Adjuvants in veterinary vaccines: modes of action and adverse effects

Vaccine adjuvants are chemicals, microbial components, or mammalian proteins that enhance the immune response to vaccine antigens. Interest in reducing vaccine-related adverse effects and inducing specific types of immunity has led to the development of numerous new adjuvants. Adjuvants in development or in experimental and commercial vaccines include aluminum salts (alum), oil emulsions, saponins, immune-stimulating complexes (ISCOMs), liposomes, microparticles, nonionic block copolymers, derivatized polysaccharides, cytokines, and a wide variety of bacterial derivatives. The mechanisms of action of these diverse compounds vary, as does their induction of cell-mediated and antibody responses. Factors influencing the selection of an adjuvant include animal species, specific pathogen, vaccine antigen, route of immunization, and type of immunity needed.     

枸杞多糖的免疫调节作用

枸杞多糖(LBP)对机体的免疫系统有积极的调节作用。综述了LBP对体液免疫、细胞免疫、单核巨噬细胞、NK细胞、空斑形成细胞、树突状细胞、细胞因子、受体表达、红细胞免疫、信号传导、神经-内分泌-免疫网络等的影响。LBP对体液免疫、细胞免疫、红细胞免疫有促进作用,能促进单核巨噬细胞、NK细胞、空斑形成细胞、树突状细胞、细胞因子的功能发挥,在受体表达、信号传导、神经-内分泌-免疫网络中起着积极的作用。     

Immunomodulatory effect of recombinant RNA‐dependent RNA polymerase protein of Macrobrachium rosenbergii nodavirus in giant freshwater prawn M. rosenbergii

The present study evaluated the role of recombinant RNA‐dependent RNA polymerase (RdRp) protein of Macrobrachium rosenbergii nodavirus (MrNV) in modulating the immune response and in reducing MrNV load in infected prawn. In the first experiment, prawns (25–30 g) were injected with recombinant RdRp protein (RP) at a concentration of 0, 1.0 and 10 μg, and immune parameters and expression of some immune‐related genes were measured up to 14 days post injection (p.i.). In the second experiment, early juveniles were injected with a similar dose of RdRp and animals were challenged by immersion with MrNV. The infection status was detected in muscles by nested RT‐PCR up to 21 days post challenge. Prawn injected with higher concentration of RP showed significantly higher total haemocyte count at different period post injection. Significant up‐regulation of immune‐related genes was observed within 24 h in prawn treated with lower dose of RP and after 7 days p.i. at higher level of RP injection compared with adult control. Most of the tested samples (63%) were found to be RT‐PCR positive for MrNV at 48 h of post‐immersion challenge. After 14 days, MrNV was detected only in control prawn, while both RP‐injected groups were MrNV negative. This study elucidated the potential viral load reduction role played by RdRP in MrNV‐infected prawn.     

Use of a Mycobacterial Cell Wall Extract (MCWE) in Susceptible Mares to Clear Experimentally Induced Endometritis With Streptococcus zooepidemicus

The ability of an immunomodulator, mycobacterial cell wall extract (MCWE), to clear uterine infection in susceptible mares after an experimental challenge withStreptococcus zooepidemicus was evaluated. Thirty mares susceptible to endometritis, based on the presence of uterine fluid during both diestrus and estrus, were selected from a herd of 896 and inoculated with a live culture of 5 × 10⁶ CFU of S. zooepidemicus on day 1 of estrus. Twenty-four hours later, mares were evaluated by ultrasonography, bacteriology, exfoliative cytology, and uterine biopsy to confirm infection. Forty-eight hours after inoculation, and on confirmation of uterine infection, mares were randomly assigned to one of four unbalanced experimental treatments to receive 1500 μg MCWE IU (n = 10) or IV (n = 10), or placebo IU (n = 5) or IV (n = 5). Mares were examined at ovulation and 7 days post-ovulation for uterine fluid via transrectal ultrasonography and for bacteriology, exfoliative cytology, and uterine biopsy. Efficacy was based on the ability of the mare to clear endometritis as determined by negative bacteriology and reduced numbers of polymorphonuclear cells (PMNs) on uterine biopsy. Because no statistical difference was detected between routes of administration on day 7 post-ovulation, the data sets were combined and re-analyzed to evaluate overall efficacy. Endometritis was observed in all placebo-treated mares 7 days post-ovulation, whereas treatment with MCWE resulted in the elimination of endometritis in 35% of the mares by the time of ovulation, and 70% of the mares by 7 days post-ovulation. Treatment with MCWE, compared with the placebo group, resulted in a significant decrease in the number of mares positive for endometritis at ovulation based on exfoliative cytology and bacteriology (P < .01) and at 7 days post-ovulation based on biopsy, exfoliative cytology, and bacteriology (P < .001). Results indicate that MCWE was an effective treatment for the elimination of endometritis caused by S. zooepidemicus in mares.     

