Granzyme A–producing T helper cells are critical for acute graft-versus-host disease
Sungtae Park, … , Mark H. Kaplan, Matthew R. Olson
Sungtae Park, … , Mark H. Kaplan, Matthew R. Olson
Published August 18, 2020
Citation Information: JCI Insight. 2020;5(18):e124465. https://doi.org/10.1172/jci.insight.124465.
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Research Article Immunology Inflammation

Granzyme A–producing T helper cells are critical for acute graft-versus-host disease

Abstract

Acute graft-versus-host disease (aGVHD) can occur after hematopoietic cell transplant in patients undergoing treatment for hematological malignancies or inborn errors. Although CD4+ T helper (Th) cells play a major role in aGVHD, the mechanisms by which they contribute, particularly within the intestines, have remained elusive. We have identified a potentially novel subset of Th cells that accumulated in the intestines and produced the serine protease granzyme A (GrA). GrA+ Th cells were distinct from other Th lineages and exhibited a noncytolytic phenotype. In vitro, GrA+ Th cells differentiated in the presence of IL-4, IL-6, and IL-21 and were transcriptionally unique from cells cultured with either IL-4 or the IL-6/IL-21 combination alone. In vivo, both STAT3 and STAT6 were required for GrA+ Th cell differentiation and played roles in maintenance of the lineage identity. Importantly, GrA+ Th cells promoted aGVHD-associated morbidity and mortality and contributed to crypt destruction within intestines but were not required for the beneficial graft-versus-leukemia effect. Our data indicate that GrA+ Th cells represent a distinct Th subset and are critical mediators of aGVHD.

Authors

Sungtae Park, Brad Griesenauer, Hua Jiang, Djamilatou Adom, Pegah Mehrpouya-Bahrami, Srishti Chakravorty, Majid Kazemian, Tanbeena Imam, Rajneesh Srivastava, Tristan A. Hayes, Julian Pardo, Sarath Chandra Janga, Sophie Paczesny, Mark H. Kaplan, Matthew R. Olson

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Figure 3

IL-4 and IL-6 signaling synergize in the induction of GrA+ Th cells.

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IL-4 and IL-6 signaling synergize in the induction of GrA+ Th cells. (A)...
(A) Naive Th cells were differentiated in the presence of the indicated cytokines (TLR2 = PAM3CSK4) and stained for intracellular GrA. Data represents a single screen with cells pooled from 3 mice. These data are representative of 3 individual screening experiments. Nil, no treatment. (B) Indicated Th cells from 3 individual mice were cultured with/without IL-6 (10 ng/mL) followed by stimulation and intracellular staining for cytokines and GrA. Representative contour plots are depicted (left panel), and the frequency of GrA+ cells is depicted in the right panel. (C) Cells from 3 mice were cultured with IL-4, anti–IFN-γ, and increasing doses of IL-6. On day 5 of culture mRNA was measured by real-time PCR. Statistical analysis was done by Student’s t test, and reported values are corrected for multiple comparisons. (D) Cells from 3 individual mice were cultured with IL-4, IL-4+IL-6, or IL-4+IL-6 and with IL-21 (100 ng/mL) added at day 3 of culture. On day 5 of culture, cells were harvested and stained for intracellular GrA and GrB (left panel), and frequencies of GrA+ and GrB+ cells were determined by flow cytometry (right panel). Statistical analysis was done by 2-way ANOVA with Holm-Šidák correction for multiple comparisons. (E) Indicated Th subsets were analyzed by CyTOF and displayed in a dot overlays plot. Cytokine screening assays were performed 4 times with pooled naive CD4+ T cells. Th polarization experiments were repeated 3–6 times. Error bars represent standard deviation of the mean. CyTOF analysis was performed twice with pooled naive CD4+ T cells isolated from multiple animals.