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Susceptibility of Treponema pallidum to host-derived antimicrobial peptides

David L Cox1, Yongcheng Sun, Hsi Liu

  • 1Sexually Transmitted Infections Branch, Division of AIDS, STD and TB Laboratory Research, Center for HIV and STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. dlc6@cdc.gov

Peptides
|March 17, 2004
PubMed

Insights

Human cathelicidin LL-37 and a related rabbit peptide show antimicrobial activity against Treponema pallidum, the syphilis agent. A truncated LL-37 peptide blocked T. pallidum infectivity in rabbits.

Area of Science:

  • Microbiology
  • Immunology
  • Infectious Diseases

Background:

  • LL-37 is a human cathelicidin with broad-spectrum antimicrobial properties.
  • Antimicrobial peptides are crucial in innate immunity against pathogens.
  • The causative agent of syphilis, Treponema pallidum, remains a significant health concern.

Purpose of the Study:

  • To investigate the antimicrobial activity of human LL-37 and a rabbit CAP-18-derived peptide against Treponema pallidum.
  • To evaluate the efficacy of a truncated LL-37 peptide in blocking T. pallidum infectivity.

Main Methods:

  • Testing the antimicrobial activity of LL-37 and CAP-18 peptides against T. pallidum in vitro.
  • Assessing the salt sensitivity of the antimicrobial effect.
  • Utilizing a rabbit model to evaluate the in vivo infectivity blocking capacity of a truncated LL-37 peptide (WS22-N-amide).

Main Results:

  • Both human LL-37 and the rabbit CAP-18 peptide demonstrated rapid antimicrobial activity against T. pallidum.
  • The antimicrobial activity was found to be salt-sensitive.
  • The synthetic truncated LL-37 peptide WS22-N-amide effectively blocked T. pallidum infectivity in a rabbit model.

Conclusions:

  • Human and rabbit cathelicidin-derived peptides exhibit potent antimicrobial effects against Treponema pallidum.
  • A truncated LL-37 peptide shows therapeutic potential for blocking syphilis infection.

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