A Notch/IL-21 signaling axis primes bone marrow T cell progenitor expansion
Kilian Sottoriva, Na Yoon Paik, Zachary White, Thilinie Bandara, Lijian Shao, Teruyuki Sano, Kostandin V. Pajcini
Kilian Sottoriva, Na Yoon Paik, Zachary White, Thilinie Bandara, Lijian Shao, Teruyuki Sano, Kostandin V. Pajcini
View: Text | PDF
Research Article Hematology Transplantation

A Notch/IL-21 signaling axis primes bone marrow T cell progenitor expansion

Abstract

Long-term impairment in T cell–mediated adaptive immunity is a major clinical obstacle following treatment of blood disorders with hematopoietic stem cell transplantation. Although T cell development in the thymus has been extensively characterized, there are significant gaps in our understanding of prethymic processes that influence early T cell potential. We have uncovered a Notch/IL-21 signaling axis in bone marrow common lymphoid progenitor (CLP) cells. IL-21 receptor expression was driven by Notch activation in CLPs, and in vivo treatment with IL-21 induced Notch-dependent CLP proliferation. Taking advantage of this potentially novel signaling axis, we generated T cell progenitors ex vivo, which improved repopulation of the thymus and peripheral lymphoid organs of mice in an allogeneic transplant model. Importantly, Notch and IL-21 activation were equally effective in the priming and expansion of human cord blood cells toward the T cell fate, confirming the translational potential of the combined treatment.

Authors

Kilian Sottoriva, Na Yoon Paik, Zachary White, Thilinie Bandara, Lijian Shao, Teruyuki Sano, Kostandin V. Pajcini

×

Figure 5

Notch/IL-21–primed T cell progenitors efficiently reconstitute allogeneic recipients.

Options: View larger image (or click on image) Download as PowerPoint
Notch/IL-21–primed T cell progenitors efficiently reconstitute allogenei...
(A) Sorted BM LSK cells (CD45.1) were cultured on OP9-Dll1 cells with indicated cytokines. After 2 weeks, 2 × 106 T cell–primed progenitors were cotransplanted with 1000 fresh HSCs (CD45.1/.2) into lethally irradiated LP/J (Ly9.1+) recipient mice. (B) Representative flow plot (left) and absolute number (right) of donor splenic T cells from control (n = 4) and IL-21–treated (n = 4) culture recipients, 1 month posttransplant. Gated on Ly9.1–CD3+. (C) Representative flow plot for CD4 and CD8 staining of donor splenic T cells, 1 month posttransplant. Gated on Ly9.1–CD3+CD45.1+CD45.2–. (D) Absolute number of donor splenic CD4+ and CD8+ cells and CD4/CD8 ratio of cells from control (n = 4) and IL-21–treated (n = 4) culture recipients, 1 month posttransplant. (E) (Left) Representative flow plot for donor T cells in MLNs, 1 month posttransplant. Gated on MHCII–Ly9.1–CD4+TCRb+CD44+. (Right) Absolute number of donor T cells in MLNs from control (n = 4) and IL-21–treated (n = 4) culture recipients. (F) (Left) Representative flow plot for IFN-γ of host Ly9.1+ and control and IL-21–treated culture (CD45.1+) cells from recipient SI, 1 month posttransplant. Gated on MHCII–CD4+TCRb+CD44+. (Right) Percentages of T cells expressing IFN-γ of host Ly9.1+ (n = 4) and control (n = 4) and IL-21–treated (n = 4) culture (CD45.1+) cells from recipient SI, 1 month posttransplant. (G) (Left) Representative flow plot for IL-17a of host Ly9.1+ and control and IL-21–treated culture (CD45.1+) cells from recipient SI, 1 month posttransplant. Gated on MHCII–CD4+TCRb+CD44+. (Right) Percentages of T cells expressing IL-17a of host Ly9.1+ (n = 4) and control (n = 4) and IL-21–treated (n = 4) culture (CD45.1+) cells from recipient SI, 1 month posttransplant. MLN, mesenteric lymph nodes; SI, small intestine. *P < 0.05, **P < 0.01. Statistical analysis performed using Student’s 2-tailed t test (B–E) and 1-way ANOVA (F and G).