It is well known that immunization of radiation-attenuated (RA) schistosoma cercariae or schistosomula can induce high levels of protective immunity against schistosoma cercariae reinfection in many animals. Many studies have shown that the Th1 cellular immune response is crucial for the protective effect elicited by RA schistosomula. However, the molecular mechanism of this strong protective immunity remains unclear. The expression profiles of Schistosoma japonicum calreticulin (SjCRT) in RA and normal schistosoma-derived cells were investigated by flow cytometry. The effect of recombinant SjCRT (rSjCRT) on mouse dendritic cells (DCs) was determined by FACS, ELISA and RT-PCR analysis. We also analyzed the effects of SjCRT on the activation of spleen cells from mice immunized with rSjCRT by detecting lymphocyte proliferation and the cytokine profiles of splenocytes. We found that the expression level of SjCRT in the cells from RA larvae was significantly higher than that in cells from normal schistosomula at early stages of development (day 4). The results of effect of rSjCRT on mouse DCs showed that rSjCRT could induce phenotypic and functional maturation of DCs, and SjCRT bound to the surface of DCs through the CD91 receptor and could be engulfed by DCs. The results of activation of splenocytes from mice immunized with rSjCRT also demonstrate that rSjCRT can effectively stimulate the proliferative response of splenic lymphocytes, elicit splenocytes from immunized mice to secrete high levels of IFN-γ, TNF-α and IL-4, and activate CD4+ T cells to produce high levels of IFN-γ. SjCRT is one of the immunostimulatory molecules released from RA schistosomula cells, might play a crucial role in conferring a Th1-polarized immune response induced by RA cercariae/schistosomula in mice, and is a candidate molecule responsible for the high levels of protective immunity induced by RA schistosomula.
Oocyte maturation and ovarian development are critical for insect reproduction. Vitellogenesis, the timely production and uptake of yolk proteins (YPs), is essential for female fecundity. Yps are synthesized in follicle cells and fat bodies, and are taken up by oocytes through endocytosis during insect oogenesis. In the silkworm, Bombyx mori, there are three Yps: vitellin, 30-kDa protein, and egg-specific protein (Esp). We discovered that a nucleus-enriched long-noncoding RNA (lncRNA) lncR26319 regulates Endophilin A (EndoA), a member of the endophilin protein family of endocytosis, by competitively binding to miR-2834. The lncR26319-miR-2834-EndoA axis is required for yolk endocytosis in the silkworm, loss of EndoA, or overexpression of miR-2834 leads to egg number reduction significantly in virgin moths. Accumulation of miR-2834 also causes abdomen protrusion of pupae and reduced female fecundity. Eggs laid by female mutants did not hatch. The expression of Yps such as vitellogenin (Vg), 30-kDa protein, Esp as well as vitellogenin receptor (VgR) was decreased after knockdown of EndoA or overexpression of miR-2834. These results show that lncR26319-miR-2834-EndoA axis contributes to the endocytic activity in the yolk uptake process, and lead to the normal progression of oogenesis in the silkworm. Thus, mir-2834 and endophilinA are crucial for female reproduction and will be potential target for pest control.
Staphylococcus aureus is a significant pathogen in dairy animals, particularly when it infects the mammary gland; however, its prevalence among dairy goats in China remains poorly understood. This study aimed to investigate the distribution and characteristics of S. aureus isolates in dairy goats across China. A total of 515 milk samples were collected from goats diagnosed with mastitis in 14 provinces. These samples underwent bacterial isolation and identification, capsular polysaccharides typing, spa typing, antimicrobial susceptibility testing, and assessment of antimicrobial resistance and virulence gene. The findings revealed the isolation of 61 S. aureus strains. The highest prevalence rate was recorded in 2018, at 20.4% (11 out of 54 samples), while the lowest prevalence rate was noted in 2023, at 5.2% (3 out of 58 samples). Among the five regions studied, southern China exhibited the highest prevalence rate of 17.5% (10 out of 57 samples), whereas northeastern China showed the lowest rate at 8.2% (8 out of 97 samples). Capsular polysaccharide type 5 emerged as the most prevalent, accounting for 52.5%, and spa type t521 was identified most frequently, at 19.7%. Notably, 52 isolates (85.2%) demonstrated multidrug resistance, displaying resistance to three or more antibiotics. The resistance rates of S. aureus isolates were significantly high to penicillin (95.1%), followed by enrofloxacin (82.0%), kanamycin (78.7%), and levofloxacin (77.0%). Trimethoprim-sulfamethoxazole exhibited the lowest resistance rate at 11.5%. Resistance rates varied across the five different regions. Additionally, eight genes associated with resistance to six classes of antimicrobials were detected, with the blaZ gene (93.4%) being the most prevalent at 93.4%. Furthermore, nine virulence-associated genes were identified, with clfA being the most common virulence gene, present in all isolates. In conclusion, most S. aureus isolates were multiresistant with diverse resistance patterns. Those diverse antimicrobial resistance profiles associated with corresponding resistance genes ( p < 0.05) were reported for the first time in S. aureus from caprine mastitis. Sulfonamides could be prioritized preferentially for the treatment of S. aureus mastitis.
