Figure 1.
Effect of Immunization on Mice Infested with Virus-Infected and -Uninfected Ticks
Comparison of immunization with either 64TRP antigens, a commercial TBEV vaccine, or the commercial anti-tick vaccine (TickGARD) on (A) transmission = % uninfected nymphal ticks that became infected; (B) support = % mice supporting cofeeding virus transmission between an infected adult female tick and uninfected nymphs; and (C) survival = % mice that survived an infected tick bite (only animals surviving subsequent i.p. inoculation with 1,000 PFU TBEV were included in the analyses).
Table 1.
Evaluation of the 64TRP Anti-Tick Vaccine in Protecting Mice against Transmission of a Lethal TBEV Infection by Its Natural Vector, I. ricinus, and Comparison with Commercial Antiviral (FSME-IMMUN) and Anti-Tick (TickGARD) Vaccines
Table 2.
Immunization Regimes
Figure 2.
Skin Histological Response in Immunized Mice Infested with Virus-Infected and -Uninfected Ticks
Histological profiles of skin sections taken at d 4 of TBEV-infected I. ricinus tick challenge on Balb/c mice immunized with either TRP2 (A, D), TRP5 (E), or GST (C, F), or unimmunized (B). Stained with hematoxylin and eosin (A–D) or “Hema Gurr” Rapid stain BDH (E, F) [19]. (A) (magnification 20×) TRP2-immunized animals, (B) (magnification 20×) control unimmunized, and (C) (magnification 20×) GST-immunized animals. Ep, epidermis; De, dermis; CC, cement cone of I. ricinus. (D–E) (magnification 63×) denote skin sections from TRP2 and TRP5 immunized mice, respectively, showing: perivascular cuffing = yellow circle; degranulating mast cells = green arrow; numerous lymphocytes = blue arrow; frequent macrophages = yellow arrow; and some eosinophils = white arrow; dermal dendrocytes = black arrow; neutrophils = gray arrow; and basophils = light blue arrow. (F) (magnification 63×) skin sections from GST control immunized mice showing lymphocytes, macrophages, and dermal dendrocytes.
Figure 3.
Skin Immunocytochemical Profile of Immunized Mice Infested with Virus-Infected and -Uninfected Ticks
Immunocytochemical profiles of skin sections taken at d 4 of TBEV-infected I. ricinus tick challenge on Balb/c mice immunized with either GST (A, B) or TRP5 (C, D), or unimmunized (E, F), using rat anti-mouse CD4+ antiserum (B, D, and F) and rat anti-mouse CD8+ (A, C, and E) antiserum, with a negative control sample (G, PBS plus normal rabbit serum). (C) TRP5-immunized mice: red arrowheads = numerous CD8+ T cells; red circles = CD8+ T cells occluding the dermal blood vessels; and (D) yellow arrows = CD4+ T cells. (E) and (F) unimmunized mice, few CD8+ T cells = red arrows and CD4+ T cells = yellow arrows/yellow circle, respectively. (B) Control GST-immunized mice yellow arrows = few CD4+ T cells. (G) PBS-negative control skin sample = no T cells. Magnification 20×.