Replace special chars not tags, php trigered by html

[Peuplarchie]

Good day to you all,
I working on a code which take a txt file and display it through php, but this thing is triggered by ajax.

      in the txt files there is html tags and html special chars.

What I'm trying to do is encode only the special chars.
ex : é è ì

Php read those character not a problem, it when I pass it by ajax that i get some weird chars like squares with a question mark.

Does anybody have an idea on how I can fix this ?

Here is the code that get triggered when i click on a ajax link :

<?php
$textsectb = file_get_contents('dep_en_tb.txt');
$textsechttb = htmlentities($textsectb);
echo $textsechttb;
?>

I only need to replace the special char not the html tags.

Thanks!