CD4+ and CD8+ T Cells in Human Skin Equivalents Reveal Psoriasis Pathogenesis

10 Apr 20264 min read0 viewsJournal Feed

GIST

The limited translational potential of experimental animal models for human skin disease pathophysiology demands the development of more suitable immunocompetent human experimental models. Psoriasis ranks among the most prevalent human inflammatory skin disorders, initiated and manifested by the interplay of T cells with epidermal keratinocytes.

Current in vitro models recapitulate psoriasis-like pathology by incorporating CD4+ T cell subsets into skin equivalents, but lack CD8+ T cells, key mediators of epidermal inflammation and chronic disease. Our aim was to establish a human experimental model incorporating different CD4+ and CD8+ T cell subsets into a human full-thickness skin equivalent (hFTSE) to investigate their individual and combined contribution to the pathogenesis of psoriasis.

Across all conditions, migration of inserted T cells towards the epidermis and the secretion of psoriasis-associated cytokines (IFN-γ, IL-17, TNF-α, IL-1β, CCL20, IL-6, and IL-10) was observed. Immunohistological analysis revealed psoriasis-associated alteration of epidermal differentiation, as well as enhanced expression of keratinocyte-mediated antimicrobial peptides (AMPs) in T cell-incorporated hFTSEs.

Notably, the presence of CD8+ T cells altered the efficacy of treatment with the psoriasis drug apremilast.

Clinical Editorial

Study aim and model design

The work addresses limitations of animal models by developing a human full-thickness skin equivalent (hFTSE) incorporating immune T cells.
The objective was to assess how distinct CD4+ and CD8+ T cell subsets, singly and in combination, influence psoriasis-like pathology in a human skin context.

Experimental approach and immune components

T cells were integrated into the hFTSE, and their migration toward the epidermis was monitored across conditions.
Cytokine secretion associated with psoriasis was measured, including IFN-γ, IL-17, TNF-α, IL-1β, CCL20, IL-6, and IL-10.
Immunohistology evaluated epidermal differentiation markers and antimicrobial peptide (AMP) expression by keratinocytes.

Key observations and signals of disease pathology

T cell presence consistently drove epidermal changes consistent with psoriasis-like pathology.
Enhanced keratinocyte AMP expression accompanied T cell–influenced epidermal remodeling.
The inclusion of CD8+ T cells produced a distinct effect on treatment response to a psoriasis-targeted therapy.

Treatment relevance and context

Notably, CD8+ T cells modulated the efficacy of apremilast within the model, suggesting immune subset composition can alter drug responsiveness in this human skin context.

Limitations and interpretive boundaries

The summary notes represent in vitro findings within the engineered skin model; extrapolation to in vivo disease requires cautious interpretation.
Explicit limitations were not detailed in the provided content.