Column X enlists some of the common animal viruses, and Column Y enlists cell surface proteins that serve as their receptors.

Column X	Column Y
A. Hepatitis A virus	i. Immunoglobulin superfamily
B. Rotavirus	ii. Acetylcholine receptor on neurons
C. Polio virus	iii. Alpha 2-macroglobulin
D. Rabies virus	iv. Acetylated sialic acid on glycoprotein

Which one of the following options represents the correct match between columns X and Y?

Correct option is A

Explanation:

Let’s match each virus from Column X to its receptor from Column Y:​

A. Hepatitis A Virus:

• Receptor: Alpha 2-macroglobulin (iii)
  Hepatitis A virus (HAV) binds to Alpha 2-macroglobulin as its receptor on the surface of liver cells. This receptor is a major protein involved in the immune response, but it also facilitates the entry of the virus into host cells.

  • Alpha 2-macroglobulin plays a role in the immune system's defense, but it also inadvertently serves as the entry point for Hepatitis A virus.

  • Hepatitis A typically affects liver cells, and the binding to this receptor is a crucial step in viral infection.

B. Rotavirus:

• Receptor: Acetylated sialic acid on glycoprotein (iv)
  Rotavirus infects cells in the gastrointestinal tract, and its primary receptor is acetylated sialic acid found on glycoproteins on the surface of epithelial cells in the small intestine.

  • Sialic acid residues are commonly found on the glycoproteins of the cell membrane. Rotavirus binds to these residues, which helps it enter the cell and start the infection.

  • The acetylation of sialic acid is a modification that enhances the binding of the virus to the cells.

C. Polio Virus:

• Receptor: Immunoglobulin superfamily (i)
  Polio virus binds to the immunoglobulin superfamily of proteins, specifically CD155 (also known as the poliovirus receptor) on the surface of host cells.

  • The CD155 receptor is a member of the immunoglobulin superfamily. It is found on the surface of many cells, including motor neurons, which makes it the perfect target for polio virus to enter and infect.

  • Polio virus has a highly specific interaction with CD155, allowing it to initiate infection, particularly in the central nervous system.

D. Rabies Virus:

• Receptor: Acetylcholine receptor on neurons (ii)
  Rabies virus primarily infects neurons and binds to the acetylcholine receptor on their surfaces.

  • The acetylcholine receptor is a type of neurotransmitter receptor found in nerve cells, and it plays a key role in the transmission of signals between nerve cells. Rabies virus uses this receptor to enter and spread within the nervous system.

  • The binding of the rabies virus to acetylcholine receptors facilitates the virus's entry into the neuron, allowing it to spread to the brain and cause the severe neurological symptoms associated with rabies.