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Effects of interferon-alpha/beta and interferon-gamma preparations on phagocytosis by mouse peritoneal macrophages
Abstract:
The influence of murine alpha/beta-interferon (Mu IFN-alpha/beta) and murine gamma-interferon (Mu IFN-gamma) preparations on the attachment and ingestion phase of phagocytosis by mouse peritoneal macrophages (MPM) was studied. A non-opsonized strain of Escherichia coli, IgG-opsonized E. coli, and sheep erythrocytes opsonized with IgG (E-IgG) and IgM plus complement factor C3b (E-IgMC) were used as test particles. Pretreatment of MPM with 10(2)-10(3) U/ml of Mu IFN-alpha/beta for 24 h enhanced both attachment and ingestion of bacteria or erythrocytes mediated by the non-specific receptor, the Fc receptor, or the C3b receptor. Higher concentrations had no such effects. In contrast, treatment of MPM with 10(1)-10(2)U/ml of Mu IFN-gamma suppressed attachment and ingestion of non-opsonized and IgG-opsonized E. coli and of E-IgG by 10-40%. Mu IFN-gamma did not influence attachment and ingestion of E-IgMC. The effects were neutralized by specific anti-IFN antiserum. The data indicate that the IFN effect on phagocytic activity is, at least to a large extent, due to modifications of the surface receptors.
Insights
Murine alpha/beta-interferon (Mu IFN-alpha/beta) boosts macrophage phagocytosis, while murine gamma-interferon (Mu IFN-gamma) suppresses it. These interferon effects on phagocytic activity are linked to modifications of macrophage surface receptors.
Area of Science:
- Immunology
- Cell Biology
Background:
- Phagocytosis is a crucial cellular process for immune defense and tissue homeostasis.
- Macrophages play a central role in phagocytosis, engulfing pathogens and cellular debris.
Purpose of the Study:
- To investigate the impact of murine alpha/beta-interferon (Mu IFN-alpha/beta) and murine gamma-interferon (Mu IFN-gamma) on macrophage phagocytic activity.
- To determine how these interferons affect the attachment and ingestion phases of phagocytosis.
Main Methods:
- Mouse peritoneal macrophages (MPM) were pretreated with different concentrations of Mu IFN-alpha/beta or Mu IFN-gamma.
- Phagocytosis assays were performed using non-opsonized Escherichia coli, IgG-opsonized E. coli, sheep erythrocytes opsonized with IgG (E-IgG), and E-IgM plus complement factor C3b (E-IgMC).
- Interferon effects were assessed by measuring attachment and ingestion rates, and specific anti-interferon antiserum was used for neutralization studies.
Main Results:
- Mu IFN-alpha/beta (10^2-10^3 U/ml) significantly enhanced the attachment and ingestion of bacteria and erythrocytes via Fc and C3b receptors.
- Mu IFN-gamma (10^1-10^2 U/ml) suppressed the attachment and ingestion of non-opsonized and IgG-opsonized bacteria and E-IgG by 10-40%.
- Mu IFN-gamma did not affect the uptake of E-IgMC, suggesting receptor-specific modulation.
Conclusions:
- Interferon treatment differentially modulates macrophage phagocytic activity.
- Mu IFN-alpha/beta enhances phagocytosis, while Mu IFN-gamma inhibits it, depending on the particle type and opsonization.
- The findings suggest that interferon-induced modifications of macrophage surface receptors are a primary mechanism underlying these effects on phagocytosis.