Selective cytotoxicity of ricin A chain immunotoxins towards murine cytomegalovirus-infected cells.
Immunotoxins were constructed by linking immunoglobulins specific for murine cytomegalovirus (MCMV) to deglycosylated ricin A chain. Toxicities toward MCMV-infected and uninfected cells were determined by measuring the inhibition of protein synthesis following a 48-h exposure to immunotoxins commencing 24 h after infection. The 50% inhibitory concentrations ranged from 0.4 to 4 micrograms/ml for infected cells and from 22 to 120 micrograms/ml for uninfected cells. Selectivity indices ranged from 30 to 157. Control immunotoxins, which were constructed identically except that the immunoglobulin moiety had no specificity toward MCMV antigens, had 50% inhibitory concentrations of 50 and 100 micrograms/ml toward infected and uninfected cells, respectively.
Barnett
B B
BB
Department of Biology, Utah State University, Logan 84322-5305, USA. bbarnett@cc.usu.edu
Smee
D F
DF
Malek
S M
SM
Sidwell
R W
RW
D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D007074:Immunoglobulin G / Q000633:toxicity; D000922:Immunotoxins / Q000633:toxicity*; D051379:Mice; D008807:Mice, Inbred BALB C; D018146:Muromegalovirus / Q000187:drug effects* / Q000276:immunology; D014176:Protein Biosynthesis; D012276:Ricin / Q000633:toxicity*
D007074:Immunoglobulin G; D000922:Immunotoxins; D012276:Ricin