Defective interfering (DI) particles are virus-like byproducts of viral infections characterized by functionally important genomic deletions making them unable to infect cells. Therefore, they require virus particles for spreading the infection. While DI particles cannot survive in absence of the ‘helper’ viruses, during an infection they act as parasite interfering and competing with viruses on cellular and viral resources. For these reasons, DI particles have been proposed as antiviral therapeutics. In addition, it has been hypothesized that DI genome triggers the immune response but the principles underlying the competition between DI and viral particles in presence of the immune response are still unclear. Given that the immune response is spatially heterogeneous, we turn to ABMs to elucidate the spatiotemporal pattern of such type of infection. We defined the rules of interactions between particles based on our previous theoretical studies and we found a complex interplay between the immune system, the DI and the viral particles modulating the spread of infection. In addition, we clarify the role of the DI particles in causing a delay of the infection onset and of the activation of the immune response. Our results will be discussed along with experimental data.