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Phenotypic and functional separation of memory and effector human CD8+ T cells.

Hamann D, Baars PA, Rep MH, Hooibrink B, Kerkhof-Garde SR, Klein MR, van Lier RA - J. Exp. Med. (1997)

Bottom Line: These T cells do not secrete IL-2 or -4 but can produce IFN-gamma and TNF-alpha.Interestingly, CD8+CD45RA+CD27- cells parallel effector CTLs, as they abundantly express Fas-ligand mRNA, contain perforin and granzyme B, and have high cytolytic activity without in vitro prestimulation.Based on both phenotypic and functional properties, we conclude that memory- and effector-type T cells can be separated as distinct entities within the human CD8+ T cell subset.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Viro-Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, University of Amsterdam.

ABSTRACT
Human CD8+ memory- and effector-type T cells are poorly defined. We show here that, next to a naive compartment, two discrete primed subpopulations can be found within the circulating human CD8+ T cell subset. First, CD45RA-CD45R0(+) cells are reminiscent of memory-type T cells in that they express elevated levels of CD95 (Fas) and the integrin family members CD11a, CD18, CD29, CD49d, and CD49e, compared to naive CD8+ T cells, and are able to secrete not only interleukin (IL) 2 but also interferon gamma, tumor necrosis factor alpha, and IL-4. This subset does not exert cytolytic activity without prior in vitro stimulation but does contain virus-specific cytotoxic T lymphocyte (CTL) precursors. A second primed population is characterized by CD45RA expression with concomitant absence of expression of the costimulatory molecules CD27 and CD28. The CD8+CD45RA+CD27- population contains T cells expressing high levels of CD11a, CD11b, CD18, and CD49d, whereas CD62L (L-selectin) is not expressed. These T cells do not secrete IL-2 or -4 but can produce IFN-gamma and TNF-alpha. In accordance with this finding, cells contained within this subpopulation depend for proliferation on exogenous growth factors such as IL-2 and -15. Interestingly, CD8+CD45RA+CD27- cells parallel effector CTLs, as they abundantly express Fas-ligand mRNA, contain perforin and granzyme B, and have high cytolytic activity without in vitro prestimulation. Based on both phenotypic and functional properties, we conclude that memory- and effector-type T cells can be separated as distinct entities within the human CD8+ T cell subset.

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Using standard limiting dilution analysis, the CTLp  frequencies for the HIV-1LAI  RT-derived peptide aa 244-252  (IVLPEKDSW) were quantified  in CD8+ T cell subsets from an  HIV-infected individual. Peptide-specific CTLp frequencies  were calculated by subtracting  CTLp frequencies determined  with targets without peptide  from CTLp frequencies determined with targets pulsed with 5  μg/ml of RTLAI peptide aa 244-252. Mean + SD of three separate experiments.
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Figure 7: Using standard limiting dilution analysis, the CTLp frequencies for the HIV-1LAI RT-derived peptide aa 244-252 (IVLPEKDSW) were quantified in CD8+ T cell subsets from an HIV-infected individual. Peptide-specific CTLp frequencies were calculated by subtracting CTLp frequencies determined with targets without peptide from CTLp frequencies determined with targets pulsed with 5 μg/ml of RTLAI peptide aa 244-252. Mean + SD of three separate experiments.

Mentions: CTL effectors exert direct ex vivo cytolytic activity, whereas memory cells need restimulation with antigen to acquire cytotoxic function. Since CD45RA− CD27+ cells, which resemble memory T cells with respect to membrane phenotype and cytokine secretion ability, showed no direct ex vivo cytolytic activity, we studied whether cytotoxic effectors could be generated from this population. To this purpose, PBMCs from an HIV-1 seropositive individual were sorted into CD8+CD45RA+CD27+ and CD8+ CD45RA−CD27+ subsets. CTLs from this individual had been previously found to recognize an HLA-B57 restricted epitope of the HIV-1LAI RT aa 244-252 (Klein, M.R., unpublished results). Neither CD45RA+CD27+ nor CD45RA− CD27+ cells showed direct ex vivo cytotoxicity as measured in a redirected kill assay as described above. To determine the frequency of peptide-specific CTLp within the distinct subsets, sorted cells were seeded in serial dilutions and stimulated with autologous B-LCL infected with recombinant vaccinia virus expressing the HIV-1LAI RT gene. On day 15, effector cells were tested for cytotoxicity on autologous B-LCL pulsed with the HIV-1LAI reverse transcriptase–derived peptide aa 244-252 (Fig. 7). Indeed, cytotoxic effector cells could be generated from the CD45RA− CD27+ subset, which had an enhanced frequency of peptide-specific CTLps (61/106 cells) as compared to the CD45RA+CD27+ subset (15/106 cells).


