B cells are required as APC for antigen-specific T cell proliferation but not for the differentiation or priming of those T cells.
We studied the influences of B cells on functional differentiation of T cells using SCID mice grafted with fetal thymus of C.B-17 mice (TG mice). T cells were shown to be reconstituted in TG mice without B cell development. These mice showed normal DTH response to SRBC and OVA. LN cells of these mice produced cytokines including IL-2, IL-4, IL-6 and IFN-gamma according to Con A stimulation. Thus, majority of T cell functions seem to differentiate in the absence of B cells. However, T cells of TG mice failed to proliferate in response to immunizing antigens in vitro, although they responded well to stimulation with Con A. This unresponsiveness of T cells in TG mice to these antigens was restored when antigen-primed B cells were added to the proliferation assay. Such an inability of T cells in antigen-specific proliferation was not seen in SCID mice grafted with C.B-17 fetal liver cells, in which B cells as well as T cells were efficiently reconstituted (FLT mice). T cell proliferation to immunizing antigen was also abrogated in FLT mice when B cells were depleted from lymphoid population. These results indicate that T cells can functionally differentiate and be primed in the absence of B cells, but they require B cells to proliferate in response to foreign antigens.
Chowdhury
M G
MG
Department of Urology, School of Medicine, University of Tokushima, Japan.
Maeda
K
K
Furukawa
A
A
Yasutomo
K
K
Kagawa
S
S
Himeno
K
K
D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology; D001402:B-Lymphocytes / Q000502:physiology*; D002454:Cell Differentiation; D002455:Cell Division; D003208:Concanavalin A / Q000494:pharmacology; D000939:Epitopes; D007114:Immunization; D008213:Lymphocyte Activation; D051379:Mice; D016513:Mice, SCID; D013601:T-Lymphocytes / Q000166:cytology*; D013950:Thymus Gland / Q000637:transplantation
D000939:Epitopes; D003208:Concanavalin A