Final answer:
The protein tyrosine kinase involved in T-cell activation, which eventually leads to T-cell proliferation and differentiation, is ZAP-70. ZAP-70 activation is crucial for signal transduction following antigen recognition by the T-cell receptor.
Step-by-step explanation:
The correct option is B:
The correct answer to the question of which protein tyrosine kinase is involved in T-cell activation leading to T-cell proliferation and differentiation is b. ZAP-70.
T-cell activation is a complex process that involves multiple steps and proteins. Among these, ZAP-70 (Zeta-chain-associated protein kinase 70) plays a critical role. It is directly associated with the T-cell receptor (TCR) and gets activated upon antigen recognition. Once activated, ZAP-70 phosphorylates different substrates, leading to further signal transduction pathways that result in T-cell proliferation and differentiation. This process is essential for the adaptive immune response.
While other options such as NF-κB and NFAT are also involved in T-cell function, they are not tyrosine kinases. NF-κB, for example, is a transcription factor that is involved in inflammation and immune responses, but it is not responsible for the initial T-cell activation signal that comes from tyrosine kinase activity.