devices. And yet, the microscopic origin of such effective, non-Hermitian models is not well understood. Here, we show that a non-Hermitian Hamiltonian emerges naturally in a double-quantum-dot-circuit-QED (DQD-circuit QED) set-up, which can be controllably tuned to the PT-symmetric point. This effective Hamiltonian, derived from a microscopic model for the set-up, governs the dynamics of two coupled circuit-QED cavities with a voltage-biased DQD in one of them. Our analysis also reveals the effect of quantum fluctuations on the PT symmetric system. The PT-transition is, then, observed both in the dynamics of cavity observables as well as via an input-output experiment. As a simple application of the PT-transition in this set-up, we show that loss-induced enhancement of amplification and lasing can be observed in the coupled cavities. Our results pave the way for an on-chip realization of a potentially scalable non-Hermitian system with a gain medium in quantum regime, as well as its potential applications for quantum technology.