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Trichinella spiralis Paramyosin Binds Human Complement C1q and Inhibits Classical Complement Activation.

Sun R, Zhao X, Wang Z, Yang J, Zhao L, Zhan B, Zhu X - PLoS Negl Trop Dis (2015)

Bottom Line: Trichinella spiralis expresses paramyosin (Ts-Pmy) as a defense mechanism.The binding of recombinant and natural Ts-Pmy to human C1q were determined by ELISA, Far Western blotting and immunoprecipitation, respectively.Binding of recombinant Ts-Pmy (rTs-Pmy) to C1q inhibited C1q binding to IgM and consequently inhibited C3 deposition.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China.

ABSTRACT

Background: Trichinella spiralis expresses paramyosin (Ts-Pmy) as a defense mechanism. Ts-Pmy is a functional protein with binding activity to human complement C8 and C9 and thus plays a role in evading the attack of the host's immune system. In the present study, the binding activity of Ts-Pmy to human complement C1q and its ability to inhibit classical complement activation were investigated.

Methods and findings: The binding of recombinant and natural Ts-Pmy to human C1q were determined by ELISA, Far Western blotting and immunoprecipitation, respectively. Binding of recombinant Ts-Pmy (rTs-Pmy) to C1q inhibited C1q binding to IgM and consequently inhibited C3 deposition. The lysis of antibody-sensitized erythrocytes (EAs) elicited by the classical complement pathway was also inhibited in the presence of rTs-Pmy. In addition to inhibiting classical complement activation, rTs-Pmy also suppressed C1q binding to THP-1-derived macrophages, thereby reducing C1q-induced macrophages migration.

Conclusion: Our results suggest that T. spiralis paramyosin plays an important role in immune evasion by interfering with complement activation through binding to C1q in addition to C8 and C9.

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Related in: MedlinePlus

C1q-induced chemotaxis of THP-1-derived M2 macrophages was inhibited by rTs-Pmy.Transwell-24-well plates were used for the migration assay. THP-1 cells were induced into M2 type macrophages in the upper chamber. LPS (100 ng/ml), C1q (10 nM) and C1q with different amounts of rTs-Pmy (0, 3, 6, or 12 μg) were added into the lower chamber. The cells that migrated though the membrane were counted under a microscope, and the cells from 8 randomly selected fields were counted. The results shown are means ± SD and are representative of three independent experiments. ***p<0.001. ns, no significant difference.
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pntd.0004310.g007: C1q-induced chemotaxis of THP-1-derived M2 macrophages was inhibited by rTs-Pmy.Transwell-24-well plates were used for the migration assay. THP-1 cells were induced into M2 type macrophages in the upper chamber. LPS (100 ng/ml), C1q (10 nM) and C1q with different amounts of rTs-Pmy (0, 3, 6, or 12 μg) were added into the lower chamber. The cells that migrated though the membrane were counted under a microscope, and the cells from 8 randomly selected fields were counted. The results shown are means ± SD and are representative of three independent experiments. ***p<0.001. ns, no significant difference.

Mentions: To investigate the effect of rTs-Pmy on C1q-induced chemotaxis of THP-1-derived macrophages, a migration assay using a transwell chamber was performed. Both human C1q and LPS significantly induced the migration of THP-1-derived M2 macrophages through the membrane (Fig 7). After incubating C1q with increasing amounts of rTs-Pmy (0, 3, 6, or 12 μg), the cell migration through the membrane was significantly reduced in a dose-dependent manner (***p<0.001). No obvious inhibition was detected in the group incubated with BSA at high concentration of 12 μg. The result revealed that rTs-Pmy inhibited the chemotaxis of M2 phenotype macrophages towards C1q.


Trichinella spiralis Paramyosin Binds Human Complement C1q and Inhibits Classical Complement Activation.

Sun R, Zhao X, Wang Z, Yang J, Zhao L, Zhan B, Zhu X - PLoS Negl Trop Dis (2015)

C1q-induced chemotaxis of THP-1-derived M2 macrophages was inhibited by rTs-Pmy.Transwell-24-well plates were used for the migration assay. THP-1 cells were induced into M2 type macrophages in the upper chamber. LPS (100 ng/ml), C1q (10 nM) and C1q with different amounts of rTs-Pmy (0, 3, 6, or 12 μg) were added into the lower chamber. The cells that migrated though the membrane were counted under a microscope, and the cells from 8 randomly selected fields were counted. The results shown are means ± SD and are representative of three independent experiments. ***p<0.001. ns, no significant difference.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4697845&req=5

pntd.0004310.g007: C1q-induced chemotaxis of THP-1-derived M2 macrophages was inhibited by rTs-Pmy.Transwell-24-well plates were used for the migration assay. THP-1 cells were induced into M2 type macrophages in the upper chamber. LPS (100 ng/ml), C1q (10 nM) and C1q with different amounts of rTs-Pmy (0, 3, 6, or 12 μg) were added into the lower chamber. The cells that migrated though the membrane were counted under a microscope, and the cells from 8 randomly selected fields were counted. The results shown are means ± SD and are representative of three independent experiments. ***p<0.001. ns, no significant difference.
Mentions: To investigate the effect of rTs-Pmy on C1q-induced chemotaxis of THP-1-derived macrophages, a migration assay using a transwell chamber was performed. Both human C1q and LPS significantly induced the migration of THP-1-derived M2 macrophages through the membrane (Fig 7). After incubating C1q with increasing amounts of rTs-Pmy (0, 3, 6, or 12 μg), the cell migration through the membrane was significantly reduced in a dose-dependent manner (***p<0.001). No obvious inhibition was detected in the group incubated with BSA at high concentration of 12 μg. The result revealed that rTs-Pmy inhibited the chemotaxis of M2 phenotype macrophages towards C1q.

Bottom Line: Trichinella spiralis expresses paramyosin (Ts-Pmy) as a defense mechanism.The binding of recombinant and natural Ts-Pmy to human C1q were determined by ELISA, Far Western blotting and immunoprecipitation, respectively.Binding of recombinant Ts-Pmy (rTs-Pmy) to C1q inhibited C1q binding to IgM and consequently inhibited C3 deposition.

View Article: PubMed Central - PubMed

Affiliation: Department of Parasitology, School of Basic Medical Sciences, Capital Medical University, Beijing, PR China.

ABSTRACT

Background: Trichinella spiralis expresses paramyosin (Ts-Pmy) as a defense mechanism. Ts-Pmy is a functional protein with binding activity to human complement C8 and C9 and thus plays a role in evading the attack of the host's immune system. In the present study, the binding activity of Ts-Pmy to human complement C1q and its ability to inhibit classical complement activation were investigated.

Methods and findings: The binding of recombinant and natural Ts-Pmy to human C1q were determined by ELISA, Far Western blotting and immunoprecipitation, respectively. Binding of recombinant Ts-Pmy (rTs-Pmy) to C1q inhibited C1q binding to IgM and consequently inhibited C3 deposition. The lysis of antibody-sensitized erythrocytes (EAs) elicited by the classical complement pathway was also inhibited in the presence of rTs-Pmy. In addition to inhibiting classical complement activation, rTs-Pmy also suppressed C1q binding to THP-1-derived macrophages, thereby reducing C1q-induced macrophages migration.

Conclusion: Our results suggest that T. spiralis paramyosin plays an important role in immune evasion by interfering with complement activation through binding to C1q in addition to C8 and C9.

Show MeSH
Related in: MedlinePlus