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Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays
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Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays

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Circulating immune complexes from HIV-1+ patients induces apoptosis on normal lymphocytes

E Aceituno1, S Castañón, C Jiménez

  • 1Department of Immunology, Fundación Jiménez Díaz, Madrid, Spain.

Immunology
|March 5, 1998
PubMed

Insights

Immune complexes in human immunodeficiency virus-1 (HIV-1) patients can trigger apoptosis, programmed cell death, in CD4+ lymphocytes. This finding suggests a mechanism by which HIV-1 infection may deplete crucial immune cells, particularly in asymptomatic individuals.

Area of Science:

  • Immunology
  • Virology
  • Cell Biology

Background:

  • Immune complexes (ICs) are implicated in various autoimmune and infectious diseases.
  • Human immunodeficiency virus-1 (HIV-1) infection leads to progressive depletion of CD4+ T lymphocytes, a hallmark of AIDS.
  • The precise mechanisms driving CD4+ T cell loss in HIV-1 infection are not fully understood.

Purpose of the Study:

  • To investigate the potential of immune complexes from HIV-1-positive patients to induce apoptosis in normal lymphocytes.
  • To identify the specific lymphocyte subset targeted by these immune complexes.
  • To explore the role of Fas antigen expression in the observed apoptotic process.

Main Methods:

  • Isolation of immune complexes (CICs) from the sera of HIV-1-positive patients.
  • Induction of apoptosis in phytohemagglutinin (PHA)-activated lymphocytes.
  • Detection of DNA degradation using propidium iodide staining.
  • Assessment of CD4+ lymphocyte targeting via double binding assays with anti-CD4 antibodies.
  • Evaluation of Fas antigen expression on apoptotic cells.

Main Results:

  • Immune complexes from 49 out of 67 HIV-1-positive patients induced apoptosis in PHA-activated lymphocytes.
  • The apoptosis-inducing activity was specifically directed against CD4+ lymphocytes.
  • Fas antigen expression preceded the apoptotic events.
  • The apoptosis inducers were predominantly found in asymptomatic HIV-infected patients.

Conclusions:

  • Immune complexes in HIV-1-positive individuals can directly induce apoptosis in CD4+ lymphocytes.
  • This mechanism may contribute to the depletion of CD4+ T cells during HIV-1 infection, even in the asymptomatic stage.
  • Targeting of CD4+ lymphocytes by HIV-1 immune complexes highlights a potential pathway for immune system dysfunction.

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