Detailed immunophenotype of CD8+ memory cytotoxic T-lymphocytes (CTL) against HIV-1 with respect to expression of CD45RA/RO, CD62L and CD28 antigens.
We have previously reported that circulating effector cytotoxic CD8+ T-lymphocytes (CTLs) against HIV-1 express CD38 and HLA-DR activation antigens. In this study, we performed two series of FACS sorts to phenotype and characterize precursors of CTL effectors. First we looked at memory CTL activity against HIV-1 stimulated by antigen as well as CTL activity stimulated by CD3 mAb with regard to whether the precursors expressed CD45RA and/or CD62L. We found that the precursor cells that could be stimulated with antigen to become effectors within 7 days predominated in the CD45RA CD62L subset. However. in donors with low levels of CD8+ T-cell activation as measured by CD38 antigen expression, memory cells could also be found in the CD45RA+ CD62L+ subset. Our data indicate that reversion of memory cells to the CD45RA+ CD62L+ phenotype can occur in humans, especially in donors with low levels of virus replication and minimal CD8 + T-cell activation. Next, we looked at CD28 expression with regard to antigen specific memory cells and again found that the level of virus replication and CD8+ T-cell activation influenced the subset that contained the memory cells. In donors with high levels of virus replication, our results indicated that CTL were being actively recruited from both CD28+ and CD28 subsets, while in donors with undetectable levels of viral replication, the memory cells were entirely in the CD28 compartment.
Giorgi
J V
JV
UCLA School of Medicine and the multicenter AIDS Cohort Study, Los Angeles, CA 90095-1745, USA. giorgi@mednet.ucla.edu
Hausner
M A
MA
Hultin
L E
LE
D018106:CD28 Antigens / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory / Q000276:immunology*; D016130:Immunophenotyping; D019041:L-Selectin / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000276:immunology*; D008297:Male; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*
D018106:CD28 Antigens; D019041:L-Selectin; D017493:Leukocyte Common Antigens