Figure 10.

Proposed model. The left panel shows (i) how the expression of the heteromeric complex formed by CCR9 and DRD5 in effector CD4⁺ T cells works as a dual sensor of low dopamine levels and high CCL25 concentration, triggering migratory signaling required to (ii) infiltrate into the colonic lamina propria upon inflammation. The right panel shows how in the presence of transmembrane peptides able to disrupt the CCR9:DRD5 heteromer assembly (TM5C, TM6C, TM5D, and TM6D from Table 1) induce a shift in intracellular pathways triggered (iii) by the stimulation of CCR9 and DRD5, (iv) impairing the recruitment of effector CD4⁺ T cells into the colonic mucosa.