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Specificity and Effector Functions of Human RSV-Specific IgG from Bovine Milk.

den Hartog G, Jacobino S, Bont L, Cox L, Ulfman LH, Leusen JH, van Neerven RJ - PLoS ONE (2014)

Bottom Line: Yet, many infants depend on bovine milk-based nutrition, which at present lacks intact immunoglobulins.The data presented here show that bIgG binds to hRSV and other human respiratory pathogens and induces effector functions through binding to human FcγRII on phagocytes.Thus bovine IgG may contribute to immune protection against RSV.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Translational Immunology, Immunotherapy group, UMC Utrecht, Utrecht, The Netherlands; Cell Biology and Immunology, Wageningen University, Wageningen, The Netherlands.

ABSTRACT

Background: Respiratory syncytial virus (RSV) infection is the second most important cause of death in the first year of life, and early RSV infections are associated with the development of asthma. Breastfeeding and serum IgG have been shown to protect against RSV infection. Yet, many infants depend on bovine milk-based nutrition, which at present lacks intact immunoglobulins.

Objective: To investigate whether IgG purified from bovine milk (bIgG) can modulate immune responses against human RSV.

Methods: ELISAs were performed to analyse binding of bIgG to human respiratory pathogens. bIgG or hRSV was coated to plates to assess dose-dependent binding of bIgG to human Fcγ receptors (FcγR) or bIgG-mediated binding of myeloid cells to hRSV respectively. S. Epidermidis and RSV were used to test bIgG-mediated binding and internalisation of pathogens by myeloid cells. Finally, the ability of bIgG to neutralise infection of HEp2 cells by hRSV was evaluated.

Results: bIgG recognised human RSV, influenza haemagglutinin and Haemophilus influenza. bIgG bound to FcγRII on neutrophils, monocytes and macrophages, but not to FcγRI and FcγRIII, and could bind simultaneously to hRSV and human FcγRII on neutrophils. In addition, human neutrophils and dendritic cells internalised pathogens that were opsonised with bIgG. Finally, bIgG could prevent infection of HEp2 cells by hRSV.

Conclusions: The data presented here show that bIgG binds to hRSV and other human respiratory pathogens and induces effector functions through binding to human FcγRII on phagocytes. Thus bovine IgG may contribute to immune protection against RSV.

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Related in: MedlinePlus

bIgG binds to human FcγRII.A) IgG was immobilised on 96 wells ELISA plates. Monocytes were incubated overnight in the absence or presence of 10 ng/ml IFN-γ. B) Different concentrations of IgG were coated and IFN-γ stimulated monocytes were added. C) Binding of PMNs to 10 µg/ml human (IVIg) and bovine IgG (bIg). PMNs were incubated for 10 minutes in the absence (–) or presence of 3 µg/ml Fabs recognizing FcγRIII (CD16) or FcγRII (CD32). As negative control, plates were coated with gelatin (none) instead of Ig. Binding of bIgG by monocytes and PMNs was observed for three different donors. For all panels binding of cells after five washes is shown and expressed as percentage of initial. Mean and S.E.M. is shown of triplicate measurements.
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pone-0112047-g002: bIgG binds to human FcγRII.A) IgG was immobilised on 96 wells ELISA plates. Monocytes were incubated overnight in the absence or presence of 10 ng/ml IFN-γ. B) Different concentrations of IgG were coated and IFN-γ stimulated monocytes were added. C) Binding of PMNs to 10 µg/ml human (IVIg) and bovine IgG (bIg). PMNs were incubated for 10 minutes in the absence (–) or presence of 3 µg/ml Fabs recognizing FcγRIII (CD16) or FcγRII (CD32). As negative control, plates were coated with gelatin (none) instead of Ig. Binding of bIgG by monocytes and PMNs was observed for three different donors. For all panels binding of cells after five washes is shown and expressed as percentage of initial. Mean and S.E.M. is shown of triplicate measurements.

Mentions: To study binding of bIgG to human FcγRs, monocytes were incubated overnight in the presence or absence of IFN-γ to enhance FcγR expression, and exposed to plate-bound bIgG. Human monocytes of 5 out of 5 donors bound to immobilised bIgG, as well as to IVIg, which was increased by pre-incubating the cells with IFN-γ (Figure 2A). Binding of monocytes to bIgG was dose-dependent and comparable or slightly lower compared to human IVIg (Figure 2B).


