Immunological profile of periapical endodontic infections from HIV and HIV+ patients L. C. N. de Brito 1 , F. R. Teles 2,3 , R. P. Teles 2,3 , P. M. Nogueira 4 , L. Q. Vieira 5,6 & A. P. Ribeiro Sobrinho 4 1 Faculdade de Odontologia, Universidade de Ita una, Ita una, Brazil; 2 Departament of Applied Oral Sciences, The Forsyth Institute, Boston, MA; 3 Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; 4 Departamento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte; 5 Departamento de Bioqu  ımica e Imunologia Instituto de Ci^ encias Biol ogicas, Universidade Federal de Minas Gerais, Belo Horizonte; and 6 Nucleo de Pesquisa em Ci^ encias Biol ogicas, Universidade Federal de Ouro Preto, Ouro Preto, Brazil Abstract de Brito LCN, Teles FR, Teles RP, Nogueira PM, Vieira LQ, Ribeiro Sobrinho AP. Immunological profile of periapical endodontic infections from HIV and HIV+ patients. International Endodontic Journal, 48, 533–541, 2015. Aim To evaluate CD4 + CD28 + and CD8 + T-cell genes and the gene expression of IFN-c, TNF-a, IL-1-b, IL- 17A, IL-10, CCL-2/MCP-1, CCL-4, CCL-5 (RANTES), CXCR4, CCR5 and RANKL from cells in the periapical interstitial fluid from root canal infections in healthy patients (HIV) and HIV-positive individuals (HIV+). Methodology Subjects included 20 HIV and 23 HIV+ patients referred to the School of Dentistry at the Universidade Federal de Minas Gerais (Belo Hori- zonte, MG, Brazil). Almost all HIV+ patients were undergoing highly active antiretroviral therapy (HA- ART). Clinical samples were taken from teeth with pulp necrosis, and no patients had acute periapical symptoms at the time of the appointments. After cleaning and drying, 3 paper points were introduced into the root canal, passing passively through the root apex (2 mm) into the periapical tissues for 1 min. The samples were collected immediately after root canal cleaning and 7 days later (restrained root canal bacterial load) to characterize those gene expressions using real-time PCR. Results Significantly higher levels of CD4 + CD28 + and CD8 + T cells in teeth with restrained bacterial loads (second collection) compared with the first col- lection were observed in both HIV and HIV+ sam- ples. In HIV patients, an increase in IL-10 and CXCR4 expression was demonstrated as well as a decrease in pro-inflammatory cytokines such as RANKL, IFN-c, IL1-b and CCL5. However, in HIV+ patients an increase in cytokines IFN-c, IL-1-b, TNF-a and IL-17A, and chemokines CCL-2, CXCR4 and CCR5 were observed. The chemokine CCL-5 was not detected in HIV+ individuals. Conclusions These findings suggest that after reducing the root canal bacterial load in HIV indi- viduals an anti-inflammatory response is generated whilst in HIV+ patients a pro-inflammatory response is sustained in the periapical area. Keywords: chemokines, cytokines, human immu- nodeficiency virus (HIV), periapical lesion, T-cell expression. Received 23 April 2014; accepted 25 July 2014 Introduction Periradicular lesions are characterized by the host immune response to the egress of bacteria or bacterial by-products from the infected root canal system (Stashenko et al. 1998). CD4 + T cells, which play a role in the development, progression and resolution of Correspondence: Ant^ onio Paulino Ribeiro Sobrinho, Departa- mento de Odontologia Restauradora, Faculdade de Odontologia, Universidade Federal de Minas Gerais, CEP 31270-901, Belo Horizonte, MG, Brazil (Tel.: 55-31-3409-2406; Fax: 55-31- 3409-2470; e-mail: sobrinho.bhz@terra.com.br). International Endodontic Journal, 48, 533–541, 2015 © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd doi:10.1111/iej.12345 533