NLRP3 Plays a Key Role in Antihelminth Immunity in the Enteral and Parenteral Stages of Trichinella spiralis-Infected Mice.

Trichinellosis is an important foodborne zoonosis, and no effective treatments are yet available. Nod-like receptor (NLR) plays a critical role in the host response against nematodes. Therefore, we aimed to explore the role of the NLRP3 inflammasome (NLRP3) during the adult, migrating, and encysted stages of Trichinella spiralis infection. The mice were treated with the specific NLRP3 inhibitor MCC950 after inoculation with T. spiralis. Then, the role that NLRP3 plays during T. spiralis infection of mice was evaluated using enzyme-linked immunosorbent assay (ELISA), Western blotting, flow cytometry, histopathological evaluation, bone marrow-derived macrophage (BMDM) stimulation, and immunofluorescence. The in vivo results showed that NLRP3 enhanced the Th1 immune response in the adult and migrating stages and weakened the Th2 immune response in the encysted stage. NLRP3 promoted the release of proinflammatory factors (interferon gamma [IFN-γ]) and suppressed the release of anti-inflammatory factors (interleukin 4 [IL-4]). Pathological changes were also improved in the absence of NLRP3 in mice during T. spiralis infection. Importantly, a significant reduction in adult worm burden and muscle larvae burden at 7 and 35 days postinfection was observed in mice treated with the specific NLRP3 inhibitor MCC950. In vitro, we first demonstrated that NLRP3 in macrophages can be activated by T. spiralis proteins and promotes IL-1ß and IL-18 release. This study revealed that NLRP3 is involved in the host response to T. spiralis infection and that targeted inhibition of NLRP3 enhanced the Th2 response and accelerated T. spiralis expulsion. These findings may help in the development of protocols for controlling trichinellosis.

Immune responses induced by recombinant Lactobacillus plantarum expressing the spike protein derived from transmissible gastroenteritis virus in piglets.

Transmissible gastroenteritis coronavirus (TGEV) is one of the most severe threats to the swine industry. In this study, we constructed a suite of recombinant Lactobacillus plantarum with surface displaying the spike (S) protein coming from TGEV and fused with DC cells targeting peptides (DCpep) to develop an effective, safe, and convenient vaccine against transmissible gastroenteritis. Our research results found that the recombinant Lactobacillus plantarum (NC8-pSIP409-pgsA-S-DCpep) group expressing S fused with DCpep could not only significantly increase the percentages of MHC-II+CD80+ B cells and CD3+CD4+ T cells but also the number of IgA+ B cells and CD3+CD4+ T cells of ileum lamina propria, which elevated the specific secretory immunoglobulin A (SIgA) titers in feces and IgG titers in serum. Taken together, these results suggest that NC8-pSIP409-pgsA-S-DCpep expressing the S of TGEV fused with DCpep could effectively induce immune responses and provide a feasible original strategy and approach for the design of TGEV vaccines.

Dissection of the cecal microbial community in chickens after Eimeria tenella infection.

BACKGROUND: Eimeria spp. are responsible for chicken coccidiosis which is the most important enteric protozoan disease resulting in tremendous economic losses in the poultry industry. Understanding the interaction between the avian cecal microbiota and coccidia is of interest in the development of alternative treatments that do not rely on chemotherapeutics and do not lead to drug resistance. METHODS: We utilized 16S rRNA gene sequencing to detect the dynamics of the cecal microbial community in AA broilers challenged with Eimeria tenella. Histopathological analysis of the cecum was also conducted. RESULTS: We found that microbial shifts occur during the infection. Lactobacillus, Faecalibacterium, Ruminococcaceae UCG-013, Romboutsia and Shuttleworthia decreased in abundance. However, the opportunistic pathogens Enterococcus and Streptococcus increased in abundance over time in response to the infection. CONCLUSIONS: Eimeria tenella disrupts the integrity of the cecal microbiota and could promote the establishment and growth of potentially pathogenic bacteria. Defining bacterial populations affected by coccidial infection might help identify bacterial markers for intestinal disease as well as populations or species that could be beneficial in maintaining and restoring gut homeostasis during and after infection with E. tenella.