Ryan Rego Ph.D. (@tickeurope.bsky.social)

Peromyscus leucopus, Mus musculus, and humans have distinct transcriptomic responses to larval Ixodes scapularis bites | Infection and Immunity Ixodes scapularis (formerly Ixodes dammini) ticks are the most important invertebrate vector of human diseases in North America (1). These ticks are responsible for spreading most cases of Lyme disease (predominantly caused by Borrelia burgdorferi sensu stricto in North America), which affects an estimated 476,000 individuals in the United States yearly (2), as well as six other human pathogens—Anaplasma phagocytophilum, Babesia microti, Borrelia miyamotoi, Borrelia mayonii, Ehrlichia muris eauclairensis, and deer tick virus/Powassan virus (3, 4). Tick feeding can trigger immunologic processes at the bite site in the skin, which may threaten the ability of the tick to survive during the blood meal (5). To prevent this from occurring, Ixodes ticks secrete saliva containing anticoagulants and immunomodulatory compounds into the feeding site, which dampens the host’s immune response and ensures that the tick can remain attached until completion of feeding (6–8). This secretion also contributes to the spread of B. burgdorferi into new hosts, both by providing a mechanism to exit the tick (9–11) and by dampening the immune response while the pathogen establishes the infection (12–19). https://journals.asm.org/doi/10.1128/iai.00065-25