The influence of Peyer's patch apoptosis on intestinal mucosal immunity in burned mice

Compound small peptide of Chinese medicine alleviates cyclophosphamide induced immunosuppression in mice by Th17/Treg and jejunum intestinal flora

The aim of this study was to explore the efficacy of Compound small peptide of Chinese medicine (CSPCM) on cyclophosphamide (CTX) induced immunosuppression in mice. The 100 male Kunming mice were divided into 5 groups: group A (control group), group B (model group), group C (100 mg/kg.bw CSPCM), group D (200 mg/kg.bw CSPCM) and group E (400 mg/kg.bw CSPCM). At 1–3 days, mice of group B, C, D and E were intraperitoneally injected with 80 mg/kg.bw CTX. The results showed that compared with group A, the immune organ index, body weight change, RORγ T gene expression, RORγ T protein expression, CD3+ cell number, Th17 number and Alpha index, white blood cell count, lymphocyte count and monocyte count were significantly decreased in group B (p < 0.05), while Foxp3 gene expression, Foxp3 protein expression and Treg cell number were significantly increased (p < 0.05), CSPCM has a good therapeutic effect on the above abnormalities caused by CTX. CTX caused the decrease of intestinal flora richness and the abnormal structure of intestinal flora, and CSPCM could change the intestinal flora destroyed by CTX to the direction of intestinal flora of healthy mice. On the whole, CSPCM has a good therapeutic effect on CTX-induced immunosuppression in mice, which is reflected in the index of immune organs, the number of T lymphocytes and Th17 cells increased, the number of Treg cells decreased and the structure of intestinal flora was reconstructed.

Dendritic Cell Targeting of Bovine Viral Diarrhea Virus E2 Protein Expressed by Lactobacillus casei Effectively Induces Antigen-Specific Immune Responses via Oral Vaccination

Bovine viral diarrhea caused by bovine viral diarrhea virus (BVDV) is an important disease in cattle, resulting in significant economic losses to the cattle industry worldwide. In order to develop an effective vaccine against BVDV infection, we constructed a dendritic cell (DC)-targeting oral probiotic vaccine (pPG-E2-DCpep/LC W56) using Lactobacillus casei as antigen delivery carrier to express BVDV glycoprotein E2 fused with DC-targeting peptide, and the immunogenicity of orally administered probiotic vaccine was evaluated in mice model. Our results showed that after immunization with the probiotic vaccine, significantly levels of antigen-specific sera IgG and mucosal sIgA antibodies (p < 0.05) with BVDV-neutralizing activity were induced in vivo. Challenge experiment showed that pPG-E2-DCpep/LC W56 can provide effective immune protection against BVDV, and BVDV could be effectively cleared from the intestine of immunized mice post-challenge. Moreover, the pPG-E2-DCpep/LC W56 could efficiently activate DCs in the intestinal Peyer’s patches, and significantly levels of lymphoproliferative responses, Th1-associated IFN-γ, and Th2-associated IL-4 were observed in mice immunized with pPG-E2-DCpep/LC W56 (p < 0.01). Our results clearly demonstrate that the probiotic vaccine could efficiently induce anti-BVDV mucosal, humoral, and cellular immune responses via oral immunization, indicating a promising strategy for the development of oral vaccine against BVDV.

Effect of parenteral glutamine supplementation combined with enteral nutrition on Hsp90 expression and lymphoid organ apoptosis in severely burned rats

OBJECTIVE

The aim of this study is to investigate the effects of parenteral glutamine(GLN) supplementation combined with enteral nutrition (EN) on heat shock protein 90(Hsp90) expression, apoptosis of lymphoid organs and circulating lymphocytes, immunological function and survival in severely burned rats.

