ANKRD54 preferentially selects Bruton's Tyrosine Kinase (BTK) from a Human Src-Homology 3 (SH3) domain library

The role of Bruton's tyrosine kinase in the immune system and disease

Bruton's tyrosine kinase (BTK) is a TEC kinase with a multifaceted role in B-cell biology and function, highlighted by its position as a critical component of the B-cell receptor signalling pathway. Due to its role as a therapeutic target in several haematological malignancies including chronic lymphocytic leukaemia, BTK has been gaining tremendous momentum in recent years. Within the immune system, BTK plays a part in numerous pathways and cells beyond B cells (i.e. T cells, macrophages). Not surprisingly, BTK has been elucidated to be a driving factor not only in lymphoproliferative disorders but also in autoimmune diseases and response to infection. To extort this role, BTK inhibitors such as ibrutinib have been developed to target BTK in other diseases. However, due to rising levels of resistance, the urgency to develop new inhibitors with alternative modes of targeting BTK is high. To meet this demand, an expanding list of BTK inhibitors is currently being trialled. In this review, we synopsize recent discoveries regarding BTK and its role within different immune cells and pathways. Additionally, we discuss the broad significance and relevance of BTK for various diseases ranging from haematology and rheumatology to the COVID-19 pandemic. Overall, BTK signalling and its targetable nature have emerged as immensely important for a wide range of clinical applications. The development of novel, more specific and less toxic BTK inhibitors could be revolutionary for a significant number of diseases with yet unmet treatment needs.

Generating FN3-Based Affinity Reagents Through Phage Display

Antibodies are useful tools for detecting individual proteins in complex samples and for learning about their location, amount, binding partners, and function in cells. Unfortunately, generating antibodies is time consuming and laborious, and their affinity and/or specificity is often limited. This protocol offers a fast and inexpensive alternative to generate antibody surrogates through phage display of a library of fibronectin type III (FN3) monobody variants and affinity selection for binders. © 2018 by John Wiley & Sons, Inc.