If you can't stand up for yourself (some people are just very nice, have a hard time doing that, etc), then your boss should stand up for you.
Email or speak directly to your boss that you've been getting teased about Russian stuff after the meeting, and it's interfering with your work performance. You're not sure how to tell the rest of the staff to please leave it alone, so you're asking your boss to step in.
Any boss worth their salt will step up to the plate and straighten the team out. Some coworkers think razzing each other builds morale (eg: might have a couple of coworkers that constantly prank each other.. that's their thing, they love it, and it creates a bond between them). What creates flak is when an action coworkers do that builds a bond between others is what they do to someone else that doesn't like that similar action (in this case, teasing), and the folks have such a low EQ (emotional quotient) to pick up on the fact that you're not liking it.
A bad boss will handle this by telling you to stand up for yourself, take care of this yourself, stop wasting their time. Start looking for another job if that's the case. This is not a boss that has your back, and doesn't realize that small things they let slide today turn into major issues that drive away employees tomorrow.
A so-so boss will have a "come to jesus" meeting with the offenders and make it a negative experience for them.. basically reaming them out like a parent scolding a child.. or they'll bring it up in the next team meeting in awkward fashion "I'm not gonna name names, but some people have been teasing others" (and immediately the folks teasing you know you narc'ed them out and hate you more).
A good boss will get with the offenders one by one or in a group, and explain to them firmly but politely that some people don't respond to teasing the same way others do. That teasing can feel like personal attacks, and, as the boss, it's his/her job to make sure everyone on the team functions well together. So, if the teasing is creating tension in the group, it creates lowered work performance, lower morale, and is not conducive to a good work environment. If folks want the PRIVILAGE of teasing (yes, it's a privilage, b/c it's an extracurricular activity that isn't mandatory for work to happen) then they must also have the RESPONSIBILITY to know when someone they're teasing isn't responding well to it and how that is affecting that person's self esteem and their role in the team. As the boss, it's their job to make sure things get done, and to ensure the team runs smoothly.
How this plays out also depends on if you have professional coworkers, or unprofessional ones. Professional ones simply need to have something pointed out and they go "oh, I never thought it was hurting them.. sorry.. I won't do it again." These are reasonable people that we all hope to work with.
Unprofessional employees will get upset that they feel someoen narc'ed on them, and are some how having some form of power stripped away from them. (Teasing is ultimately a power trip... some people do it to try to test others and run them down to see who stands up for themselves and who wilts. Teasing and bullying are forms of social dynamic darwinism where some folks feel the need to harass others to find some form of pecking order.. who will stand up to them, who will dominate them, and who they can keep kicking around.)
Unprofessional employees also won't respect yours or the boss' wishes, and keep trying to slyly sneak the teasing in. They'll down-play it and switch to using glances to each other at meetings and smirks, or will do passive-aggressive BS to try to irritate you.
If it escalates, then you go to HR.. b/c either your coworkers are unprofessional and don't realize they need to get their s*** together, or they don't respect your boss when s/he tells them to get their s*** together. So, head to HR, explain the situaiton, and start getting it documented. Because when folks get away with things, they tend to escalate it. So, you need to have documentation of what's going on happening sooner rather then later.
Depending on how bad this teasing is, HR may step in immediately, or simply document a complaint, or go speak to your boss... If you're a timid person, you may be downplaying the teasing.. what you consider "teasing" others may consider full-blown harassment. If HR decides it's harassment, then the individuals could have to go to sensitivity training or start facing some serious repercussions at the job.
1) next time they tease you, stop them politely and calmly explain that the jokes are getting old and it's making you uncomfortable, so you'd like them to stop. And use the word "uncomfortable". That is a polite keyword most people understand means "I'm feeling harassed". Don't say "unhappy" or what-not.. "uncomfortable" is the word you need to use.
2) if they don't stop (or escalate), then speak with your boss.. tell him / her you're feeling uncomfortable (again.. use that word specifically)
3) if your boss can't make them stop, or they simply switch to passive-aggressive BS after a good talking-to from the boss... head to HR... use the word "uncomfortable" with them, watch their eye brows raise and their faces get serious, and they'll start documenting things and getting the ball rolling on the teasers being straightened out.