Synthesis of species-specific stress proteins by virulent strains of Listeria monocytogenes

Abstract

Listeriolysin is a virulence factor that appears to be necessary for the intracellular survival of Listeria monocytogenes. As shown in this investigation, listeriolysin is produced in only small amounts by clinical isolates of L. monocytogenes belonging to the serogroup 1/2a, but its synthesis can be induced by heat shock and to a lesser extent by oxidative stress. In addition to about 15 heat shock proteins that appear to be common to L. monocytogenes and Listeria species that are nonpathogenic for humans, at least five heat shock proteins are specifically coinduced with listeriolysin in all L. monocytogenes strains under heat shock conditions but not in the other Listeria species. One type of L. monocytogenes mutant blocked in the expression of listeriolysin failed to synthesize several of these specific heat shock proteins.

Analysis of heat and cold shock proteins in Listeria by two‐dimensional electrophoresis

“…The acidic and basic proteins should preferably be analyzed by acidic or basic nonequilibrium 2-D gels [33]. Finally, some Listeria proteins such as listeriolysin, the synthesis of which is known to be enhanced by heat shock, are secreted extracellulary into the culture medium [19] and not investigated in this report. The heat stress proteins of Listeria presented above will be the basis for the study of other stress proteins.…”

“…Far fewer studies were done with other microorganisms [17, 181. Recently, proteins induced in Listeria by heat, acid, and oxidants have been reported [19,201. These stress proteins, however, were mainly analyzed by one-dimensional electrophoresis and those shown by two-dimensional electrophoresis were of very limited number.…”

Identification of a ClpC ATPase required for stress tolerance and in vivo survival of Listeria monocytogenes

“…Each step of the intracellular parasitism is dependent upon the production of virulence factors, including internalin, listeriolysin O, phospholipases and Act A. These genes are co-ordinated under the control of PrfA, a transcriptional autoregulated activator (Sheehan et al, 1994), and are thermoregulated and synthesized under stress conditions (Sokolovic et al, 1990;Leismeister-Wächter et al, 1992;Sokolovic et al, 1993;Bohne et al, 1994;Sheehan et al, 1995). At least 13 oxidative stress proteins and 14 heat-shock proteins, including GroEL and DnaK homologues, are induced under stress conditions by L. monocytogenes (Hanawa et al, 1995).…”

Do Stress Proteins Play a Role in Arthritis and Autoimmunity?

“…Just as Stress proteins are important factors in the intracellular survival of infectious microorganisms (;Sokolovic et al 1990), stress proteins or the stress response could protect against tissue injury in inflammatory arthritis or other types of tissue injury (Johnson et al 1990). In addition to prevention ofprotein aggregation and renaturation of damaged proteins (Skowyra et al 1990, Gaitanaris et al 1990, there are at least three theoretical mechanisms by which such protection might occur: a) promotion of resistance to arthritis induction (van den Broek et al 1989, Billingham et al 1990, Yang et al 1990); b) downregulation of cytokines, e.g., IL-1, that mediate inflammation in arthritis (Henderson et al 1987); and c) protection from oxidative injury (Polla 1988).…”