Retinoic acid acts as a selective human IgA switch factor

Hum Immunol. 2014 Aug;75(8):923-9. doi: 10.1016/j.humimm.2014.06.021. Epub 2014 Jun 30.

Abstract

Retinoic acid (RA) is known to have several functions that lead to a potent mucosal IgA response. Nevertheless, its exact role in human IgA synthesis has yet to be elucidated. Thus, we investigated the role of RA in promoting IgA isotype switching in human B cells. We found that RA increased IgA production and the expression of germ-line IgA1 and IgA2 transcripts (GLTα1 and GLTα2). This induction occurred alongside an increase in the frequency of IgA1-secreting B cell clones, as assessed by limiting dilution analysis. Under the same conditions, RA did not increase IgM and IgG production. Am80, an agonist of RA receptor α (RARα), increased IgA production. In addition, RA activity was abrogated by LE540, an antagonist of RAR, suggesting that the RAR pathway is involved in RA-induced IgA production. Taken together, these results indicate that RA induces IgA isotype switching mainly through RARα in human B cells.

Keywords: B cell; Class switch; IgA; RARα; Retinoic acid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes / cytology
  • B-Lymphocytes / drug effects*
  • B-Lymphocytes / immunology
  • Benzoates / pharmacology
  • Dibenzazepines / pharmacology
  • Gene Expression Regulation
  • Humans
  • Immunoglobulin A / genetics*
  • Immunoglobulin A / immunology
  • Immunoglobulin Class Switching / drug effects*
  • Immunoglobulin G
  • Immunoglobulin M
  • Palatine Tonsil / cytology
  • Palatine Tonsil / immunology
  • Primary Cell Culture
  • RNA, Messenger / genetics
  • RNA, Messenger / immunology
  • Receptors, Retinoic Acid / agonists
  • Receptors, Retinoic Acid / antagonists & inhibitors
  • Receptors, Retinoic Acid / genetics
  • Receptors, Retinoic Acid / immunology
  • Retinoic Acid Receptor alpha
  • Signal Transduction
  • Tetrahydronaphthalenes / pharmacology
  • Transforming Growth Factor beta1 / pharmacology
  • Tretinoin / pharmacology*

Substances

  • Benzoates
  • Dibenzazepines
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • LE 540
  • RARA protein, human
  • RNA, Messenger
  • Receptors, Retinoic Acid
  • Retinoic Acid Receptor alpha
  • Tetrahydronaphthalenes
  • Transforming Growth Factor beta1
  • tamibarotene
  • Tretinoin