CD4 and Alzheimer disease: Single-cell RNA sequencing (scRNAseq) of CD45HIGH leukocytes isolated from the meninges and brains of 3xTg-AD (n = 8) mice as well as sex and age-matched WT controls (n = 8) at the onset of cognitive deficit21,22 (Fig. 1a) revealed 13 cell types, including CD8+ and CD4+ T cells, neutrophils, B cells, natural killer (NK) cells, innate lymphoid cells (ILCs), macrophages, and microglia (Fig. 1b; Supp.