scholarly journals Detection and characterization of apoptotic peripheral blood lymphocytes in human immunodeficiency virus infection and cancer chemotherapy by a novel flow immunocytometric method

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1268-1277 ◽  
Author(s):  
M Carbonari ◽  
M Cibati ◽  
M Cherchi ◽  
D Sbarigia ◽  
AM Pesce ◽  
...  

Abstract We have developed a quantitative and sensitive flow cytometric method for the detection of human apoptotic lymphocytes that, unlike previously described assays, allows their identification in mixed populations of peripheral blood leukocytes as well as their immunophenotyping. Apoptotic lymphocytes are identified on the basis of peculiar light scatter changes, reflecting their smaller size and their modified nucleus/cytoplasm organization, and of the decreased expression of surface CD45 molecules. Based on these criteria, apoptotic lymphocytes generated by exposure to ionizing radiation can be easily distinguished from viable cells and from necrotic lymphocytes generated by treatment with antibody and complement. Using this assay, we reappraised the phenomenon of the in vitro apoptosis of lymphocytes from patients with human immunodeficiency virus (HIV) infection. Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, undergo apoptosis upon simple in vitro culture. We found that the percentages of lymphocytes undergoing apoptosis were significantly higher in patients with low CD4 cell counts (< 400/microL) than in patients at earlier stages (> 400 CD4 cells/microL). However, phenotypic analysis disclosed that apoptotic lymphocytes generated in these cultures were mostly CD8+ T cells and CD19+ B cells. Thus, in contrast to what has been previously suggested, the phenomenon of in vitro lymphocyte apoptosis might not be pathogenetically related to the depletion of CD4+ T cells in acquired immunodeficiency syndrome. Nevertheless, it might represent an useful marker of disease progression. Our assay allows the analysis of unfractionated peripheral blood leukocytes and thus the identification of apoptotic lymphocytes circulating in vivo. Apoptotic lymphocytes could indeed be detected in the circulation of a patient with cancer shortly after high-dose cytotoxic chemotherapy. By contrast, no apoptotic lymphocytes could be detected in vivo in patients with early or advanced HIV infection.

Blood ◽  
1994 ◽  
Vol 83 (5) ◽  
pp. 1268-1277 ◽  
Author(s):  
M Carbonari ◽  
M Cibati ◽  
M Cherchi ◽  
D Sbarigia ◽  
AM Pesce ◽  
...  

We have developed a quantitative and sensitive flow cytometric method for the detection of human apoptotic lymphocytes that, unlike previously described assays, allows their identification in mixed populations of peripheral blood leukocytes as well as their immunophenotyping. Apoptotic lymphocytes are identified on the basis of peculiar light scatter changes, reflecting their smaller size and their modified nucleus/cytoplasm organization, and of the decreased expression of surface CD45 molecules. Based on these criteria, apoptotic lymphocytes generated by exposure to ionizing radiation can be easily distinguished from viable cells and from necrotic lymphocytes generated by treatment with antibody and complement. Using this assay, we reappraised the phenomenon of the in vitro apoptosis of lymphocytes from patients with human immunodeficiency virus (HIV) infection. Lymphocytes from HIV patients, unlike those from normal HIV-negative subjects, undergo apoptosis upon simple in vitro culture. We found that the percentages of lymphocytes undergoing apoptosis were significantly higher in patients with low CD4 cell counts (< 400/microL) than in patients at earlier stages (> 400 CD4 cells/microL). However, phenotypic analysis disclosed that apoptotic lymphocytes generated in these cultures were mostly CD8+ T cells and CD19+ B cells. Thus, in contrast to what has been previously suggested, the phenomenon of in vitro lymphocyte apoptosis might not be pathogenetically related to the depletion of CD4+ T cells in acquired immunodeficiency syndrome. Nevertheless, it might represent an useful marker of disease progression. Our assay allows the analysis of unfractionated peripheral blood leukocytes and thus the identification of apoptotic lymphocytes circulating in vivo. Apoptotic lymphocytes could indeed be detected in the circulation of a patient with cancer shortly after high-dose cytotoxic chemotherapy. By contrast, no apoptotic lymphocytes could be detected in vivo in patients with early or advanced HIV infection.


1993 ◽  
Vol 178 (4) ◽  
pp. 1151-1163 ◽  
Author(s):  
S K Stanley ◽  
J M McCune ◽  
H Kaneshima ◽  
J S Justement ◽  
M Sullivan ◽  
...  

