Functional channel formation associated with cytotoxic T-cell granules Academic Article uri icon

Overview

MeSH Major

  • Cytoplasmic Granules
  • Ion Channels
  • T-Lymphocytes, Cytotoxic

abstract

  • Lymphocyte granules from cytotoxic T-lymphocyte lines A2, A11, and R8 were enriched by subcellular fractionation using a Percoll gradient. Granule-enriched fractions showed potent hemolytic activity in the presence of Ca2+. Isolated granules induced rapid Ca2+-dependent membrane depolarization of J774 macrophage-like cells. When tested in planar bilayers, granules induced the formation of Ca2+-dependent functional ion channels of large conductance steps of 1-6 nS in 0.1 M NaCl. Granule-induced channels were resistant to closing by an increase in transmembrane potential, with few channels shifting to the closed state only at voltages of greater than 70 mV, following a Poisson process. These channels showed poor ion selectivity and were permeable to all monovalent and divalent ions (K+, Na+, Li+, Cl-, Ca2+, Mg2+, Zn2+, Ba2+). Ultrastructural examination of soluble granule proteins incubated for 48 hr at 37 degrees C in the presence of Ca2+ revealed ring-like structures of 150-200 A. Structural and functional channel formation may be involved in cytolysis induced by cytotoxic T lymphocytes.

publication date

  • July 2, 1986

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC322809

PubMed ID

  • 2417234

Additional Document Info

start page

  • 150

end page

  • 4

volume

  • 83

number

  • 1