A 20-year-old woman comes to the office due to blisters around her mouth associated with a mild burning sensation. She reports that she has been having frequent recurrence of these lesions, which resolve spontaneously within a few days. She has no medical problems and does not take any medications. Physical examination findings are shown in the image below. It is determined that the causative organism of this patient's condition remains in a latent state in the neuronal cell bodies of sensory ganglia. Upon reactivation, the virus is transported through the nerve axon to the skin. Which of the following proteins is most likely involved in the transport process leading to disease recurrence?

Question

A 20-year-old woman comes to the office due to blisters around her mouth associated with a mild burning sensation.  She reports that she has been having frequent recurrence of these lesions, which resolve spontaneously within a few days.  She has no medical problems and does not take any medications.  Physical examination findings are shown in the image below.  It is determined that the causative organism of this patient's condition remains in a latent state in the neuronal cell bodies of sensory ganglia.  Upon reactivation, the virus is transported through the nerve axon to the skin.  Which of the following proteins is most likely involved in the transport process leading to disease recurrence?

Quizplus · Accepted Answer

11ec160b_3790_f1f0_9249_1f0862c006e0_MD0001_00 This patient is suffering from recurrent bouts of herpes labialis ("cold sores"), which is most commonly caused by herpes simplex virus 1 (HSV-1). Primary infection occurs following contact with an affected individual's saliva. Although it is often asymptomatic, infection can result in painful blister formation on the oral mucosa and surrounding skin of the mouth and lips. After resolution of the initial infection, the virus enters a latent phase where viral particles lay dormant in neural sensory ganglia (most commonly the trigeminal). Reactivation of the virus occurs during times of stress or illness, resulting in recurrence of the characteristic perioral vesicular lesions. During reactivation, HSV particles rely on anterograde axonal transport to reach the skin and oral mucosa. Anterograde axonal transport is mediated by kinesin, a motor protein that moves intracellular cargo (eg, organelles, viral particles) away from the nucleus, down the axon, and toward the nerve terminal. Kinesin-mediated movement is powered by ATP hydrolysis and guided by microtubule filaments, which function as an intracellular "track" system. (Choice A) Dynein is a microtubular motor protein that participates in retrograde axonal transport (ie, moving organelles toward the nucleus). Dynein is important in establishing the latent phase following primary HSV infection by transporting viral particles to the neural sensory ganglia. However, it is not responsible for disease recurrence. (Choice C) Lamins are proteins that help form the fibrillar network that lines the inside of the nuclear envelope. In addition to providing structural support, they also help to organize the genome and regulate gene transcription. (Choice D) Selectins are a group of cell adhesion molecules that are expressed on endothelial cells during the inflammatory response. They function to bind leukocytes, allowing them to exit blood vessels at the site of inflammation. (Choice E) Spectrin is a cytoskeletal protein located intracellularly along the plasma membrane. It is responsible for maintaining the distinct shape of red blood cells. Protein defects may result in hereditary elliptocytosis and spherocytosis. (Choice F) Vimentin is a type of intermediate filament expressed in mesenchymal cells. It is responsible for securing organelles inside the cytosol and provides resistance to mechanical stress. Educational objective: Kinesin is a microtubule-associated motor protein that functions in the anterograde transport of materials and organelles within cells. Reactivation of latent herpes simplex virus requires anterograde transport of viral particles from neuronal cell bodies in the sensory ganglia to the skin and oral mucosa.

A 20-Year-Old Woman Comes to the Office Due to Blisters