Limits...
Lyn is essential for fcgamma receptor III-mediated systemic anaphylaxis but not for the Arthus reaction.

Yuasa T, Ono M, Watanabe T, Takai T - J. Exp. Med. (2001)

Bottom Line: The Src family kinase Lyn initiates intracellular signal transduction by associating with a variety of immune receptors such as antigen receptor on B cells and high-affinity Fc receptor (FcR) for immunoglobulin Ig(E) (FcepsilonRI) on mast cells.Involvement of Lyn in the IgE-mediated immediate-type hypersensitivity is well documented, but the physiological significance of Lyn in IgG-dependent, type III low-affinity FcR for IgG (FcgammaRIII)-mediated responses is largely unknown.The Lyn deficiency attenuated IgG-mediated systemic anaphylaxis in vivo, and significantly reduced calcium mobilization and degranulation responses of bone marrow-derived mast cells (BMMCs) in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Immunology and the Core Research for Evolutional Science and Technology (CREST) Program of Japan Science and Technology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan.

ABSTRACT
The Src family kinase Lyn initiates intracellular signal transduction by associating with a variety of immune receptors such as antigen receptor on B cells and high-affinity Fc receptor (FcR) for immunoglobulin Ig(E) (FcepsilonRI) on mast cells. Involvement of Lyn in the IgE-mediated immediate-type hypersensitivity is well documented, but the physiological significance of Lyn in IgG-dependent, type III low-affinity FcR for IgG (FcgammaRIII)-mediated responses is largely unknown. In this study, we generated a double-mutant mouse strain deficient in both type II FcR for IgG (FcgammaRIIB) and Lyn to exclude any involvement of inhibitory signaling by FcgammaRIIB, which otherwise downregulates FcgammaRIII-mediated cellular responses. FcgammaRIIB-deficient but Lyn-sufficient mice served as controls. The Lyn deficiency attenuated IgG-mediated systemic anaphylaxis in vivo, and significantly reduced calcium mobilization and degranulation responses of bone marrow-derived mast cells (BMMCs) in vitro. However, we found that either interleukin 4 or tumor necrosis factor alpha release by BMMCs was comparable to that from Lyn-deficient and control mice, and the reverse-passive Arthus reaction was equally induced in both mutant mice, indicating that Lyn is not involved in the onset of the IgG-mediated, FcgammaRIII-dependent late phase responses of mast cells. These findings provide us with insight into distinct signaling mechanisms in mast cells underlying the development of diverse pathologies as well as a therapeutic potential for selective treatment of allergic disorders.

Show MeSH

Related in: MedlinePlus

Reverse-passive Arthus reaction in Lyn−IIB− and control (IIB−) mice evoked by IgG immune complexes. Each mouse was treated with intradermal injection of 0 (PBS), 16, or 80 μg of rabbit anti-OVA IgG per site followed by intravenous injection of 1 mg of OVA in 0.2 ml saline. (A) Photomicrographs of a representative lesion of the Arthus reaction at 8 h after antigen challenge. Hematoxylin and eosin staining. Original magnifications: ×40 or ×1,000 as indicated in each photomicrograph. (B) MPO activity in a skin lesion at 8 h after antigen challenge. Mean ± SD of five mice is indicated. One unit represents MPO activity in 0.25 μl of whole blood sample. (C) Amount of TNF-α released in skin lesions at 3 h after antigen challenge. Each column represents the mean ± SD of TNF-α density (pg/mm2) in skin lesions obtained from five mice.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2193394&req=5

Figure 6: Reverse-passive Arthus reaction in Lyn−IIB− and control (IIB−) mice evoked by IgG immune complexes. Each mouse was treated with intradermal injection of 0 (PBS), 16, or 80 μg of rabbit anti-OVA IgG per site followed by intravenous injection of 1 mg of OVA in 0.2 ml saline. (A) Photomicrographs of a representative lesion of the Arthus reaction at 8 h after antigen challenge. Hematoxylin and eosin staining. Original magnifications: ×40 or ×1,000 as indicated in each photomicrograph. (B) MPO activity in a skin lesion at 8 h after antigen challenge. Mean ± SD of five mice is indicated. One unit represents MPO activity in 0.25 μl of whole blood sample. (C) Amount of TNF-α released in skin lesions at 3 h after antigen challenge. Each column represents the mean ± SD of TNF-α density (pg/mm2) in skin lesions obtained from five mice.

