Immunomodulation by genetically engineered lactic acid bacteria

The taxonomically diverse lactic acid bacteria (LAB) are unified by their capability to produce lactic acid from carbohydrates by fermentation. The LAB Lactococcus (L.) lactis has been characterized into great detail and is increasingly used as a production host for heterologous proteins. L. lactis is a non-pathogenic and non-colonizing LAB species and can be efficiently engineered to produce proteins of viral, bacterial or eukaryotic origin, both intra- or extracellularly. Importantly, orally formulated L. lactis strains (ActoBiotics), engineered to synthesize and secrete therapeutic peptides and proteins in the gastrointestinal tract, are already in advanced stages of preclinical and clinical development. This review focuses on the genetic engineering of LAB in general and L. lactis in specific to secrete high-quality, correctly processed, bioactive molecules derived from a eukaryotic background. The therapeutic applications of these genetically modified strains are discussed, as well as the need for a sound environmental containment strategy, and a detailed review is presented on Lactococcus strains engineered to produce specific antigens, antibodies, cytokines and trefoil factors, with special regards to immunomodulation

Oral delivery of glutamic acid decarboxylase (GAD)-65 and IL10 by lactococcus lactis reverses diabetes in recent-onset NOD mice

Growing insight into the pathogenesis of type 1 diabetes (T1D) and numerous studies in preclinical models highlight the potential of antigen-specific approaches to restore tolerance efficiently and safely. Oral administration of protein antigens is a preferred method for tolerance induction, but degradation during gastrointestinal passage can impede such protein-based therapies, reducing their efficacy and making them cost-ineffective. To overcome these limitations, we generated a tolerogenic bacterial delivery technology based on live Lactococcus lactis (LL) bacteria for controlled secretion of the T1D autoantigen GAD65370-575 and the anti-inflammatory cytokine interleukin-10 in the gut. In combination with short-course low-dose anti-CD3, this treatment stabilized insulitis, preserved functional β-cell mass, and restored normoglycemia in recent-onset NOD mice, even when hyperglycemia was severe at diagnosis. Combination therapy did not eliminate pathogenic effector T cells, but increased the presence of functional CD4+Foxp3 +CD25+ regulatory T cells. These preclinical data indicate a great therapeutic potential of orally administered autoantigen-secreting LL for tolerance induction in T1D. © 2014 by the American Diabetes Association.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Oral L.Lactis secreting human pro-insulin plus IL-10 combuned with short-term low-dose anti-CD3 induces long lasting diabetes remission

info:eu-repo/semantics/nonPublishe

Reversal of autoimmune diabetes by restoration of antigen-specific tolerance using genetically modified Lactococcus lactis in mice

Current interventions for arresting autoimmune diabetes have yet to strike the balance between sufficient efficacy, minimal side effects, and lack of generalized immunosuppression. Introduction of antigen via the gut represents an appealing method for induction of antigen-specific tolerance. Here, we developed a strategy for tolerance restoration using mucosal delivery in mice of biologically contained Lactococcus lactis genetically modified to secrete the whole proinsulin autoantigen along with the immunomodulatory cytokine IL-10. We show that combination therapy with low-dose systemic anti-CD3 stably reverted diabetes in NOD mice and increased frequencies of local Tregs, which not only accumulated in the pancreatic islets, but also suppressed immune response in an autoantigen-specific way. Cured mice remained responsive to disease-unrelated antigens, which argues against excessive immunosuppression. Application of this therapeutic tool achieved gut mucosal delivery of a diabetes-relevant autoantigen and a biologically active immunomodulatory cytokine, IL-10, and, when combined with a low dose of systemic anti-CD3, was well tolerated and induced autoantigen-specific long-term tolerance, allowing reversal of established autoimmune diabetes. Therefore, we believe this method could be an effective treatment strategy for type 1 diabetes in humans