Premium
Inhibition of Macromolecular Synthesis in Cultured Macrophages by Pseudomonas pseudomallei Exotoxin
Author(s) -
Mohamed Rahmah,
Nathan Sheila,
Embi Noor,
Razak Nyonya,
Ismail Ghazally
Publication year - 1989
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1989.tb00967.x
Subject(s) - exotoxin , dna synthesis , biology , incubation , toxin , pseudomonas exotoxin , protein biosynthesis , microbiology and biotechnology , thymidine , dna , protein synthesis inhibitor , pseudomonas , biochemistry , bacteria , cytotoxicity , in vitro , cycloheximide , genetics
Pseudomonas pseudomallei exotoxin was found to be a potent inhibitor of protein and DNA synthesis in cultured macrophages. Inhibition of DNA synthesis occurred at toxin concentrations as low as 1–2 μ g/ml and inhibition of 3 H‐thymidine uptake was almost complete at concentrations of 8 μ g/ml or more. A close correlation between cell damage and inhibition by DNA synthesis was observed. For protein synthesis, inhibition was obtained at much lower doses (0.06–2.0 μ g/ml) of the toxin. At similar toxin concentrations, DNA synthesis was marginally affected. Further, it was shown that protein synthesis inhibition occurred almost immediately after incubation, reaching its maximal inhibitory effect of 70% after 6 hr. DNA synthesis, however, was minimally affected by a similar toxin concentration even after 10 hr of incubation. The inhibition of macromolecular synthesis in macrophages by P. pseudomallei exotoxin may be relevant to its modulatory effect on the host defense mechanism.