METHODS

Male SD rats were randomly assigned into 4 groups: a sham burn+EN+GLN-free amino acid (AA) group (n=10), a sham burn+EN+GLN group (n=10), a burn+EN+AA group (n=10), and a burn +EN +GLN group (n=10). Two hours after a 30% total body surface area (TBSA), full-thickness scald burn injury on the back was made, the burned rats in two experimental groups (the burn+EN+AA group and the burn+EN +GLN group) were fed with a conventional enteral nutrition solution by oral gavage for 7 days. Simultaneously, the rats in the burn+EN+GLN group were given 0.35g GLN/kg body weight/day once via a tail vein injection for 7 days, whereas those in the burn+EN+AA group were administered isocaloric/isonitrogenous GLN-free amino acid solution (Tyrosine) for comparison. The rats in two sham burn control groups (the sham burn+EN+AA group and the sham burn+EN +GLN group) were treated in the same procedure as above, except for burn injury. All rats in each of the four groups were given 175kcal/kg body wt/day. There was isonitrogenous, isovolumic and isocaloric intake among four groups. At the end of the 7th day after nutritional programme were finished, all rats were anesthetized and samples were collected for further analysis. Serum immunoglobulin quantification was conducted by ELISA. Circulating lymphocyte numbers were counted by Coulter LH-750 Analyzer. The percentages and apoptotic ratio of CD4 and CD8T lymphocytes in circulation were determined by flow cytometry (FCM). The neutrophil phagocytosis index (NPI) was examined. The GLN concentrations in plasma, thymus, spleen and skeletal muscle were measured by high performance liquid chromatography (HPLC). The organ index evaluation and TUNEL analysis of thymus and spleen were carried out. The expression of Hsp90 in thymus and spleen was analyzed by western blotting. Moreover, the survival in burned rats was observed.

RESULTS

The results revealed that parenteral GLN supplementation combined with EN significantly increased the GLN concentrations of plasma and tissues, the serum immunoglobulin content, the circulating lymphocyte number, the CD4/CD8 ratio, the indexes of thymus and spleen, NPI and survival as compared with the burn+EN+AA group (p<0.05). The expression of Hsp90 in thymus and spleen in the burn+EN+GLN group was significantly up-regulated as compared with the burn+EN+AA group (p<0.05). The apoptosis in circulating CD4 and CD8 lymphocytes, thymus and spleen in the burn+EN+GLN group was significantly decreased as compared with the burn+EN+AA group (p<0.05).

CONCLUSION

The results of this study show that parenteral GLN supplementation combined with EN may increase the GLN concentrations of plasma and tissues, up-regulate the expression of Hsp90, attenuate apoptosis in lymphoid organ and circulating lymphocyte, enhance the immunological function and improve survival in severely burned rats. Clinically, therapeutic efforts at the modulation of the immune dysfunction may contribute to a favorable outcome in severely burned patients.

Oral Vaccination with Attenuated Salmonella typhimurium-Delivered TsPmy DNA Vaccine Elicits Protective Immunity against Trichinella spiralis in BALB/c Mice

Background

Our previous studies showed that Trichinella spiralis paramyosin (TsPmy) is an immunomodulatory protein that inhibits complement C1q and C8/C9 to evade host complement attack. Vaccination with recombinant TsPmy protein induced protective immunity against T. spiralis larval challenge. Due to the difficulty in producing TsPmy as a soluble recombinant protein, we prepared a DNA vaccine as an alternative approach in order to elicit a robust immunity against Trichinella infection.

Methods and Findings

The full-length TsPmy coding DNA was cloned into the eukaryotic expression plasmid pVAX1, and the recombinant pVAX1/TsPmy was transformed into attenuated Salmonella typhimurium strain SL7207. Oral vaccination of mice with this attenuated Salmonella-delivered TsPmy DNA vaccine elicited a significant mucosal sIgA response in the intestine and a systemic IgG antibody response with IgG2a as the predominant subclass. Cytokine analysis also showed a significant increase in the Th1 (IFN-γ, IL-2) and Th2 (IL-4, 5, 6, 10) responses in lymphocytes from the spleen and MLNs of immunized mice upon stimulation with TsPmy protein. The expression of the homing receptors CCR9/CCR10 on antibody secreting B cells may be related to the translocation of IgA-secreted B cells to local intestinal mucosa. The mice immunized with Salmonella-delivered TsPmy DNA vaccine produced a significant 44.8% reduction in adult worm and a 46.6% reduction in muscle larvae after challenge with T. spiralis larvae.

