Fig. 1

Identification of pQE80L-rFel d 1-Can f 1 A. Double digestion identification of recombinant plasmids (M. DL5000 DNA marker; 1. pQE80L-rFel d 1-Can f 1 recombinant plasmid; 2. pQE80L-rFel d 1-Can f 1 recombinant plasmid digested by BamH Ⅰ and Sal Ⅰ); B. PCR identification of recombinant plasmids (M. DL5000 DNA marker; 1. pQE80L-rFel d 1-Can f 1 recombinant plasmid; 2. pQE80L-rFel d 1-Can f 1 recombinant plasmid PCR validation)"

Fig. 2

Expression, purification and identification of rFel d 1-Can f 1 A. Prokaryotic expression and purification of recombinant protein rFel d 1-Can f 1 (M. Protein amount standard; IPTG-. Expression product of the induced bacteriophage without IPTG; IPTG +. Expression product of the induced bacteriophage with IPTG; S. Supernatant Effluent of the broken supernatant of the bacteriophage; E1-E6. Fractions eluted at different times by affinity purification of the nickel column); B. Western blot analysis of recombinant protein rFel d 1-Can f 1 (M. Protein amount standard; 1. Purified rFel d 1-Can f 1)"

Fig. 3

Characterization of LDH A. Laser particle size analysis of LDH; B. Field emission transmission electron microscopy analysis of LDH"

Fig. 4

Adsorption test of LDH with rFel d 1-Can f 1 M. Protein amount standard; 1. LDH; 2. rFel d 1-Can f 1; 3 to 9. LDH was loaded with rFel d 1-Can f 1 in mass ratios of 3 ∶1, 4 ∶1, 5 ∶1, 6 ∶1, 7 ∶1, 8 ∶1, and 9 ∶1, respectively"

Fig. 5

Protective effect of LDH-rFel d 1-Can f 1 on allergic reactions induced by cats and dogs A. Schematic diagram of immunization steps of LDH-rFel d 1-Can f 1; B. Stress allergic reaction caused changes in body temperature in mice; C. The area statistical chart surrounded by the body temperature change curve of mice and Y=0; D. IgE levels in mouse serum. n=6, **. P < 0.01, NS. P>0.05"

Fig. 6

Mouse ear prick test A. Normal mice (Naive); B. Allergic mice model group (Allergic mice); C. LDH-rFel d 1-Can f 1 immune group (LDH-rFel d 1-Can f 1); D. Statistical plot of mouse ear prick. The red arrow indicates the area penetrated by the Evans blue dye. n=6, **. P < 0.01"

Fig. 7

HE staining of mouse lung tissue A. Normal mice (Naive); B. Allergic mice model group (Allergic mice); C. LDH-rFel d 1-Can f 1 immune group (LDH-rFel d 1-Can f 1); D. Statistical plot of the degree of lung tissue cell infiltration in mice. The black arrow indicates the area where the invaded cells accumulate. n=6, *. P < 0.05"

Fig. 8

Serum IgG, IgG1, and IgG2a levels of mice A. IgG levels in mice serum; B. IgG1 levels in mice serum; C. IgG2a levels in mice serum; D. Changes in IgG2a/IgG1. n=6, *. P < 0.05, **. P < 0.01, ***. P < 0.001"