Immunization of BALB/c mice with pigeon IgY induces the production of anti-IgG autoantibodies

Abstract

The breakdown of immunological tolerance due to the activation of autoreactive B and T cells triggers physiopathological processes. An example of such conditions is the production of IgG autoantibodies specific for the Fc portion of IgG (anti-Fcγ IgG). Previous reports have shown that patients with pigeon-related hypersensitivity pneumonitis exhibit an increase in the serum levels of anti-Fcγ IgG. There is no in vivo model for the study of this condition and the immunological mechanisms of tolerance breakdown associated with sensitization by pigeon antigens are still unknown. In this work, we show that the repeated immunization of BALB/c mice with pigeon IgY during 16-weeks induces the production of anti-Fcγ IgG and keeps their high levels for seven weeks. The late appearance of anti-Fcγ IgG autoantibodies in the plasma is similar to what has been reported in other experimental autoimmune models. With the occurrence of anti-Fcγ IgG, there is a reduction in the proportion of Foxp3 + cells (regulatory T cells, Tregs) within the population of splenic CD4 + CD25 + T cells. Thus, our data showed that the immunization of BALB/c mice with IgY promotes the production of anti-Fcγ IgG along with a decrease in Tregs in the spleen. We propose that immunization of mice with pigeon antigens, like IgY can provide a model to study the immunological mechanisms involved in the development of pigeon-related hypersensitivity pneumonitis.

Keywords:

• Autoantibody
• rheumatoid factor
• molecular mimicry
• regulatory T cells
• pigeon IgY
• hypersensitivity pnemonitis
• bird fancier’s lung
• pigeon breeder’s disease

Acknowledgments

M. Sc. Ivan Sammir Aranda Uribe is a PhD candidate from the Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, and received a fellowship (324181) from CONACYT for his doctoral studies. The authors thank Dr. Karen Manoutcharian, Institituo de Investigaciones Biomédicas, UNAM. México City, México; Dr. Lucía Rangel Porta (Departamento de Reproducción, Facultad de Medicina Veterinaria y Zootecnia, UNAM) for donation of pigeon eggs, Dr. Adriana Karina Chávez-Rueda for donation of plasma from MRL/lpr mice, Chemist Dámaris Romero Rodriguez for flow cytometry services (Unidad de Citometría de Flujo INER) and workers at the animal facility of the INER for animal care. We acknowledge the Academic Writing Team of the Centro de Estudios de Posgrado, UNAM for their help with this manuscript.

Disclosure statement

The authors declare no conflict of interest.