About this blog
Newest kudos -- Maki and students' work is published!; Andy Smith and his lab gets published; Dave Gondek is in print
Thursday, October 20, 2016
Inada M, *Nichols RJ, Parsa JY, Homer CM, *Benn RA, *Hoxie RS, Madhani HD, Shuman S, Schwer B, Pleiss JA. Phospho-site mutants of the RNA Polymerase II C-terminal domain alter subtelomeric gene expression and chromatin modification state in fission yeast. Nucleic Acids Res. 2016 Jul 8. pii: gkw603. [Epub ahead of print]
* IC undergraduates
Thursday, October 8, 2015
Alex M. Wilks (’15), Sarah R. Rabice(’14), Holland S. Garbacz (’15), Cailin C. Harro (’17), Andrew M. Smith. 2015. Double-network gels and the toughness of terrestrial slug glue. Journal of Experimental Biology 218, 3128-3137; doi: 10.1242/jeb.128991 View the article here.
Monday, June 22, 2015
Georg Stary, Andrew Olive, Aleksandar F. Radovic-Moreno, David Gondek, David Alvarez, Pamela A. Basto, Mario Perro, Vladimir D. Vrbanac, Andrew M. Tager, Jinjun Shi, Jeremy A. Yethon, Omid C. Farokhzad, Robert Langer, Michael N. Starnbach, Ulrich H. von Andrian. (2015). A mucosal vaccine against Chlamydia trachomatis generates two waves of protective memory T cells. Science (348) 6241. DOI: 10.1126/science.aaa8205.
Genital Chlamydia trachomatis (Ct) infection induces protective immunity that depends on interferon-γ–producing CD4 T cells. By contrast, we report that mucosal exposure to ultraviolet light (UV)–inactivated Ct (UV-Ct) generated regulatory T cells that exacerbated subsequent Ct infection. We show that mucosal immunization with UV-Ct complexed with charge-switching synthetic adjuvant particles (cSAPs) elicited long-lived protection in conventional and humanized mice. UV-Ct–cSAP targeted immunogenic uterine CD11b+CD103– dendritic cells (DCs), whereas UV-Ct accumulated in tolerogenic CD11b–CD103+ DCs. Regardless of vaccination route, UV-Ct–cSAP induced systemic memory T cells, but only mucosal vaccination induced effector T cells that rapidly seeded uterine mucosa with resident memory T cells (TRM cells). Optimal Ct clearance required both TRM seeding and subsequent infection-induced recruitment of circulating memory T cells. Thus, UV-Ct–cSAP vaccination generated two synergistic memory T cell subsets with distinct migratory properties.
Wednesday, July 3, 2013
Melcher P, and Zwieniecki MA. (2013). Functional analysis of embolism induced by air injection in Acer rubrum and Salix nigra. Frontiers in Plant Biophysics and Modeling. Link to more information here.
Maciej A. Zwieniecki, Peter J. Melcher, and Eric T. Ahrens (2013). Analysis of spatial and temporal dynamics of xylem refilling in Acer rubrum L. using magnetic resonance imaging (MRI). Frontiers in Plant Biophysics and Modeling. doi: 10.3389/fpls/2013.00265.
Thursday, March 28, 2013
M. Braun (Biology ’11), M. Menges (Biology '10), F. Opoku (Biochemistry ’13) and A. M. Smith. 2013. The relative contribution of calcium, zinc and oxidation-based cross-links to the stiffness of Arion subfuscus glue. The Journal of Experimental Biology 216, 1475-148. View the article here.
Metal ions are present in many different biological materials, and are capable of forming strong cross-links in aqueous environments. The relative contribution of different metal-based cross-links was measured in the defensive glue produced by the terrestrial slug Arion subfuscus. This glue contains calcium, zinc, manganese, iron and copper. These metals are essential to the integrity of the glue and to gel stiffening. Removal of all metals caused at least a fifteen-fold decrease in the storage modulus of the glue. Selectively disrupting cross-links involving hard Lewis acids such as calcium weakened the glue, while disrupting cross-links involving borderline Lewis acids such as zinc did not. Calcium is the most common cation bound to the glue (40 mmol L-1), and its charge is balanced primarily by sulfate at 82 to 84 mmol L-1. Thus, these ions likely play a primary role in bringing polymers together directly. Imine bonds formed as a result of protein oxidation also contribute substantially to the strength of the glue. Disrupting these bonds with hydroxylamine caused a 33% decrease in storage modulus of the glue, while stabilizing them by reduction with sodium borohydride increased the storage modulus by 40%. Thus, a combination of metal-based bonds operates in this glue. Most likely, cross-links directly involving calcium play a primary role in bringing together and stabilizing the polymer network, followed by imine bond formation and possible iron coordination.