Very interesting. There seems to have been a large settlement of Latins there. Perhaps it was an outpost near Samnite lands.
See:
"Interamna Lirenas was founded in 312 BC as a colony of Latins in an area perhaps already housing Volscan settlements, on the route of the Via Latina.[2] It was situated at the confluence of the Liri and Rio Spalla Bassa rivers, whence the name "Interamna" (meaning "between the rivers").[3]Interamna Lirenas served as a military base during the Samnite Wars, leading to its destruction by the Samnites in 294 BC.[4] It was again ravaged by Hannibal in 212 BC; since it later sided with Carthage, after the Carthaginian defeat at Zama in 202 BC it was forced by Rome to pay heavy tribute. It became a municipium in 90 BC. The site received further settled veterans ca. 40 BC.[5]"
https://en.wikipedia.org/wiki/Interamna_Lirenas
Whether he was of Latin origin or not, however, it shows that Rome was to some extent an upwardly mobile society. Someone from a backwater could rise through merit to become a Plebeian Tribune of Rome. There are other examples, of course. Not all that long afterwards, Vespasian, who certainly didn't come from an old senatorial family, rose to become Emperor.