Abstract
IL-2 administration in vivo has been shown to increase CD4+ T cell counts in HIV+ patients. We have previously reported that PBMC from HIV-infected patients undergo marked spontaneous apoptosis in vitro. In this study, we examined the effect of IL-2 added in vitro upon culture-induced apoptosis in PBMC from 80 HIV-infected patients by flow cytometry. IL-2 at concentrations of ≥10 U/ml significantly reduced spontaneous apoptosis in CD3+ T lymphocytes in patients but not in healthy volunteers. Interestingly, we observed that Bcl-2 expression in patient lymphocytes decreased rapidly upon in vitro culture while that in cells of healthy volunteers was relatively unaffected. The most significant decrease in Bcl-2 expression was noted in the apoptotic cell population. The IL-2-mediated reduction in lymphocyte apoptosis was found to be associated with the blocking of this culture-induced down-modulation of Bcl-2 expression. IL-2 did not induce significant expansion of lymphocytes during the culture period nor did it affect Fas Ag expression in patient cells, which were already expressing Fas maximally. These findings strongly suggest that IL-2 mediates its apoptosis-blocking effects via suppressing down-modulation of Bcl-2. Our findings also provide an experimental basis for the ongoing therapies utilizing this cytokine for slowing HIV disease progression.
| Original language | English |
|---|---|
| Pages (from-to) | 4184-4193 |
| Number of pages | 10 |
| Journal | Journal of Immunology |
| Volume | 157 |
| Issue number | 9 |
| State | Published - Nov 1 1996 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Immunology
Cite this
IL-2 Rescues in Vitro Lymphocyte Apoptosis in Patients with HIV Infection : Correlation with Its Ability to Block Culture-Induced Down-Modulation of Bcl-2. / Adachi, Yasushi; Oyaizu, Naoki; Than, Soe; McCloskey, Thomas W.; Pahwa, Savita G.
In: Journal of Immunology, Vol. 157, No. 9, 01.11.1996, p. 4184-4193.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - IL-2 Rescues in Vitro Lymphocyte Apoptosis in Patients with HIV Infection
T2 - Correlation with Its Ability to Block Culture-Induced Down-Modulation of Bcl-2
AU - Adachi, Yasushi
AU - Oyaizu, Naoki
AU - Than, Soe
AU - McCloskey, Thomas W.
AU - Pahwa, Savita G
PY - 1996/11/1
Y1 - 1996/11/1
N2 - IL-2 administration in vivo has been shown to increase CD4+ T cell counts in HIV+ patients. We have previously reported that PBMC from HIV-infected patients undergo marked spontaneous apoptosis in vitro. In this study, we examined the effect of IL-2 added in vitro upon culture-induced apoptosis in PBMC from 80 HIV-infected patients by flow cytometry. IL-2 at concentrations of ≥10 U/ml significantly reduced spontaneous apoptosis in CD3+ T lymphocytes in patients but not in healthy volunteers. Interestingly, we observed that Bcl-2 expression in patient lymphocytes decreased rapidly upon in vitro culture while that in cells of healthy volunteers was relatively unaffected. The most significant decrease in Bcl-2 expression was noted in the apoptotic cell population. The IL-2-mediated reduction in lymphocyte apoptosis was found to be associated with the blocking of this culture-induced down-modulation of Bcl-2 expression. IL-2 did not induce significant expansion of lymphocytes during the culture period nor did it affect Fas Ag expression in patient cells, which were already expressing Fas maximally. These findings strongly suggest that IL-2 mediates its apoptosis-blocking effects via suppressing down-modulation of Bcl-2. Our findings also provide an experimental basis for the ongoing therapies utilizing this cytokine for slowing HIV disease progression.
AB - IL-2 administration in vivo has been shown to increase CD4+ T cell counts in HIV+ patients. We have previously reported that PBMC from HIV-infected patients undergo marked spontaneous apoptosis in vitro. In this study, we examined the effect of IL-2 added in vitro upon culture-induced apoptosis in PBMC from 80 HIV-infected patients by flow cytometry. IL-2 at concentrations of ≥10 U/ml significantly reduced spontaneous apoptosis in CD3+ T lymphocytes in patients but not in healthy volunteers. Interestingly, we observed that Bcl-2 expression in patient lymphocytes decreased rapidly upon in vitro culture while that in cells of healthy volunteers was relatively unaffected. The most significant decrease in Bcl-2 expression was noted in the apoptotic cell population. The IL-2-mediated reduction in lymphocyte apoptosis was found to be associated with the blocking of this culture-induced down-modulation of Bcl-2 expression. IL-2 did not induce significant expansion of lymphocytes during the culture period nor did it affect Fas Ag expression in patient cells, which were already expressing Fas maximally. These findings strongly suggest that IL-2 mediates its apoptosis-blocking effects via suppressing down-modulation of Bcl-2. Our findings also provide an experimental basis for the ongoing therapies utilizing this cytokine for slowing HIV disease progression.
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M3 - Article
VL - 157
SP - 4184
EP - 4193
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 9
ER -