Abstract: The invention relates to a method of expanding a population of regulatory T cells in a tissue or organ of a subject, wherein said method comprises administration of IL-2 and a targeting moiety specific for said tissue or organ, and wherein said tissue or organ is the lung. The invention further relates to populations of regulatory T cells produced according to the method and the production of said population in vivo. Also provided is a pharmaceutical composition comprising IL-2 and a targeting moiety as defined herein as well as a method of treating a disease or disorder mediated by inflammation or for the reduction of inflammation which comprises the methods defined herein or administration of a pharmaceutical composition as defined herein.