Infection with the human immunodeficiency virus (HIV) results in immunosuppression and depletion of circulating CD4+ T cells. Since the thymus is the primary organ in which T cells mature it is of interest to examine the effects of HIV infection in this tissue. HIV infection has been demonstrated in the thymuses of infected individuals and thymocytes have been previously demonstrated to be susceptible to HIV infection both in vivo, using the SCID-hu mouse, and in vitro. The present study sought to determine which subsets of thymocytes were infected in the SCID-hu mouse model and to evaluate HIV-related alterations in the thymic microenvironment. Using two different primary HIV isolates, infection was found in CD4+/CD8+ double positive thymocytes as well as in both the CD4+ and CD8+ single positive subsets of thymocytes. The kinetics of infection and resulting viral burden differed among the three thymocyte subsets and depended on which HIV isolate was used for infection. Thymic epithelial (TE) cells were also shown to endocytose virus and to often contain copious amounts of viral RNA in the cytoplasm by in situ hybridization, although productive infection of these cells could not be definitively shown. Furthermore, degenerating TE cells were observed even without detection of HIV in the degenerating cells. Two striking morphologic patterns of infection were seen, involving either predominantly thymocyte infection and depletion, or TE cell involvement with detectable cytoplasmic viral RNA and/or TE cell toxicity. Thus, a variety of cells in the human thymus is susceptible to HIV infection, and infection with HIV results in a marked disruption of the thymic microenvironment leading to depletion of thymocytes and degeneration of TE cells.


1996 ◽  
Vol 40 (10) ◽  
pp. 2369-2374 ◽  
Author(s):  
K Ruxrungtham ◽  
E Boone ◽  
H Ford ◽  
J S Driscoll ◽  
R T Davey ◽  
...  

A new antiretroviral agent, 2'-beta-fluoro-2',3'-dideoxyadenosine (FddA), is an acid-stable compound whose triphosphate form is a potent reverse transcriptase inhibitor with in vitro anti-human immunodeficiency virus (HIV) activity and a favorable pharmacokinetic profile. Severe combined immunodeficiency (SCID) mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID mice) provide a useful small-animal model for HIV research. In the present study we utilized this experimental system for the in vivo evaluation of the anti-HIV activity of this new compound when administered prior to infection. Initial studies revealed that, following a challenge with 50 100% tissue culture infective doses of HIV type 1 lymphadenopathy-associated virus, 39 of 42 (93%) control mice developed HIV infection, as evidenced by positive coculture or positive PCR. Administration of zidovudine decreased the infection rate to 5 of 16 (31%), while administration of FddA decreased the infection rate to 0 of 44 (0%). In follow-up controlled studies, the anti-HIV activity of FddA was confirmed, with 18 of 20 control mice showing evidence of HIV infection, compared with 4 of 20 FddA-treated mice. In addition to having direct anti-HIV effects, FddA was found to have a protective effect on human CD4+ T cells in the face of HIV infection. Mice treated with FddA were found to have a significantly higher percentage of CD4+ T cells than controls (10.3% +/- 3.4% versus 0.27% +/- 0.21%; P = 0.01). Thus, FddA, with its potent anti-HIV activity in vivo, high oral bioavailability, long intracellular half-life, and ability to preserve CD4+ cells in the presence of HIV, appears to be a promising agent for clinical investigation.


2006 ◽  
Vol 80 (16) ◽  
pp. 8236-8247 ◽  
Author(s):  
Moraima Guadalupe ◽  
Sumathi Sankaran ◽  
Michael D. George ◽  
Elizabeth Reay ◽  
David Verhoeven ◽  
...  

ABSTRACT Although the gut-associated lymphoid tissue (GALT) is an important early site for human immunodeficiency virus (HIV) replication and severe CD4+ T-cell depletion, our understanding is limited about the restoration of the gut mucosal immune system during highly active antiretroviral therapy (HAART). We evaluated the kinetics of viral suppression, CD4+ T-cell restoration, gene expression, and HIV-specific CD8+ T-cell responses in longitudinal gastrointestinal biopsy and peripheral blood samples from patients initiating HAART during primary HIV infection (PHI) or chronic HIV infection (CHI) using flow cytometry, real-time PCR, and DNA microarray analysis. Viral suppression was more effective in GALT of PHI patients than CHI patients during HAART. Mucosal CD4+ T-cell restoration was delayed compared to peripheral blood and independent of the time of HAART initiation. Immunophenotypic analysis showed that repopulating mucosal CD4+ T cells were predominantly of a memory phenotype and expressed CD11α, αEβ7, CCR5, and CXCR4. Incomplete suppression of viral replication in GALT during HAART correlated with increased HIV-specific CD8+ T-cell responses. DNA microarray analysis revealed that genes involved in inflammation and cell activation were up regulated in patients who did not replenish mucosal CD4+ T cells efficiently, while expression of genes involved in growth and repair was increased in patients with efficient mucosal CD4+ T-cell restoration. Our findings suggest that the discordance in CD4+ T-cell restoration between GALT and peripheral blood during therapy can be attributed to the incomplete viral suppression and increased immune activation and inflammation that may prevent restoration of CD4+ T cells and the gut microenvironment.


