Identification of the Fc-alpha/mu receptor in Xenopus provides insight into the emergence of the poly-Ig receptor (pIgR) and mucosal Ig transport.
Eur J Immunol
; 51(11): 2590-2606, 2021 11.
Article
en En
| MEDLINE
| ID: mdl-34411303
ABSTRACT
The polyimmunoglobulin receptor (pIgR) transcytoses J chain-containing antibodies through mucosal epithelia. In mammals, two cis-duplicates of PIGR, FCMR, and FCAMR, flank the PIGR gene. A PIGR duplication is first found in amphibians, previously annotated as PIGR2 (herein xlFCAMR), and is expressed by APCs. We demonstrate that xlFcamR is the equivalent of mammalian FcamR. It has been assumed that pIgR is the oldest member of this family, yet our data could not distinguish whether PIGR or FCAMR emerged first; however, FCMR was the last family member to emerge. Interestingly, bony fish "pIgR" is not an orthologue of tetrapod pIgR, and possibly acquired its function via convergent evolution. PIGR/FCAMR/FCMR are members of a larger superfamily, including TREM, CD300, and NKp44, which we name the "double-disulfide Ig superfamily" (ddIgSF). Domains related to each ddIgSF family were identified in cartilaginous fish (sharks, chimeras) and encoded in a single gene cluster syntenic to the human pIgR locus. Thus, the ddIgSF families date back to the earliest antibody-based adaptive immunity, but apparently not before. Finally, our data strongly suggest that the J chain arose in evolution only for Ig multimerization. This study provides a framework for further studies of pIgR and the ddIgSF in vertebrates.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Receptores Fc
/
Antígenos CD
/
Receptores Opioides mu
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Receptores de Inmunoglobulina Polimérica
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Inmunidad Mucosa
/
Transcitosis
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Eur J Immunol
Año:
2021
Tipo del documento:
Article
País de afiliación:
Estados Unidos