Macrophages, as a critical component of innate immune cells, exhibit significant plasticity. When confronted with danger signals such as pathogens or microenvironmental alterations, macrophages can differentiate into various phenotypes and functions to safeguard the host. However, numerous pathogens manipulate macrophage metabolic pathways to modify their functional expression, facilitating immune evasion and ensuring long-term survival during chronic infections. Therefore, the role of macrophage metabolic reprogramming in chronic infections has received growing attention. This review elucidates the primary metabolic pathways of macrophages and their association with polarization. It examines how pathogens modulate macrophage functional expression through metabolic reprogramming to sustain chronic infection. Additionally, it delineates how macrophage metabolic reprogramming in chronic infections reconfigures the microenvironment through interaction with other immune cells and its contribution to trained immunity.

After eight generations of laboratory selection with β-cypermethrin, a P. okadai strain was cultivated that displayed a 10.04-fold increase in resistance (RS) relative to the susceptible strain (SS), with an estimation of heritability (h²) of 0.34. Compared with the SS, the developmental duration of the eggs was significantly prolonged (p < 0.05); however, the pupal stage duration was shorter, with no statistically significant difference. Moreover, the levels of GSTs, CarEs, and CYP450 activity were notably higher in the RS than in the SS. In addition, the level of CarE and CYP450 activity in the RS was significantly higher in the midgut (MG), fat body (FB), and Malpighian tubules (MTs) compared to the SS; however, the GSTs showed no statistically significant difference in the MTs. These results suggest that P. okadai‘s resistance to β-cypermethrin could be selected rapidly and the decreases in the intrinsic rate of increase (r) observed in the RS are likely due to mutations in the detoxification enzyme genes under the strong selection pressure exerted by β-cypermethrin. The increased activity of GSTs, CarEs, and CYP450 was associated with β-cypermethrin resistance in the RS of P. okadai. The data reported herein provide a foundation for future studies on the mechanisms responsible for β-cypermethrin resistance in P. okadai.

In China, Phortica okadai is the only established vector for Thelazia callipaeda and transmits infective larvae to various animals feeding on ocular secretions. Insect opsins are key components of the visual system and play essential roles in host location. However, the opsin repertoire and phylogenetic relationships in P. okadai remain unknown. Here, we identified five opsin genes from adult P. okadai genomic data and profiled their expression across developmental stages and tissues by real-time polymerase chain reaction. The results showed that four opsin genes (PoRh1, PoRh3, PoRh5, and PoRh6) were predominantly expressed in adult compound eyes and peaked during the adult stage, suggesting important roles in vision-dependent behaviors of adult P. okadai. These findings provide a foundation for elucidating the visual mechanisms and host-seeking behavior of P. okadai.