Increased cell division but not thymic dysfunction rapidly affects the T-cell receptor excision circle content of the naive T cell population in HIV-1 infection.
Recent thymic emigrants can be identified by T cell receptor excision circles (TRECs) formed during T-cell receptor rearrangement. Decreasing numbers of TRECs have been observed with aging and in human immunodeficiency virus (HIV)-1 infected individuals, suggesting thymic impairment. Here, we show that in healthy individuals, declining thymic output will affect the TREC content only when accompanied by naive T-cell division. The rapid decline in TRECs observed during HIV-1 infection and the increase following HAART are better explained not by thymic impairment, but by changes in peripheral T-cell division rates. Our data indicate that TREC content in healthy individuals is only indirectly related to thymic output, and in HIV-1 infection is mainly affected by immune activation.
Hazenberg
M D
MD
Department of Clinical Viro-Immunology, CLB, and the Laboratory for Experimental and Clinical Immunology, Academic Medical Center, University of Amsterdam, Plesmanlaan 125, 1066CX, Amsterdam, The Netherlands.
Otto
S A
SA
Cohen Stuart
J W
JW
Verschuren
M C
MC
Borleffs
J C
JC
Boucher
C A
CA
Coutinho
R A
RA
Lange
J M
JM
Rinke de Wit
T F
TF
Tsegaye
A
A
van Dongen
J J
JJ
Hamann
D
D
de Boer
R J
RJ
Miedema
F
F
D019380:Anti-HIV Agents / Q000627:therapeutic use; D002455:Cell Division; D015329:Gene Rearrangement, T-Lymphocyte; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*
D019380:Anti-HIV Agents; D011948:Receptors, Antigen, T-Cell