This invention relates to cellular-based therapies for increasing the level of regulatory T cells (Treg) and/or decreasing the level of pro-inflammatory T cells (Th17) to induce anergy or immune tolerance. To provide these therapeutic effects, a non-proliferative allogeneic leukocyte population is contacted with another leukocyte population. The non-proliferative allogeneic leukocyte population is modified to bear on its surface a low-immunogenic biocompatible polymer so as to prevent pro-inflammatory allo-recognition with the latter leukocyte population. Cellular-based preparations and processes for achieving cellular therapy are also provided.
