In order for a virus to infect a cell, it has to be able to bind to one or more receptors on the cell's surface (often proteins on the cell's surface, but can be other things like specific lipids in the cell membrane, or carbohydrates on the membrane's surface) and use them as a foothold to somehow deliver its genetic information into the cell.
If a cell doesn't have the right receptors on its surface, the virus can't grab on to them, and that affects which kinds of cells it can infect. For instance, HIV uses receptors such as CCR5 and CXCR4 to enter certain kinds of white blood cells - cells that don't have those receptors, (e.g. pretty much any other kind of cell in our bodies) can't be infected by HIV. Changes in the receptor's structures can also affect binding ability - for instance, you may have heard about people who are naturally resistant to HIV because they have a mutation in CCR5.
It's also worth noting that successful infection often requires successful interactions with multiple different kinds of receptors and not just a single one - so if a cell doesn't have the right mix of other receptors on its surface, it may not get infected even if it also has what researchers have determined to be the "primary" receptor.
Presumably, the epithelial cells in the hands, feet, and mouth just happen to have the right mix of receptors that enable infection by coxsackievirus A16 (or enterovirus 71, the other main virus that can cause hand, foot, and mouth disease). This paper says a protein called SCARB2 is a receptor used by both coxsackievirus A16 and enterovirus 71, and this paper indicates that certain carbohydrates on the cell membrane are also necessary for infection by coxsackievirus A16.
the_dan_man t1_iwsl3zh wrote
Reply to Why does hand foot and mouth disease (coxsackievirus) cause blisters in the hands, feet, and mouth? by aubergine_alibi_
In order for a virus to infect a cell, it has to be able to bind to one or more receptors on the cell's surface (often proteins on the cell's surface, but can be other things like specific lipids in the cell membrane, or carbohydrates on the membrane's surface) and use them as a foothold to somehow deliver its genetic information into the cell.
If a cell doesn't have the right receptors on its surface, the virus can't grab on to them, and that affects which kinds of cells it can infect. For instance, HIV uses receptors such as CCR5 and CXCR4 to enter certain kinds of white blood cells - cells that don't have those receptors, (e.g. pretty much any other kind of cell in our bodies) can't be infected by HIV. Changes in the receptor's structures can also affect binding ability - for instance, you may have heard about people who are naturally resistant to HIV because they have a mutation in CCR5.
It's also worth noting that successful infection often requires successful interactions with multiple different kinds of receptors and not just a single one - so if a cell doesn't have the right mix of other receptors on its surface, it may not get infected even if it also has what researchers have determined to be the "primary" receptor.
Presumably, the epithelial cells in the hands, feet, and mouth just happen to have the right mix of receptors that enable infection by coxsackievirus A16 (or enterovirus 71, the other main virus that can cause hand, foot, and mouth disease). This paper says a protein called SCARB2 is a receptor used by both coxsackievirus A16 and enterovirus 71, and this paper indicates that certain carbohydrates on the cell membrane are also necessary for infection by coxsackievirus A16.