IgG hexamers initiate complement-dependent acute lung injury.
J Clin Invest
; 134(11)2024 Mar 26.
Article
en En
| MEDLINE
| ID: mdl-38530369
ABSTRACT
Antibodies can initiate lung injury in a variety of disease states such as autoimmunity, in reactions to transfusions, or after organ transplantation, but the key factors determining in vivo pathogenicity of injury-inducing antibodies are unclear. Harmful antibodies often activate the complement cascade. A model for how IgG antibodies trigger complement activation involves interactions between IgG Fc domains driving the assembly of IgG hexamer structures that activate C1 complexes. The importance of IgG hexamers in initiating injury responses was not clear, so we tested their relevance in a mouse model of alloantibody- and complement-mediated acute lung injury. We used 3 approaches to block alloantibody hexamerization (antibody carbamylation, the K439E Fc mutation, or treatment with domain B from staphylococcal protein A), all of which reduced acute lung injury. Conversely, Fc mutations promoting spontaneous hexamerization made a harmful alloantibody into a more potent inducer of acute lung injury and rendered an innocuous alloantibody pathogenic. Treatment with a recombinant Fc hexamer "decoy" therapeutic protected mice from lung injury, including in a model with transgenic human FCGR2A expression that exacerbated pathology. These results indicate an in vivo role of IgG hexamerization in initiating acute lung injury and the potential for therapeutics that inhibit or mimic hexamerization to treat antibody-mediated diseases.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Inmunoglobulina G
/
Receptores de IgG
/
Lesión Pulmonar Aguda
Límite:
Animals
/
Humans
Idioma:
En
Revista:
J Clin Invest
Año:
2024
Tipo del documento:
Article