Defects in TCR signaling pathways & X-linked agammaglobulinemia (XLA)

What happens when there are mutations in CD3 signaling proteins or ZAP70?

Mutations in CD3 signaling proteins or ZAP70 can result in reduced T-cell production and impaired T-cell activation, as TCR signaling is crucial for both development and activation.

How can immunosuppressive drugs affect T-cell signaling?

Immunosuppressive drugs can block T-cell signaling pathways, leading to defects in TCR signaling and affecting T-cell function.

What is X-linked agammaglobulinemia (XLA)?

Is the most common B-cell SCID immunodeficiency, where a mutation in a gene on the X-chromosome causes B-cell dysfunction, as only one mutated copy of the gene is needed.

What is the cause of X-linked agammaglobulinemia (XLA)?

Is caused by mutations in Bruton’s tyrosine kinase (BTK), which is responsible for BCR signaling at the pre-B stage.

What happens in X-linked agammaglobulinemia (XLA)?

Due to the BTK mutation, B-cells are unable to mature in the bone marrow, leading to a lack of mature B-cells.

What are patients with X-linked agammaglobulinemia (XLA) susceptible to?

Patients with XLA are highly susceptible to many microbial infections, particularly those caused by extracellular microbes.