Differential expression of mRNA encoding cytokines and chemokines in the reproductive tract after infection of mice with Chlamydia trachomatis

Chlamydia trachomatis is an obligate intracellular pathogen and the most frequently reported sexually transmitted bacteria in the United States. Infection with Chlamydia trachomatis targets epithelial cells within the genital tract which respond by secreting chemokines and cytokines. Persistent inflammation can lead to fibrosis, tubal infertility and/or ectopic pregnancy. Our objective was to determine the inflammatory mediators involved in clearance of low-grade infection and the potential involvement in chronic inflammation. Our hypothesis was that mRNA encoding pro-inflammatory cytokines and chemokines will be differentially expressed in the female reproductive tract of mice infected with C. trachomatis at both 28 and 35 days post-infection compared to controls. Superarray analysis was performed using RT2 Profiler PCR arrays for mouse Cytokines and Chemokines (Qiagen). Six to eight week old female C3H/HeJ mice (Jackson Laboratories, Sacramento, CA) were pretreated with 2.5 mg medroxyprogesterone acetate (SICOR Pharmaceuticals) on Days -10 and -3 before infection. On Day 0, mice were infected via vaginal challenge with 0 or 5 x 102 inclusion-forming units (IFUs) of C. trachomatis, serovar D in 0.01 mL of Eagle Minimal essential media (MEM, Gibco). Mice were killed on day 28 (n = 3 for control and infected) in experiment 1 and day 35 (n = 3 for control and infected) in experiment 2. Vaginal tissue, uterine horns and the oviducts were collected and processed for superarray analysis.