Limits...
The vitronectin receptor and its associated CD47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble CD23.

Hermann P, Armant M, Brown E, Rubio M, Ishihara H, Ulrich D, Caspary RG, Lindberg FP, Armitage R, Maliszewski C, Delespesse G, Sarfati M - J. Cell Biol. (1999)

Bottom Line: Surprisingly, anti-CD47 and beta3 mAbs do not block sCD23 binding to alphav+beta3+ T cell lines, whereas Vn and an alphav mAb (clone AMF7) do inhibit sCD23 binding, suggesting the VnR complex may be a functional receptor for sCD23. sCD23 directly binds alphav+beta3+/CD47(-) cell lines, but coexpression of CD47 increases binding.Moreover, sCD23 binds purified alphav protein and a single human alphav chain CHO transfectant.We conclude that the VnR and its associated CD47 molecule may function as a novel receptor for sCD23 to mediate its proinflammatory activity and, as such, may be involved in the inflammatory process of the immune response.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Allergie, Centre de recherch¿e Louis-Charles Simard, Pavillon Notre-Dame, Centre Hospitalier Université de Montréal (CHUM), Montreal, Quebec H2L 4M1, Canada.

ABSTRACT
The vitronectin receptor, alphavbeta3 integrin, plays an important role in tumor cell invasion, angiogenesis, and phagocytosis of apoptotic cells. CD47, a member of the multispan transmembrane receptor family, physically and functionally associates with vitronectin receptor (VnR). Although vitronectin (Vn) is not a ligand of CD47, anti-CD47 and beta3 mAbs suppress Vn, but not fibronectin (Fn) binding and function. Here, we show that anti-CD47, anti-beta3 mAb and Vn, but not Fn, inhibit sCD23-mediated proinflammatory function (TNF-alpha, IL-12, and IFN-gamma release). Surprisingly, anti-CD47 and beta3 mAbs do not block sCD23 binding to alphav+beta3+ T cell lines, whereas Vn and an alphav mAb (clone AMF7) do inhibit sCD23 binding, suggesting the VnR complex may be a functional receptor for sCD23. sCD23 directly binds alphav+beta3+/CD47(-) cell lines, but coexpression of CD47 increases binding. Moreover, sCD23 binds purified alphav protein and a single human alphav chain CHO transfectant. We conclude that the VnR and its associated CD47 molecule may function as a novel receptor for sCD23 to mediate its proinflammatory activity and, as such, may be involved in the inflammatory process of the immune response.

Show MeSH

Related in: MedlinePlus

Clone 10G2 neutralizes sCD23 biological activities and  recognizes CD47 Ag. (A) Inhibition of sCD23 costimulation of  IFN-γ production in T cell/monocyte cocultures by anti-CD47  mAbs (clones 10G2, B6H12, C1Km1, and BRIC126). Mean ±  SD for 10G2 P < 0.03 (ten experiments) and for other mAbs P <  0.001 (five independent experiments). (B) 10G2 mAb staining of  untransfected (COS, dotted line) or CD47-transfected COS cell  line (COS-47, bold line). Control mAb staining of both cell lines:  (COS, thin line; COS-47, dashed line). (C) Fluorescence staining  of Jurkat T cell line (left) and THP-1 monocyte cell line (right)  by increasing concentrations of anti-CD47 mAbs (clones 10G2  and B6H12). One representative experiment out of three.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2132927&req=5

Figure 1: Clone 10G2 neutralizes sCD23 biological activities and recognizes CD47 Ag. (A) Inhibition of sCD23 costimulation of IFN-γ production in T cell/monocyte cocultures by anti-CD47 mAbs (clones 10G2, B6H12, C1Km1, and BRIC126). Mean ± SD for 10G2 P < 0.03 (ten experiments) and for other mAbs P < 0.001 (five independent experiments). (B) 10G2 mAb staining of untransfected (COS, dotted line) or CD47-transfected COS cell line (COS-47, bold line). Control mAb staining of both cell lines: (COS, thin line; COS-47, dashed line). (C) Fluorescence staining of Jurkat T cell line (left) and THP-1 monocyte cell line (right) by increasing concentrations of anti-CD47 mAbs (clones 10G2 and B6H12). One representative experiment out of three.

Mentions: sCD23 displays potent proinflammatory activity by directly triggering monokine release from purified monocytes in the absence of costimulatory signals, such as bacterial antigens (LPS or SAC) or T cell–dependent signal (sCD40L; Armant et al., 1994, 1995; Lecoanet-Henchoz et al., 1995). Although CD21 (CR2) and CD11b (CR3) were previously described as novel CD23 counterreceptors (Aubry et al., 1992; Leconaet-Henchoz et al., 1995), we also detected binding of sCD23 to several T cell lines lacking CR2 or CR3 expression (Ishihara et al., 1995; Table I). In an effort to identify sCD23 binding component, we generated mAbs to Jurkat T cells. We identified one mAb, clone 10G2, which neutralized sCD23 biological activities (Fig. 1 A), and displayed similar cell reactivity as sCD23 (Table I). Specifically, 10G2 mAb, like sCD23, did not stain the CD11b+ (CR3) and CD11c+ (CR4) THP-1 cell line. It recognized weakly, but with similar intensity, K562 and K562-CR2 cell lines. 10G2 mAb also stained peripheral blood T, B cells, and monocytes (Table I). 10G2 mAb significantly suppressed sCD23 costimulation of IFN-γ production by IL-2–stimulated T cells cocultured with autologous monocytes (mean inhibition of 10 experiments, 66%, P < 0.03; Fig. 1 A).


