|ZFIN ID: ZDB-PUB-151122-1|
Conserved IL-2Rγc Signaling Mediates Lymphopoiesis in Zebrafish
Sertori, R., Liongue, C., Basheer, F., Lewis, K.L., Rasighaemi, P., de Coninck, D., Traver, D., Ward, A.C.
|Source:||Journal of immunology (Baltimore, Md. : 1950) 196(1): 135-43 (Journal)|
|Registered Authors:||Liongue, Clifford, Rasighaemi, Parisa, Traver, David, Ward, Alister C.|
|PubMed:||26590317 Full text @ J. Immunol.|
Sertori, R., Liongue, C., Basheer, F., Lewis, K.L., Rasighaemi, P., de Coninck, D., Traver, D., Ward, A.C. (2016) Conserved IL-2Rγc Signaling Mediates Lymphopoiesis in Zebrafish. Journal of immunology (Baltimore, Md. : 1950). 196(1):135-43.
ABSTRACTThe IL-2 receptor γ common (IL-2Rγc) chain is the shared subunit of the receptors for the IL-2 family of cytokines, which mediate signaling through JAK3 and various downstream pathways to regulate lymphopoiesis. Inactivating mutations in human IL-2Rγc result in SCID, a primary immunodeficiency characterized by greatly reduced numbers of lymphocytes. This study used bioinformatics, expression analysis, gene ablation, and specific pharmacologic inhibitors to investigate the function of two putative zebrafish IL-2Rγc paralogs, il-2rγc.a and il-2rγc.b, and downstream signaling components during early lymphopoiesis. Expression of il-2rγc.a commenced at 16 h post fertilization (hpf) and rose steadily from 4-6 d postfertilization (dpf) in the developing thymus, with il-2rγc.a expression also confirmed in adult T and B lymphocytes. Transcripts of il-2rγc.b were first observed from 8 hpf, but waned from 16 hpf before reaching maximal expression at 6 dpf, but this was not evident in the thymus. Knockdown of il-2rγc.a, but not il-2rγc.b, substantially reduced embryonic lymphopoiesis without affecting other aspects of hematopoiesis. Specific targeting of zebrafish Jak3 exerted a similar effect on lymphopoiesis, whereas ablation of zebrafish Stat5.1 and pharmacologic inhibition of PI3K and MEK also produced significant but smaller effects. Ablation of il-2rγc.a was further demonstrated to lead to an absence of mature T cells, but not B cells in juvenile fish. These results indicate that conserved IL-2Rγc signaling via JAK3 plays a key role during early zebrafish lymphopoiesis, which can be potentially targeted to generate a zebrafish model of human SCID.