Mentions: The in vitro results for Lyn-independent cytokine induction prompted us to examine the role of Lyn in reverse-passive Arthus reaction. It has been shown that this model represents an immune complex–triggered mode of inflammation in vivo, and that its onset in the murine model largely depends on FcγRIII-mediated mast cell activation 34151619. TNF-α is known to play a pivotal role in recruitment of neutrophils in mast cell–dependent cutaneous injury 4344. We examined the onset of reverse-passive Arthus reaction in Lyn-deficient mice after the treatment with intradermal injections of anti-OVA rabbit IgG followed by OVA challenge through the tail vein. Diseased reaction was evaluated by these three means: (a) histopathological feature; (b) MPO activity in situ at the late inflamed phase (8 h), which paralleled the extent of PMN infiltration; and (c) TNF-α release at the initial phase (3 h). We first showed that Lyn-deficient mice as well as control mice display inflammatory tissue damage with massive neutrophil infiltration in the challenged sites (Fig. 6 A). Consistently, comparable induction of MPO activity in situ was detected in these two strains of mice (Fig. 6 B). We next examined increase of TNF-α production at the initial phase of the Arthus reaction in the challenged sites (dorsal skin and ear). Although the results from two different lesions are somewhat unparallel, there was found to be no statistic significance in the TNF-α production between Lyn-deficient and control mice (Fig. 6 C). This finding cannot affirm the intact TNF-α production in Lyn-deficient mice; however, it may mean that in vivo mechanisms for TNF-α production are not affected as much as mechanisms for the immediate phase reaction in Lyn-deficient mice. Collectively, these findings indicate that activation of the Lyn-independent signaling pathway downstream of FcγRIII is sufficient for initiating the reverse-passive Arthus reaction, suggesting that Lyn is not necessary for the onset of late phase responses of mast cells.


Lyn is essential for fcgamma receptor III-mediated systemic anaphylaxis but not for the Arthus reaction.

Yuasa T, Ono M, Watanabe T, Takai T - J. Exp. Med. (2001)

Reverse-passive Arthus reaction in Lyn−IIB− and control (IIB−) mice evoked by IgG immune complexes. Each mouse was treated with intradermal injection of 0 (PBS), 16, or 80 μg of rabbit anti-OVA IgG per site followed by intravenous injection of 1 mg of OVA in 0.2 ml saline. (A) Photomicrographs of a representative lesion of the Arthus reaction at 8 h after antigen challenge. Hematoxylin and eosin staining. Original magnifications: ×40 or ×1,000 as indicated in each photomicrograph. (B) MPO activity in a skin lesion at 8 h after antigen challenge. Mean ± SD of five mice is indicated. One unit represents MPO activity in 0.25 μl of whole blood sample. (C) Amount of TNF-α released in skin lesions at 3 h after antigen challenge. Each column represents the mean ± SD of TNF-α density (pg/mm2) in skin lesions obtained from five mice.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2193394&req=5

