Abstract
BACKGROUND: Chlamydial Inclusion membrane proteins (Incs), are involved in biochemical interactions with host cells and infecting Chlamydiae. We have previously reported the role of two Chlamydia trachomatis (CT) Incs, namely IncB and IncC in generating host immunity in CT infected women. Emerging data shows involvement of Inc stimulated CD4 positive T cells in aiding host immunity in infected fertile and infertile women through the secretion of interferon gamma. However the lack of data on the intra-cytokine interplay to these Incs in infected cell milieu prompted us to investigate further. METHODS: A total of 14 CT-positive fertile, 18 CT-positive infertile women and 25 uninfected controls were enrolled in this study. CD8 depleted, CD4 enriched cervical cells were isolated and upon stimulation with IncB and IncC, modulation of cytokines (Interleukin (IL)-1 Beta, IL-4, IL-5, IL-6, IL-10, Interferon-gamma, IL-12, IL-23, Tumor Necrosis Factor-alpha and Granulocyte macrophage colony-stimulating factor (GM-CSF) and T cell lineage regulating transcription factors T-Bet and GATA3 was determined by real-time reverse-transcriptase (RT)-PCR and ELISA. RESULTS: Significant higher expression (P < 0.05) of Interferon-gamma, IL-12, IL-23 and GM-CSF were found in Inc-stimulated CD4 enriched cervical cells of CT-positive fertile women and contrastingly high IL-1 Beta, IL-4, IL-5, IL-6 and IL-10 levels were found in CT-positive infertile women. Positive correlation (P < 0.05) was found between Interferon-gamma and T-Bet levels in CT-positive fertile women and IL-4 mRNA and GATA3 levels in CT-positive infertile patients upon IncB and IncC stimulation. CONCLUSION: Overall our data shows that CT IncB and IncC are able to upregulate expression of cytokines, namely interferon-gamma, IL-12, IL-23 and GM-CSF in CT-positive fertile women while expression of IL-1 Beta, IL-4, IL-5, IL-6 and IL-10 were upregulated in CT-positive infertile women. Our study also suggests that Incs are able to modulate expression of T cell lineage determinants indicating their involvement in regulation of immune cells.