CD4+ T cells are the major producers of lymphotoxin-β (LTbeta). (A-B) Immunofluorescent staining of LTbeta (red), CD4 or CD8 (green) in LNs from rhesus macaques (RMs), showing that LTbeta is mainly expressed by CD4+ T cells. (C) Immunofluorescent staining of CD45RA (red), LTbeta (green) in LNs from RMs, showing that LTbeta is mainly expressed by naive T cells.