Mucosal-associated invariant T (MAIT) cells, which are enriched in human blood and express a semi-invariant TCR chain, play important roles in conditions such as infectious diseases and cancer. The influence of age on levels and functional characteristics of circulating MAIT cells have not been fully addressed. Here we have collected blood samples from a large cohort of healthy Chinese individuals from newborn (cord blood) to the elderly and assessed the levels of circulating MAIT cells as well as their phenotype, activation and apoptosis status and cytokine expression profiles after in vitro stimulation. We found that the frequencies of circulating MAIT cells gradually increased in blood from newborns as they progressed into adulthood (20-40 years old) but then decreased during further progression towards old age (>60 years old). The lowered numbers of circulating MAIT cells in the elderly was correlated with a gradual increase of apoptosis. A majority of circulating MAIT cells expressed the chemokine receptors CCR5 and CCR6, and most also expressed CD8 and CD45RO. Few expressed CD69 in cord blood, but the frequency increased with age. Upon in vitro activation with PMA plus ionomycin or IL12 plus IL18, fewer MAIT cells isolated from the young adult group expressed IFN-γ, IL17A and Granzyme B then cells from other age groups while the proportion of cells that expressed TNF-α was similar. Taken together, our data provide information for guiding the assessment of normal levels and phenotypes of MAIT cells at different ages in healthy individuals and patients.
Abstract Background : 20-hydroxyecdysone (20E) plays important roles in insect molting and metamorphosis. 20E-induced autophagy has been detected during the larval–pupal transition in different insects. In Bombyx mori, autophagy is induced by 20E in the larval fat body. Long non-coding RNAs (lncRNAs) function in various biological processes in many organisms, including insects. Many lncRNAs have been reported to be potential for autophagy occurrence in mammals, but it has not been investigated in insects. Results : RNA libraries from the fat body of B. mori dissected at 2 and 6 h post-injection with 20E were sequenced, and comprehensive analysis of lncRNAs and mRNAs was performed. A total of 1035 lncRNAs were identified, including 905 lincRNAs and 130 antisense lncRNAs. Compared with mRNAs, lncRNAs had longer transcript length and fewer exons. 132 lncRNAs were found differentially expressed at 2 h post injection, compared with 64 lncRNAs at 6 h post injection. Thirty differentially expressed lncRNAs were common at 2 and 6 h post-injection, and were hypothesized to be associated with the 20E response. Target gene analysis predicted 6493 lncRNA-mRNA cis pairs and 42797 lncRNA-mRNA trans pairs. The expression profiles of LNC_000560 were highly consistent with its potential target genes, Atg4B, and RNAi of LNC_000560 significantly decreased the expression of Atg4B. These results indicated that LNC_000560 was potentially involved in the 20E-induced autophagy of the fat body by regulating Atg4B. Conclusions : This study provides the genome-wide identification and functional characterization of lncRNAs associated with 20E-induced autophagy in the fat body of B. mori. LNC_000560 and its potential target gene were identified to be related to 20-regulated autophagy in B. mori. These results will be helpful for further studying the regulatory mechanisms of lncRNAs in autophagy and other biological processes in this insect model.
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