Effect of diets with different omega 3 fatty acids content on lymphocyte activation of C57B/6 mice

• Grant number: 11/15260-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2011
• End date: September 30, 2013
• Field of knowledge: Biological Sciences - Physiology - General Physiology
• Principal Investigator: Renata Gorjao
• Grantee: Heloísa Helena de Oliveira Alves
• Host Institution: Pró-Reitoria de Pós-Graduação e Pesquisa. Universidade Cruzeiro do Sul (UNICSUL). São Paulo , SP, Brazil

Abstract

Lymphocyte activation plays an important role in several inflammatory diseases. Obesity development modulates immune response leading to a disruption in immunohomeostasis. These alterations may be related to immunosenescence that is characterized by disruption in the regulatory process of immune cell activation. Studies have demonstrated a higher incidence of inflammatory diseases in patients with different levels of obesity. High-fat diets rich in saturated fatty acids is related to obesity and induce accumulation of lipid mediators involved in the development of inflammatory diseases. Saturated and n-6 fatty acids have a pro-inflammatory function promoting an excessive activation of immune system. N-3 fatty acids decrease inflammatory response and are characterized as immunossupressor agents. Although several studies have demonstrated the antiinflammatory effect of n-3 fatty acids, few studies have been performed showing the role of these fatty acids when incorporated in the diet in T lymphocyte activation process. In the present study male C57B/6 mice will be fed with control diet (chow) or diets containing either fish oil at 4% (NFO) and 40% (HFO) or lard at 4% (NL) and 40% (HL) (wt/wt) for eight weeks. After the period of supplementation the mesenteric lymph nodes will be removed and lymphocyte isolated. Afterwards lymphocyte proliferative capacity will be evaluated by thymidine incorporation and concanavalin A stimulation. The percentage of T regulatory cells (CD4+, CD25+, Foxp3+) will be determined by flow cytometry. Expression of activation (CD25 e CD28) and suppression related molecules (CTLA-4 e CD95) in effector T lymphocytes also will be determined by flow cytometry.