Cross-linked recombinant gp120 or HIV(+) serum sensitizes moDC for apoptosis after activation by LPS, TNF-α or IL-1β, and DC-SIGN(+) cells in HIV(+) blood are pre-sensitized for LPS/TNFα/IL-1β-induced apoptosis.

<p>(<b><i>A,B</i></b>) moDC were treated with gp120_ADA in the presence of isotype control or anti-DC-SIGN Abs and subsequently cultured in the absence or presence of 100 ng/ml LPS for 3 d. Data are representative of 5 experiments in <b><i>A</i></b> and are expressed as mean ± SD in <b><i>B</i></b>; **p<0.01, ***P<0.005. Similar findings were made after treatment with gp120_BAL or gp120_HXBc2 (not shown). (<b><i>C</i></b>) moDC were treated with anti-His cross-linked recombinant gp120_ADA (gp120-DC) or anti-His Ab alone (Control DC), and cultured for 3 d in the absence (no activation) or presence of 100 ng/ml LPS, TNF-α or IL-1β. Data represent mean ± SD from 4 experiments; **p<0.01 and ***p<0.005. (<b><i>D</i></b>) moDC were treated with normal AB serum or HIV-1(+) sera (viral RNA copies >400,000/ml; n = 4) before or after gp120 immunoprecipitation (IP), with or without pre-pretreatment with anti-CD4 plus anti-CCR5, or anti-DC-SIGN mAbs and subsequently exposed to 100 ng/ml LPS for 3 d; **P<0.01 and †P<0.001. (<b><i>E,F</i></b>) DC-SIGN(+) cells from HIV(+) and HIV(−) blood were cultured in the absence (‘No stimuli’) or presence of 100 ng/ml of LPS, TNFα, or IL-1β for 3 d prior to analysis of cell viability. Data are representative of 4 experiments in <b><i>E</i></b> and expressed as mean ± SD (n = 4) in <b><i>F</i></b>. †P<0.001 between cells from HIV(+) blood and from HIV(−) blood.