Ixodes scapularis salivary gland protein 27 (SG27)

SG27 is a salivary gland protein from the black-legged tick, Ixodes scapularis, which is the primary vector for Lyme disease in North America [17, 23]. It is one of the 19 key antigens included in the 19ISP mRNA-LNP vaccine, a novel therapeutic approach designed to induce acquired resistance to ticks (ATR) in the host [23, 59]. By targeting SG27 and other salivary proteins, the vaccine triggers an immune response that interferes with the tick's ability to feed and remain attached to the host [28, 63]. This immune recognition often manifests as rapid erythema at the bite site, which serves as a biological signal for the host to remove the tick before pathogen transmission occurs [23, 28]. SG27 plays a role in the complex interface between the tick and the host's skin, facilitating the blood meal and potentially suppressing local host defenses [23, 31]. The development of vaccines targeting SG27 represents a shift from targeting the pathogen itself to targeting the vector's ability to transmit the disease [17, 43].

Other names

Salivary gland protein 27SG27 antigenI. scapularis SG27

Induction of acquired resistance to ticks (ATR) via host antibodies (IgG) that recognize SG27 in tick saliva, leading to early erythema, reduced feeding, and early detachment.