AIDS. 1998 Aug 20;12(12):1437-49. Unique Identifier : AIDSLINE
OBJECTIVE: This study was performed to investigate the hyporeactivity of
purified B lymphocytes from HIV-1-infected patients. DESIGN: Given the
importance of the B-cell Ag receptor (BCR) and CD40 in B-lymphocyte
activation, we assessed the capacity of purified peripheral blood B
lymphocytes from HIV-1-infected patients to differentiate into
Ig-secreting cells in a T-cell- and accessory-cell-independent system of
BCR and CD40 costimulation. METHODS: B lymphocytes from 21
HIV-1-infected patients were purified by immunomagnetic cell separation
and costimulated with immobilized anti-CD40 monoclonal antibodies and
Staphylococcus aureus Cowan I particles in the presence of interleukin
(IL)-2 and IL-10. Homotypic aggregate formation, apoptosis, cell cycle
entrance, proliferation and Ig secretion of B cells were analysed.
RESULTS: Costimulation by the BCR and CD40 induced proliferation and
differentiation of B lymphocytes into Ig-secreting cells in 13 patients
(group I) but not in eight patients (group II). For three patients in
group II, the dual triggering induced apoptosis of B cells. The
unexpected inability of these cells to differentiate was associated with
a high CD38 expression and a weak spontaneous production of Ig or
anti-HIV-1 antibodies in patients with a high viral load and a low CD4+
lymphocyte count. Despite this anomaly, the B cells from group II were
able to progress through the cell cycle after stimulation with a
combination of phorbol ester and ionomycin in complete medium,
suggesting an impairment in BCR and CD40 early signal transduction.
CONCLUSION: Intrinsic in vitro hyporeactivity of B lymphocytes to dual
triggering of BCR and CD40 was observed in advanced HIV-1 disease and
appeared to be related to in vivo hyperactivation of B cells.
JOURNAL ARTICLE Adult Antibodies, Monoclonal Antigens,
CD40/*IMMUNOLOGY Apoptosis B-Lymphocytes/*IMMUNOLOGY Cell Cycle Cell
Differentiation Enzyme-Linked Immunosorbent Assay Female Human HIV
Antibodies/BLOOD HIV Infections/*IMMUNOLOGY *HIV-1 IgG/BLOOD
Immunomagnetic Separation Lymphocyte Transformation Male Middle Age
Receptors, Antigen, B-Cell/*IMMUNOLOGY Support, Non-U.S. Gov't Viral
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