Targeting the Mycobacterium tuberculosis 30/32-kDa mycolyl transferase complex as a therapeutic strategy against tuberculosis: Proof of principle by using antisense technology.
We have investigated the effect of sequence-specific antisense phosphorothioate-modified oligodeoxyribonucleotides (PS-ODNs) targeting different regions of each of the 3032-kDa protein complex (antigen 85 complex) encoding genes on the multiplication of Mycobacterium tuberculosis. Single PS-ODNs to one of the three mycolyl transferase transcripts, added either once or weekly over the 6-wk observation period, inhibited bacterial growth by up to 1 log unit. A combination of three PS-ODNs specifically targeting all three transcripts inhibited bacterial growth by approximately 2 logs; the addition of these PS-ODNs weekly for 6 wk was somewhat more effective than a one-time addition. Targeting the 5' end of the transcripts was more inhibitory than targeting internal sites; the most effective PS-ODNs and target sites had minimal or no secondary structure. The effect of the PS-ODNs was specific, as mismatched PS-ODNs had little or no inhibitory activity. The antisense PS-ODNs, which were highly stable in M. tuberculosis cultures, specifically blocked protein expression by their gene target. PS-ODNs targeting the transcript of a related 24-kDa protein (mpt51) had little inhibitory effect by themselves and did not increase the effect of PS-ODNs against the three members of the 3032-kDa protein complex. The addition of PS-ODNs against the transcripts of glutamine synthetase I (glnA1) and alanine racemase (alr) modestly increased the inhibitory efficacy of the 3032-kDa protein complex-specific PS-ODNs to approximately 2.5 logs. This study shows that the three mycolyl transferases are highly promising targets for antituberculous therapy by using antisense or other antimicrobial technologies.
Harth
Günter
G
Division of Infectious Diseases, Department of Medicine, 37-121 Center for Health Sciences, School of Medicine, University of California, 10833 Le Conte Avenue, Los Angeles 90095, USA.
Horwitz
Marcus A
MA
Tabatadze
David
D
Zamecnik
Paul C
PC
D000217:Acyltransferases / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D000411:Alanine Racemase / Q000187:drug effects / Q000235:genetics; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D002352:Carrier Proteins / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005974:Glutamate-Ammonia Ligase / Q000187:drug effects / Q000235:genetics; D009097:Multienzyme Complexes / Q000187:drug effects* / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development; D020319:Oligodeoxyribonucleotides, Antisense / Q000737:chemistry / Q000494:pharmacology*; D012329:RNA, Bacterial / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000037:antagonists & inhibitors; D013873:Thionucleotides / Q000737:chemistry / Q000494:pharmacology*; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014376:Tuberculosis / Q000188:drug therapy*
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D009097:Multienzyme Complexes; D020319:Oligodeoxyribonucleotides, Antisense; D012329:RNA, Bacterial; D012333:RNA, Messenger; D013873:Thionucleotides; D000217:Acyltransferases; C112580:antigen 85A, Mycobacterium tuberculosis; C121433:antigen 85B, Mycobacterium tuberculosis; D000411:Alanine Racemase; C081173:glutamine synthetase I; D005974:Glutamate-Ammonia Ligase