Abstract:
Introduction
Cationic polyelectrolytes play important roles in many biological
systems. Histones [20] and cationic proteins of lysosomal
origin [8, 18, 24, 25, 28, 33, 36, 37], both rich in
arginine, and synthetic poly a-amino acids [3, 4, 5, 6, 23,
30] have been shown to be bactericidal and cytotoxic to a
variety of bacteria and mammalian cells. In addition, these
compounds modulate blood coagulation [30] and fibrinolysis
[10]; agglutinate bacteria and mammalian cells [30];
modulate chemotaxis [16]; enhance adherence of mammalian
cells to surfaces [26]; function as opsonins for phagocytosis
by both "professional" and "nonprofessional" cells
[3,5,6,17,27,28,34]; activate autolytic cell wall enzymes
of Staphylococci [15]; and block Fe receptors for IgG upon
certain group A Streptococci [14]. More recent studies have
shown that histone-opsonized bacteria induced intense Iuminot-
dependent chemiluminescence (LDCL) in human
polymorphonuclear leukocytes (PMNs) and mouse peritoneal
macrophages [In Furthermore, poly-i.-arginine collaborated
with mixtures of lectins, calcium ionophore and
the chemotactic peptide formyl-methionyl-Ieucyl-phenylalanine
to induce synergistic LDCL and superoxide production
in human PMNs [12,13]. Thus, arginine-rich polyelectrolytes
appear to participate in many cellular functions related
to host defenses against infection, presumably by
mechanisms involving electrostatic interactions and ligand-
receptor coupling phenomena. The objective of this
present study was to investigate the possibility that arginine-
rich polycations might facilitate the introduction of a variety of agents into eukaryotic cells. For this purpose, we
have studied phagocytosis by Entamoeba histolytica of
Candida albicans, and by Acanthamoeba palestinensis of
Mycobacterium marinum.