1. Roles of T follicular helper cells and T follicular regulatory cells in Autoantibody Production in IL-2-deficient mice
- Author
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Markus M. Xie, Byunghee Koh, Matthew J. Turner, Alexander L. Dent, Mark H. Kaplan, Hong Liu, and Caleb Corn
- Subjects
Cellular differentiation ,Immunology ,Cell ,Autoimmunity ,Biology ,medicine.disease_cause ,T-Lymphocytes, Regulatory ,Article ,Gene Knockout Techniques ,Mice ,medicine ,Immunology and Allergy ,Animals ,Transcription factor ,Autoantibodies ,Autoimmune disease ,Mice, Knockout ,Mice, Inbred BALB C ,Autoantibody ,Germinal center ,Cell Differentiation ,General Medicine ,T-Lymphocytes, Helper-Inducer ,medicine.disease ,BCL6 ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Models, Animal ,Myeloid Differentiation Factor 88 ,Proto-Oncogene Proteins c-bcl-6 ,Interleukin-2 - Abstract
Autoantibodies can result from excessive T follicular helper (Tfh) cell activity, whereas T follicular regulatory (Tfr) cells negatively regulate autoantibody production. IL-2 knockout (KO) mice on the BALB/c background have elevated Tfh responses, produce autoantibodies, and develop lethal autoimmunity. We analyzed Tfh and Tfr cells in IL-2 KO mice on the C57BL/6 (B6) genetic background. In B6 IL-2 KO mice, the spontaneous formation of Tfh cells and germinal center B cells was greatly enhanced, along with production of anti-DNA autoantibodies. IL-2 has been reported to repress Tfr cell differentiation; however, Tfr cells were not increased over wild-type levels in the B6 IL-2 KO mice. To assess Tfh and Tfr cell regulation of autoantibody production in IL-2 KO mice, we generated IL-2 KO mice with a T cell–specific deletion of the master Tfh cell transcription factor Bcl6. In IL-2 KO Bcl6 conditional KO (2KO-Bcl6TC) mice, Tfh cells, Tfr cells, and germinal center B cells were ablated. In contrast to expectations, autoantibody IgG titers in 2KO-Bcl6TC mice were significantly elevated over autoantibody IgG titers in IL-2 KO mice. Specific deletion of Tfr cells with Foxp3-cre Bcl6-flox alleles in IL-2 KO mice led to early lethality, before high levels of autoantibodies could develop. We found IL-2+/+ Tfr cell–deficient mice produce significant levels of autoantibodies. Our overall findings provide evidence that Tfh cells are dispensable for high-level production of autoantibodies and also reveal a complex interplay between Tfh and Tfr cells in autoantibody production and autoimmune disease.
- Published
- 2019