Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 3 2015 10 18 313 320 EN Reza Mirzaei Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Iran Samaneh Arab Department of Molecular Medicine, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Iran Masoumeh Motamedi Razi Herbal Medicines Research Center, Lorestan University of Medical sciences, Khorramabad, Iran Afshin Amari Department of Immunology, Ahvaz Jondishapur University of Medical Sciences, Iran Jamshid Hadjati Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Iran 2015 10 18 2015 10 18 The innate immune system utilizes pattern recognition receptors (PRRs) to recognize microbes. Pathogens contain various molecules with diverse effects on immune response. In this study, we evaluated the effect of DNA and protein components derived from two intracellular microorganisms including Listeria monocytogenes (L.monocytogenes) and Toxoplasma gondii (T. gondii) on dendritic cells (DCs) activation and ensuing adaptive immune responses.DNA and protein components of L. monocytogenes and T. gondii were prepared using relevant kits. DNA and protein components of these two pathogens were added to immature DCs (iDCs). Subsequently, co-stimulatory expression and cytokine production by DCs were measured. Finally, we evaluated the stimulatory capacity of mature DCs (mDCs) in DC-T cells co-culture.The results showed that protein matured-DCs produced higher level of IL (Interleukin)-12p70. There was also a significant increase in Interferon-Gamma (IFN-γ) production and proliferative capacity in T cells co- cultured with protein matured-DCs. On the other hand, DNA matured-DCs produced significantly higher amounts of Transforming growth factor-beta (TGF-β).Collectively, these results imply a regulatory nature for DNA and potent stimulatory character for protein components of these two intracellular microorganisms. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/573 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/573/458