The Effect of Mycobacterium Cell Wall Fraction on Histologic,Immunologic, and Clinical Parameters of Postpartum Involution in the Mare

Maintaining yearly foal production is important for the economic success of the broodmare, and this requires breeding to occur as quickly postpartum as possible. The initial postpartum estrus occurs within 5–20 days postpartum, whereas the uterus is still undergoing repair from tissue alterations during pregnancy and parturition, a process known as involution. Attempts have been made to hasten this process, but with minimal success. Mycobacterium cell wall fraction (MCWF) is an immunomodulator that has been shown to reduce bacterial growth and alter aspects of the immune response to breeding, but it is unknown if MCWF hastens the process of involution. Therefore, the objectives of this study were to (1) investigate the effect of MCWF on tissue remodeling, (2) assess the effect of MCWF on the local immune system of the uterus, and (3) determine the optimal treatment interval needed for these processes to occur. We hypothesize that repeated treatments of MCWF postpartum will hasten the process of involution. To study this, 16 pregnant mares of mixed breeds were evaluated postpartum. Control mares (n = 4) received 1.5 mL lactated Ringer’s solution intravenously on Day 1 (Day 0 = day of parturition) postpartum and again on Day 7, whereas treated mares either received 1.5 mL Settle intravenously on Day 1 and Day 7 (TX1; n = 6) or 1.5 mL Settle intravenously on Day 1 and then every 3 days until ovulation was detected (TX2; n = 6) and then evaluated until 15 days postpartum. Mares were assessed every 3 days for clinical, immunologic, and histologic parameters. Clinical parameters were assessed with transrectal ultrasonography and included ovarian activity, uterine fluid retention, and measurement of the uterine diameter, in addition to endometrial culture. Immunologic parameters included endometrial biopsies for quantitative polymerase chain reaction for expression of various cytokines (interleukin [IL]-1β, IL-1RN, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor [TNF], interferon [IFN]-γ, and granulocyte-macrophage colony-stimulating factor) in addition to endometrial cytology. Formalin-fixed endometrial biopsies were histologically assessed for the retention of microcaruncles, dilation of endometrial glands, and inflammation of the mucosa, stratum compactum, and spongiosum. Statistics were performed using SAS 9.4, using a mixed model for repeated measures with mare and treatment as a random effect. All post-hoc analysis was done using a Tukey’s honestly significant difference test. Involution was considered complete by Day 15 postpartum in all mares, and the day postpartum had a significant effect on almost all parameters investigated, indicating the immunologic process of involution. Treatment with MCWF decreased the magnitude of bacterial growth in addition to time to negative culture. In addition, MCWF increased the expression of IL-1β, IFNγ, and TNF. Although minimal treatment effect was noted histologically, a decrease in mucosal inflammation was seen in MCWF-treated mares. In conclusion, involution appears to be influenced by the immune system. In addition, MCWF appears to have a bactericidal effect on the postpartum mare, and this may be because of an increase in proinflammatory cytokines. It is unknown if this bactericidal property will improve fertility on the first estrous cycle postpartum, and future studies are needed to determine this.     

灵芝水溶性小分子化合物的生物活性研究

通过测定小鼠的肌糖原和肝糖原、采用抗肿瘤药物体外筛选试验、小鼠腹腔巨噬细胞吞噬试验,分别研究了灵芝水溶性小分子化合物(WSLMFGL,M＜10000Da)的抗疲劳、抗肿瘤和免疫调节活性.结果显示,当灵芝水溶性小分子化合物的灌胃剂量超过400mg/kg·d(12d)时,可显著提高小鼠的肌糖原和肝糖原贮备量,并呈剂量-效应关系;灵芝水溶性小分子化合物对小鼠Sarcoma-180型肿瘤细胞的抑制率达80%;灵芝水溶性小分子化合物的灌胃剂量与小鼠巨噬细胞吞噬能力的增强及免疫器官的增重存在剂量-效应关系.灵芝水溶性小分子化合物具有抗疲劳、抗肿瘤和免疫调节活性.     

