CHICAGO--(BUSINESS WIRE)--Fitch Ratings has upgraded three and affirmed 10 classes of Deutsche Bank Securities COMM 2010-C1 commercial mortgage pass-through certificates. A detailed list of rating actions follows at the end of this release. KEY RATING DRIVERS The upgrades reflect an increase in credit enhancement, defeasance, the expectation of future paydown due to upcoming loan maturities and the stable performance of the underlying collateral pool since issuance. Fitch modelled losses of 2.8