Chlamydia trachomatis e Inmunidad

Transient detection of Chlamydial-specific Th1 memory cells in the peripheral circulation of women with history of Chlamydia trachomatis genital tract infection.

Vicetti Miguel RD¹, Reighard SD, Chavez JM, Rabe LK, Maryak SA, Wiesenfeld HC, Cherpes TL.

¹Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA.

 

Abstract

PROBLEM:

Development of safe and effective Chlamydia trachomatis vaccines requires better understanding of the host immune responses elicited by natural infection.

METHOD OF STUDY:

Peripheral blood mononuclear cells isolated from women with or without history of genital tract chlamydial infection were stimulated with inactivated C. trachomatis elementary bodies (EB) in ELISPOT assays that enumerated frequencies of cells producing interferon (IFN)-γ or interleukin (IL)-17.

RESULTS:

IFN-γ-positive cells were highest among women sampled 30-60 days after diagnosis of C. trachomatis infection and treatment initiation, while the numbers of IFN-γ-positive cells were equally low among uninfected women and women sampled <30 or >60 days after diagnosis of infection. Conversely, IL-17-positive cell numbers were uniformly low among all participants.

CONCLUSION:

Dramatically reduced numbers of Chlamydia-specific Th1 memory cells in the peripheral circulation of study participants sampled more than 2 months after diagnosis, and initiation of treatment provides new insight into the results from C. trachomatis vaccine trials, in which immunization with EB provided only short-lived protection. Our results also suggest that an effective vaccine against this weakly antigenic intracellular pathogen will need to generate immunological memory more durable than that elicited by natural infection.

© 2012 John Wiley & Sons A/S.

Am J Reprod Immunol. 2012 Dec;68(6):499-506. doi: 10.1111/aji.12008. Epub 2012 Aug 31.

http://onlinelibrary.wiley.com/doi/10.1111/aji.12008/abstract;jsessionid=B95D7E5E29926F60FB0D65C3E2DB60D8.f02t01

Md. Rodolfo Vicetti. Ex-miembro del GII. 

Chlamydia trachomatis e Inmunidad

Hypothesis: Chlamydia trachomatis infection of the female genital tract is controlled by Type 2 immunity.

Vicetti Miguel RD¹, Cherpes TL.

¹Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.

 

Abstract

Chlamydia trachomatis is an obligate intracellular bacterium sexually transmitted to more than 90 million individuals each year. As this level of infectivity implies, C. trachomatis is a successful human parasite; a success facilitated by its ability to cause asymptomatic infection. Host defense against C. trachomatis in the female genital tract is not well defined, but current dogma suggests infection is controlled largely by T(H)1 immunity. Conversely, it is well established that T(H)2 immunity controls allergens, helminths, and other extracellular pathogens that cause repetitive or persistent T cell stimulation but do not induce the exuberant inflammation that drives T(H)1 and T(H)17 immunity. As C. trachomatis persists in female genital tract epithelial cells but does not elicit over tissue inflammation, we now posit that defense is maintained by Type 2 immune responses that control bacterial growth but minimize immunopathological damage to vital reproductive tract anatomy. Evaluation of this hypothesis may uncover novel mechanisms by which Type 2 immunity can control growth of C. trachomatis and other intracellular pathogens, while confirmation that T(H)2 immunity was selected by evolution to control C. trachomatis infection in the female genital tract will transform current research, now focused on developing vaccines that elicit strong, and therefore potentially tissue destructive, Chlamydia-specific T(H)1 immunity.

Copyright © 2012 Elsevier Ltd. All rights reserved.

Med Hypotheses. 2012 Dec;79(6):713-6. doi: 10.1016/j.mehy.2012.07.032. Epub 2012 Sep 15.

http://www.sciencedirect.com/science/article/pii/S0306987712003568

Md. Rodolfo Vicetti. Ex-miembro del GII.