RESUMEN
Aims: To evaluate the immunomodulatory effect of using non-cholesterol lowering dose of atorvastatin (AS) on skin allograft survival and on tumor growth in mice. Study Design: Experimental Study. Place and Duration of Study: Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut; 2011-2012. Methodology: BALB/c mice were transplanted with skin allografts from C57BL/6 mice and given either AS alone or in combination with immunosuppressive agents. Average survival days of skin allografts were recorded and serum levels of interleukin-1β (IL-1β) and interferon-γ (IFN-γ) were quantified. BALB/c mice and C57BL/6 mice were challenged intraperitoneally with B16F10 melanoma cancer cells (cancer cell line syngeneic to C57BL/6 mice) and were then treated with AS. They were observed regularly for tumor growth. Results: The results indicated that in transplant mice AS given alone or in combination with immunosuppressive agents prolonged allograft survival time through noncholesterol lowering mechanisms in spite of a non-significant change in serum cytokine levels. Furthermore, AS treatment enhanced tumor growth in C57BL/6 mice and promoted tumor growth in BALB/C mice. Conclusion: It can be speculated that AS down expresses TLR and modifies MHC presentation resulting in hindering the generation of an innate and adaptive immune response.