Conclusion

Our results demonstrated that oral vaccination with TsPmy DNA delivered by live attenuated S. typhimurium elicited a significant local IgA response and a mixed Th1/Th2 immune response that elicited a significant protection against T. spiralis infection in mice.

Trichinellosis is one of the most important food-borne parasitic zoonoses, and a serious public health issue worldwide. Developing a vaccine is an alternative approach to control the disease. TsPmy is a paramyosin expressed by Trichinella spiralis to bind and neutralize human complement and a vaccine antigen. We made a DNA vaccine of TsPmy orally delivered by attenuated Salmonella typhimurium that elicited a robust Th1/Th2 and mucosa IgA responses, and protected mice against T. spiralis infection with significant worm reduction against larval challenge. The attenuated Salmonella-delivered TsPmy DNA vaccine provides a feasible and promising approach for controlling trichinellosis in human and domestic animals.

The improvement effects of edible bird's nest on proliferation and activation of B lymphocyte and its antagonistic effects on immunosuppression induced by cyclophosphamide

Edible bird's nest (EBN) is regarded as an immune-enhancing food in the People's Republic of China. The aim of this study is to demonstrate the efficiency of EBN in improving the immunity of mouse both in vivo and in vitro. We observed the effects of EBN on spleen lymphocytes proliferation and activation, as well as immunoglobulin isotypes as indicators. In addition, we evaluated the content of total sIgA in the intestinal juice to assess mucosal immunity. The results showed that EBN could promote the proliferation and activation of B-cells and increase IgE, IgA, IgM, and IgG3 levels. We also found that EBN extract can promote the secretion of sIgA in the small intestine. Using cyclophosphamide (CY), we established an immunosuppressed mouse model in which we identified a reversal influence on the ratio of CD3(+)/CD19(+) cells, which indicates that EBN also protects B-cells from the damage induced by CY. We also applied polymyxin B to exclude the interference of lipopolysaccharide throughout the experiment. In conclusion, we found that EBN can reduce the intestinal immune injury induced by CY by accelerating the proliferation and activation of B-cells and enhancing antibody secretion of B-cells.

Dietary Apostichopus japonicus enhances the respiratory and intestinal mucosal immunity in immunosuppressive mice

Although Apostichopus japonicus is recognized as a food and drug resource with significant immunomodulatory activity, its role in regulating the mucosal immunity remains unclear. This study aimed to explore the effects of dietary A. japonicus on mucosal immunity with an immunosuppressive mouse model. The expression of lysozyme, secretory immunoglobulin A(sIgA), and immunoglobulin A(IgA) as well as polymeric immunoglobulin receptor(pIgR) in respiratory and intestine organs was investigated. The results showed that A. japonicus could improve both the systematic and mucosal immunity. The expression of lysozyme, sIgA, and IgA in the respiratory organ was increased more significantly. Consumption of A. japonicus with the dose of 512 mg kg−1, which equals to 1/2 sea cucumber per day for adults, showed better effects. This study elucidated positive effects of A. japonicus on mucosal immunity for the first time, suggesting that moderate consumption of A. japonicus is helpful in improving mucosal immunity and preventing exogenous infection.

