Nanoparticle-Based Vaccines for Brucellosis: Calcium Phosphate Nanoparticles-Adsorbed Antigens Induce Cross Protective Response in Mice

Figures & data

Figure 1 Scanning electron microscope of CaPNs.

Figure 2 Release profile of different antigens-CaPNs at pH 7.4 and 37 °C for 96 hours (data are mean± SD, n = 3).

Figure 3 The specific antibody levels in different dilutions of mice sera after immunization with BhuA-, FliC-, 7α-HSDH-, poly B-, poly T-, and poly B+T-CaPNs. (A) After the first immunization. (B) After the second immunization. (C) After the third immunization.

Figure 4 IgG subtypes in mice sera after immunization with different vaccine formulations.

Figure 5 Splenocyte proliferative responses of different mice groups. Data are the mean SI ± SD of three mice from each group were evaluated in triplicate. Statistically significant difference (p < 0.05) with the control groups is indicated by an asterisk.

Figure 6 The levels of IFN-γ (A), IL-2 (B), and IL-10 (C) production by splenocytes of immunized mice with BhuA-, FliC-, 7α-HSDH-, poly B-, poly T-, poly B+T-CaPNs, Rev.1 and RB51. Statistically significant difference (p < 0.05) compared to the control groups is indicated by an asterisk.

Table 1 Protection Against B. melitensis 16M and B. abortus 544 Challenge in Immunized Mice

Vaccine	Log10 CFU of B. melitensis 16M in Spleen	Units of Protection	Log10 CFU of B. abortus 544 in Spleen	Units of Protection
PBS	5.77 ±0.38	0	5.29±0.27	0
CaPNs	5.67±0.33	0.1	5.15±0.16	0.14
BhuA+CaPNs	4.87±0.13*	0.9	4.44±0.19*	0.85
7α-HSDH+CaPNs	4.72±0.31*	1.05	4.26±0.1*	1.03
FliC+CaPNs	4.65±0.18*	1.12	4.29±0.14*	1
Poly B+CaPNs	4.59±0.19*	1.18	4.16±0.19*	1.13
Poly T+CaPNs	4.53±0.3*	1.24	4.08±0.33*	1.21
Poly B+T+CaPNs	4.27±0.33*	1.5	3.92±0.25*	1.37
B. melitensis Rev1	4.03±0.12*	1.74	–	–
B. abortus RB51	–	–	3.76± 0.22*	1.53

Notes: *Significantly different compared to the control groups (P < 0.05).