Figure 6: Reverse-passive Arthus reaction in Lyn−IIB− and control (IIB−) mice evoked by IgG immune complexes. Each mouse was treated with intradermal injection of 0 (PBS), 16, or 80 μg of rabbit anti-OVA IgG per site followed by intravenous injection of 1 mg of OVA in 0.2 ml saline. (A) Photomicrographs of a representative lesion of the Arthus reaction at 8 h after antigen challenge. Hematoxylin and eosin staining. Original magnifications: ×40 or ×1,000 as indicated in each photomicrograph. (B) MPO activity in a skin lesion at 8 h after antigen challenge. Mean ± SD of five mice is indicated. One unit represents MPO activity in 0.25 μl of whole blood sample. (C) Amount of TNF-α released in skin lesions at 3 h after antigen challenge. Each column represents the mean ± SD of TNF-α density (pg/mm2) in skin lesions obtained from five mice.
Mentions: The in vitro results for Lyn-independent cytokine induction prompted us to examine the role of Lyn in reverse-passive Arthus reaction. It has been shown that this model represents an immune complex–triggered mode of inflammation in vivo, and that its onset in the murine model largely depends on FcγRIII-mediated mast cell activation 34151619. TNF-α is known to play a pivotal role in recruitment of neutrophils in mast cell–dependent cutaneous injury 4344. We examined the onset of reverse-passive Arthus reaction in Lyn-deficient mice after the treatment with intradermal injections of anti-OVA rabbit IgG followed by OVA challenge through the tail vein. Diseased reaction was evaluated by these three means: (a) histopathological feature; (b) MPO activity in situ at the late inflamed phase (8 h), which paralleled the extent of PMN infiltration; and (c) TNF-α release at the initial phase (3 h). We first showed that Lyn-deficient mice as well as control mice display inflammatory tissue damage with massive neutrophil infiltration in the challenged sites (Fig. 6 A). Consistently, comparable induction of MPO activity in situ was detected in these two strains of mice (Fig. 6 B). We next examined increase of TNF-α production at the initial phase of the Arthus reaction in the challenged sites (dorsal skin and ear). Although the results from two different lesions are somewhat unparallel, there was found to be no statistic significance in the TNF-α production between Lyn-deficient and control mice (Fig. 6 C). This finding cannot affirm the intact TNF-α production in Lyn-deficient mice; however, it may mean that in vivo mechanisms for TNF-α production are not affected as much as mechanisms for the immediate phase reaction in Lyn-deficient mice. Collectively, these findings indicate that activation of the Lyn-independent signaling pathway downstream of FcγRIII is sufficient for initiating the reverse-passive Arthus reaction, suggesting that Lyn is not necessary for the onset of late phase responses of mast cells.

Bottom Line: The Src family kinase Lyn initiates intracellular signal transduction by associating with a variety of immune receptors such as antigen receptor on B cells and high-affinity Fc receptor (FcR) for immunoglobulin Ig(E) (FcepsilonRI) on mast cells.Involvement of Lyn in the IgE-mediated immediate-type hypersensitivity is well documented, but the physiological significance of Lyn in IgG-dependent, type III low-affinity FcR for IgG (FcgammaRIII)-mediated responses is largely unknown.The Lyn deficiency attenuated IgG-mediated systemic anaphylaxis in vivo, and significantly reduced calcium mobilization and degranulation responses of bone marrow-derived mast cells (BMMCs) in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Immunology and the Core Research for Evolutional Science and Technology (CREST) Program of Japan Science and Technology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan.

ABSTRACT
The Src family kinase Lyn initiates intracellular signal transduction by associating with a variety of immune receptors such as antigen receptor on B cells and high-affinity Fc receptor (FcR) for immunoglobulin Ig(E) (FcepsilonRI) on mast cells. Involvement of Lyn in the IgE-mediated immediate-type hypersensitivity is well documented, but the physiological significance of Lyn in IgG-dependent, type III low-affinity FcR for IgG (FcgammaRIII)-mediated responses is largely unknown. In this study, we generated a double-mutant mouse strain deficient in both type II FcR for IgG (FcgammaRIIB) and Lyn to exclude any involvement of inhibitory signaling by FcgammaRIIB, which otherwise downregulates FcgammaRIII-mediated cellular responses. FcgammaRIIB-deficient but Lyn-sufficient mice served as controls. The Lyn deficiency attenuated IgG-mediated systemic anaphylaxis in vivo, and significantly reduced calcium mobilization and degranulation responses of bone marrow-derived mast cells (BMMCs) in vitro. However, we found that either interleukin 4 or tumor necrosis factor alpha release by BMMCs was comparable to that from Lyn-deficient and control mice, and the reverse-passive Arthus reaction was equally induced in both mutant mice, indicating that Lyn is not involved in the onset of the IgG-mediated, FcgammaRIII-dependent late phase responses of mast cells. These findings provide us with insight into distinct signaling mechanisms in mast cells underlying the development of diverse pathologies as well as a therapeutic potential for selective treatment of allergic disorders.

Show MeSH
Related in: MedlinePlus