C# Log4Net - How to increase/decrease indenting when stepping in/out of methods

I'm performing some data driven testing and using the log file as one of the testing outputs. It works something like this-

• Read first file in folder
  • Process first line and convert to a test
  • Run Test
    • Perform Validation 1
    • ...
  • ...
• Read next file
• Etc.

My log file reflects this:

INFO - Start RunAllFilesInFolder  
INFO - File1:
INFO -      Some info
INFO -      Executing Test 1  
INFO -          Validation A result
INFO -          ...
INFO -      ...  
INFO - File2:  
...

At the moment I use/call Log 4 net like this-

static class LogHelper
{
    internal static readonly log4net.ILog Log = log4net.LogManager.GetLogger
            (System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
}

// another file
using static Some.Namespace.LogHelper;
class SomeClass
{
     Log.Info($"{indent}Executing {t.Number}-{t.Name}");
}

Where indent = "\t", "\t\t" or "\t\t\t" depending on the level the test is in.

Is there a way to refactor the call to LogHelper.Log so that it takes into account a static "indent" that can be increased/decreased as I step into the different test levels without having to change the existing code calling it?