Details

Autor(en) / Beteiligte

• Clanchy, Felix I.L.
• Borghese, Federica
• Bystrom, Jonas
• Balog, Attila
• Penn, Henry
• Taylor, Peter C.
• Stone, Trevor W.
• Mageed, Rizgar A.
• Williams, Richard O.

Titel

Disease status in human and experimental arthritis, and response to TNF blockade, is associated with MHC class II invariant chain (CD74) isoform expression

Ist Teil von

• Journal of autoimmunity, 2022-04, Vol.128, p.102810-102810, Article 102810

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2022

Quelle

MEDLINE

Beschreibungen/Notizen

• Splice variants of CD74 differentially modulate the activity of cathepsin L (CTSL). As CD74 and CTSL participate in the pathogenesis of inflammatory diseases such as rheumatoid arthritis (RA), we determined whether splice variants of CD74 could be biomarkers of disease activity. Gene expression was measured in mice with collagen-induced arthritis using quantitative PCR (qPCR). In vitro studies using murine macrophage/DC-lineage cells determined the relative influence of macrophage phenotype on isoform expression and the potential to produce CTSL in response to TNF. CD74 splice variants were measured in human RA synovium and RA patients’ monocytes. In arthritic mice, the expression of the p41 CD74 isoform was significantly higher in severely affected paws compared with unaffected paws or the paws of naïve mice; the p41 isoform significantly correlated with the expression of TNF in arthritic paws. Compared with M2-like macrophages, M1-like macrophages expressed increased levels of CD74 and had higher expression, secretion and activity of CTSL. RA patients that responded to TNF blockade had significantly higher expression levels of CD74 in circulating monocytes after treatment, compared with non-responders. The expression of the human CD74 isoform a was significantly higher in RA synovia, compared with osteoarthritis synovia, and was associated with CSTL enzymatic activity. This study is the first to demonstrate differential expression of the CD74 p41 isoform in an auto-immune disorder and in response to therapy. The differential expression of CD74 splice variants indicates an association, and potentially a mechanistic role, in the pathogenesis of RA. •Isoforms of the MHC-II invariant chain (CD74) are differentially expressed in tissues affected by inflammation.•The expression of CD74 isoform a is increased after therapy in RA anti-TNF responders, but is reduced in non-responders.•CD74 isoform a is associated with increased cathepsin L activity in human rheumatoid arthritis synovial explant cultures.