Protective effect of a prime-boost strategy with the Ts87 vaccine against Trichinella spiralis infection in mice

Trichinellosis is a widespread zoonosis primarily caused by Trichinella spiralis. Mucosal immunity is crucial for preventing Trichinella spiralis infection. In our previous study, a DNA vaccine with the Trichinella antigen Ts87 delivered by an attenuated Salmonella typhimurium elicited partial protection against Trichinella spiralis infection in mice. In the current study, to elicit a more robust immune response and develop a potent vaccination strategy against trichinellosis, a heterologous prime-boost vaccination regimen for Ts87 was used in mice and the protective efficacy was evaluated compared to the homologous DNA prime-boost or protein prime-boost immunization alone. The results revealed that the DNA-prime/protein-boost vaccination with Ts87 induced higher levels of both humoral and cellular immune responses. The challenge results showed that mice with the DNA-prime/protein-boost vaccination displayed higher muscle larval reduction than those immunized with DNA prime-boost or protein prime-boost. The results demonstrated that mice vaccinated with Ts87 in a DNA-prime/protein-boost strategy effectively elicited a local IgA response and mixed Th1/Th2 immune response that might be responsible for improved protection against Trichinella spiralis infection.

Animal models in burn research

Burn injury is a severe form of trauma affecting more than 2 million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury, to elucidate the pathophysiology, and to explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research.

Effect of treatment with compound Lactobacillus acidophilus on complements and T lymphocyte subsets in patients with compensated liver cirrhosis

AIM: To explore the effect of early oral compound Lactobacillus acidophilus on complements and T lymphocyte subsets in patients with compensated liver cirrhosis.

METHODS: Sixty-six patients with compensated liver cirrhosis were randomly divided into either a control group or a treatment group. The control group received conventional symptomatic treatment, while the treatment group was treated with compound Lactobacillus acidophilus (1.0 g, three times per day) for 12 wk on the basis of conventional symptomatic treatment. The changes in serum complements and T lymphocyte subsets between before and after treatment were observed and compared between the two groups of patients.

RESULTS: After treatment, the levels of complements C3 and C4 (0.97 g/L ± 0.16 g/L vs 0.85 g/L ± 0.24 g/L, 0.22 g/L ± 0.05 g/L vs 0.15 g/L ± 0.07 g/L, both P < 0.05) and the percentages of CD4⁺ and CD4⁺/CD8⁺ T lymphocyte subsets (37.9% ± 6.5% vs 33.8% ± 8.6%, 1.6% ± 0.5% vs 1.3% ± 0.7%, both P < 0.05) were significantly increased in the treatment group.

CONCLUSION: Oral compound Lactobacillus acidophilus can regulate intestinal flora imbalance and modulate immunity in patients with compensated liver cirrhosis.

Decreased IgA+ plasma cells and IgA expression in acute liver necrosis mice

AIM: To investigate the number of intestinal immunoglobulin A (IgA+) plasma cells and expression of intestinal IgA in mice with acute liver necrosis.

METHODS: A model of acute liver necrosis was established by intraperitoneal injection of galactosamine (GalN) and lipopolysaccharide (LPS). Sixty mice were randomly divided into one of 4 equal groups: normal control, acute liver necrosis, LPS, or GalN. Hematoxylin and eosin staining, immunohistochemistry, and an enzyme-linked immunosorbent assay were employed to assess liver and intestinal injury, count intestinal IgA+ plasma cells, and measure the expression level of IgA and interferon γ (IFN-γ) in the small intestinal mucosa of mice.

RESULTS: Injured intestinal mucosa was observed in the acute liver necrosis group but not in the normal, LPS or GalN groups. Compared with the normal group, intestinal IgA+ plasma cells were slightly decreased in the LPS and GalN groups [429 ± 20 per high power field (HPF), 406 ± 18/HPF, respectively], whereas they were markedly decreased in the acute liver necrosis group (282 ± 17/HPF vs 495 ± 26/HPF in normal group, P < 0.05). The expression of intestinal IgA was also slightly decreased in LPS and GalN groups, but was markedly reduced in the acute liver necrosis group as determined by enzyme-linked immunosorbent assay (P < 0.05). In contrast, the level of IFN-γ was slightly increased in LPS, GalN and acute liver necrosis groups, but with no statistical significance (P > 0.05).

