Studies indicate that many language teachers have a tendency to view language as an abstract linguistic system and are, therefore, hesitant to acknowledge new dimensions of literacy and that learning a language in the digital age involves new communicative competencies including the ability to construct knowledge collaboratively and create and interpret texts that combine various resources made available by digital technologies. The main purpose of this thesis was to investigate the Technological Pedagogical Content Knowledge (TPACK) of language teachers engaged in the digital literacy practice of producing a multimodal ensemble with machinima with a view to proposing an updated TPACK model for integration of digital literacies into language teacher education. To this end, language teachers participated in a course specifically designed to train them to make machinima videos as well as prompt them to reflect on the affordances of the tool and their transformative effect on the concepts of language and literacy. Findings show that while participating teachers express traditional views of literacy, they demonstrate profound knowledge of multimodal composition by collaboratively constructing complex mode relationships during the machinima production process. Findings also suggest that if digital literacies are seen as encompassing the ability to adapt affordances and constraints of digital technologies to particular circumstances, then, teachers possess digital literacies as they enact the affordances and overcome the constraints of digital technologies through synaesthesia, spontaneous improvising and coaction. This thesis proposes a reconceptualisation of the Content Knowledge domain to include ecological perspectives on language and language learning and teaching and a metalanguage that would enable teachers to discuss and explain the creation of various mode relationships enabled by digital tools. The TPACK model proposed in this thesis allows for the consideration of concepts such as multimodal meaning-making, synaesthesia and coaction which are deemed to be relevant to a discussion of digital literacies within language teacher education programmes.