Two is better than one: advances in pathogen-boosted immunotherapy and adoptive T-cell therapy

The recent tremendous successes in clinical trials take cancer immunotherapy into a new era and have attracted major attention from both academia and industry. Among the variety of immunotherapy strategies developed to boost patients' own immune systems to fight against malignant cells, the pathogen-based and adoptive cell transfer therapies have shown the most promise for treating multiple types of cancer. Pathogen-based therapies could either break the immune tolerance to enhance the effectiveness of cancer vaccines or directly infect and kill cancer cells. Adoptive cell transfer can induce a strong durable antitumor response, with recent advances including engineering dual specificity into T cells to recognize multiple antigens and improving the metabolic fitness of transferred cells. In this review, we focus on the recent prospects in these two areas and summarize some ongoing studies that represent potential advancements for anticancer immunotherapy, including testing combinations of these two strategies.