A novel role for B cells in early protective immunity to an intracellular pathogen, Francisella tularensis strain LVS
Culkin, S.J.; Rhinehart-Jones, T.; Elkins, K.L.
Journal of Immunology 158(7): 3277-3284
1997
ISSN/ISBN: 0022-1767 PMID: 9120284 Document Number: 477565
Normal BALB/cByJ mice given a sublethal infection of F. tularensis strain LVS survived 106 LD50s of lethal challenge given only 3 days later. The cell types responsible for this very strong early protective immunity were determined. Early protection was observed in athymic nu/nu mice but not fully immunodeficient scid mice, implicating a lymphocyte in this response. Using scid mice that were reconstituted with various purified cell subpopulations, as well as mice with genetically targeted disruptions in lymphocyte subpopulations (knockout mice), it was demonstrated that strong early protection is highly dependent on B cells. This protective mechanism, which limits bacterial growth in the organs of the reticuloendothelial system very quickly after infection, requires IFN- gamma but is unlikely to involve specific antibody.