Two strains of mice were infected with 5 $\times$ 10⁴ PFU of Influenza A virus, and the survival data shown in Figure were obtained. Next, both strains were infected again with Influenza A, and levels of type I interferons (IFN-$\alpha$ and IFN-$\beta$) were measured and found to be similar between the two strains. Likewise, cells from both strains expressed similar levels of the IFN-$\alpha$/$\beta$receptor (IFNAR). Which of the following proteins might be more highly expressed in strain B than in strain A following Influenza A infection? A) MHC class I B) Mx-1 C) TLR4 D) Complement C3 E) ICAM-1

Question

Quizplus · Accepted Answer

Mx-1 is an antiviral protein that is induced by type I interferons and plays a role in limiting the replication of Influenza A virus. Since both strains express similar levels of type I interferons and the IFNAR receptor, the difference in survival between the two strains may be due to differences in the expression of downstream antiviral proteins such as Mx-1. The other proteins listed are not directly related to viral replication and would not be expected to differ between the two strains in this context.

Two Strains of Mice Were Infected with 5 ×\times× 104 PFU of Influenza a Virus, and the Survival Data

Two Strains of Mice Were Infected with 5 $\times$ 10⁴ PFU of Influenza a Virus, and the Survival Data