Abstract
A unique subset of CD8 T cells has been recently observed in germinal centers (GCs), a location traditionally associated with CD4 T-B interaction and humoral immune response. These follicular CD8 (fCD8) T cells appear to play a role in controlling chronic viral infections such as lymphocytic choriomeningitis virus, hepatitis B, or HIV and are expanded in malignant lymphoproliferation, but their role may be more diverse, as illustrated by their involvement in promoting antibody class switch in mice with autoimmune disease.
Susceptibility to viral and bacterial infections, lymphoproliferation, cancer, and autoimmunity are complications seen in most patients with common variable immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency with the hallmark of impaired GC-derived specific antibody responses. Our group has previously described an increased prevalence of CD8+ cells in the GCs of patients with CVID and lymphadenopathy.
Given the recent emergence of fCD8 T cells as important players in lymphoproliferation and regulation of the GC reaction, we investigated these cells in greater detail using methods described in this article's Online Repository at www.jacionline.org.