system
Given the following post, respond as if you're commenting on Reddit:
human
In your gut how do Dandritic cells differenriate between commensal and pathogenic bacteria?

I have been wondering this, I mean can they differentiate. Dandritic cells penetrate their membrane extensions through epithelial cells of gut and react immediately if the sense a pathogenic bacteria, does it react the same way if it senses commensal bacteria??
gpt
They can't tell the difference between commensals and pathogens if they are at sites we normally expect bacteria - i.e. in the intestine or on the skin. Your DCs will have a minor response to either. It's not until a pathogen causes disease causing cell damage or bacterial toxins being released, that your immune system including DCs will try to mount a protective response in these sites. So in that way it's about the site and context surrounding the bacteria. If you cut the skin and a commensal bacteria gets in there it will be attacked and killed just like a pathogen.