Quantifying innate immune response of an insect host challenged by non‐replicative immune inducers

Non‐linear immune response is one of the causes of multi‐stability of infection outcomes. In order to avoid the uncertainty caused by multi‐stability in experiments, one needs to quantitatively measure immune response and other traits as well. Here, we took a quantitative approach, which combines mathematical model and time‐series data, to measure the immune response of the Tenebrio moliter challenged by non‐replicative immune inducers. The results showed that the host immunity that characterized by in‐vitro bacterial killing rapidly mounted after immune challenging, then slowly declined to an undetectable level within 100 h. We then quantified the immunity at 15 h after challenging. The results showed that immune response was non‐linearly correlated with the titter of inducer, which fits well to a Hill‐like function. Our results have verified the non‐linear immune response with respect to amount of invading pathogens and may also help to rigorously test the concepts and theories in host–pathogen interaction, such as resistance and tolerance. We took a quantitative approach to measure the immune response of the Tenebrio moliter. We found that immune response was non‐linearly correlated with the titter of inducer and fits well to a Hill‐like function. Our work can help to rigorously test the concepts and theories in host–pathogen interaction, such as resistance and tolerance.