Human Immunodeficiency Virus Type 1 Protease Inhibitor Modulates Activation of Peripheral Blood CD4+ T Cells and Decreases Their Susceptibility to Apoptosis In Vitro and In Vivo by Elaine M. Sloand, Princy N. Kumar, Sonnie Kim, Aniruddho Chaudhuri, Frank F. Weichold, and Neal S. Young Blood Volume 94(3):1021-1027 August 1, 1999 ©1999 by American Society of Hematology

Combination treatment with protease inhibitors decreases ICE expression and apoptosis in CD4 cells from HIV-infected patients. Combination treatment with protease inhibitors decreases ICE expression and apoptosis in CD4 cells from HIV-infected patients. Fifteen patients who failed nucleoside analog treatment were placed on antiviral therapy that included a protease inhibitor. Blood was analyzed before and 6 to 8 weeks after treatment. Cells were analyzed for ICE and Fas-R expression, and apoptotic cells assessed by annexin V binding. There were significant decreases in ICE expression and apoptosis following treatment (P < .01), while there was no significant change in Fas-R expression. CD4 counts increased a mean of 20 cells/mL. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

HIV-infected persons with undetectable viral loads still demonstrate excessive apoptosis when compared with normal controls. HIV-infected persons with undetectable viral loads still demonstrate excessive apoptosis when compared with normal controls. Ten HIV patients receiving combination antiviral therapy with a protease inhibitor combination demonstrated normal Fas-R and ICE expression, but excessive apoptosis when compared with 6 normal controls. Scattergrams of apoptotic cells are seen above form-selected HIV-infected patients and normals. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir decreases ICE expression and apoptosis in normal CD4+ cells deprived of IL-2. Ritonavir decreases ICE expression and apoptosis in normal CD4+ cells deprived of IL-2. PBMC from normal donors were cultured without IL-2. After 72 hours, cells were analyzed by flow cytometry; ICE expression and apoptosis were significantly decreased in cells cocultivated with ritonavir (P < .01). Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir decreases apoptosis in normal CD4+ T cells deprived of IL-2 using the TdT assay. Ritonavir decreases apoptosis in normal CD4+ T cells deprived of IL-2 using the TdT assay. PBMC from normal donors prepared and cultured as described in Fig 3 demonstrate decreased apoptosis as measured by the TdT assay after exposure to ritonavir. The number of apoptotic cells was determined using 2-color flow cytometry. Cells were gated to include only CD4+ cells (stained with FITC-labeled CD4-PE MoAb) are seen in the histogram above. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir increases cell viability of CD4+cells treated with Fas agonist (CH11). Ritonavir increases cell viability of CD4+cells treated with Fas agonist (CH11). PBMC from normal donors were cultured with Fas agonist with and without ritonavir (5 nmol/L). Viability is expressed as percentage of untreated (ie, without Fas agonist) control. Cell viability was determined by PI staining. Examples of scattergrams are shown. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir decreases apoptosis in CD4+cells cultured with Fas agonist. Ritonavir decreases apoptosis in CD4+cells cultured with Fas agonist. Normal PBMC were cultured with Fas agonist, with and without ritonavir (5 nmol/L). Cells were stained with CD4-PE and FITC-annexin V and analyzed by flow cytometry. There was a significant (P < .05) decrease in annexin V binding in cells treated with ritonavir. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir decreases ICE expression in CD4+cells cultured with Fas agonist. Ritonavir decreases ICE expression in CD4+cells cultured with Fas agonist. Normal PBMC were cultured with and without ritonavir. Cells were surface-stained with CD4-PE, permeabilized, and stained with ICE-FITC. CD4+ cells expressing ICE are shown. There was a significant, dose-dependent decrease in ICE expression (P < .01). Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology

Ritonavir decreases Fas-L expression, but does not alter Fas-R expression in CD4+ cells stimulated with PHA. Samples of normal PBMC were cultured with PHA for 72 hours at 37°C at different concentrations of ritonavir. Ritonavir decreases Fas-L expression, but does not alter Fas-R expression in CD4+ cells stimulated with PHA. Samples of normal PBMC were cultured with PHA for 72 hours at 37°C at different concentrations of ritonavir. There was a significant dose-dependent decrease in Fas-L expression with ritonavir, although there was no change in Fas-R expression. Elaine M. Sloand et al. Blood 1999;94:1021-1027 ©1999 by American Society of Hematology