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Burns JC, Touma R, Song Y, Padilla RL, Tremoulet AH, Sidney J, Sette A, Franco A. Fine specificities of natural regulatory T cells after IVIG therapy in patients with Kawasaki disease. Autoimmunity 2015; 48:181-8. [PMID: 25822882 DOI: 10.3109/08916934.2015.1027817] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The activation of natural regulatory T cells (nTreg) recognizing the heavy constant region (Fc) of IgG is an important mechanism of action of intravenous immunoglobulin (IVIG) therapy in Kawasaki disease (KD). Lack of circulating Fc-specific nTreg in the sub-acute phase of KD is correlated with the development of coronary artery abnormalities (CAA). Here, we characterize the fine specificity of nTreg in sub-acute (2- to 8-week post-IVIG) and convalescent (1- to 10-year post-IVIG) KD subjects by testing the immunogenicity of 64 peptides, 15 amino acids in length with a 10 amino acid-overlap spanning the entire Fc protein. About 12 Fc peptides (6 pools of 2 consecutive peptides) were recognized by nTreg in the cohorts studied, including two patients with CAA. To test whether IVIG expands the same nTreg populations that maintain vascular homeostasis in healthy subjects, we compared these results with results obtained in healthy adult controls. Similar nTreg fine specificities were observed in KD patients after IVIG and in healthy donors. These results suggest that T cell fitness rather than T cell clonal deletion or anergy is responsible for the lack of Fc-specific nTreg in KD patients who develop CAA. Furthermore, we found that adolescents and adults who had KD during childhood without developing CAA did not respond to the Fc protein in vitro, suggesting that the nTreg response induced by IVIG in KD patients is short-lived. Our results support the concept that peptide epitopes may be a viable therapeutic approach to expand Fc-specific nTreg and more effectively prevent CAA in KD patients.
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Affiliation(s)
- Jane C Burns
- Department of Pediatrics, Rady Children's Hospital, School of Medicine, University of California San Diego , La Jolla, CA , USA and
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Franco A, Touma R, Song Y, Shimizu C, Tremoulet AH, Kanegaye JT, Burns JC. Specificity of regulatory T cells that modulate vascular inflammation. Autoimmunity 2014; 47:95-104. [PMID: 24490882 DOI: 10.3109/08916934.2013.860524] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Intravenous immunoglobulin therapy (IVIG) is the treatment of choice for many immune-mediated diseases, yet its mechanisms of action are incompletely elucidated. We investigated the possibility that IVIG played a direct role in the expansion of regulatory T cells (Treg) that recognize the heavy chain constant region of immunoglobulin G (Fc) as a mechanism for the recovery of Kawasaki disease (KD), a T cell mediated pediatric vasculitis of the coronary arteries. We successfully generated Fc-specific Treg clones from sub-acute KD subjects that did not develop arterial complications after IVIG and defined an unusual functional phenotype: Fc-specific Treg secrete IL-10 and small amounts of IL-4 but not TGF-β. Antigen presentation studies demonstrated that these Treg clones can be activated by autologous B cells that express IgG on their cell surface in the absence of exogenous Fc. The IgG molecule has to be canonically processed and presented by autologous MHC molecules to be recognized by Treg. In support of the importance of this novel Treg population in downsizing vascular inflammation, KD patients with dilated coronary arteries or aneurysms despite IVIG treatment failed to expand Fc-specific Treg. Our results point to a specificity of a previously un-described Treg population for the clinical benefit provided by IVIG therapy in children.
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Affiliation(s)
- Alessandra Franco
- Department of Pediatrics, School of Medicine, University of California San Diego , La Jolla, CA , USA and
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Ogata S, Shimizu C, Franco A, Touma R, Kanegaye JT, Choudhury BP, Naidu NN, Kanda Y, Hoang LT, Hibberd ML, Tremoulet AH, Varki A, Burns JC. Treatment response in Kawasaki disease is associated with sialylation levels of endogenous but not therapeutic intravenous immunoglobulin G. PLoS One 2013; 8:e81448. [PMID: 24324693 PMCID: PMC3855660 DOI: 10.1371/journal.pone.0081448] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/12/2013] [Indexed: 12/12/2022] Open
Abstract
Objectives Although intravenous immunoglobulin (IVIG) is highly effective in Kawasaki disease (KD), mechanisms are not understood and 10-20% of patients are treatment-resistant, manifesting a higher rate of coronary artery aneurysms. Murine models suggest that α2-6-linked sialic acid (α2-6Sia) content of IVIG is critical for suppressing inflammation. However, pro-inflammatory states also up-regulate endogenous levels of β-galactoside:α2-6 sialyltransferase-I (ST6Gal-I), the enzyme that catalyzes addition of α2-6Sias to N-glycans. We asked whether IVIG failures correlated with levels of α2-6Sia on infused IVIG or on the patient’s own endogenous IgG. Methods We quantified levels of α2-6Sia in infused IVIG and endogenous IgG from 10 IVIG-responsive and 10 resistant KD subjects using multiple approaches. Transcript levels of ST6GAL1, in patient whole blood and B cell lines were evaluated by RT-PCR. Plasma soluble (s)ST6Gal-I levels were measured by ELISA. Results There was no consistent difference in median sialylation levels of infused IVIG between groups. However, α2-6Sia levels in endogenous IgG, ST6GAL1 transcript levels, and ST6Gal-I protein in serum from IVIG-resistant KD subjects were lower than in responsive subjects at both pre-treatment and one-year time points (p <0.001, respectively). Conclusions Our data indicate sialylation levels of therapeutic IVIG are unrelated to treatment response in KD. Rather, lower sialylation of endogenous IgG and lower blood levels of ST6GALI mRNA and ST6Gal-I enzyme predict therapy resistance. These differences were stable over time, suggesting a genetic basis. Because IVIG-resistance increases risk of coronary artery aneurysms, our findings have important implications for the identification and treatment of such individuals.
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Affiliation(s)
- Shohei Ogata
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Chisato Shimizu
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Alessandra Franco
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - Ranim Touma
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
| | - John T. Kanegaye
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
- Rady Children’s Hospital San Diego, San Diego, California, United States of America
| | - Biswa P. Choudhury
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of San Diego, School of Medicine, La Jolla, California, United States of America
| | - Natasha N. Naidu
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of San Diego, School of Medicine, La Jolla, California, United States of America
| | - Yutaka Kanda
- Kyowa Hakko Kirin California, Inc., La Jolla, California, United States of America
| | - Long T. Hoang
- Division of Infectious Disease 1, Genome Institute of Singapore, Singapore, Singapore
| | - Martin L. Hibberd
- Division of Human Genetics, Genome Institute of Singapore, Singapore, Singapore
| | - Adriana H. Tremoulet
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
- Rady Children’s Hospital San Diego, San Diego, California, United States of America
| | - Ajit Varki
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of San Diego, School of Medicine, La Jolla, California, United States of America
| | - Jane C. Burns
- Department of Pediatrics, University of California San Diego, School of Medicine, La Jolla, California, United States of America
- Rady Children’s Hospital San Diego, San Diego, California, United States of America
- * E-mail:
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