Do IL23R rs11209026 GG and ATG16L1 rs2241880 AG increase intestinal inflammation?

Genetic variations in the IL23R and ATG16L1 genes alter crucial immune and cellular pathways, directly predisposing individuals to heightened gut inflammation.

Genetic and cellular impact

• Lacking IL23R Protection: The IL23R rs11209026 GG genotype lacks the protective A (R381Q) allele, a hypomorphic variant that normally dampens receptor activity. Consequently, GG individuals exhibit un-attenuated, standard IL-23 immune signaling.
• Impaired Autophagy: The ATG16L1 rs2241880 AG genotype carries one copy of the G (T300A) risk allele. This compromises macroautophagy efficiency and reduces autophagosome formation compared to the protective AA genotype.

Mechanistic pathways

• Dysregulated Myeloid Secretion: Autophagy pathways normally restrain IL-23 secretion. Impaired autophagy in myeloid cells disinhibits this system, increasing IL-23 production under Toll-like receptor (TLR) stimulation and amplifying pro-inflammatory signaling.
• Paneth Cell Dysfunction: The ATG16L1 G risk variant leads to abnormal Paneth cell granule morphology, endoplasmic reticulum (ER) stress, and compromised antimicrobial peptide secretion, which allows bacterial persistence and gut dysbiosis.
• JAK-STAT Activation: Un-attenuated IL-23 signaling activates downstream JAK-STAT pathways, driving Th17 cell maintenance and pro-inflammatory cytokine production (e.g., IL-17) to fuel chronic mucosal inflammation.

Bottom line

• The absence of the protective IL23R A allele (rs11209026 GG) combined with the impaired autophagic capacity of the ATG16L1 rs2241880 AG genotype synergistically drives chronic intestinal inflammation by pairing defective bacterial clearance with heightened IL-23-driven Th17 immune responses.