RORγt inverse agonist 35

Naïve CD4+ T-cell subset differentiation/polarization is an in vitro assay in which purified naïve CD4+ T cells are activated through TCR and CD28 costimulation and cultured with defined cytokines and neutralizing antibodies to generate Th0, Th1, Th2, Th17, or induced Treg-like populations. Differentiation is detected by subset-associated cytokines and transcription factors: IFN-γ/T-bet for Th1, IL-4/GATA3 for Th2, IL-17A/RORγt for Th17, and Foxp3 for induced Treg cells. The assay readout is usually generated by intracellular cytokine staining after restimulation, transcription-factor staining by flow cytometry, ELISA of secreted cytokines, or gene-expression analysis. The result reflects cytokine-directed lineage commitment or polarization rather than antigen-specific immune protection by itself.

Imiquimod (IMQ)-induced psoriasiform dermatitis is a widely used murine model in which topical application of IMQ, a Toll-like receptor 7 (TLR7) agonist, triggers innate immune activation in the skin and induces a psoriasis-like inflammatory cascade characterized by epidermal hyperplasia, immune cell infiltration, and cytokine production dominated by the IL-23/IL-17 axis. This inflammatory response is mediated through activation of dendritic cells and downstream induction of IL-23, IL-17A, IL-22, and related pro-inflammatory mediators, recapitulating key features of human plaque psoriasis and enabling mechanistic and therapeutic studies. The model is commonly induced using Aldara (5% IMQ cream) applied topically to murine skin, resulting in rapid onset of erythema, scaling, and thickening that can be quantified as disease severity indices and validated histologically.

Dextran sulfate sodium (DSS)-induced colitis is generated by administering DSS in mouse drinking water, producing epithelial injury, barrier disruption, weight loss, diarrhea, fecal blood, colon shortening, histologic mucosal damage, and inflammatory mediator changes; the model is mainly used to study acute or chronic intestinal inflammation resembling selected features of ulcerative colitis. DSS injury is interpreted through clinical and tissue readouts rather than a single molecular endpoint: daily body weight, stool consistency, and bleeding are combined into a disease activity index, while colon length, histology, cytokines, myeloperoxidase activity, intestinal permeability, and tight-junction markers provide complementary measures of inflammation and barrier damage.

TNBS-induced colitis is produced by intrarectal delivery of 2,4,6-trinitrobenzene sulfonic acid in ethanol, where ethanol disrupts the mucosal barrier and TNBS haptenates colonic proteins, generating immune-mediated colonic inflammation with weight loss, diarrhea, ulceration, transmural injury, inflammatory-cell infiltration, and cytokine responses. The model is used as an experimental intestinal inflammation model with Crohn’s disease–like features, especially when Th1-type responses, IL-12–dependent inflammation, chronic relapsing inflammation, or fibrosis-related endpoints are studied.