Effect Of Mycobacterium Vaccae Research Articles

Regulation of γδT17 cells by Mycobacterium vaccae through interference with Notch/Jagged1 signaling pathway.

The objective of this study was to investigate the effect of Mycobacterium vaccae on Jagged 1 and gamma delta T17 (γδT17) cells in asthmatic mice. An asthma mouse model was established through immunization with ovalbumin (OVA). Gamma-secretase inhibitor (DAPT) was used to block the Notch signaling pathway. M. vaccae was used to treat asthma, and related indicators were measured. Blocking Notch signaling inhibited the production of γδT17 cells and secretion of cytokine interleukin (IL)-17, which was accompanied by a decrease in Jagged1 mRNA and protein expression in the treated asthma group compared with the untreated asthma group. Similarly, treatment with M. vaccae inhibited Jagged1 expression and γδT17 cell production, which was associated with decreased airway inflammation and reactivity. The Notch signaling pathway may play a role in the pathogenesis of asthma through the induction of Jagged1 receptor. On the other hand, the inhibitory effect of M. vaccae on Jagged1 receptor in γδT17 cells could be used for the prevention and treatment of asthma.

Abstract # 4266 Peripheral and central effects of Mycobacterium vaccae on mice exposed to both early life adversity and chronic stress during adulthood

Abstract # 4266 Peripheral and central effects of Mycobacterium vaccae on mice exposed to both early life adversity and chronic stress during adulthood

Atopic dermatitis: Therapeutic concepts evolving from new pathophysiologic insights

Recent insights into the relevance of the epidermal barrier function and its interaction with components of the innate and adaptive immune responses in patients with atopic dermatitis (AD) give rise to a number of novel potential treatment options. In particular, the identification of loss-of-function mutations in the barrier protein filaggrin and of a diminished expression of certain antimicrobial peptides in AD skin stimulates new concepts to think beyond the T(H)1/T(H)2 paradigm. This review will focus on these most recent discoveries and will discuss new and corresponding proof-of-concept trials in patients with AD. It will further speculate on novel ways to restore the homeostasis among the 3 major components in AD skin suspected to be clinically relevant.

Intradermal injection of heat‐killed Mycobacterium vaccae in dogs with atopic dermatitis: a multicentre pilot study

Canine atopic dermatitis (cAD) is a common disease with a multifactorial aetiology associated with impaired immunoregulation. The immunopathogenesis has similarities to that of human atopic dermatitis. Clinical signs of allergic disease in humans and mice are reduced by administration of saprophytic mycobacteria that amplify regulatory cytokines and hence the effect of Mycobacterium vaccae on the clinical severity of cAD was investigated. Sixty-two dogs with cAD, selected according to strict criteria, were treated with a single intradermal injection and evaluated monthly for 3 months in a placebo-controlled double-blind clinical trial. Clinical severity was quantified using standardized scores and by owner assessment of pruritus. A single injection of a heat-killed suspension of M. vaccae was found to be well tolerated and effective in treating mild to moderate cases of cAD demonstrable for 3 months, but was insignificant in more severely affected dogs.

Effects of Mycobacterium vaccae on toll-like receptor expression

Rationale Toll-like receptors (TLRs), transmembrane proteins expressed on the surface of antigen presenting cells (APCs), contribute to the activation of the innate immune system by recognizing specific pathogen-associated molecular patterns and by directing T cell responses. For example schistosomal lysophosphatidylserine stimulation of dendritic cells (DCs) drives the development of regulatory T cells (Tregs). Since Mycobacterium vaccae has similarly been found to induce Tregs and to improve symptoms of pulmonary allergic inflammation, we investigated its effects on the expression of TLRs to assess their involvement in the bacterium's mode of action. Methods Using real-time PCR, TLRs and cytokine expression were measured from both M. vaccae-stimulated pulmonary CD11c+ APCs from allergic mice and from M. vaccae-stimulated THP-1 cells. We determined the expression of TLR2, -4, -7 and -8 and of CD14, a surface molecule involved in mediating TLR signaling. Results M. vaccae differentially influenced the expression of TLRs both in vitro and in vivo. For example, expression of TLR2 and CD14 was increased in both stimulated THP-1 cells and pulmonary CD11c+ cells. Moreover, TLR2 increased expression in this CD11c+ population correlates with an increased expression of the regulatory cytokines IL-10 and IFN-α. Conclusions These results suggest that stimulation with M. vaccae influences the expression of TLRs on APCs, thereby directing the host's immune responses. It could be speculated that M. vaccae-induced CD11c+ cells have a potential regulatory role through their secretion of immunomodulatory cytokines that are TLRs-dependent.