Modulation of immune cells and Th1/Th2 cytokines in insulin-treated type 2 diabetes mellitus.

Magloire Pandoua Nekoua1 , Rufine Fachinan , Amidou K Atchamou , Odilon Nouatin,  Daniel Amoussou-Guenou3 , Marcellin K Amoussou-Guenou, Kabirou Moutairou , Akadiri Yessoufou
1. Laboratory of Cell Biology and Physiology, Institute of Applied Biomedical Sciences (ISBA) and Faculty
of Sciences and Techniques, University of Abomey-Calavi, 01 BP 526 Cotonou, Bénin.
2. Centre d’Etude et de Recherche sur le Paludisme associé à la Grossesse et à l’Enfance IRD/UMR-216,
Cotonou, Bénin.
3. Service of Internal Medicine, Centre National Hospitalier et Universitaire (CNHU) and Faculty of Health
Sciences (FSS);, Cotonou, Bénin.
4. Service of Radio-immuno-assay (SERID), Faculty of Health Sciences (FSS); Cotonou, Bénin.

Abstract
Background: The role of the immune system in insulin resistance associated with type 2 diabetes has been suggested.

Objectives: We assessed the profile of Th1/Th2 cytokines along with the frequencies of immune cells in insulin-treated type 2  diabetic patients (T2DP).

Methods: 45 T2D patients and 43 age-matched healthy subjects were selected. Serum concentrations of T-helper type 1 (Th1)  and Th2 cytokines and the frequencies of innate and adaptive immunity cells were assessed.

Results: T2DP were hyperglycemic and showed high level of insulin, normal levels of triglycerides and total-cholesterol and  without any change in HDL-cholesterol.Compared to healthy subjects, T2DP exhibited significant decreased frequencies of  neutrophils, without any change in monocytes, eosinophils and natural killer cells. The percentages of total lymphocytes (CD3+)  and CD8+-T-cells decreased whereas those of regulatory T-cells increased without any change in CD4+ T-cells in T2DP. Interestingly, the frequencies of effector CD4+-T and B-cells increased in T2DP. Serum concentrations of IL-2, IFN-γ and IL-4  decreased while IL-10 significantly enhanced in T2DP, suggesting a differentiation of CD4+T helper cells towards IL-10-producing-Teff-cells in these patients.

Conclusion: Insulin-treated type 2 diabetes is associated with anti-inflammatory profile consistent with differentiation of  CD4+-Th-cells towards IL-10-producing-Teff-cells, concomitant with increased frequencies of Treg and B-cells, and this may  probably offer prevention against certain infections or autoimmune/inflammatory diseases.

Keywords:Type 2 diabetes, Insulin, Immune cells, Th1/Th2 polarization.