Explanation:

About LY6e Protein

• LY6e was discovered in 2017, during research, in order to identify genes that prevent coronavirus infections. 
• Since then, further investigations have shown that the protein exerted this inhibitory effect on all analyzed coronaviruses. 
• This was validated in an animal model. Mice lacking Ly6e in immune cells were found highly susceptible to a normally non-lethal mouse coronavirus and succumb to infection. 

About  PLpro 

• Usually, when a virus attacks human cells, the infected body cells release messenger substances known as ‘type 1 interferons’ which attract the killer cells in human bodies. These killer cells kill the infected cells and save humans from getting sick.
• When the novel coronavirus (SARS-CoV-2) enters a human cell, it hijacks the cell mechanism and fights back by letting the human cell produce PLpro.

Hence option 2nd is correct.