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DC-HIL-expressing myelomonocytic cells are critical promoters of melanoma growth.

Chung JS, Tamura K, Cruz PD, Ariizumi K - J. Invest. Dermatol. (2014)

Bottom Line: Deletion of the DC-HIL gene or infusion of anti-DC-HIL mAb abrogated these cells' suppressor function and expansion, and markedly diminished melanoma growth and metastasis.IL-1β and IFN-γ were elevated in mice bearing melanoma, and concurrent exposure to both cytokines optimally induced DC-HIL expression by tumor-infiltrating CD11b(+)Gr1(+) cells.Ligation of DC-HIL transduced phosphorylation of its intracellular immunoreceptor tyrosine-based activation motif, which in turn induced intracellular expression of IFN-γ and inducible nitric oxide synthase (iNOS), known to mediate T-cell suppression by CD11b(+)Gr1(+) cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, The University of Texas Southwestern Medical Center and Dermatology Section (Medical Service), Dallas Veterans Affairs Medical Center, Dallas, Texas, USA.

ABSTRACT
A major barrier to successful cancer immunotherapy is the tumor's ability to induce T-cell tolerance by exploiting host regulatory mechanisms. Having discovered the DC-HIL receptor, which inhibits T-cell responses by binding to syndecan-4 on effector T cells, we posited the DC-HIL/syndecan-4 pathway to have an important role in cancer promotion. Among DC-HIL(+) myelomonocytic cells, during growth of implanted mouse melanoma, CD11b(+)Gr1(+) cells were the most expanded population and the most potent at suppressing T-cell activation. Deletion of the DC-HIL gene or infusion of anti-DC-HIL mAb abrogated these cells' suppressor function and expansion, and markedly diminished melanoma growth and metastasis. IL-1β and IFN-γ were elevated in mice bearing melanoma, and concurrent exposure to both cytokines optimally induced DC-HIL expression by tumor-infiltrating CD11b(+)Gr1(+) cells. Ligation of DC-HIL transduced phosphorylation of its intracellular immunoreceptor tyrosine-based activation motif, which in turn induced intracellular expression of IFN-γ and inducible nitric oxide synthase (iNOS), known to mediate T-cell suppression by CD11b(+)Gr1(+) cells. Thus, DC-HIL is the critical mediator of these cells' suppressor function in melanoma-bearing mice and a potential target for improving melanoma immunotherapy.

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Crosslinked DC-HIL on CD11b+Gr1+ cells induces tyrosine phosphorylation and IFN-γ/iNOS expression(a-c) CD11b+Gr1+ (CGr1) cells cocultured with pmel-1 splenocytes (1:1 ratio) with inhibitors; including (a) anti-cytokine Ab; (b) 5 mM L-NG-monomethyl-arginine citrate (NOSs); 0.5 mM N6-(1-iminoethyl)-L-lysine (NOS-2); 1 mM N-hydroxyl-nor-arginine (Arg); 0.2 mM 1-methyl-tryptophan (Indol); 1000 U/ml catalase (C-ROS); and 200 U/ml superoxide dismutase (S-ROS); and (c) anti-DC-HIL mAb or DC-HIL-Fc. 3H-TdR uptake was measured. (d) CGr1 cells cocultured with SD-4+/+ or SD-4−/− pmel-1 splenocytes. (e-i) At varying times after crosslinking with Ab, CGr1 cells were assayed for: tyrosine-phosphorylation (p-Tyr) on DC-HIL protein (e); cytokine mRNA and secretion (f, g); mRNA of NOS genes (h); or NO production (i). Data (mean ± sd, n=3) are shown as fold increase relative to control. *p<0.01.
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Figure 4: Crosslinked DC-HIL on CD11b+Gr1+ cells induces tyrosine phosphorylation and IFN-γ/iNOS expression(a-c) CD11b+Gr1+ (CGr1) cells cocultured with pmel-1 splenocytes (1:1 ratio) with inhibitors; including (a) anti-cytokine Ab; (b) 5 mM L-NG-monomethyl-arginine citrate (NOSs); 0.5 mM N6-(1-iminoethyl)-L-lysine (NOS-2); 1 mM N-hydroxyl-nor-arginine (Arg); 0.2 mM 1-methyl-tryptophan (Indol); 1000 U/ml catalase (C-ROS); and 200 U/ml superoxide dismutase (S-ROS); and (c) anti-DC-HIL mAb or DC-HIL-Fc. 3H-TdR uptake was measured. (d) CGr1 cells cocultured with SD-4+/+ or SD-4−/− pmel-1 splenocytes. (e-i) At varying times after crosslinking with Ab, CGr1 cells were assayed for: tyrosine-phosphorylation (p-Tyr) on DC-HIL protein (e); cytokine mRNA and secretion (f, g); mRNA of NOS genes (h); or NO production (i). Data (mean ± sd, n=3) are shown as fold increase relative to control. *p<0.01.

Mentions: We addressed the contribution of soluble factors to T-cell suppression by adding specific inhibitors to cocultures of pmel-1 splenocytes and CD11b+Gr1+ cells. Neutralizing Ab to TGF-β (Filipazzi et al., 2007) or IL-10 (Wang et al., 2010) had no effect on suppressor activity, whereas anti-IFN-γ Ab blocked suppression completely (Figure 4a). Chemical inhibitors for arginase and indoleamine restored T-cell activation marginally; and catalase and superoxide dismutase for neutralizing ROS had no effect (Figure 4b). By contrast, inhibitors of all NOS molecules or specific to NOS-2 blocked suppressor function substantially or completely. Thus IFN-γ and NOS-2 independently mediated suppressor activity of CD11b+Gr1+ cells induced by melanoma.


