The 'immunocamouflage' of foreign cells and tissues via cell surface modification with biocompatible polymers such as methoxypoly(ethylene glycol) [mPEG] can be used to modulate the immune response both in vitro and in vivo.  This immune modulation arises consequent to the upregulation of regulatory T cells (Tregs) and the down regulation of effector (Teff; pro-inflammatory) T cells.  The INCREASE in the Treg:Teff ratio induces a tolerogenic state in the treated animal.

The 'immunocamouflage' of allogenic leukocytes with biocompatible polymers results in a dramatic shift in the immune status of the treated animal.  Shown are the differential effects of unmodied and mPEG-modidified allogenic splenocytes on T Regulatory (Treg) and proinflammatory Th17 (Teff)  lymphocytes in mice.  As shown, immune modulation arises consequent to the upregulation of regulatory T cells (Tregs) and the down regulation of effector (Teff; pro-inflammatory) T cells in the mice treated with mPEG-splenocytes.  The INCREASE in the Treg:Teff ratio induces a tolerogenic state in the treated animal.  In contrast, the unmodified leukocytes creates a proinflammatory state characterized by decreased Tregs and increased Teff cells.

Wang, D., Toyofuku, W.M., Chen, A.M. and Scott, M.D. Induction of Immunotolerance via mPEG Grafting to Allogeneic Leukocytes.  Biomaterials 32:9494-9503 (2011).