What is the effect of mutations in TLR 4 on the risk of sepsis and gram-negative infections?

Mutations in TLR4 (Toll-like receptor 4) can significantly impact the immune response to gram-negative bacteria, particularly those that contain lipopolysaccharides (LPS) in their cell walls. TLR4 is a critical receptor in the innate immune system that recognizes LPS, thereby initiating an immune response.

When mutations occur in the TLR4 gene, the binding and activation of this receptor can be impaired. As a result, the body’s ability to respond to infections caused by gram-negative bacteria is compromised. This leads to an increased risk of sepsis and other severe infections since the immune system is less capable of detecting and responding to these pathogens effectively. Therefore, the presence of mutations in TLR4 contributes to an increased susceptibility to gram-negative infections and subsequently heightens the risk of developing sepsis.

In summary, mutations in TLR4 lead to an impaired immune response, resulting in an increase in both the risk of gram-negative infections and the likelihood of sepsis. This aligns with the correct answer choice, which indicates that both the risk of sepsis and the risk of gram-negative infections are increased due to these mutations.