It is difficult to stimulate efficient gut mucosal immune response to intestinal
infection. This article critically reviews the research
progressin Escherichia coli strain Nisslel917 (
EcN) actingas a safe vehicle for the intestinal mucosal immunity, to restore
gastrointestinal disorder and relieve
ulcerative colitis.
EcN is an orally administered probiotics, combining the excellent colonization and non-immunogenic character, and can be an ideal live vector candidate. This strain could be a
tumor-targeted delivery of TAT-Apoptin fusion gene to
colorectal cancer. In the treatment of
ulcerative colitis and
Crohn's disease, the recombinant strain of
EcN can be used as a target
therapeutics for
defensins presenting. Genetically modified
EcN could be an ideal carrier organism for gut-focused in situ synthesis and expression of specific localized
antigen delivery into the intestine, and stimulate specific mucosal immune response. In vitro trial demonstrated that intestinal recombinant E. coli Nissle-HA110-120 has the potential to stimulate
antigen specific response, but
EcN itself does not induce mucosal immune response and influence peripheral tolerance to
self-antigen. At the same time, there are evidences that
EcN is safe. Recombinant E. coli Nissle-HA110-120 does not migrate, clonally expand and activate specific CD4+ T cells, neither in healthy mice nor in other animals with acute
colitis, even when the intestinal epithelium suffer from
inflammation and the barrier function of the epithelial layer being destroyed.