Even though they came from a prestigious work and school background as you said, they're there working with you in the end. Which must mean you're pretty darn smart and capable of the job, and you don't need to talk up a big game or kiss ass to be there, like they probably had to do. They sound like a pack of you know whats if they have an issue with you tbh maybe they're feeling insecure because 'someone like you' is there working with them on their high horse level. Have you taken the initiative before, like for you and your coworkers to go out for lunch or a drink after work? Sometimes waiting for an invite isn't the best move, if you can set something up yourself maybe that can help? Atleast if they refuse you can be entirely sure of their stance with you. Also, why can't you bring it up with a manager or HR? This sounds like classic workplace bullying to me, it's also blatant ableist behaviour. Your workplace hired them to work and be a team, not to bitch about you and treat you poorly.