EphB6-null mutation results in compromised T cell function
Hongyu Luo, … , Johanne Tremblay, Jiangping Wu
Hongyu Luo, … , Johanne Tremblay, Jiangping Wu
Published December 15, 2004
Citation Information: J Clin Invest. 2004;114(12):1762-1773. https://doi.org/10.1172/JCI21846.
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Article Immunology

EphB6-null mutation results in compromised T cell function

Abstract

So far, there is very limited knowledge about the role of Eph kinases, the largest family of receptor tyrosine kinases, in the immune system. Here, using EphB6–/– mice, we demonstrated that in vitro and in vivo T cell responses such as lymphokine secretion, proliferation, and the development of delayed-type skin hypersensitivity and experimental autoimmune encephalitis in EphB6–/– mice were compromised. On the other hand, humoral immune responses, such as serum levels of different Ig isotypes and IgG response to tetanus toxoid, were normal in these mice. Mechanistically, we showed that EphB6 migrated to the aggregated TCRs and rafts after TCR activation. Further downstream, in the absence of EphB6, ZAP-70 activation, LAT phosphorylation, the association of PLCγ1 with SLP-76, and p44/42 MAPK activation were diminished. Thus, we have shown that EphB6 is pivotal in T cell function.

Authors

Hongyu Luo, Guang Yu, Johanne Tremblay, Jiangping Wu

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Figure 3

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Compromised in vitro function of EphB6–/– T cells. (A) CD25 and CD69 exp...
Compromised in vitro function of EphB6–/– T cells. (A) CD25 and CD69 expression according to flow cytometry. Purified spleen T cells from EphB6–/– or WT mice were cultured in wells precoated with PBS, anti-CD3 mAb (suboptimal), anti-CD3 mAb (suboptimal) plus anti-CD28 mAb, or PMA plus ionomycin (iono), as indicated. CD25 and CD69 expression was assessed after 24 hours by 2-color flow cytometry. The percentages represent positive populations among Thy1.2+ cells, after deduction of background staining (shaded areas; isotypic Ab). (B) Lymphokine production by EphB6–/– and EphB6+/+ T cells. Supernatants of T cell cultures were collected after 48 hours, and IL-2, IL-4, and IFN-γ in the supernatants were measured by ELISA. Samples were in duplicate. The pooled results of 7 independent experiments are shown. Paired Student’s t test was performed. *Significant difference (P < 0.05). **Highly significant difference (P < 0.01). (C–E) Proliferation of EphB6–/– and EphB6+/+ thymocytes and spleen T cells. (C) Thymocytes from EphB6–/– mice or their WT littermates were cultured in the presence of solid phase anti-CD3 or soluble concanavalin A (Con A). The cells were harvested at 72 hours for 3H-thymidine uptake during the last 16 hours. Purified spleen T cells (D and E) and spleen CD4+ or CD8+ cells (E) from EphB6 KO or WT mice were cultured as indicated. The cells were pulsed with 3H-thymidine for the last 16 hours of culture and harvested at 72 hours (D) or at 40 hours, 64 hours, and 88 hours (E). All experiments were performed at least 3 times and were reproducible; representative results are shown. The difference between KO and WT cell proliferation shown in all the panels in C–E is highly significant (P < 0.01, Student’s t test).