An attenuated quadruple gene mutant of Mycobacterium tuberculosis imparts protection against tuberculosis in guinea pigs

Ritika Kar Bahal, Shubhita Mathur, Priyanka Chauhan, Anil K. Tyagi

Research output: Contribution to journalArticlepeer-review

Abstract

Previously we had developed a triple gene mutant of Mycobacterium tuberculosis (MtbΔmms) harboring disruption in three genes, namely mptpA, mptpB and sapM. Though vaccination with MtbΔmms strain induced protection in the lungs of guinea pigs, the mutant strain failed to control the hematogenous spread of the challenge strain to the spleen. Additionally, inoculation with MtbΔmms resulted in some pathological damage to the spleens in the early phase of infection. In order to generate a strain that overcomes the pathology caused by MtbΔmms in spleen of guinea pigs and controls dissemination of the challenge strain, MtbΔmms was genetically modified by disrupting bioA gene to generate MtbΔmmsb strain. Further, in vivo attenuation of MtbΔmmsb was evaluated and its protective efficacy was assessed against virulent M. tuberculosis challenge in guinea pigs. MtbΔmmsb mutant strain was highly attenuated for growth and virulence in guinea pigs. Vaccination with MtbΔmmsb mutant generated significant protection in comparison to sham-immunized animals at 4 and 12 weeks post-infection in lungs and spleen of infected animals. However, the protection imparted by MtbΔmmsb was significantly less in comparison to BCG immunized animals. This study indicates the importance of attenuated multiple gene deletion mutants of M. tuberculosis for generating protection against tuberculosis.

Original languageEnglish (US)
Article numberbio029546
JournalBiology Open
Volume7
Issue number1
DOIs
StatePublished - 2018

Bibliographical note

Funding Information:
This work was supported by a financial grant received from the Department of Biotechnology, Ministry of Science and Technology (DBT), Government of India (Grant Number BT/01/COE/05/06-II). The DBT, Government of India is acknowledged for a research fellowship to S.M. The Council of Scientific and Industrial Research, Government of India is acknowledged for research fellowships to R.K.B. and P.C.

Funding Information:
Reagents for recombineering method were kindly provided by Dr Graham F. Hatfull and Dr Julia C van Kessel, University of Pittsburgh, Pennsylvania, USA. We are thankful to Dr Sabine Ehrt and Dr Dirk Schnappinger, Weill Cornell Medical College, New York, USA for providing us with anti-BioA antibodies. Dr Ashok Mukherjee is acknowledged for providing help in histopathological analysis. We are also thankful to DBT-supported DNA sequencing Facility and DBT-supported Distributed Information Sub-Centre, at Department of Biochemistry, University of Delhi South Campus, New Delhi. We thank Dr Prachi Nangpal for help with the guinea pig experiment. We acknowledge Dr Garima Khare, Dr Prachi Nangpal and Akshay Rohilla for critical reading of the manuscript. We thank Priti Singh for technical support. Bahadur Singh and Devender are acknowledged for their help in BSL-3 facility and lab attendant Jeevan is acknowledged for his assistance. This work was supported by a financial grant received from the Department of Biotechnology, Ministry of Science and Technology (DBT), Government of India (Grant Number BT/01/COE/05/06-II). The DBT, Government of India is acknowledged for a research fellowship to S.M. The Council of Scientific and Industrial Research, Government of India is acknowledged for research fellowships to R.K.B. and P.C.

Publisher Copyright:
© 2018. Published by The Company of Biologists Ltd.

Keywords

  • Attenuation
  • Auxotrophic vaccines
  • BCG
  • Biotin
  • Multi-gene mutant
  • Tuberculosis

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