Phenotypic and functional separation of memory and effector human CD8+ T cells.

Hamann D, Baars PA, Rep MH, Hooibrink B, Kerkhof-Garde SR, Klein MR, van Lier RA - J. Exp. Med. (1997)

Using standard limiting dilution analysis, the CTLp  frequencies for the HIV-1LAI  RT-derived peptide aa 244-252  (IVLPEKDSW) were quantified  in CD8+ T cell subsets from an  HIV-infected individual. Peptide-specific CTLp frequencies  were calculated by subtracting  CTLp frequencies determined  with targets without peptide  from CTLp frequencies determined with targets pulsed with 5  μg/ml of RTLAI peptide aa 244-252. Mean + SD of three separate experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199103&req=5

Figure 7: Using standard limiting dilution analysis, the CTLp frequencies for the HIV-1LAI RT-derived peptide aa 244-252 (IVLPEKDSW) were quantified in CD8+ T cell subsets from an HIV-infected individual. Peptide-specific CTLp frequencies were calculated by subtracting CTLp frequencies determined with targets without peptide from CTLp frequencies determined with targets pulsed with 5 μg/ml of RTLAI peptide aa 244-252. Mean + SD of three separate experiments.
Mentions: CTL effectors exert direct ex vivo cytolytic activity, whereas memory cells need restimulation with antigen to acquire cytotoxic function. Since CD45RA− CD27+ cells, which resemble memory T cells with respect to membrane phenotype and cytokine secretion ability, showed no direct ex vivo cytolytic activity, we studied whether cytotoxic effectors could be generated from this population. To this purpose, PBMCs from an HIV-1 seropositive individual were sorted into CD8+CD45RA+CD27+ and CD8+ CD45RA−CD27+ subsets. CTLs from this individual had been previously found to recognize an HLA-B57 restricted epitope of the HIV-1LAI RT aa 244-252 (Klein, M.R., unpublished results). Neither CD45RA+CD27+ nor CD45RA− CD27+ cells showed direct ex vivo cytotoxicity as measured in a redirected kill assay as described above. To determine the frequency of peptide-specific CTLp within the distinct subsets, sorted cells were seeded in serial dilutions and stimulated with autologous B-LCL infected with recombinant vaccinia virus expressing the HIV-1LAI RT gene. On day 15, effector cells were tested for cytotoxicity on autologous B-LCL pulsed with the HIV-1LAI reverse transcriptase–derived peptide aa 244-252 (Fig. 7). Indeed, cytotoxic effector cells could be generated from the CD45RA− CD27+ subset, which had an enhanced frequency of peptide-specific CTLps (61/106 cells) as compared to the CD45RA+CD27+ subset (15/106 cells).

Bottom Line: These T cells do not secrete IL-2 or -4 but can produce IFN-gamma and TNF-alpha.Interestingly, CD8+CD45RA+CD27- cells parallel effector CTLs, as they abundantly express Fas-ligand mRNA, contain perforin and granzyme B, and have high cytolytic activity without in vitro prestimulation.Based on both phenotypic and functional properties, we conclude that memory- and effector-type T cells can be separated as distinct entities within the human CD8+ T cell subset.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Viro-Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, University of Amsterdam.

ABSTRACT
Human CD8+ memory- and effector-type T cells are poorly defined. We show here that, next to a naive compartment, two discrete primed subpopulations can be found within the circulating human CD8+ T cell subset. First, CD45RA-CD45R0(+) cells are reminiscent of memory-type T cells in that they express elevated levels of CD95 (Fas) and the integrin family members CD11a, CD18, CD29, CD49d, and CD49e, compared to naive CD8+ T cells, and are able to secrete not only interleukin (IL) 2 but also interferon gamma, tumor necrosis factor alpha, and IL-4. This subset does not exert cytolytic activity without prior in vitro stimulation but does contain virus-specific cytotoxic T lymphocyte (CTL) precursors. A second primed population is characterized by CD45RA expression with concomitant absence of expression of the costimulatory molecules CD27 and CD28. The CD8+CD45RA+CD27- population contains T cells expressing high levels of CD11a, CD11b, CD18, and CD49d, whereas CD62L (L-selectin) is not expressed. These T cells do not secrete IL-2 or -4 but can produce IFN-gamma and TNF-alpha. In accordance with this finding, cells contained within this subpopulation depend for proliferation on exogenous growth factors such as IL-2 and -15. Interestingly, CD8+CD45RA+CD27- cells parallel effector CTLs, as they abundantly express Fas-ligand mRNA, contain perforin and granzyme B, and have high cytolytic activity without in vitro prestimulation. Based on both phenotypic and functional properties, we conclude that memory- and effector-type T cells can be separated as distinct entities within the human CD8+ T cell subset.

Show MeSH
Related in: MedlinePlus