LAUSR

ABSTRACT Lymphocytes play a central role in the pathology of a range of chronic conditions such as autoimmune disease, transplant rejection, leukemia, lymphoma HIV/AIDs and cardiometabolic diseases such as atherosclerosis. Current treatments for lymphocyte‐associated conditions are incompletely effective and/or complicated by a range of off‐target toxicities. One major challenge is poor drug access to lymphocytes via the systemic blood and this may be attributed, at least in part, to the fact that lymphocytes are concentrated within lymph fluid and lymphoid tissues, particularly in gut‐associated lymphatics. Here we demonstrate that promoting drug uptake into the intestinal lymphatics with a long chain fatty acid, thereby increasing lymphocyte access, enhances the pharmacodynamic effect of a highly lipophilic liver X receptor (LXR) agonist, WAY‐252623, that has been suggested as a potential treatment for atherosclerosis. This has been exemplified by: (1) increased mRNA expression of key markers of LXR activation (ABCA1) and regulatory T cells (Foxp3) in local lymphatic lymphocytes and (2) enhanced numbers of CD4+CD25+Foxp3+ regulatory T cells in the systemic circulation, after administration of a 5‐fold lower dose with a lymph directing lipid formulation when compared with a non‐lipid containing formulation. These data suggest that combining lipophilic, lymphotropic drug candidates such as WAY‐252,623, with lymph‐directing long chain lipid based formulations can enhance drug targeting to, and activity on, lymphocytes in lymph and that this effect persists through to the systemic circulation. This presents a promising approach to achieve more selective and effective therapeutic outcomes for the treatment of lymphocyte associated diseases. HIGHLIGHTSOral administration of WAY‐252,623 with lipids increases GI lymphatic transport.Lymphatic transport increases ABCA1 and Foxp3 expression in lymph lymphocytes.Increased lymph transport of WAY‐252,623 also increases Treg cell numbers in blood.Lymph targeting strategies promote the immunomodulatory activity of WAY‐252,623.