IFNAR1 and infection: Second, and consistent with our chimeric transfer studies, infection of mixed bone marrow chimeras in which ifnar1 deficiency was restricted to the T cell compartment (Fig 5L) revealed 2-fold greater parasite-specific secreted IgG (Fig 5M), as well as elevated Tfh (Fig 5N and S5E Fig), and GC B cell responses (S5F and S5G Fig).