Dendritic Cells and their role in Allergic Asthma as modulators and mediators – A systematic review

Abstract

Background: Dendritic cells (DCs) are pivotal for the initiation and regulation of immune responses, particularly in the pathogenesis of allergic asthma. DC subsets, distinguished by surface markers, function, and origin, orchestrate the activation of T helper 2 cells, leading to the secretion of cytokines such as IL-4, IL-5, and IL-13, which drive airway inflammation and hyperresponsiveness. Recent findings reveal immunoregulatory DC subsets capable of promoting tolerance and suppressing excessive inflammatory responses in allergic asthma.

Methods: This comprehensive review evaluates current literature concerning DC subset differentiation, their signalling pathways, interactions with T cells, and roles in the development, progression, and regulation of allergic asthma. The focus is on mechanistic insights gleaned from cellular, molecular, and in vivo studies.

Results:  Evidence demonstrates that classical DCs contribute to Th2 polarization and allergic inflammation, yet regulatory DCs can induce Treg responses and suppress effector mechanisms, thus maintaining immune homeostasis. Animal model and human studies confirm that transfer or expansion of regulatory DCs alleviates airway hyperresponsiveness and limits Th2-driven pathology. Investigations have identified several DC-associated pathways—such as dectin-2, TSLP, and IL-10—central to immune modulation.

Discussion: Recognition of functional and phenotypic heterogeneity among DC subsets has expanded our understanding of immune dynamics in asthma. Targeting immunoregulatory DCs or their signalling networks represents a promising avenue for the development of novel asthma therapies. However, significant knowledge gaps remain regarding the precise mechanisms by which DCs maintain tolerance or provoke inflammation.

Conclusion: Dendritic cells critically regulate allergic asthma through distinct inflammatory and tolerogenic roles. Strategic modulation of DC subsets and their pathways offers new opportunities for targeted therapies, warranting further mechanistic and translational research to optimize clinical applications.