Effect of CD151 on biological characteristics of human umbilical cord mesenchymal stem cells

AIM：To study the effect of CD151 on the biological characteristics of human umbilical cord mesenchymal stem cells (hUC-MSCs). METHODS：CD151 expression on hUC-MSCs was interfered by siRNA. The cells were divided into siRNA-CD151 group and negative control group (treated with siRNA-NC). The efficiency of interference after 72 h and the changes of other surface markers were detected by flow cytometry. The ability of differentiation was assessed by oil red O and von Kossa staining. The cell cycle was analyzed by flow cytometry. The mRNA expression of CD151, hepatocyte growth factor (HGF), transforming growth factor β1 (TGF-β1), cyclooxygenase 2 (COX-2) and indoleamine 2, 3-dioxygenase (IDO) in hUC-MSCs was detected by real-time PCR. The secretion of HGF by hUC-MSCs was measured by ELISA. RESULTS：The results of flow cytometry showed that the expression of CD151 (11.97±2.63 vs 95.66±1.56, P<0.01) and CD105 (93.66±0.21 vs 83.37±0.71, P<0.05) on hUC-MSCs in siRNA-CD151 group was lower than that in negative control group. The consistent results were also achieved by using the method of real-time PCR. Treatment with siRNA-CD151 down-regulated the progress of the cell cycle as the G1 phase increased and the S phase decreased. The mRNA expression levels of HGF and TGF-β1 in hUC-MSCs in siRNA-CD151 group were lower than those in negative control group, and opposite result of COX-2 mRNA expression was observed. The IDO mRNA in hUC-MSCs was unchanged with IFN-γ stimulation for 24 h. HGF concentration in siRNA-CD151 group was decreased as compared with negative control group. CONCLUSION：Interfering CD151 expression on hUC-MSCs doesn’t change other surface markers except CD105, and maintains the capacity of adipogenic differentiation. However, it changes the osteogenic differentiation, proliferation and the expression of immunomodulatory cytokines.     

Immunomodulatory effect of Sema4D on Th1/Th2 in asthmatic rats induced by RSV and intervention of Kechuanning oral liquid

AIM To explore the effect of semaphorin 4D (Sema4D) on the immune regulation of Th1/Th2 in asthmatic rats induced by respiratory syncytial virus (RSV) and the effect of Kechuanning (KCN) intervention on the asthmatic rats. METHODS Healthy SPF female Wistar rats (n=100) were randomly divided into 10 groups: normal group, model group, Sema4D group, Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middle and high doses of KCN groups. Except the rats in normal group, the other rats were treated with RSV combined with ovalbumin (OVA) to induce asthmatic model. The pathological changes of the lung tissue were observed by HE staining, and the levels of interleukin-4 (IL-4), IL-6, IL-8, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by ELISA. RESULTS Inflammatory cell infiltration and inflammatory damage in lung tissues of the rats in model group, Sema4D group and Sema4D+low dose of KCN group were observed by HE staining, while these pathological changes were attenuated in Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+middle and high doses of KCN groups. Compared with normal group, the levels of IL-4, IL-6, IL-8 and TNF-α in BALF of the rats in the other groups were significantly increased, and the level of IFN-γ was significantly lowered (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D group were increased, and the content of IFN-γ was decreased (P<0.05 or P<0.01). Compared with model group, the levels of IL-4, IL-6, IL-8 and TNF-α in Sema4D antibody group, low, middle and high doses of KCN groups, and Sema4D+low, middel and high doses of KCN groups were significantly decreased (P<0.01), while the content of IFN-γ was significantly increased (P<0.05 or P<0.01). No significant difference among Sema4D antibody group, Sema4D+middle and high doses of KCN groups, and low, middle and high doses of KCN groups was observed (P>0.05). CONCLUSION Sema4D causes Th1/Th2 immune imbalance and aggravates asthma. Inhibition of Sema4D reduces the production of inflammatory factors and regulates the balance of Th1/Th2. KCN may attenuate RSV-induced immune inflammation of asthmatic rats by inhibiting Sema4D, so as to achieve the anti-asthma effect.