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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.

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Related in: MedlinePlus

Western blot analysis of αv+β3+ (CD51+/CD61+) melanoma cell line. Cell lysate was purified on anti-β3 (CD61) mAb-affinity column. The eluate was separated by SDS-PAGE (5%)  and transferred to membrane. Staining by anti-αv (CD51) mAb  (clone AMF7 and LM142; lane 2), anti-β3 (CD61, clone AP3;  lane 4), isotype-control matched mAbs (lanes 1 and 3), B-BSA  (lane 5), and B-sCD23 (lane 6) is shown.
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Figure 6: Western blot analysis of αv+β3+ (CD51+/CD61+) melanoma cell line. Cell lysate was purified on anti-β3 (CD61) mAb-affinity column. The eluate was separated by SDS-PAGE (5%) and transferred to membrane. Staining by anti-αv (CD51) mAb (clone AMF7 and LM142; lane 2), anti-β3 (CD61, clone AP3; lane 4), isotype-control matched mAbs (lanes 1 and 3), B-BSA (lane 5), and B-sCD23 (lane 6) is shown.

Mentions: Next, we selected a melanoma cell line, strongly expressing αvβ3 to purify this integrin by affinity chromatography using anti-β3 (CD61) immobilized AFFi-gel. Western blot analysis (Fig. 6) shows sCD23 (lane 6) reacted with a single band of ∼135 kD, displaying a similar migration pattern as molecular species recognized by a cocktail of anti-CD51 mAbs (lane 2). However, sCD23 did not appear to bind purified β3 (CD61) chain which was identified by anti-CD61 mAb (lane 4), or purified recombinant CD47 (not shown).


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)

Western blot analysis of αv+β3+ (CD51+/CD61+) melanoma cell line. Cell lysate was purified on anti-β3 (CD61) mAb-affinity column. The eluate was separated by SDS-PAGE (5%)  and transferred to membrane. Staining by anti-αv (CD51) mAb  (clone AMF7 and LM142; lane 2), anti-β3 (CD61, clone AP3;  lane 4), isotype-control matched mAbs (lanes 1 and 3), B-BSA  (lane 5), and B-sCD23 (lane 6) is shown.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 6: Western blot analysis of αv+β3+ (CD51+/CD61+) melanoma cell line. Cell lysate was purified on anti-β3 (CD61) mAb-affinity column. The eluate was separated by SDS-PAGE (5%) and transferred to membrane. Staining by anti-αv (CD51) mAb (clone AMF7 and LM142; lane 2), anti-β3 (CD61, clone AP3; lane 4), isotype-control matched mAbs (lanes 1 and 3), B-BSA (lane 5), and B-sCD23 (lane 6) is shown.
Mentions: Next, we selected a melanoma cell line, strongly expressing αvβ3 to purify this integrin by affinity chromatography using anti-β3 (CD61) immobilized AFFi-gel. Western blot analysis (Fig. 6) shows sCD23 (lane 6) reacted with a single band of ∼135 kD, displaying a similar migration pattern as molecular species recognized by a cocktail of anti-CD51 mAbs (lane 2). However, sCD23 did not appear to bind purified β3 (CD61) chain which was identified by anti-CD61 mAb (lane 4), or purified recombinant CD47 (not shown).

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