B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement

A. Amadori, R. Zamarchi, M. L. Veronese, M. Panozzo, A. Barelli, A. Borri, M. Sironi, F. Colotta, A. Mantovani, L. Chieco-Bianchi

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This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6,but not other cytokines,to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

Original languageEnglish
Pages (from-to)57-62
Number of pages6
JournalJournal of Immunology
Issue number1
Publication statusPublished - 1991

ASJC Scopus subject areas

  • Immunology


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