Specificity and Effector Functions of Human RSV-Specific IgG from Bovine Milk.

den Hartog G, Jacobino S, Bont L, Cox L, Ulfman LH, Leusen JH, van Neerven RJ - PLoS ONE (2014)

bIgG binds to human FcγRII.A) IgG was immobilised on 96 wells ELISA plates. Monocytes were incubated overnight in the absence or presence of 10 ng/ml IFN-γ. B) Different concentrations of IgG were coated and IFN-γ stimulated monocytes were added. C) Binding of PMNs to 10 µg/ml human (IVIg) and bovine IgG (bIg). PMNs were incubated for 10 minutes in the absence (–) or presence of 3 µg/ml Fabs recognizing FcγRIII (CD16) or FcγRII (CD32). As negative control, plates were coated with gelatin (none) instead of Ig. Binding of bIgG by monocytes and PMNs was observed for three different donors. For all panels binding of cells after five washes is shown and expressed as percentage of initial. Mean and S.E.M. is shown of triplicate measurements.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222812&req=5

pone-0112047-g002: bIgG binds to human FcγRII.A) IgG was immobilised on 96 wells ELISA plates. Monocytes were incubated overnight in the absence or presence of 10 ng/ml IFN-γ. B) Different concentrations of IgG were coated and IFN-γ stimulated monocytes were added. C) Binding of PMNs to 10 µg/ml human (IVIg) and bovine IgG (bIg). PMNs were incubated for 10 minutes in the absence (–) or presence of 3 µg/ml Fabs recognizing FcγRIII (CD16) or FcγRII (CD32). As negative control, plates were coated with gelatin (none) instead of Ig. Binding of bIgG by monocytes and PMNs was observed for three different donors. For all panels binding of cells after five washes is shown and expressed as percentage of initial. Mean and S.E.M. is shown of triplicate measurements.
Mentions: To study binding of bIgG to human FcγRs, monocytes were incubated overnight in the presence or absence of IFN-γ to enhance FcγR expression, and exposed to plate-bound bIgG. Human monocytes of 5 out of 5 donors bound to immobilised bIgG, as well as to IVIg, which was increased by pre-incubating the cells with IFN-γ (Figure 2A). Binding of monocytes to bIgG was dose-dependent and comparable or slightly lower compared to human IVIg (Figure 2B).

Bottom Line: Yet, many infants depend on bovine milk-based nutrition, which at present lacks intact immunoglobulins.The data presented here show that bIgG binds to hRSV and other human respiratory pathogens and induces effector functions through binding to human FcγRII on phagocytes.Thus bovine IgG may contribute to immune protection against RSV.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Translational Immunology, Immunotherapy group, UMC Utrecht, Utrecht, The Netherlands; Cell Biology and Immunology, Wageningen University, Wageningen, The Netherlands.

ABSTRACT

Background: Respiratory syncytial virus (RSV) infection is the second most important cause of death in the first year of life, and early RSV infections are associated with the development of asthma. Breastfeeding and serum IgG have been shown to protect against RSV infection. Yet, many infants depend on bovine milk-based nutrition, which at present lacks intact immunoglobulins.

Objective: To investigate whether IgG purified from bovine milk (bIgG) can modulate immune responses against human RSV.

Methods: ELISAs were performed to analyse binding of bIgG to human respiratory pathogens. bIgG or hRSV was coated to plates to assess dose-dependent binding of bIgG to human Fcγ receptors (FcγR) or bIgG-mediated binding of myeloid cells to hRSV respectively. S. Epidermidis and RSV were used to test bIgG-mediated binding and internalisation of pathogens by myeloid cells. Finally, the ability of bIgG to neutralise infection of HEp2 cells by hRSV was evaluated.

Results: bIgG recognised human RSV, influenza haemagglutinin and Haemophilus influenza. bIgG bound to FcγRII on neutrophils, monocytes and macrophages, but not to FcγRI and FcγRIII, and could bind simultaneously to hRSV and human FcγRII on neutrophils. In addition, human neutrophils and dendritic cells internalised pathogens that were opsonised with bIgG. Finally, bIgG could prevent infection of HEp2 cells by hRSV.

Conclusions: The data presented here show that bIgG binds to hRSV and other human respiratory pathogens and induces effector functions through binding to human FcγRII on phagocytes. Thus bovine IgG may contribute to immune protection against RSV.

Show MeSH
Related in: MedlinePlus