T follicular regulatory cells (TFR) are a suppressive CD4(+) T cell subset that migrates to germinal centers (GC) during Ag presentation by upregulating the chemokine receptor CXCR5. In the GC, TFR control T follicular helper cell (TFH) expansion and modulate the development of high-affinity Ag-specific responses. In this study, we identified and characterized TFR as CXCR5(+)CCR7(-) "follicular" T regulatory cells in lymphoid tissues of healthy rhesus macaques, and we studied their dynamics throughout infection in a well-defined animal model of HIV pathogenesis. TFR were infected by SIVmac251 and had comparable levels of SIV DNA to CXCR5(-)CCR7(+) "T zone" T regulatory cells and TFH. Contrary to the SIV-associated TFH expansion in the chronic phase of infection, we observed an apparent reduction of TFR frequency in cell suspension, as well as a decrease of CD3(+)Foxp3(+) cells in the GC of intact lymph nodes. TFR frequency was inversely associated with the percentage of TFH and, interestingly, with the avidity of the Abs that recognize the SIV gp120 envelope protein. Our findings show changes in the TFH/TFR ratio during chronic infection and suggest possible mechanisms for the unchecked expansion of TFH cells in HIV/SIV infection.
Regulatory and Helper Follicular T Cells and Antibody Avidity to Simian Immunodeficiency Virus Glycoprotein 120 / M.J. Blackburn, M. Zhong-Min, F. Caccuri, K. Mckinnon, L. Schifanella, Y. Guan, G. Gorini, D. Venzon, C. Fenizia, N. Binello, S.N. Gordon, C.J. Miller, G. Franchini, M. Vaccari. - In: THE JOURNAL OF IMMUNOLOGY. - ISSN 1550-6606. - 195:7(2015 Oct 01), pp. 3227-3236.
|Titolo:||Regulatory and Helper Follicular T Cells and Antibody Avidity to Simian Immunodeficiency Virus Glycoprotein 120|
VACCARI, MONICA (Ultimo)
|Parole Chiave:||Animals; Antibodies, Viral; Antibody Affinity; Antigen Presentation; Antigens, CD3; CD4 Lymphocyte Count; Cell Movement; Cell Proliferation; Forkhead Transcription Factors; Germinal Center; Macaca mulatta; Membrane Glycoproteins; Receptors, CCR7; Receptors, CXCR5; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory; Viral Envelope Proteins|
|Settore Scientifico Disciplinare:||Settore MED/17 - Malattie Infettive|
Settore BIO/19 - Microbiologia Generale
Settore MED/04 - Patologia Generale
|Data di pubblicazione:||1-ott-2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.4049/jimmunol.1402699|
|Appare nelle tipologie:||01 - Articolo su periodico|