title: Entrapment of recent thymic emigrants in lymphoid tissues from HIV-infected patients: association with HIV cellular viral load.
abstract: OBJECTIVE
  Depletion of thymus derived naive T-cells is a feature of HIV infection. Here the impact of HIV infection on the compartmentalization of recent thymic emigrants of (RTE) and naive T-cells was examined.
  
  
  METHODS
  Peripheral blood mononuclear cells (PBMC) and lymphoid tissue (LT) from 43 HIV-infected patients and 12 controls were examined for RTE distribution by measuring coding joint T-cell receptor excisional circles (cjTREC) by PCR and naive and memory T-cell subsets and adhesion molecules (L-selection, LFA-1) by flow cytometry.
  
  
  RESULTS
  In HIV-infected patients, the RTE as quantified by cjTRECs in CD4 LT cells were significantly higher than in PBMC. Their values, however, were less than in control subjects, in both the LT and PBMC compartments. This was associated with an increase in L-selectin and LFA-1 expression on LT derived T cells. In PBMC, a significant positive relationship between TREC and naive CD4 cells and an inverse relationship between TREC and cellular viral load (CVL) was observed. Whereas in LT, there was a positive relationship between cjTREC and both naive CD4 cell percentage and CVL.
  
  
  CONCLUSIONS
  Collectively, the data suggests that LT is a significant reservoir for RTE. The RTE appeared to be entrapped in LT from HIV-infected subjects. Such entrapment is probably a response to the high viral load in these tissues. These observations may partially explain the decline in RTE observed in the peripheral blood of HIV-infected patients, and the delay in recovery of naive cells in blood after initiation of HAART.
authors.affiliation: University of Texas Medical Branch, Galveston 77555, USA.
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: Nokta
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Li
authors.forename: Lena
authors.initials: L
authors.lastname: Al-Harthi
authors.forename: Joan
authors.initials: J
authors.lastname: Nichols
authors.forename: Anna
authors.initials: A
authors.lastname: Pou
authors.forename: David
authors.initials: D
authors.lastname: Asmuth
authors.forename: Alan
authors.initials: A
authors.lastname: Landay
authors.forename: Richard B
authors.initials: RB
authors.lastname: Pollard
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D019041:L-Selectin / Q000378:metabolism; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D008221:Lymphoid Tissue / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013950:Thymus Gland / Q000276:immunology*; D019562:Viral Load
chemical_list: D016169:Lymphocyte Function-Associated Antigen-1; D012367:RNA, Viral; D011948:Receptors, Antigen, T-Cell; D019041:L-Selectin