Limiting read access to virtual directory under full-trust

In MVC 5, support for medium trust is gone. Refer: http://stackoverflow.com/questions/21075735/microsoft-mvc-template-full-trust-microsoft-owin-alternatives

Medium trust, limited application's read access to virtual directory only. On shared hosting that is necessary requirement, so is there a way to limit asp.net mvc 5 application to virtual directory running under full trust?

I've already done what is written in the following KB article http://support.microsoft.com/kb/2698981

1. Each application is in seperate site.

2. Each application is in seperate app pool.

3. Each application has seperate ApplicationPoolIdentity.

But I don't know how i can limit read access to application's virtual directory only. It was previously done through Medium-Trust.

Thanks in advance and best regards