Adoptive immunotherapy induces CNS dendritic cell recruitment and antigen presentation during clearance of a persistent viral infection.
Given the global impact of persistent infections on the human population, it is of the utmost importance to devise strategies to noncytopathically purge tissues of infectious agents. The central nervous system (CNS) poses a unique challenge when considering such strategies, as it is an immunologically specialized compartment that contains a nonreplicative cell population. Administration of exogenously derived pathogen-specific memory T cells (referred to as adoptive immunotherapy) to mice burdened with a persistent lymphocytic choriomeningitis virus (LCMV) infection from birth results in eradication of the pathogen from all tissues, including the CNS. In this study, we sought mechanistic insights into this highly successful therapeutic approach. By monitoring the migration of traceable LCMV-specific memory CD8+ T cells after immunotherapy, it was revealed that cytotoxic T lymphocytes (CTLs) distributed widely throughout the CNS compartment early after immunotherapy, which resulted in a dramatic elevation in the activity of CNS antigen-presenting cells (APCs). Immunotherapy induced microglia activation as well as the recruitment of macrophages and dendritic cells (DCs) into the brain parenchyma. However, DCs emerged as the only CNS APC population capable of inducing memory CTLs to preferentially produce the antiviral cytokine tumor necrosis factor-alpha, a cytokine demonstrated to be required for successful immunotherapeutic clearance. DCs were also found to be an essential element of the immunotherapeutic process because in their absence, memory T cells failed to undergo secondary expansion, and viral clearance was not attained in the CNS. These experiments underscore the importance of DCs in the immunotherapeutic clearance of a persistent viral infection and suggest that strategies to elevate the activation/migration of DCs (especially within the CNS) may facilitate pathogen clearance.
Lauterbach
Henning
H
Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, CA 92037, USA.
Zuniga
Elina I
EI
Truong
Phi
P
Oldstone
Michael B A
MB
McGavern
Dorian B
DB
D000818:Animals; D000831:Animals, Newborn; D017951:Antigen Presentation / Q000276:immunology*; D001921:Brain / Q000166:cytology* / Q000473:pathology / Q000821:virology; D002353:Carrier State; D002465:Cell Movement; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology* / Q000821:virology; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology; D016219:Immunotherapy, Adoptive; D007700:Kinetics; D008216:Lymphocytic Choriomeningitis / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D000949:Histocompatibility Antigens Class II; D014409:Tumor Necrosis Factor-alpha