Lymphoid tissue engineering: invoking lymphoid tissue neogenesis in immunotherapy and models of immunity.

The plasticity of the immune system is evident in the reorganization of secondary lymphoid organs during immune responses, lymphoid tissue neogenesis occurring during chronic inflammation or graft rejection, and the engineered lymphoid tissue formation induced by ectopic expression of single lymphoid tissue-associated genes. Approaches seeking to harness this plasticity for immunotherapy are under investigation, particularly by controlling immune cell recruitment and lymphoid tissue formation at tumor sites. By combining strategies from ectopic tissue induction models with methods from tissue engineering, new approaches for studying lymphoid tissue development and immunotherapy may be possible.