A20-silenced Mф immunization enhances NK cell-, CD8⁺ T cell- and CD4⁺ T cell-mediated cytotoxicity.

<p>Splenocytes pooled from 2–3 immunized mice were cultured overnight for NK-mediated cytotoxicity assay or 5–6 days in the presence of OT-I or OT-II peptide for T cells-mediated cytotoxicity assay. The splenocytes cultured with OT-II peptide were selected using anti-CD4 beads prior to cytotoxicity assay. Cytotoxic activities were analyzed by LDH release assay as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048930#s4" target="_blank">Material and Methods</a>. Experiments were repeated three times with similar results. *p<0.05, Ad-shA20-Mф immunization vs. Ad-con-Mф immunization for specific killing.</p

A20-silenced Mф elicits a cytotoxic CD4⁺ T cell response via activation of IFN-γ signaling and by an MHC-class-II-restricted mechanism.

<p>A. Adenoviral-transduced BMMфs were used to immunize IFNGR^−/− mice or the wildtype littermates (2–3 mice/group) twice. The inguinal LNs were harvested for analyzing expression of granzyme B in CD4⁺ or CD8⁺ T cells by ICS. p<0.01 Ad-shA20-IFNGR KO mice vs. Ad-ShA20 WT mice. B. Adenoviral-transduced BMMфs were used to immunize Stat1^−/− mice or the wild-type littermates twice (2–3 mice/group). The LNs were harvested for analyzing expression of granzyme B in CD4⁺ (p<0.05, Ad-shA20-Stat1 KO mice vs. Ad-shA20-WT mice) or CD8⁺ T cells by ICS. C. BMMфs were prepared from MHCII^−/− mice or the wild-type littermates. The adenoviral-transduced BMMфs were used to immunize wild-type mice (2–3 mice/group) twice. The LNs were harvested for analyzing expression of granzyme B in CD4⁺ (p<0.01, Ad-shA20-MHC-II KO Mф immunization vs. Ad-shA20-WT Mф immunization) or CD8⁺ T cells by ICS. Experiments were repeated with similar results.</p

A20-silenced Mф enhances expression of granzyme B in CD4⁺ T cells, CD8⁺T cells or NK cells.

<p><b>A,</b> adenoviral-transduced BMMфs were cocultured with freshly isolated OT-I (<b>uppe</b>r) or OT-II cells (<b>lower</b>) at a raito of 1∶10. 3–5 days later, the cocultured T cells were harvested for analyzing expression of granzyme B by ICS. The data is shown as a representative of 3 independent experiments. (p<0.05, OT-I/shA20-Mф vs. OT-I/con- Mф; p<0.01, OT-II/shA20-Mф vs. OT-II/con-Mф). <b>B,</b> C57BL/6 mice (5–6 mice/group) were immunized (<i>i.p</i>) twice with different adenoviral-transduced Mфs or PBS. Lymphocytes were isolated from the inguinal LNs to analyze expression of granzyme B in NK cells, CD8<b>⁺</b> or CD4<b>⁺</b> T cells by ICS. <b>C.</b> C57BL/6 mice were immunized (<i>i.p</i>) twice with OT-II-pulsed, different adenoviral-transduced BMMфs or PBS. Splenocytes were harvested and in vitro restimulated with OT-II peptide for 48 hrs. CD4⁺ T cells were isolated for analysis of granzyme B expression by qPCR. The data is shown as a representation of three independent experiments. (* p<0.01, shA20- Mф-mice vs. con- Mф-mice).</p

A20-silenced Mф immunization induces enhanced immune protection.

<p><b>A & B.</b> C57BL/6 mice (5–6 mice/group) were immunized twice. The mice were s.c. injected with 5×10⁵ EG-7 (<b>A</b>) or M05 (<b>B</b>). Tumor growth was monitored on the indicated days. * p<0.05, Ad-shA20-Mф immunization vs. Ad-con-Mф immunization. <b>C</b>. CD4^−/− C57BL/6 or the wildtype littermates (5–6 mice/group) were immunized with OT-II-peptide-pulsed, Ad-shA20-transduced BMMфs twice followed by s.c. injection of 5×10⁵ M05 tumor cells. Tumor occurrence and growth were monitored on the indicated days. **p<0.01, wild-type mice vs. CD4^−/− mice. <b>D</b>. Transferred OT-II-specific immune pretection. In vitro primed OT-II T cells (5×10⁶) were transplanted into naïve RAG^−/−C57BL/6 mice (5 mice/group) by retro-orbital injection following s.c injection of OVA-expressed B6SJ1003 tumor cells (6×10⁵). The transplantation of OT-II T cells was repeated one week later. One group of mice were transplanted with CMA-treated, Ad-shA20-transduced Mф-primed OT-II T cells. Tumor growth was monitored on the indicated days. *p<0.05, Ad-shA20-Mф-primed OT-II T cell transfer vs. Ad-con-Mф-primed OT-II T cell transfer, or Ad-shA20-Mф-primed OT-II T cell transfer vs. Ad-shA20-Mф-primed OT-II T cell+ CMT transfer. All the experiments were repeated with similar results.</p

Neutralization of IFN-γ reduces A20-silenced MФ to prime cytotoxic T cell response <i>in vitro.</i>

<p>BMMфs were transduced with Ad-shA20 and cocultured with CD4⁺ OT-II (<b>A</b>) or CD8⁺ OT-I (<b>B</b>) T cells in the presence of the different doses of anti-IL-6, anti-IL-12 or anti-IFN-γ (2.5 ug/ml, 10 ug/ml, or 20 ug/ml ) for 3–5 days. Expression of granzyme B in T cells was assessed by ICS assay. The data is a representative of three independent experiments. p<0.01, OT-II/AdshA20-Mф vs. OT-II/AdshA20-Mф+anti-IFN-γ(20 ug/ml).</p

IFN-γ impacts MФ to trigger cytotoxic T cell responses in immunized mice.

