title: Frequency and phenotype of B cell subpopulations in young and aged HIV-1 infected patients receiving ART.
abstract: BACKGROUND
  Aged individuals respond poorly to vaccination and have a higher risk of contracting infections in comparison to younger individuals; whether age impacts on the composition and function of B cell subpopulations relevant for immune responses is still controversial. It is also not known whether increased age during HIV-1 infection further synergizes with the virus to alter B cell subpopulations. In view of the increased number of HIV-1 infected patients living to high age as a result of anti-retroviral treatment this is an important issue to clarify.
  
  
  RESULTS
  In this work we evaluated the distribution of B cell subpopulations in young and aged healthy individuals and HIV-1 infected patients, treated and naïve to treatment. B cell populations were characterized for the expression of inhibitory molecules (PD-1 and FcRL4) and activation markers (CD25 and CD69); the capacity of B cells to respond to activation signals through up-regulation of IL-6 expression was also evaluated. Increased frequencies of activated and tissue-like memory B cells occurring during HIV-1 infection are corrected by prolonged ART therapy. Our findings also reveal that, in spite of prolonged treatment, resting memory B cells in both young and aged HIV-1 infected patients are reduced in number, and all memory B cell subsets show a low level of expression of the activation marker CD25.
  
  
  CONCLUSIONS
  The results of our study show that resting memory B cells in ART-treated young and aged HIV-1 infected patients are reduced in number and memory B cell subsets exhibit low expression of the activation marker CD25. Aging per se in the HIV-1 infected population does not worsen impairments initiated by HIV-1 in the memory B cell populations of young individuals.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Amu
authors.forename: Gitit
authors.initials: G
authors.lastname: Lavy-Shahaf
authors.forename: Alberto
authors.initials: A
authors.lastname: Cagigi
authors.forename: Bo
authors.initials: B
authors.lastname: Hejdeman
authors.forename: Silvia
authors.initials: S
authors.lastname: Nozza
authors.forename: Lucia
authors.initials: L
authors.lastname: Lopalco
authors.forename: Ramit
authors.initials: R
authors.lastname: Mehr
authors.forename: Francesca
authors.initials: F
authors.lastname: Chiodi
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D015497:HIV-1; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D015850:Interleukin-6 / Q000096:biosynthesis; D037181:Lectins, C-Type / Q000032:analysis; D008875:Middle Aged; D010641:Phenotype; D000099192:CD69 Antigens
chemical_list: D019380:Anti-HIV Agents; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D053645:Interleukin-2 Receptor alpha Subunit; D015850:Interleukin-6; D037181:Lectins, C-Type; D000099192:CD69 Antigens; C508017:IL2RA protein, human