IL-33 protects from recurrent C. difficile infection by restoration of humoral immunity
Farha Naz, Md Jashim Uddin, Nicholas Hagspiel, Mary K. Young, David Tyus, Rachel Boone, Audrey C. Brown, Girija Ramakrishnan, Isaura Rigo, Claire Fleming, Gregory R. Madden, William A. Petri Jr.
Farha Naz, Md Jashim Uddin, Nicholas Hagspiel, Mary K. Young, David Tyus, Rachel Boone, Audrey C. Brown, Girija Ramakrishnan, Isaura Rigo, Claire Fleming, Gregory R. Madden, William A. Petri Jr.
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Research Article Immunology Infectious disease

IL-33 protects from recurrent C. difficile infection by restoration of humoral immunity

Abstract

Clostridioides difficile infection (CDI) recurs in 1 of 5 patients. Monoclonal antibodies targeting the virulence factor TcdB reduce disease recurrence, suggesting that an inadequate anti-TcdB response to CDI leads to recurrence. In patients with CDI, we discovered that IL-33 measured at diagnosis predicts future recurrence, leading us to test the role of IL-33 signaling in the induction of humoral immunity during CDI. Using a mouse recurrence model, IL-33 was demonstrated to be integral for anti-TcdB antibody production. IL-33 acted via ST2+ ILC2 cells, facilitating germinal center T follicular helper (GC-Tfh) cell generation of antibodies. IL-33 protection from reinfection was antibody-dependent, as μMT KO mice and mice treated with anti-CD20 mAb were not protected. These findings demonstrate the critical role of IL-33 in generating humoral immunity to prevent recurrent CDI.

Authors

Farha Naz, Md Jashim Uddin, Nicholas Hagspiel, Mary K. Young, David Tyus, Rachel Boone, Audrey C. Brown, Girija Ramakrishnan, Isaura Rigo, Claire Fleming, Gregory R. Madden, William A. Petri Jr.

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Figure 7

ILC2s mediated production of toxin B–specific antibodies, protecting against CDI reinfection.

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ILC2s mediated production of toxin B–specific antibodies, protecting aga...
ST2+ ILC2s (from uninfected IL-33 treated mice) were ex-vivo expanded, purified by flow-sorting, and adoptively transferred into ST2-KO mice. (A and B) Mice were pretreated with antibiotics and injected with 0.75 μg per dose per mouse of IL-33 in the gut 1 day after the adoptive transfer of 3 × 105 ILC2s (n = 12) or saline (n = 12) per mouse. At day 16 after primary infection, plasma toxin B–specific (B) IgG was measured in plasma. (C–G) Mice were rechallenged with C. difficile on day 60. On day 70 (10 days after the second infection), (C–E), ILC2 was measured in the colon and MLN. (F and G) GC-TFH measured in the MLN (H) Day 70 representative epithelial damage (H&E) of treatment groups and (I) assessed by blinded scoring of infected tissue. Scale bars: 184.4 μm (left) and 114.3 μm (right). Depletion of ILC2 decreased toxin-specific antibodies in CDI; IL-33 (0.75 μg) was administered intraperitoneally from days –4 to 0 to R26-DTRNmur1 mice (n = 9) or littermate control R26-DTR mice (n = 9) (in which ILC2s lack DTR). Mice were then given intraperitoneal (i.p.) injections with diphtheria toxin (DT) on days –12, –9, –6, 1, and 8 after infection and infection was done with C. difficile strain R20291. (J) Experimental design; On day 15 after infection, ILC2 abundance and anti-TcdB antibodies were measured. (K) Density plot to show the depletion of ILC2s from the colon (L) Toxin-specific antibodies were measured in plasma and cecal content. A 2-tailed t test for normally distributed data and a Mann-Whitney test for nonnormally distributed data were used. (J) Šídák’s multiple comparisons test was used. *P < 0.05, **P < 0.01, and ***P < 0.001. The error bar indicates SEM.