Involvement of H-Ras in the adaptive immunity of Nile tilapia by regulating lymphocyte activation

H-Ras is a guanosine triphosphatase (GTPase), which acts as a molecular switch and controls multiple important
cellular processes including lymphocyte activation and function. However, regulatory mechanism of adaptive
immune response by H-Ras remains unclear in non-mammalian animals. In the present study, we investigated
the involvement of H-Ras in lymphocyte activation with a teleost model Oreochromis niloticus. H-Ras from O.
niloticus (On-H-Ras) is highly conserved with those from other vertebrates. The mRNA of On-H-Ras showed a
wide expression pattern in the lymphoid-tissues and with the highest level in liver. After Aeromonas hydrophila
infection, transcription of On-H-Ras was significantly induced on day 8 but came back to basal level on day 16,
suggesting that On-H-Ras potentially participated in primary response during the adaptive immunity.
Furthermore, On-H-Ras mRNA was obviously up-regulated when leukocytes were activated by T lymphocyte
mitogen PHA in vitro. Meanwhile, protein level of H-Ras was also augmented once leukocytes were stimulated
with lymphocyte receptor signaling agonist PMA and ionomycin. More importantly, once Ras activity was inhibited
by specific inhibitor, the up-regulation of lymphocyte activation marker CD122 was obviously impaired
during lymphocyte activation process. Therefore, On-H-Ras regulated lymphocyte activation through both
mRNA and protein level. Altogether, our results illustrated the involvement of H-Ras in teleost adaptive immunity
via controlling lymphocyte activation, and thus provided a novel perspective to understand evolution of
the lymphocyte-mediated adaptive immunity.
刊物名称: 
Fish and Shellfish Immunology
年: 
2019
卷期: 
89
页码: 
281-289
作者: 
Wei, Xiumei; Zhao, Tianyu; Zhang, Yu; Ai, Kete; Li, Huiying; Yang, Jialong
论文原文: