Cross-presentation of tumor associated antigens through tumor-derived autophagosomes.
Cross-presentation of exogenous antigens by host professional antigen-presenting cells (APCs) plays a pivotal role in the initiation and development of T-cell immune responses to tumor-associated antigens, including self or mutated self-antigens derived from tumor cells, and foreign antigens derived from infectious agents. Cross-presentation requires multiple steps that involve the antigens' synthesis and compartmentalization in donor cells, packaging and delivery, and processing and presentation by MHC class I molecules on professional APCs. The intricate pathways that lead to protein degradation and the formation of MHC I-peptide complexes inside the APC are well documented for both soluble and particulate antigens. However, much less is known about how cross-presentation is regulated by the protein degradation pathways in antigen-donor cells (ADCs), including autophagy-mediated lysosomal proteolysis and proteasomal degradation. The exact nature or form of the antigens derived from donor cells at the time of delivery to the APC for cross-presentation is very controversial.
Li
Yuhuan
Y
Laboratory of Cancer Immunobiology, Providence Portland Medical Center, 4805 N.E. Glisan Street, Portland, OR 97213, USA.
Wang
Li-xin
LX
Pang
Puiyi
P
Twitty
Chris
C
Fox
Bernard A
BA
Aung
Sandra
S
Urba
Walter J
WJ
Hu
Hong-Ming
HM