Evaluation of the Relationships between Intestinal Regional Lymph Nodes and Immune Responses in Viral Infections in Children

• Published in: International journal of molecular sciences Vol. 23; no. 1; p. 318
• Main Authors: Aoki, Yayoi, Ikeda, Tomoya, Tani, Naoto, Watanabe, Miho, Ishikawa, Takaki
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 28.12.2021; MDPI
• Subjects: Antigens; Autopsies; Autopsy; Bacterial infections; Bone marrow; Cell culture; Cell Size - drug effects; Cells, Cultured; Child; Children; Dendritic cells; Disruption; Edema; Female; Gastrointestinal system; Histopathology; Homeostasis; Humans; Immune response; Immune system; Immunity; Immunoglobulin A; Immunoglobulin A - blood; Infant; Infant, Newborn; Infections; Interferon; interferon β; Interferon-beta - blood; Intestine; Intestines - immunology; Intestines - pathology; Lymph nodes; Lymph Nodes - immunology; Lymph Nodes - pathology; Lymphatic system; Lymphocyte Activation - drug effects; Lymphocyte Activation - immunology; Male; Mucosa; Pediatrics; Peyer's Patches - drug effects; Peyer's Patches - immunology; Peyer’s patch; Poly I-C - pharmacology; Reference Values; regional lymph node; Respiratory system; viral infection; Viral infections; Virus Diseases - blood; Virus Diseases - immunology; β-Interferon; viral infection; cell culture; interferon β; immune system; immunoglobulin A; Peyer’s patch; child; regional lymph node
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23010318

Viral infections increase the risk of developing allergies in childhood, and disruption of mucosal homeostasis is presumed to be involved. However, no study has reported a role for viral infections in such disruption. In this study, we clarified the mechanism of immunoglobulin A (IgA) overproduction in viral infections. Autopsies were performed on 33 pediatric cases, IgA and interferon (IFN)β levels were measured, and histopathological and immunohistochemical examinations were conducted. Furthermore, we cultured human cells and measured IFNβ and IgA levels to examine the effect of viral infections on IgA production. Blood IgA levels in viral infections were higher than in bacterial infections. Moreover, IFNβ levels in most viral cases were below the detection limit. Cell culture revealed increased IgA in gastrointestinal lymph nodes, especially in Peyer's patches, due to enhanced IFNβ after viral stimulation. Conversely, respiratory regional lymph nodes showed enhanced IgA with no marked change in IFNβ. Overproduction of IgA, identified as an aberration of the immune system and resulting from excessive viral infection-induced IFNβ was observed in the intestinal regional lymph nodes, particularly in Peyer's patches. Further, increased IgA without elevated IFNβ in the respiratory system suggested the possibility of a different mechanism from the gastrointestinal system.