Overall our data on cytokine modulation in cervical cells and PBMCs on in vitro stimulation with IncB or IncC suggests that CT- negative women who encounter chlamydial antigens for the first time and CT-positive fertile women produce higher amounts of IFN-γ, IL-12 and GM-CSF than in women with reproductive sequalae to chlamydial infection where the infected cells secrete higher levels of IL-1β, IL-4, IL-5, IL-6 and IL-10. This evidence concerns the gene IL5 and chlamydia trachomatis infectious disease.