Depression-like behavior is associated with changes in the meningeal lymphatic vasculature and meningeal B cells in a murine lupus model.

Meningeal lymphatic vasculature (mLV) comprises a network of vessels responsible for draining immune cells and fluid from the central nervous system (CNS) into the deep cervical lymph nodes. While changes in mLV function have been implicated in several neurodegenerative disorders, its role in autoimmune diseases is less clear. Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organs. When SLE affects the CNS, it is known as neuropsychiatric lupus (NPSLE), although the status of mLV during NPSLE has not been yet evaluated. Here, by using the lupus FcγRIIb-/- murine model, we found that this model develops NPSLE along with increased mLV coverage and function at 4 mo of age. Altered B cell developmental stages were evident in this lupus mouse model. In fact, increased B cell clusters in the meninges of FcγRIIb-/- mice were also observed. These findings suggest that mLV morphology and function are increased in FcγRIIb-/- mice together with changes in the meningeal B cell population that could have an impact on NPSLE symptoms.