<p>C57BL/6 mice (2–3 mice per group) were immunized twice with 1, PBS plus IgG; 2, PBS plus IFN-γ; 3, Ad-con-Mф; 4, Ad-con-Mф plus IFN-γ; 5, Ad-shA20-Mф plus IgG; or 6, Ad-shA20-Mф plus anti-IFN-γ. Two weeks after the 2^nd immunization, inguinal lymph nodes were harvested to analyze expression of granzyme B in CD4⁺ T cells (<b>A</b>) (p<0.05, shA20-Mф+ anti-IFN-γ immunization vs. shA20-Mф+IgG immunization; p<0.01, con-Mф+ IFN-γ immunization vs. con-Mф immunization) or CD8⁺ T cells (<b>B</b>) (p<0.01, shA20-Mф+ anti-IFN-γ immunization vs. shA20-Mф+IgG immunization; p<0.05, con-Mф+ IFN-γ immunization vs. con-Mф immunization) by ICS assay.</p

shS1/FliC-expressing DC immunization induces more potent HCV E2-specific T cell immune responses in mice.

<p>Murine BMDCs were transduced with the recombinant Ad vectors followed by pulse with recombinant HCV-E2 protein (20 µg/ml) for overnight, or pulsed with HCV-E2 for 6 hr prior to addition with LPS (100 ng/ml) and then cultured for overnight. Groups of C57BL/6 mice (6 mice/group) were immunized via footpads with the transduced or LPS-stimulated DCs (1×10⁶ cells per mouse) twice. 2 weeks after the 2^nd immunization, splenocytes were isolated for activation marker CD69 staining (<b>A</b>), and intracellular IFN-γ staining (<b>B</b>). Data are representative of three repeated experiments.</p

Enhanced gp120-Specific Antibody and T Cell Responses Induced by SOCS1-Silenced DCs

<p>Groups of C57BL/6 mice were immunized with gp120 (SF162) protein-pulsed, transduced BM-derived DCs (1 × 10⁶ cells/mouse) twice at a weekly interval, followed by PolyI:C or R837 stimulation (30 μg/mouse) in vivo three times on days 1, 3, and 5 after each DC immunization, and sera and splenocytes were collected from each group of mice 14 d later. HIV gp120-specific IgG subclass titers (A) from the pooled sera of each group (4–6 mice/group) were quantified by capture ELISA. CD8⁺ T cells (B) and CD4⁺ T cells (C) isolated from pooled splenocytes were used for IFN-γ ELISPOT assays stimulated with gp120 proteins. Intracellular IFN-γ staining of CD8⁺ T cells from the pooled splenocytes were also performed (D). Representative data from one of three experiments are presented. NS, no stimulation. *<i>P</i> < 0.01, LV-SOCS1-siRNA-DCs versus LV-GFP-siRNA-DCs.</p

The expression of shS1/FliC enhances the acetylation of histone H3 at Lys9/14 and binding of transcription factor sp1 to the promoter of TNF-α in DCs.

<p>Murine BMDCs were transduced with the recombinant Ad vectors or stimulated with LPS (100 ng/ml). 24 h later, cultures were washed and replaced with fresh medium that contains LPS or not (for Ad-transduced DCs) for 72 hr. The cells were fixed with formaldehyde and a ChIP assay was performed using anti-acetyl histone H3 (Lys9/14) antibody (<b>A</b>) or anti-sp1 antibody (<b>B</b>). The precipitated DNA was amplified by real-time PCR using a pair of TNF-α promoter primers. The results were normalized to the input DNA and expressed as a ratio of Ad-shS1/FliC DC or LPS-stimulated DC to Ad-shGFP DC. *<i>p</i><0.01.</p

Resistance of SOCS1-Silenced DCs to HIV gp120-Mediated Suppression

<div><p>(A) Effects of gp120 on cytokine production by DCs. BM-DCs were transfected with SOCS1-siRNA or a SOCS1-siRNA mutant oligonucleotide as described previously [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030011#pmed-0030011-b024" target="_blank">24</a>], and then cultured with or without SF162 gp120 (20 μg/ml) or LPS (100 ng/ml), and cytokine levels were determined at the different times of cultures, as indicated.</p> <p>(B–E) Effects of gp120 on DC antigen presentation in vivo. Transfected BM-DCs were pulsed with OVA, incubated with or without gp120 for 2 d, and then stimulated with LPS (100 ng/ml) ex vivo overnight. Mice were then immunized with the transduced DCs twice, following three in vivo LPS stimulations. OVA-specific antibody IgG (B) and IgG1 (C) titers and frequencies of IFN-γ-producing OVA-specific CD8⁺ T cells (D) and CD4⁺ T cells (E) were examined 2 wk after the second DC immunization. Data are representative of two repeats.</p></div