Analysis of Cellular Immune Responses in Lepidopteran Larvae

The immune system in insects is innate and relies both on humoral components and cellular response, which includes phagocytosis, nodulation, and encapsulation. Humoral and cellular defenses are inextricably linked in a complex immune reaction, modulated by a number of cross-talking pathways, which can result in a remarkable variability of any measurement. Protocols to assess the immune response are quite critical and should be carefully standardized, in order to achieve a desirable level of reproducibility. Here we report methods for measuring the cellular immune response in insects, using lepidopteran larvae as model. These protocols have been developed starting from the fragmented information available in the literature, which has been integrated and refined on the basis of our experience on the study of insect immunosuppression by parasitoids and pathogens.