title: Transient detection of Chlamydial-specific Th1 memory cells in the peripheral circulation of women with history of Chlamydia trachomatis genital tract infection.
abstract: OBJECTIVE
  Development of safe and effective Chlamydia trachomatis vaccines requires better understanding of the host immune responses elicited by natural infection.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA.
authors.forename: Rodolfo D
authors.initials: RD
authors.lastname: Vicetti Miguel
authors.forename: Seth D
authors.initials: SD
authors.lastname: Reighard
authors.forename: Jean M
authors.initials: JM
authors.lastname: Chavez
authors.forename: Lorna K
authors.initials: LK
authors.lastname: Rabe
authors.forename: Samantha A
authors.initials: SA
authors.lastname: Maryak
authors.forename: Harold C
authors.initials: HC
authors.lastname: Wiesenfeld
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Cherpes
mesh_terms: D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000276:immunology*; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D020381:Interleukin-17 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000276:immunology; D018655:Lymphocyte Count; D010835:Phytohemagglutinins / Q000276:immunology; D060737:Reproductive Tract Infections / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D055815:Young Adult
chemical_list: D020381:Interleukin-17; D010835:Phytohemagglutinins; D007371:Interferon-gamma