Distinct roles for transforming growth factor-beta2 and tumour necrosis factor-alpha in immune deviation elicited by hapten-derivatized antigen-presenting cells.
The role of antigen-presenting cells (APC) in the induction of antigen-specific unresponsiveness was examined, using two functionally distinct murine macrophage hybridomas, #59 and #63 cells. Derivatized with the hapten (dinitrofluorobenzene; DNFB), #59 cells induced contact hypersensitivity (CH) in mice. Hapten-derivatized #63 cells failed to induce CH. Instead, they prevented recipients from acquiring CH when exposed subsequently to a sensitizing dose of the hapten. Similarly, hapten-derivatized #59 cells, pretreated in vitro with transforming growth factor-beta2 (TGF-beta2) lost their capacity to evoke CH, and induced tolerance. Hapten-derivatized #63 cells and TGF-beta2-treated #59 cells eliminated CH in mice sensitized to hapten. Reverse transcription-polymerase chain reaction analysis of mRNAs for various accessory molecules important in T-cell activation revealed that #63 and TGF-beta2-treated #59 cells differed only in their expression of tumour necrosis factor-alpha (TNF-alpha) mRNA. The latter expressed higher levels of TNF-alpha mRNA than did untreated #59 cells. As a consequence, #63 and TGF-beta2-treated #59 cells, both of which induce tolerance, secrete TNF-alpha protein unlike untreated #59 cells, which do not induce tolerance to hapten. Since neutralizing anti-TNF-alpha antibodies abrogated the tolerogenic potential of #63 cells in vivo, we conclude that TGF-beta2 equips hapten-bearing APC with the capacity to evoke systemic immune deviation in which CH is selectively silenced. We speculate that one effect of TGF-beta2 is to cause APC to up-regulate TNF-alpha production. In turn, this cytokine biases the functional property of responding hapten-specific T cells in a direction that not only interferes with acquisition, but suppresses induction of CH.
Hecker
K H
KH
Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA.
Niizeki
H
H
Streilein
J W
JW
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D003877:Dermatitis, Contact / Q000276:immunology; D004139:Dinitrofluorobenzene / Q000276:immunology; D006241:Haptens / Q000276:immunology*; D007108:Immune Tolerance; D051379:Mice; D008807:Mice, Inbred BALB C; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D006241:Haptens; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D004139:Dinitrofluorobenzene