CD4+CD25+ Foxp3+ T regulatory cell (Tregs) represents approximately 8-10% of the total CD4+ T cell population and are important for immune homeostasis and preventing autoimmune development. Thus, harnessing their functions as immune modulator may be coupled with the rapid advancement of nanotechnology development. Plant-mediated biosynthesis of silver nanoparticle (AgNP) is noteworthy due to simplicity, rapid rate and potentially render more biocompatibility with biomolecules. This study identified the effect of biosynthesized-AgNPs from Garcinia atroviridis (GA) in modulating inflammatory properties of Treg cells in Non-Obese Resistant (NOR). GA extract was used to biosynthesized AgNPs and was tested on the effect of inducing inflammatory properties in CD4+IL17Rhigh cells following 72hr in vitro treatment. Methods: Conventional CD4+CD25-Foxp3- cells from female NOR mice were sorted using magnetic separation and cultured in RPMI in the presence of anti-CD3/CD28 antibodies, TGF-β and IL-2 cytokines. Cells were then treated with or without GA-AgNPs for 48hr of iTreg cell induction and then re-cultured with new media treated with respective treatments received. After 72hr in vitro culture, cells were stained with fluorochrome-conjugated antibodies for flow cytometry. Results: Current result showed that AgNPs suppress CD4 expression in CD4+IL17Rhigh population. MAPK pathway proteins remain unchanged in both control and AgNP-treated groups. Conclusions: The preliminary findings may suggest the properties of GA-AgNPs in modulating CD4+ T cell population in normal condition. Further studies are necessary to elucidate the molecular mechanisms involve in such interaction. Current findings serve as basis in further identifying the immunomodulatory profile of nanoparticle for potential therapeutic use.