Can you paint over a latex high gloss paint with latex primer without sanding first?

You didn't mention whether you were using latex or oil based primer and paint, but generally the point of using primer is so that you can paint over it with any form of wall paint. Just read the label on your primer can to make sure it is compatible. On the other hand, if you wanted to paint the primer over the satin gloss, you need to sand the surface lightly to remove the sheen of the paint and provide a suitable surface for the primer to adhere properly.