The vitronectin receptor and its associated CD47 molecule mediates proinflammatory cytokine synthesis in human monocytes by interaction with soluble CD23.

Hermann P, Armant M, Brown E, Rubio M, Ishihara H, Ulrich D, Caspary RG, Lindberg FP, Armitage R, Maliszewski C, Delespesse G, Sarfati M - J. Cell Biol. (1999)

Clone 10G2 neutralizes sCD23 biological activities and  recognizes CD47 Ag. (A) Inhibition of sCD23 costimulation of  IFN-γ production in T cell/monocyte cocultures by anti-CD47  mAbs (clones 10G2, B6H12, C1Km1, and BRIC126). Mean ±  SD for 10G2 P < 0.03 (ten experiments) and for other mAbs P <  0.001 (five independent experiments). (B) 10G2 mAb staining of  untransfected (COS, dotted line) or CD47-transfected COS cell  line (COS-47, bold line). Control mAb staining of both cell lines:  (COS, thin line; COS-47, dashed line). (C) Fluorescence staining  of Jurkat T cell line (left) and THP-1 monocyte cell line (right)  by increasing concentrations of anti-CD47 mAbs (clones 10G2  and B6H12). One representative experiment out of three.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2132927&req=5

Figure 1: Clone 10G2 neutralizes sCD23 biological activities and recognizes CD47 Ag. (A) Inhibition of sCD23 costimulation of IFN-γ production in T cell/monocyte cocultures by anti-CD47 mAbs (clones 10G2, B6H12, C1Km1, and BRIC126). Mean ± SD for 10G2 P < 0.03 (ten experiments) and for other mAbs P < 0.001 (five independent experiments). (B) 10G2 mAb staining of untransfected (COS, dotted line) or CD47-transfected COS cell line (COS-47, bold line). Control mAb staining of both cell lines: (COS, thin line; COS-47, dashed line). (C) Fluorescence staining of Jurkat T cell line (left) and THP-1 monocyte cell line (right) by increasing concentrations of anti-CD47 mAbs (clones 10G2 and B6H12). One representative experiment out of three.
Mentions: sCD23 displays potent proinflammatory activity by directly triggering monokine release from purified monocytes in the absence of costimulatory signals, such as bacterial antigens (LPS or SAC) or T cell–dependent signal (sCD40L; Armant et al., 1994, 1995; Lecoanet-Henchoz et al., 1995). Although CD21 (CR2) and CD11b (CR3) were previously described as novel CD23 counterreceptors (Aubry et al., 1992; Leconaet-Henchoz et al., 1995), we also detected binding of sCD23 to several T cell lines lacking CR2 or CR3 expression (Ishihara et al., 1995; Table I). In an effort to identify sCD23 binding component, we generated mAbs to Jurkat T cells. We identified one mAb, clone 10G2, which neutralized sCD23 biological activities (Fig. 1 A), and displayed similar cell reactivity as sCD23 (Table I). Specifically, 10G2 mAb, like sCD23, did not stain the CD11b+ (CR3) and CD11c+ (CR4) THP-1 cell line. It recognized weakly, but with similar intensity, K562 and K562-CR2 cell lines. 10G2 mAb also stained peripheral blood T, B cells, and monocytes (Table I). 10G2 mAb significantly suppressed sCD23 costimulation of IFN-γ production by IL-2–stimulated T cells cocultured with autologous monocytes (mean inhibition of 10 experiments, 66%, P < 0.03; Fig. 1 A).

Bottom Line: Surprisingly, anti-CD47 and beta3 mAbs do not block sCD23 binding to alphav+beta3+ T cell lines, whereas Vn and an alphav mAb (clone AMF7) do inhibit sCD23 binding, suggesting the VnR complex may be a functional receptor for sCD23. sCD23 directly binds alphav+beta3+/CD47(-) cell lines, but coexpression of CD47 increases binding.Moreover, sCD23 binds purified alphav protein and a single human alphav chain CHO transfectant.We conclude that the VnR and its associated CD47 molecule may function as a novel receptor for sCD23 to mediate its proinflammatory activity and, as such, may be involved in the inflammatory process of the immune response.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Allergie, Centre de recherch¿e Louis-Charles Simard, Pavillon Notre-Dame, Centre Hospitalier Université de Montréal (CHUM), Montreal, Quebec H2L 4M1, Canada.

ABSTRACT
The vitronectin receptor, alphavbeta3 integrin, plays an important role in tumor cell invasion, angiogenesis, and phagocytosis of apoptotic cells. CD47, a member of the multispan transmembrane receptor family, physically and functionally associates with vitronectin receptor (VnR). Although vitronectin (Vn) is not a ligand of CD47, anti-CD47 and beta3 mAbs suppress Vn, but not fibronectin (Fn) binding and function. Here, we show that anti-CD47, anti-beta3 mAb and Vn, but not Fn, inhibit sCD23-mediated proinflammatory function (TNF-alpha, IL-12, and IFN-gamma release). Surprisingly, anti-CD47 and beta3 mAbs do not block sCD23 binding to alphav+beta3+ T cell lines, whereas Vn and an alphav mAb (clone AMF7) do inhibit sCD23 binding, suggesting the VnR complex may be a functional receptor for sCD23. sCD23 directly binds alphav+beta3+/CD47(-) cell lines, but coexpression of CD47 increases binding. Moreover, sCD23 binds purified alphav protein and a single human alphav chain CHO transfectant. We conclude that the VnR and its associated CD47 molecule may function as a novel receptor for sCD23 to mediate its proinflammatory activity and, as such, may be involved in the inflammatory process of the immune response.

Show MeSH
Related in: MedlinePlus