1994 ◽  
Vol 179 (2) ◽  
pp. 513-522 ◽  
Author(s):  
T R Kollmann ◽  
M Pettoello-Mantovani ◽  
X Zhuang ◽  
A Kim ◽  
M Hachamovitch ◽  
...  

A small animal model that could be infected with human immunodeficiency virus 1 (HIV-1) after peripheral inoculation would greatly facilitate the study of the pathophysiology of acute HIV-1 infection. The utility of SCID mice implanted with human fetal thymus and liver (SCID-hu mice) for studying peripheral HIV-1 infection in vivo has been hampered by the requirement for direct intraimplant injection of HIV-1 and the continued restriction of the resultant HIV-1 infection to the human thymus and liver (hu-thy/liv) implant. This may have been due to the very low numbers of human T cells present in the SCID-hu mouse peripheral lymphoid compartment. Since the degree of the peripheral reconstitution of SCID-hu mice with human T cells may be a function of the hu-thy/liv implant size, we increased the quantity of hu-thy/liv tissue implanted under the renal capsule and implanted hu-thy/liv tissue under the capsules of both kidneys. This resulted in SCID-hu mice in which significant numbers of human T cells were detected in the peripheral blood, spleens, and lymph nodes. After intraimplant injection of HIV-1 into these modified SCID-hu mice, significant HIV-1 infection was detected by quantitative coculture not only in the hu-thy/liv implant, but also in the spleen and peripheral blood. This indicated that HIV-1 infection can spread from the thymus to the peripheral lymphoid compartment. More importantly, a similar degree of infection of the hu-thy/liv implant and peripheral lymphoid compartment occurred after peripheral intraperitoneal inoculation with HIV-1. Active viral replication was indicated by the detection of HIV-1 gag DNA, HIV-1 gag RNA, and spliced tat/rev RNA in the hu-thy/liv implants, peripheral blood mononuclear cells (PBMC), spleens, and lymph nodes of these HIV-1-infected SCID-hu mice. As a first step in using our modified SCID-hu mouse model to investigate the pathophysiological consequences of HIV-1 infection, the effect of HIV-1 infection on the expression of human cytokines shown to enhance HIV-1 replication was examined. Significantly more of the HIV-1-infected SCID-hu mice expressed mRNA for human tumor necrosis factors alpha and beta, and interleukin 2 in their spleens, lymph nodes, and PBMC than did uninfected SCID-hu mice. This suggested that HIV-1 infection in vivo can stimulate the expression of cytokine mRNA by human T cells.(ABSTRACT TRUNCATED AT 400 WORDS)


1993 ◽  
Vol 13 (3) ◽  
pp. 193-203 ◽  
Author(s):  
Danuta Kozbor ◽  
Elizabeth Hyjek ◽  
Richard Wiaderkiewicz ◽  
Grzegorz Kurzawski ◽  
Harold W. Lischner

2003 ◽  
Vol 10 (5) ◽  
pp. 757-763 ◽  
Author(s):  
Michael A. Kolber ◽  
Maria O. Saenz

ABSTRACT The accurate determination of human immunodeficiency virus type 1 (HIV-1)-specific proliferative responses is critically important when evaluating immune recovery after highly active antiretroviral therapy. Using a new assay to enhance proliferative responses to recall and HIV antigen, we addressed the questions of whether viral load affects cellular immunity and whether long-term viral load suppression results in loss of antigen-specific responder cells. This assay is based on the fact that lipopolysaccharide (LPS) can augment proliferative responses to antigen after monocyte adherence to a tissue culture plate. Twenty-six HIV-1-infected individuals donated peripheral blood leukocytes (PBL). Proliferation assays against p24, using LPS and cell adherence, were performed on all samples. Medical record abstraction provided information on CD4 cell nadir and time of viral load suppression. PBL from HIV-1-infected individuals with a viral load of <200 copies/ml had a significant proliferative response and a stimulation index of >5 to p24 (12 of 15) compared to those with a viral burden (2 of 11), using the LPS-adherence assay. Proliferative responses to p24 could be found in PBL from virally suppressed donors independent of the CD4 cell nadirs and in the majority of the donors who were virally suppressed for >10 months (7 of 10). The data presented here demonstrate that LPS and monocyte adherence provide a sensitive and specific way to boost proliferative responses to recall and HIV antigens.


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