B-cell activation during HIV-1 infection. III. Down-regulating effect of mitogens

Alberto Amadori, Rita Zamarchi, Maria L. Veronese, Marina Panozzo, Maria Rosaria Mazza, Andrea Barelli, Alfredo Borri, Luigi Chieco-Bianchi

Research output: Contribution to journalArticlepeer-review


Spontaneous in vitro production of HIV-1-specific antibodies, a hallmark of infected subjects, is often down-regulated by the addition of pokeweed mitogen. We observed that a decrease in such ongoing anti-HIV-1 antibody synthesis could also be induced in cultures from most patients by addition of phytohemagglutinin and Concanavalin A, but not by Epstein-Barr virus, a selective B-cell mitogen. In most cases, this down-regulatory effect of mitogens was evident within the first 24 h of culture. The observed mitogen-associated decrease in spontaneous antibody synthesis was prevented by treating peripheral blood mononuclear cells with agents inhibiting non-major histocompatibility complex-restricted cytotoxic activity or by adding third-party cells to the cultures. In most cases, the mitogen-induced effect was also counteracted by removal of T lymphocytes or CD8+ T-cell sub-population. These findings recall a similar phenomenon observed in normal subjects following intentional immunization, and indicate that mitogen-induced down-regulation of spontaneous in vitro anti-HIV-1-antibody production most probably occurs through a lectin-dependent cytotoxic effect on activated B cells.

Original languageEnglish
Pages (from-to)821-828
Number of pages8
JournalAIDS (London, England)
Issue number7
Publication statusPublished - Jul 1991


  • AIDS
  • Anti-HIV-1 antibody
  • HIV-1
  • Lectin-dependent cytotoxicity
  • Mitogens
  • Pokeweed mitogen

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy

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