Differential IFN-γ, TNF-α, IL-6 and SOCS3 mRNA expression levels
in healthy controls and diabetics with and without latent TB
To understand cytokine activation in our study subjects in the context
of immune-regulatory molecules, we compared gene transcription levels
and the key regulatory molecules SOCS1 and SOCS3 in healthy controls and
diabetics to investigate any effect of latent TB infection.
We measured determined PPD- stimulated mRNA levels in peripheral blood
cells from EC, LTBi, DM, DM-LTBi and TB groups. We observed increased
IFN-γ mRNA titers in DM-LTBi (p=0.033) and TB (p=0.046) as compared with
EC (Fig 1A). PPD-stimulated TNFα mRNA expression was increased in DM-LTB
as compared with EC (p=0.035, Fig. 1B). PPD-stimulated IL-6 (p=0.009,
Fig 1C) mRNA expression was increased in DM-LTBi as compared with EC.
SOCS3 mRNA expression was found to be significantly reduced in
PPD-stimulated cells of DM-LTBi (p=0.0422), TB (p=0.019) and EC
(p=0.025) as compared with LTBi cases (Fig 1D). SOCS1 mRNA expression
level was comparable in all the study groups (data not shown).
Basal levels of mRNA transcripts for IFN-γ, TNF-α, IL-6, SOCS1 and SOCS3
mRNA were determined in all groups were similar.