Characterization of culture filtrate proteins Rv1197 and Rv1198 of ESAT-6 family from Mycobacterium tuberculosis H37Rv

Himanshu Pandey, Sarita Tripathi, Kanchan Srivastava, Dinesh K. Tripathi, Mrigank Srivastava, Surya Kant, Kishore K. Srivastava, Ashish Arora

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Background We have characterized two immunogenic proteins, Rv1197 and Rv1198, of the Esx-5 system of the ESAT-6 family of Mycobacterium tuberculosis H37Rv. Methods The complex formation between Rv1197 and Rv1198 was characterized by biophysical techniques. The reactivity of serum from TB patients towards these proteins was characterized by ELISA. Lymphocyte proliferation and cytokine induction were followed in restimulated splenocytes from immunized mice by using MTT assay and CBA flowcytometry, respectively. Results Rv1197 and Rv1198 strongly interact to form a heterodimeric complex under reducing conditions, which is characterized by a dissociation constant of 97 × 10− 9 M and melting temperature, Tm, of 50.5 °C. Strong humoral responses to Rv1197, Rv1198, CFP-10 and MoaC1 (Rv3111) antigens were found in Indian patients with active pulmonary tuberculosis (n = 44), in comparison to non-infected healthy individuals (n = 20). The seroreactivity to Rv1198 was characterized by a sensitivity of 75% and specificity of 90%. In BALB/c mice, immunization with Rv1198-FIA induced a pro-inflammatory response with elevated levels of TNF and IL-6, along with low induction of IFN-γ, IL-2 and IL-10, but no induction of IL-4. Conclusion Rv1197 and Rv1198 form a stable complex, which is regulated by the redox state of Rv1198. Rv1198 is immunogenic with highly specific seroreactivity towards TB patients' serum. Rv1198 elicits a pro-inflammatory recall response in immunized mice. General Significance This study characterizes the interaction of Rv1197 and Rv1198, and establishes the immunogenic nature of Rv1198.

Original languageEnglish
Pages (from-to)396-408
Number of pages13
JournalBiochimica et Biophysica Acta - General Subjects
Issue number2
StatePublished - 1 Feb 2017
Externally publishedYes


  • ESAT-6 family
  • Mycobacterium tuberculosis
  • Rv1197
  • Rv1198
  • Seroreactivity
  • Vaccine

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology


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