Cross, but not direct, presentation of cell-associated virus antigens by spleen macrophages is influenced by their differentiation state.
The initiation of T-cell immune responses requires professional antigen-presenting cells. Emerging data point towards an important role for macrophages (Mphi) in the priming of naïve T cells. In this study we analyzed the efficiency and the mechanisms by which Mphi derived from spleen (Sp-Mphi) or bone marrow (BM-Mphi) present Lymphocytic choriomeningitis virus (LCMV) antigens to epitope-specific T cells. We demonstrate that because of phagosomal maturation, Sp-Mphi downregulate their ability to cross-present cell-associated, but not soluble, antigens, as they are further differentiated in culture without altering their capacity to directly present virus antigens after infection. We propose that Sp-Mphi are extremely efficient at direct and cross-presentation. However, if these cells undergo further M-CSF-dependent maturation, they will adapt to be more scavenger and phagocytic and concurrently reduce their cross-presenting capacity. Accordingly, Sp-Mphi can have an important role in regulating T-cell responses through cross-presentation depending on their differentiation state.
Alatery
Attiya
A
Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada.
Siddiqui
Sarah
S
Chan
Matthew
M
Kus
Agnieszka
A
Petrof
Elaine O
EO
Basta
Sameh
S
D000818:Animals; D017951:Antigen Presentation; D000956:Antigens, Viral / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology; D002454:Cell Differentiation; D002478:Cells, Cultured; D045142:Cross-Priming; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006801:Humans; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D008264:Macrophages / Q000166:cytology / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D010587:Phagocytosis; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte