1 B cell activating signals must be transduced to the cell i

1. B cell activating signals must be transduced to the cell interior to influence the developmental processes. Yet, the cytoplasmic tails of BCRs are too short to function in signal transduction.

A. Describe two signals essential for B cell activation.

B. What is the role of Src kinases in the signaling pathway leading to expression of genes necessary for B cell activation?

C. How do naïve B cells transduce the signal induced by the cross-linkage of the antigen?

2. Which complement pathway do antibodies initiate? Which classes of antibodies initiate it?

Solution

A. The 2 signals for B cell activation are -

First comes from antigens cross linking to the B cell receptor

Second comes from costimulation provided by CD40L of T cell

B.SRC kinases are tyrosine protein kinases which help in signal transduction by phosphorylation and dephosphorylation and thus activation of b cells.

C. After ligand binding or signal sensing There is transcription , translation, post translational modifications of proteins ..And there occurs protein phosphorylation and dephosphorylation .

2.antibodies initiate alternate complement system... Ig M, Ig G initiate it.