OBJECTIVE: Dendritic cells (DCs) play a major role in regulating lymphocytes, including B cells, and defective DC functions have been implicated in lupus. The purpose of this study was to assess the contribution of DCs to B cell hyperactivity in the B6.Sle1.Sle2.Sle3 (B6.TC) murine lupus model. METHODS: We compared the effects of B6 and B6.TC bone marrow-derived DCs on naive B cells cocultured in the presence of lipopolysaccharide (LPS), anti-CD40, or anti-IgM. We measured the proliferation, antibody production, and expression of activation markers and chemokine receptors for the B cells, as well as DC cytokine production. B cell proliferation was also assessed in Transwell experiments and in response to activated DC supernatants or exosomes. The role of DC-produced cytokines was evaluated with blocking antibodies and transgenic mice. RESULTS: LPS-stimulated or anti-CD40-stimulated DCs from B6.TC mice increased B cell proliferation, antibody production, and chemokine receptor expression as compared with DCs from B6 mice. Cell-to-cell contact was not necessary for the augmented effect of the lupus-prone DCs. Anti-CD40 treatment induced a higher production of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), IL-10, and tumor necrosis factor alpha in B6.TC DCs. Blocking these individual cytokines, however, did not abrogate the effects of B6.TC DCs. Additional experiments also ruled out involvement of BAFF, IL-12, and interferon-alpha. CONCLUSION: Activated DCs from B6.TC mice directly increase B cell effector functions. This effect depends on soluble factors released by activated DCs, but none of the single major DC-produced cytokines known to affect B cells are necessary. Increased sIL-6R production suggests that increased sensitivity to IL-6 may be involved.
OBJECTIVE: Dendritic cells (DCs) play a major role in regulating lymphocytes, including B cells, and defective DC functions have been implicated in lupus. The purpose of this study was to assess the contribution of DCs to B cell hyperactivity in the B6.Sle1.Sle2.Sle3 (B6.TC) murine lupus model. METHODS: We compared the effects of B6 and B6.TC bone marrow-derived DCs on naive B cells cocultured in the presence of lipopolysaccharide (LPS), anti-CD40, or anti-IgM. We measured the proliferation, antibody production, and expression of activation markers and chemokine receptors for the B cells, as well as DC cytokine production. B cell proliferation was also assessed in Transwell experiments and in response to activated DC supernatants or exosomes. The role of DC-produced cytokines was evaluated with blocking antibodies and transgenic mice. RESULTS:LPS-stimulated or anti-CD40-stimulated DCs from B6.TCmice increased B cell proliferation, antibody production, and chemokine receptor expression as compared with DCs from B6 mice. Cell-to-cell contact was not necessary for the augmented effect of the lupus-prone DCs. Anti-CD40 treatment induced a higher production of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), IL-10, and tumor necrosis factor alpha in B6.TC DCs. Blocking these individual cytokines, however, did not abrogate the effects of B6.TC DCs. Additional experiments also ruled out involvement of BAFF, IL-12, and interferon-alpha. CONCLUSION: Activated DCs from B6.TCmice directly increase B cell effector functions. This effect depends on soluble factors released by activated DCs, but none of the single major DC-produced cytokines known to affect B cells are necessary. Increased sIL-6R production suggests that increased sensitivity to IL-6 may be involved.
Authors: Juan P Mackern-Oberti; Carolina Llanos; Claudia A Riedel; Susan M Bueno; Alexis M Kalergis Journal: Immunology Date: 2015-10-12 Impact factor: 7.397
Authors: Natasha M Rogers; David A Ferenbach; Jeffrey S Isenberg; Angus W Thomson; Jeremy Hughes Journal: Nat Rev Nephrol Date: 2014-09-30 Impact factor: 28.314
Authors: Jennifer D Larson; Joshua M Thurman; Anatoly V Rubtsov; David Claypool; Philippa Marrack; Linda F van Dyk; Raul M Torres; Roberta Pelanda Journal: Proc Natl Acad Sci U S A Date: 2012-04-02 Impact factor: 11.205