Regulation von pro- und antiinflammatorischen Th17-Zellen

Microbe driven T-helper cell differentiation: lessons from Candida albicans and Staphylococcus aureus

T-helper cells integrate signals from their T-cell receptor, co-stimulatory molecules and cytokine receptors to polarize into effector T-helper subsets with specialized functions in antigen clearance or tolerance. To this end, antigen presenting cells and the local microenvironment tailor effector T-helper cells to respond appropriately to microbial challenges. These challenges comprise protection from pathogens on the one hand and tolerance for the commensal microbiota on the other hand. To accomplish these complex tasks, the host immune system needs to be highly specialized and stringently regulated. In this viewpoint article, we will concentrate on how microbes shape human T-helper cell responses and how this could relate to the emergence of chronic inflammatory diseases. Understanding the intricate communication between adaptive immunity and microbes will be important for the rational design of novel immunomodulatory therapies and also for anticipating infectious complications upon therapeutic intervention with cytokine depleting therapies, such as biologicals in dermatology.

[Effector T cells]

BACKGROUND

Although the present understanding of the immunopathogenesis of rheumatoid inflammation is still incomplete, there is substantial evidence that effector CD4+ T helper (Th) cells play a central role.

RESULTS

In recent years, in addition to the established Th cell subsets Th1 and Th2 cells, other subsets, such as Th9, Th17, Th22 and T follicular helper (Tfh) cells have been described. Defining the contribution of T cells in the initiation and maintenance of inflammation has been augmented by the identification of functionally distinct subsets of effector Th cells that can be classified based on their cytokine and transcription factor profiles.

CONCLUSION

Increasing knowledge of the role of these various T cell populations in chronic inflammation provides a better understanding and insights into the pathogenic mechanisms and chronification of rheumatic diseases.