CONCLUSION: Intestinal IgA+ plasma cells and IgA expression levels indicating that mucosal immune barrier dysfunction, does exist in acute liver necrosis.

Oral vaccination with Ts87 DNA vaccine delivered by attenuated Salmonella typhimurium elicits a protective immune response against Trichinella spiralis larval challenge

We have previously reported that Ts87 is an immunodominant antigen that induces protective immunity against Trichinella spiralis larval challenge. In this study, the Ts87 gene was cloned into an expression plasmid, pVAX1, and the recombinant Ts87 DNA was transformed into attenuated Salmonella typhimurium strain SL7207. Oral immunization of mice with Ts87 DNA delivered in S. typhimurium elicited a significant local mucosal IgA response and a systemic Th1/Th2 immune response. Cytokine profiling also showed a significant increase in the Th1 (IFN-gamma) and Th2 (IL-5, 6, 10) responses in splenocytes of immunized mice upon stimulation with Ts87 antigen. An immunofluorescence assay performed with antisera revealed that the recombinant Ts87 protein was expressed in mesenteric lymph nodes of immunized mice. The mice immunized with Salmonella-delivered Ts87 DNA displayed a statistically significant 29.8% reduction in adult worm burden and a 34.2% reduction in muscle larvae following challenge with T. spiralis larvae, compared with mice immunized with empty Salmonella or a PBS control. Our results demonstrate that Ts87 DNA delivered by attenuated live S. typhimurium elicits a local IgA response and a balanced Th1/Th2 immune response and produces partial protection against T. spiralis infection in mice.

Effects of early enteral glutamine supplementation on lymphocyte subpopulations in Peyer's patches in scalded rats

AIM: To investigate the changes in the number of total lymphocytes and each lymphocyte subpopulation in Peyer's patches in scalded rats receiving different nutrition support, and examine the effects of glutamine (Gln) supplementation on intestinal immunity.

METHODS: Healthy adult Sprague-Dawley rats were subjected to a 30% TBSA third-degree scald injury to induce scald injury. Scalded rats were randomly divided into standard enteral nutrition group (EN group) and glutamine supplementation group (EN plus Gln group). Rats in the EN group were fed standard enteral nutrition (Nutrison Multi Fibre) while those in the EN plus Gln group were fed standard enteral nutrition plus Gln. The number of total lymphocytes and each lymphocyte subpopulation in Peyer's patches were then determined by flow cytometry on days 1, 4, 7 and 10 after feeding.

RESULTS: The number of total lymphocytes, especially B lymphocytes, in Peyer's patches significantly decreased in response to scald induction. The number of total lymphocytes in Peyer's patches in rats in the EN plus Gln group, but not in the EN group, returned to normal on day 7 after scald induction [(5.29 ± 1.03) × 10⁶vs (6.13 ± 1.14) × 10⁶, P > 0.05]. The total number of B cells in Peyer's patches in rats in the EN plus Gln group on days 7 and 10 showed no significant changes when compared with pre-induction value [(2.87 ± 0.69) × 10⁶ and (3.05 ± 0.72) × 10⁶vs (3.29 ± 0.62) × 10⁶, respectively; both P> 0.05]. In contrast, the total number of B cells in Peyer's patches in rats in the EN group on day 10 was significantly lower than pre-induction value [(2.07 ± 0.63) × 10⁶vs (3.29 ± 0.62) × 10⁶; P < 0.05]. Scald induction had no significant effect on the number of CD4⁺ and CD8⁺ lymphocytes (both P > 0.05).

CONCLUSION: The number of total lymphocytes decreases significantly in response to scald induction. Early enteral glutamine supplementation can promote lymphocyte proliferation, increase the number of total lymphocytes (especially B cells) in Peyer's patches, and enhance intestinal immunity in scalded rats.