DC-HIL-expressing myelomonocytic cells are critical promoters of melanoma growth.

Chung JS, Tamura K, Cruz PD, Ariizumi K - J. Invest. Dermatol. (2014)

Crosslinked DC-HIL on CD11b+Gr1+ cells induces tyrosine phosphorylation and IFN-γ/iNOS expression(a-c) CD11b+Gr1+ (CGr1) cells cocultured with pmel-1 splenocytes (1:1 ratio) with inhibitors; including (a) anti-cytokine Ab; (b) 5 mM L-NG-monomethyl-arginine citrate (NOSs); 0.5 mM N6-(1-iminoethyl)-L-lysine (NOS-2); 1 mM N-hydroxyl-nor-arginine (Arg); 0.2 mM 1-methyl-tryptophan (Indol); 1000 U/ml catalase (C-ROS); and 200 U/ml superoxide dismutase (S-ROS); and (c) anti-DC-HIL mAb or DC-HIL-Fc. 3H-TdR uptake was measured. (d) CGr1 cells cocultured with SD-4+/+ or SD-4−/− pmel-1 splenocytes. (e-i) At varying times after crosslinking with Ab, CGr1 cells were assayed for: tyrosine-phosphorylation (p-Tyr) on DC-HIL protein (e); cytokine mRNA and secretion (f, g); mRNA of NOS genes (h); or NO production (i). Data (mean ± sd, n=3) are shown as fold increase relative to control. *p<0.01.
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Figure 4: Crosslinked DC-HIL on CD11b+Gr1+ cells induces tyrosine phosphorylation and IFN-γ/iNOS expression(a-c) CD11b+Gr1+ (CGr1) cells cocultured with pmel-1 splenocytes (1:1 ratio) with inhibitors; including (a) anti-cytokine Ab; (b) 5 mM L-NG-monomethyl-arginine citrate (NOSs); 0.5 mM N6-(1-iminoethyl)-L-lysine (NOS-2); 1 mM N-hydroxyl-nor-arginine (Arg); 0.2 mM 1-methyl-tryptophan (Indol); 1000 U/ml catalase (C-ROS); and 200 U/ml superoxide dismutase (S-ROS); and (c) anti-DC-HIL mAb or DC-HIL-Fc. 3H-TdR uptake was measured. (d) CGr1 cells cocultured with SD-4+/+ or SD-4−/− pmel-1 splenocytes. (e-i) At varying times after crosslinking with Ab, CGr1 cells were assayed for: tyrosine-phosphorylation (p-Tyr) on DC-HIL protein (e); cytokine mRNA and secretion (f, g); mRNA of NOS genes (h); or NO production (i). Data (mean ± sd, n=3) are shown as fold increase relative to control. *p<0.01.
Mentions: We addressed the contribution of soluble factors to T-cell suppression by adding specific inhibitors to cocultures of pmel-1 splenocytes and CD11b+Gr1+ cells. Neutralizing Ab to TGF-β (Filipazzi et al., 2007) or IL-10 (Wang et al., 2010) had no effect on suppressor activity, whereas anti-IFN-γ Ab blocked suppression completely (Figure 4a). Chemical inhibitors for arginase and indoleamine restored T-cell activation marginally; and catalase and superoxide dismutase for neutralizing ROS had no effect (Figure 4b). By contrast, inhibitors of all NOS molecules or specific to NOS-2 blocked suppressor function substantially or completely. Thus IFN-γ and NOS-2 independently mediated suppressor activity of CD11b+Gr1+ cells induced by melanoma.

Bottom Line: Deletion of the DC-HIL gene or infusion of anti-DC-HIL mAb abrogated these cells' suppressor function and expansion, and markedly diminished melanoma growth and metastasis.IL-1β and IFN-γ were elevated in mice bearing melanoma, and concurrent exposure to both cytokines optimally induced DC-HIL expression by tumor-infiltrating CD11b(+)Gr1(+) cells.Ligation of DC-HIL transduced phosphorylation of its intracellular immunoreceptor tyrosine-based activation motif, which in turn induced intracellular expression of IFN-γ and inducible nitric oxide synthase (iNOS), known to mediate T-cell suppression by CD11b(+)Gr1(+) cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Dermatology, The University of Texas Southwestern Medical Center and Dermatology Section (Medical Service), Dallas Veterans Affairs Medical Center, Dallas, Texas, USA.

ABSTRACT
A major barrier to successful cancer immunotherapy is the tumor's ability to induce T-cell tolerance by exploiting host regulatory mechanisms. Having discovered the DC-HIL receptor, which inhibits T-cell responses by binding to syndecan-4 on effector T cells, we posited the DC-HIL/syndecan-4 pathway to have an important role in cancer promotion. Among DC-HIL(+) myelomonocytic cells, during growth of implanted mouse melanoma, CD11b(+)Gr1(+) cells were the most expanded population and the most potent at suppressing T-cell activation. Deletion of the DC-HIL gene or infusion of anti-DC-HIL mAb abrogated these cells' suppressor function and expansion, and markedly diminished melanoma growth and metastasis. IL-1β and IFN-γ were elevated in mice bearing melanoma, and concurrent exposure to both cytokines optimally induced DC-HIL expression by tumor-infiltrating CD11b(+)Gr1(+) cells. Ligation of DC-HIL transduced phosphorylation of its intracellular immunoreceptor tyrosine-based activation motif, which in turn induced intracellular expression of IFN-γ and inducible nitric oxide synthase (iNOS), known to mediate T-cell suppression by CD11b(+)Gr1(+) cells. Thus, DC-HIL is the critical mediator of these cells' suppressor function in melanoma-bearing mice and a potential target for improving melanoma immunotherapy.

Show MeSH
Related in: MedlinePlus