Figure legend
Figure 1 . There are two types of macrophage memory: trained and
endowed immunity. In trained immunity, macrophages acquire an immune
memory phenotype via epigenetic and metabolic reprogramming and exhibit
an enhanced (training) or suppressed (tolerance) host defense response
toward a secondary challenge. In endowed immunity, macrophages primed by
allogeneic antigens acquire the potential ability to reject allogeneic
grafts bearing the same antigen, with the assistance of
helper CD4+ T
cells, although lack the capacity to reject third-party grafts. In
adaptive immunity, T and B cells display a highly specific immune memory
subsequent to primary exposure to antigens and produce a rapid, robust,
and enduring immune response.