters via its actin bundling ability. Dyn2 functions as a molecular girdle to regulate synaptic podosome turnover and promote morphogenesis of the postsynaptic apparatus. In Drosophila NMJs, Dyn2 is required to organize the postsynaptic actin cytoskeleton and to mediate its electrophysiological activities. Mechanistically, the actin binding, self-assembly, GTP hydrolysis ability, and Y597 phosphorylation of Dyn2 all regulate its actin bundling activity. Together, our study uncovers a role for Dyn2 in cytoskeleton remodeling and organization at the postsynaptic membrane of NMJs.

molecular biology↗