Cytokines in brucellosis: biological rhythm at the interface of innate and adaptive immunity

Design of an oral vaccine using Lactococcus lactis against brucellosis: an in vitro and in vivo study

Brucellosis is regarded as one of the world's most severe zoonotic diseases. This study aimed to investigate the possibility of using recombinant Lactococcus lactis (L. lactis) as a live vector to produce recombinant Brucella abortus (B. abortus) Omp10. The gene sequences were obtained from GenBank. The proteins' immunogenicity was assessed using Vaxijen. After confirming the cloning of the Omp10 gene in the pNZ8148 vector by enzymatic digestion and PCR, transformation into L. lactis was done. SDS-PAGE and western blot methods evaluated omp10 protein expression. Mice received oral recombinant L. lactis vaccines. IgG antibodies against Omp10 were tested using ELISA. Real-time PCR and ELISA were used to analyze cytokine responses. Survival rate and histopathological changes were evaluated after the challenge. Omp10 was chosen for its 1.5524 antigenicity score. Enzymatic digestion and PCR identified a 381-bp gene fragment. A 10 kDa band indicated the success of L. lactis transformation. Mice administered the L. lactis-pNZ8148-Omp10-Usp45 vaccination 14 days after priming showed significantly higher Omp10-specific total IgG and IgG1 (P < 0.001) than the PBS control group. The mice who received the L. lactis-pNZ8148-Omp10-Usp45 and IRBA vaccines had significantly elevated levels of IFN-γ, TNFα, IL-4, and IL-10 in samples collected on days 14 and 28 (P < 0.001). Inflammatory response, morphological damage, alveolar edema, and lymphocyte infiltration were reduced in the target group. A recombinant L. lactis expressing the Omp10 protein was constructed as an oral Lactococcus-based vaccine and compared to live attenuated vaccines for future brucellosis investigations.

Roles of novel IL-1 family (IL-36, IL-37, and IL-38) members in chronic brucellosis

The secretion of interleukin (IL)-1 family cytokines is one of the most potent and earliest pro-inflammatory responses triggered by brucellosis. However, the roles of the most recently discovered IL-1 family members, IL-36, IL-37, and IL-38, in the transition into the chronic form of brucellos is remain largely unknown. Therefore, in this study, the roles of IL-36, IL-37, and IL-38 in brucella infections and their effects on the transition from the acute to chronic form of the disease were investigated. Using peripheral blood samples from 40 patients with acute brucellosis, 40 patients with chronic brucellosis, and 40 healthy control subjects, we analysed the serum concentrations of secreted IL-36, IL-37, and IL-38 using ELISA. The findings were confirmed by using RT-qPCR to analyse the mRNA levels of the genes encoding IL-36, IL-37, and IL-38 in peripheral blood mononuclear cells (PBMCs) from 10 randomly selected patients from each of the three groups. Our results showed that serum IL-37 (p < 0.001) and IL-38 (p < 0.001) concentrations were lower in patients with brucellosis than in the healthy controls. In addition, serum IL-37 and IL-38 concentrations were higher in the chronic patient group than in the acute patient group. The mRNA expression levels of IL-37 and IL1F10, genes that encode IL-38, did not affect serum cytokine secretion levels. This result suggests that the high secretion levels of IL-37 and IL-38 may be related to the progression into the chronic form of brucellosis. Our findings will aid in clarifying the mechanism of the transition of brucellosis from the acute to the chronic form of the disease.