title: The relationship of T-regulatory cell subsets to disease stage, immune activation, and pathogen-specific immunity in HIV infection.
abstract: BACKGROUND
  Human immunodeficiency virus (HIV) infection is associated with abnormalities in T-regulatory (T-reg) cells, but the effect of HIV on the naive (CD45RO-) and memory (CD45RO) CD25+CD127loCD4+ T-reg cell subsets has not been defined.
  
  
  METHODS
  We measured the absolute number and relative percentage of total, naive, and memory T-reg cells in HIV-infected subjects and compared these parameters with their CD4+ T cells, viral load, levels of immune activation, and pathogen-specific immunity.
  
  
  RESULTS
  HIV infection was associated with an increased percentage of memory CD25+CD127loCD4+ T-reg cells and a decreased percentage of naive CD25+CD127loCD4+ T-reg cells as CD4+ T cells declined. The level of HIV viremia inversely correlated with total, memory, and naive CD25+CD127loCD4+ T-reg cell numbers and percentage of naive CD25+CD127loCD4+ T-reg cells. Lower total, memory, and naive CD25+CD127loCD4+ T-cell numbers were associated with higher levels of immune activation, whereas a higher percentage of CD25+CD127loCD4+ T-reg cells was associated with lower Candida- and HIV-specific immune responses.
  
  
  CONCLUSIONS
  These observations suggest that CD25+CD127loCD4+ T-reg cells contribute to the immunodeficiency seen in HIV disease.
authors.affiliation: Section of Infectious Disease, Department of Medicine, Rush Medical College, Chicago, IL 60612, USA. allan_s_tenorio@rush.edu
authors.forename: Allan R
authors.initials: AR
authors.lastname: Tenorio
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Martinson
authors.forename: David
authors.initials: D
authors.lastname: Pollard
authors.forename: Linda
authors.initials: L
authors.lastname: Baum
authors.forename: Alan
authors.initials: A
authors.lastname: Landay
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D005260:Female; D015658:HIV Infections / Q000276:immunology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D007156:Immunologic Memory; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D019562:Viral Load