Potential impact of metal oxide nanoparticles on the immune system: The role of integrins, L-selectin and the chemokine receptor CXCR4

Nanoparticles are extensively used, but their interaction with the immune system is poorly understood, regardless of potential adverse effects. We assessed the impact of metallic Nps (ZnO, CeO2, TiO2 and Al2O3) measuring the expression of adhesion molecules and the chemokine receptor CXCR4 in peripheral blood lymphocytes, T-cell proliferative responses, chemotaxis, basophil activation state and leukocyte oxidative burst after phagocytosis. We found that, although not toxic, metallic NPs do not seem inert, being able to alter key cell functions such as T-cell proliferative responses and chemotaxis, which could translate into important side effects in a medical context.187