The recombinant human CD79B protein is expressed from HEK293 cells with 10*His tag and Avi tag at the C-Terminus. The target gene encodes the 29-159aa of the human CD79B. Its purity reaches up to 90% as determined by SDS-PAGE, and its endotoxin level is Less than 1.0 EU/ug as accessed by the LAL method. Its activity is measured by its binding ability with the anti-CD79B recombinant antibody (CSB-RA004958MA2HU) in a functional ELISA. The EC50 of this CD79B protein is 31.97-35.69 ng/mL.
The CD79B protein, a critical component of the B-cell receptor (BCR), serves several essential functions in B-cell biology and immunology. As a transmembrane protein, CD79B pairs with CD79A to form the BCR complex, which is crucial for B-cell activation, signaling, and development. The primary role of CD79B is to facilitate signal transduction upon antigen engagement, which is initiated by the phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) located in its cytoplasmic domain [1][2]. This phosphorylation event activates downstream signaling pathways involving various kinases, such as SYK and BLNK, leading to B-cell proliferation, differentiation, and survival [1][3][4].
Mutations in the CD79B gene, particularly in the ITAM region, have been associated with persistent BCR signaling, which can contribute to the survival of malignant B cells in conditions such as diffuse large B-cell lymphoma (DLBCL) [1][5][6]. These mutations can inhibit normal receptor internalization, resulting in enhanced BCR expression on the cell surface, which further promotes cell activation and survival [1][7].
Moreover, CD79B plays a role in the immune response beyond mere signal transduction. It has been implicated in the modulation of immune responses, where antibodies targeting CD79B can induce anergy in B cells, potentially preventing autoimmunity [8][9]. This suggests that CD79B not only facilitates B-cell activation but also has regulatory functions that can influence the overall immune landscape.
In the context of cancer, CD79B expression is often used as a biomarker for B-cell malignancies, and therapies targeting CD79B, such as antibody-drug conjugates, have shown promise in treating various B-cell lymphomas [6][10]. The ability of CD79B to mediate both positive and negative signals in B cells highlights its dual role in promoting immune responses while also providing a target for therapeutic intervention in malignancies.
References:
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[7] M. Pfeifer, B. Zheng, T. Erdmann, H. Koeppen, R. McCord, M. Grau, et al. Anti-cd22 and anti-cd79b antibody drug conjugates are active in different molecular diffuse large b-cell lymphoma subtypes, Leukemia, vol. 29, no. 7, p. 1578-1586, 2015. https://doi.org/10.1038/leu.2015.48
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