TY - JOUR
T1 - The CD40-autophagy pathway is needed for host protection despite IFN-γ-dependent immunity and CD40 induces autophagy via control of P21 levels
AU - Portillo, Jose Andres C
AU - Okenka, Genevieve
AU - Reed, Erin
AU - Subauste, Angela
AU - Van Grol, Jennifer
AU - Gentil, Katrin
AU - Komatsu, Masaaki
AU - Tanaka, Keiji
AU - Landreth, Gary
AU - Levine, Beth
AU - Subauste, Carlos S.
PY - 2010
Y1 - 2010
N2 - Autophagy degrades pathogens in vitro. The autophagy gene Atg5 has been reported to be required for IFN-γ-dependent host protection in vivo. However, these protective effects occur independently of autophagosome formation. Thus, the in vivo role of classic autophagy in protection conferred by adaptive immunity and how adaptive immunity triggers autophagy are incompletely understood. Employing biochemical, genetic and morphological studies, we found that CD40 upregulates the autophagy molecule Beclin 1 in microglia and triggers killing of Toxoplasma gondii dependent on the autophagy machinery. Infected CD40-/- mice failed to upregulate Beclin 1 in microglia/macrophages in vivo. Autophagydeficient Beclin 1+/- mice, mice with deficiency of the autophagy protein Atg7 targeted to microglia/macrophages as well as CD40-/- mice exhibited impaired killing of T. gondii and were susceptible to cerebral and ocular toxoplasmosis. Susceptibility to toxoplasmosis occurred despite upregulation of IFN-γ, TNF-α and NOS2, preservation of IFN-γ-induced microglia/macrophage anti-T. gondii activity and the generation of anti-T. gondii T cell immunity. CD40 upregulated Beclin 1 and triggered killing of T. gondii by decreasing protein levels of p21, a molecule that degrades Beclin 1. These studies identified CD40-p21-Beclin 1 as a pathway by which adaptive immunity stimulates autophagy. In addition, they support that autophagy is a mechanism through which CD40-dependent immunity mediates in vivo protection and that the CD40-autophagic machinery is needed for host resistance despite IFN-γ.
AB - Autophagy degrades pathogens in vitro. The autophagy gene Atg5 has been reported to be required for IFN-γ-dependent host protection in vivo. However, these protective effects occur independently of autophagosome formation. Thus, the in vivo role of classic autophagy in protection conferred by adaptive immunity and how adaptive immunity triggers autophagy are incompletely understood. Employing biochemical, genetic and morphological studies, we found that CD40 upregulates the autophagy molecule Beclin 1 in microglia and triggers killing of Toxoplasma gondii dependent on the autophagy machinery. Infected CD40-/- mice failed to upregulate Beclin 1 in microglia/macrophages in vivo. Autophagydeficient Beclin 1+/- mice, mice with deficiency of the autophagy protein Atg7 targeted to microglia/macrophages as well as CD40-/- mice exhibited impaired killing of T. gondii and were susceptible to cerebral and ocular toxoplasmosis. Susceptibility to toxoplasmosis occurred despite upregulation of IFN-γ, TNF-α and NOS2, preservation of IFN-γ-induced microglia/macrophage anti-T. gondii activity and the generation of anti-T. gondii T cell immunity. CD40 upregulated Beclin 1 and triggered killing of T. gondii by decreasing protein levels of p21, a molecule that degrades Beclin 1. These studies identified CD40-p21-Beclin 1 as a pathway by which adaptive immunity stimulates autophagy. In addition, they support that autophagy is a mechanism through which CD40-dependent immunity mediates in vivo protection and that the CD40-autophagic machinery is needed for host resistance despite IFN-γ.
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U2 - 10.1371/journal.pone.0014472
DO - 10.1371/journal.pone.0014472
M3 - Article
C2 - 21217818
AN - SCOPUS:79251517741
SN - 1932-6203
VL - 5
JO - PloS one
JF - PloS one
IS - 12
M1 - e14472
ER -