Abstract
In vitro infection of PHA-stimulated, normal CD4+ human peripheral blood T lymphocytes (PBLs) with several HIV-1 isolates did not result in cytopathology, despite high levels of virus replication and the fact that some of these isolates were cytopathic in certain cell lines. In contrast, infection of unfractionated PBLs (containing CD8+ as well as CD4+ lymphocytes) with these isolates always resulted in death of the infected CD4+ T lymphocytes. It has been well documented that PHA stimulation and culture of PBLs in medium containing IL-2 generates lymphokine-activated killer (LAK) cell activity which can destroy many transformed cells and virus-infected normal cells. When CD8+ T lymphocytes from PHA-stimulated PBLs were added to HIV-1-infected purified CD4+ T lymphocytes, significant lysis occurred. This cytotoxicity was not MHC class I-restricted, and depletion of CD8+ T lymphocytes from unfractionated PBL cultures shortly after HIV infection largely abolished the killing of the infected CD4+ T lymphocytes. These results demonstrated that CD8+ LAK cells were killing the CD4+ T lymphocytes in unfractionated PBL cultures infected with these noncytopathic HIV-1 strains. Care is thus warranted when studying HIV cytopathology in unfractionated PBL cultures. Morphological and DNA gel electrophoretic analyses of HIV-infected CD4+ T lymphocytes being killed by CD8+ LAK cells demonstrated that apoptosis was the predominant mechanism of LAK cell-mediated killing. In contrast, necrosis was the major mechanism involved in killing of purified CD4+ T lymphocytes by HIV-1 strains which were directly cytopathic. These findings may explain some of the discrepancies in the literature concerning reports of either apoptotic or necrotic killing of cells by HIV in vitro. Moreover, these data strongly suggest that direct killing by replicating HIV-1 in vivo should reveal necrotic cells and immune effector cell killing should reveal apoptotic cells. Since the latter are much more frequently observed in vivo, perhaps immune effector-mediated depletion of CD4+ T lymphocytes is more important as a pathogenic mechanism.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 169-180 |
| Number of pages | 12 |
| Journal | Virology |
| Volume | 241 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 15 1998 |
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Keywords
- Apoptosis
- CD4
- CD8
- HIV
- LAK
- Necrosis
- PBL
ASJC Scopus subject areas
- Virology
- Infectious Diseases
Cite this
Apoptotic killing of CD4+ T lymphocytes in HIV-1-infected PHA- stimulated PBL cultures is mediated by CD8+ LAK cells. / Wang, Liqiang; Klimpel, Gary R.; Planas, Josè M.; Li, Hongbo; Cloyd, Miles W.
In: Virology, Vol. 241, No. 2, 15.02.1998, p. 169-180.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Apoptotic killing of CD4+ T lymphocytes in HIV-1-infected PHA- stimulated PBL cultures is mediated by CD8+ LAK cells
AU - Wang, Liqiang
AU - Klimpel, Gary R.
AU - Planas, Josè M.
AU - Li, Hongbo
AU - Cloyd, Miles W.
PY - 1998/2/15
Y1 - 1998/2/15
N2 - In vitro infection of PHA-stimulated, normal CD4+ human peripheral blood T lymphocytes (PBLs) with several HIV-1 isolates did not result in cytopathology, despite high levels of virus replication and the fact that some of these isolates were cytopathic in certain cell lines. In contrast, infection of unfractionated PBLs (containing CD8+ as well as CD4+ lymphocytes) with these isolates always resulted in death of the infected CD4+ T lymphocytes. It has been well documented that PHA stimulation and culture of PBLs in medium containing IL-2 generates lymphokine-activated killer (LAK) cell activity which can destroy many transformed cells and virus-infected normal cells. When CD8+ T lymphocytes from PHA-stimulated PBLs were added to HIV-1-infected purified CD4+ T lymphocytes, significant lysis occurred. This cytotoxicity was not MHC class I-restricted, and depletion of CD8+ T lymphocytes from unfractionated PBL cultures shortly after HIV infection largely abolished the killing of the infected CD4+ T lymphocytes. These results demonstrated that CD8+ LAK cells were killing the CD4+ T lymphocytes in unfractionated PBL cultures infected with these noncytopathic HIV-1 strains. Care is thus warranted when studying HIV cytopathology in unfractionated PBL cultures. Morphological and DNA gel electrophoretic analyses of HIV-infected CD4+ T lymphocytes being killed by CD8+ LAK cells demonstrated that apoptosis was the predominant mechanism of LAK cell-mediated killing. In contrast, necrosis was the major mechanism involved in killing of purified CD4+ T lymphocytes by HIV-1 strains which were directly cytopathic. These findings may explain some of the discrepancies in the literature concerning reports of either apoptotic or necrotic killing of cells by HIV in vitro. Moreover, these data strongly suggest that direct killing by replicating HIV-1 in vivo should reveal necrotic cells and immune effector cell killing should reveal apoptotic cells. Since the latter are much more frequently observed in vivo, perhaps immune effector-mediated depletion of CD4+ T lymphocytes is more important as a pathogenic mechanism.
AB - In vitro infection of PHA-stimulated, normal CD4+ human peripheral blood T lymphocytes (PBLs) with several HIV-1 isolates did not result in cytopathology, despite high levels of virus replication and the fact that some of these isolates were cytopathic in certain cell lines. In contrast, infection of unfractionated PBLs (containing CD8+ as well as CD4+ lymphocytes) with these isolates always resulted in death of the infected CD4+ T lymphocytes. It has been well documented that PHA stimulation and culture of PBLs in medium containing IL-2 generates lymphokine-activated killer (LAK) cell activity which can destroy many transformed cells and virus-infected normal cells. When CD8+ T lymphocytes from PHA-stimulated PBLs were added to HIV-1-infected purified CD4+ T lymphocytes, significant lysis occurred. This cytotoxicity was not MHC class I-restricted, and depletion of CD8+ T lymphocytes from unfractionated PBL cultures shortly after HIV infection largely abolished the killing of the infected CD4+ T lymphocytes. These results demonstrated that CD8+ LAK cells were killing the CD4+ T lymphocytes in unfractionated PBL cultures infected with these noncytopathic HIV-1 strains. Care is thus warranted when studying HIV cytopathology in unfractionated PBL cultures. Morphological and DNA gel electrophoretic analyses of HIV-infected CD4+ T lymphocytes being killed by CD8+ LAK cells demonstrated that apoptosis was the predominant mechanism of LAK cell-mediated killing. In contrast, necrosis was the major mechanism involved in killing of purified CD4+ T lymphocytes by HIV-1 strains which were directly cytopathic. These findings may explain some of the discrepancies in the literature concerning reports of either apoptotic or necrotic killing of cells by HIV in vitro. Moreover, these data strongly suggest that direct killing by replicating HIV-1 in vivo should reveal necrotic cells and immune effector cell killing should reveal apoptotic cells. Since the latter are much more frequently observed in vivo, perhaps immune effector-mediated depletion of CD4+ T lymphocytes is more important as a pathogenic mechanism.
KW - Apoptosis
KW - CD4
KW - CD8
KW - HIV
KW - LAK
KW - Necrosis
KW - PBL
UR - http://www.scopus.com/inward/record.url?scp=0032519892&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032519892&partnerID=8YFLogxK
U2 - 10.1006/viro.1997.8979
DO - 10.1006/viro.1997.8979
M3 - Article
VL - 241
SP - 169
EP - 180
JO - Virology
JF - Virology
SN - 0042-6822
IS - 2
ER -