Characterization of the Protective Role of Regulatory T Cells in Experimental Periapical Lesion Development and Their Chemoattraction Manipulation as a Therapeutic Tool

Author(s)

Francisconi, Carolina Favaro ^[1] ; Vieira, Andreia Espindola ^[1] ; Biguetti, Claudia Cristina ^[1] ; Glowacki, Andrew J. ^{[2, 3, 4]} ; Favaro Trombone, Ana Paula ^[5] ; Letra, Ariadne ^[6] ; Silva, Renato Menezes ^[6] ; Sfeir, Charles S. ^{[7, 2, 3]} ; Little, Steven R. ^{[8, 9, 2, 3, 4]} ; Garlet, Gustavo Pompermaier ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Dent Bauru, Dept Biol Sci, Bauru, SP - Brazil

^[2] Univ Pittsburgh, McGowan Inst Regenerat Med, Pittsburgh, PA - USA

^[3] Univ Pittsburgh, Ctr Craniofacial Regenerat, Pittsburgh, PA - USA

^[4] Univ Pittsburgh, Dept Chem & Petr Engn, Pittsburgh, PA 15261 - USA

^[5] Univ Sagrado Coracao, Bauru, SP - Brazil

^[6] Univ Texas Hlth Sci Ctr Houston, Sch Dent, Dept Endodont, Houston, TX 77030 - USA

^[7] Univ Pittsburgh, Dept Oral Biol, Pittsburgh, PA - USA

^[8] Univ Pittsburgh, Dept Bioengn, Pittsburgh, PA - USA

^[9] Univ Pittsburgh, Dept Immunol, Pittsburgh, PA - USA

• Document type: Journal article
• Source: JOURNAL OF ENDODONTICS; v. 42, n. 1, p. 120-126, JAN 2016.
• Web of Science Citations: 13

Abstract

Introduction: The pathogenesis of periapical lesions is determined by the balance between host proinflammatory immune response and counteracting anti-inflammatory and reparative responses, which include regulatory T cells (Tregs) as potential immunoregulatory agents. In this study, we investigated (in a cause-and-effect manner) the involvement of CCL22-CCR4 axis in Treg migration to the periapical area and the role of Tregs in the determination of outcomes in periapical lesions. Methods: Periapical lesions were induced in C57BI/6 (wild-type) and CCR4KO mice (pulp exposure and bacterial inoculation) and treated with anti glucocorticoid-induced TNF receptor family regulated gene to inhibit Treg function or alternatively with CCL22-releasing, polylactic-glycolic acid particles to induce site-specific migration of Tregs. After treatment, lesions were analyzed for Treg influx and phenotype, overall periapical bone loss, and inflammatory/immunologic and wound healing marker expression (analyzed by real-time polymerase chain reaction array). Results: Treg inhibition by anti glucocorticoid-induced TNF receptor family regulated gene or CCR4 depletion results in a significant increase in periapical lesion severity, associated with upregulation of proinflammatory, T-helper 1, T-helper 17, and tissue destruction markers in parallel with decreased Treg and healing marker expression. The local release of CCL22 in the root canal system resulted in the promotion of Treg migration in a CCR4-dependent manner, leading to the arrest of periapical lesion progression, associated with downregulation of proinflammatory, T-helper 1, T-helper 17, and tissue destruction markers in parallel with increased Treg and healing marker expression. Conclusions: Because the natural and CCL22-induced Treg migration switches active lesion into inactivity phenotype, Treg chemoattractant may be a promising strategy for the clinical management of periapical lesions. (AU)

• FAPESP's process: 12/15133-3 - The role of Th17 and t regulatory (Tregs) cells in the immunomodulation of experimental periapial lesions
• Grantee: Gustavo Pompermaier Garlet
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/05994-4 - The role of Th17 and Regulatory T cells (Treg) in immunomodulation of experimental periapical lesions
• Grantee: Carolina Fávaro Francisconi Mortari
• Support Opportunities: Scholarships in Brazil - Doctorate