Perforin-deficient CAR T cells recapitulate late-onset inflammatory toxicities observed in patients
Kazusa Ishii, … , Nirali N. Shah, Terry J. Fry
Kazusa Ishii, … , Nirali N. Shah, Terry J. Fry
Published September 14, 2020
Citation Information: J Clin Invest. 2020;130(10):5425-5443. https://doi.org/10.1172/JCI130059.
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Research Article Immunology Inflammation

Perforin-deficient CAR T cells recapitulate late-onset inflammatory toxicities observed in patients

Abstract

Late-onset inflammatory toxicities resembling hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) occur after chimeric antigen receptor T cell (CAR T cell) infusion and represent a therapeutic challenge. Given the established link between perforin deficiency and primary HLH, we investigated the role of perforin in anti-CD19 CAR T cell efficacy and HLH-like toxicities in a syngeneic murine model. Perforin contributed to both CD8+ and CD4+ CAR T cell cytotoxicity but was not required for in vitro or in vivo leukemia clearance. Upon CAR-mediated in vitro activation, perforin-deficient CAR T cells produced higher amounts of proinflammatory cytokines compared with WT CAR T cells. Following in vivo clearance of leukemia, perforin-deficient CAR T cells reexpanded, resulting in splenomegaly with disruption of normal splenic architecture and the presence of hemophagocytes, which are findings reminiscent of HLH. Notably, a substantial fraction of patients who received anti-CD22 CAR T cells also experienced biphasic inflammation, with the second phase occurring after the resolution of cytokine release syndrome, resembling clinical manifestations of HLH. Elevated inflammatory cytokines such as IL-1β and IL-18 and concurrent late CAR T cell expansion characterized the HLH-like syndromes occurring in the murine model and in humans. Thus, a murine model of perforin-deficient CAR T cells recapitulated late-onset inflammatory toxicities occurring in human CAR T cell recipients, providing therapeutically relevant mechanistic insights.

Authors

Kazusa Ishii, Marie Pouzolles, Christopher D. Chien, Rebecca A. Erwin-Cohen, M. Eric Kohler, Haiying Qin, Haiyan Lei, Skyler Kuhn, Amanda K. Ombrello, Alina Dulau-Florea, Michael A. Eckhaus, Haneen Shalabi, Bonnie Yates, Daniel A. Lichtenstein, Valérie S. Zimmermann, Taisuke Kondo, Jack F. Shern, Howard A. Young, Naomi Taylor, Nirali N. Shah, Terry J. Fry

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Figure 6

HLH-like manifestations associated with increased circulating CAR T cells were observed in anti-CD22 CAR T cell recipients.

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HLH-like manifestations associated with increased circulating CAR T cell...
(A) BM samples obtained on day 28 after CAR T cell infusion. H&E-stain shows decreased trilineage hematopoiesis with increased macrophages. CD3 immunohistochemical (IHC) stain highlights extensive T cell infiltration with flow cytometric confirmation of anti-CD22 CAR positivity in 59% of T cells. CD68 IHC stain highlights hemophagocytic macrophages. Giemsa stain of BM aspirate also shows hemophagocytosis. Original magnification, 50× (H&E, CD3, CD68 stains) and 100× (Giemsa stain). (B) Representative chronological changes in serum cytokine levels from patient 52 who had CRS without subsequent HLH. (C) Representative chronological changes in serum cytokine levels from patient 37 who had CRS and subsequent HLH. (D) The percentages of circulating T cells (CD3+) that stained positive for surface CAR expression were assessed by flow cytometry at the indicated time points. (E–G) Peak levels (during the first 28 days) of (E) IFN-γ, (F) IL-1β, and (G) IL-18 in serum/plasma. Data shown in D–G include all patients who were diagnosed with CRS according to previously published criteria (9), and patients who had never been diagnosed with CRS are not included. Data were stratified according to the presence or absence of HLH diagnosis (in addition to CRS) after CAR T cell infusion. Data are reported as the mean ± SD (D–G). *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001, by Mann-Whitney U test (D–G).