Dr. Hai Qi and his colleagues of Lab of Immunological Dynamics have recently reported the finding on contact-dependent repulsive guidance of Ephrin B1 in controlling the Germinal Center reaction on the journal of Science in April, 2017.

Follicular T-helper (TFH) cells are known to orchestrate the germinal center (GC) reaction. Local mechanisms regulating their dynamics and helper functions are being intensively investigated. In this report, Dr. Qi and his group found that GC-expressed Ephrin B1 (EFNB1) repulsively inhibited T cell to B cell adhesion and GC TFH retention by signaling through TFH-expressed EPHB6 receptor. At the same time, EFNB1 promoted IL-21 production from GC TFH cells by signaling predominantly through EPHB4. Consequently, EFNB1-null GCs were associated with defective production of plasma cells despite harboring excessive TFH cells. In a competitive GC reaction, EFNB1-deficient B cells interacted with TFH cells more effectively and produced more bone-marrow plasma cells, likely as a result of gaining more contact-dependent help. The results reveal a contact-dependent repulsive guidance system that controls GC TFH dynamics and effector functions locally.

Peiwen Lu and Changming Shih, the PhD students in School of Medicine, are co-first authors of this research. This work was funded in part by the Ministry of Science and Technology “973” program, National Natural Science Foundation of China, and the Tsinghua-Peking Center for Life Sciences.

The original paper could be found from the following link:  http://science.sciencemag.org/content/early/2017/04/12/science.aai9264