Splenocytes with fucosylation deficiency promote T cell proliferation and differentiation through thrombospondin-1 downregulation

Fucosylation plays a critical role in cell-to-cell interactions and disease progression. However, the effects of fucosylation on splenocytes and their interactions with T cells remain unclear. In this study, we aimed to explore the transcriptome profiles of splenocytes deficient in fucosyltransferase (FUT) 1, an enzyme that mediates fucosylation, and investigate their impact on the proliferation and differentiation of T cells. We analysed and compared the transcriptomes of splenocytes isolated from Fut1 knockout (KO) mice and those from wild-type (WT) mice using RNA-seq. Additionally, we examined the effects of Fut1 KO splenocytes on CD4 T cell proliferation and differentiation, in comparison to WT splenocytes, and elucidated the mechanisms involved. The comparative analysis of transcriptomes between Fut1 KO and WT splenocytes revealed that thrombospondin-1, among the genes related to immune response and inflammation, was the most highly downregulated gene in Fut1 KO splenocytes. The reduced expression of thrombospondin-1 was further confirmed using qRT-PCR and flow cytometry. In coculture experiments, Fut1 KO splenocytes promoted the proliferation of CD4 T cells and drove their differentiation toward Th1 and Th17 cells, compared with WT splenocytes. Moreover, the levels of IL-2, IFN-γ and IL-17 were increased, while IL-10 was decreased, in T cells cocultured with Fut1 KO splenocytes compared with those with WT splenocytes. These effects of Fut1 KO splenocytes on T cells were reversed when thrombospondin-1 was replenished. Taken together, our results demonstrate that splenocytes with Fut1 deficiency promote CD4 T cell proliferation and Th1/Th17 differentiation at least in part through thrombospondin-1 downregulation.

Yuja Juice and Concentrate Enhance Immunomodulating Effects via Increasing Immune-Related Cytokines in RAW264.7 Cells and Mouse Splenocytes

Good immunity is highly valued in modern society. Although yuja's efficacy in immunity enhancement has been elucidated, there have been few studies on its role. In this study, we investigate the immune enhancement activity of yuja juice extracts (YJEs) and yuja concentrate extracts (YCEs). The immunoregulatory potencies of YJE and YCE were examined by determining cell viability and the expression of cytokines and immune-related molecules in RAW264.7 cells and mouse primary splenocytes. YJE and YCE induced the production of inducible nitric oxide synthase and cytokines (IL-10, IL-4, IL-6, and IFN-γ) at 1000 μg/mL concentration in RAW 264.7 cells. In addition, in mice that were orally administered 3000 or 2000 mg/kg concentrations of YJE or YCE, immune-related cytokines in splenocytes were boosted to levels higher than those in control mice. Importantly, no liver toxicity was observed at all doses. Thus, our results suggest that compounds present in YJEs and YCEs represent novel natural immune-modulatory substances.

Immunocyte Populations Observed from Birth to Weaning in Blood, Spleen and Mesenteric Lymph Nodes of Piglets

Susceptibility to pathogen infections and efficacy of vaccination highly depend on the immune status of the piglet. Here, we measured immunocytes in piglets from birth to weaning to elucidate how immunocyte populations change during development and are affected by weaning. Crossbred piglets were used. Suckling piglets were euthanized at 1, 7, 14, 21, 28 or 35 days old (3~4 piglets at each time point). In addition, seven piglets were weaned at 21 days old, with four being euthanized at 28 days old and the remaining at 35 days old. Piglet carcasses were dissected, and blood, mesenteric lymph nodes (MLN) and spleen were sampled. In total, seven antibodies were used to stain the immunocyte population. Dynamics of myeloid (CD3−SWC3+CD16+), natural killer (NK; CD3−SWC3−CD16+), killer T (CD3+CD8+), helper T (CD3+CD4+) and B (CD3−CD21+) cells were analyzed. Percentage of innate immunity cells such as myeloid cells declined (p < 0.05) from the first day after birth. In contrast, percentage of NK cells increased in piglets while they were still suckling. Killer T, helper T, and B cell populations increased around 2~3 weeks after birth. No significant differences in the populations of the evaluated cell types were observed between suckling and weaned piglets at least for 14 days post weaning.

Immunomodulatory activity of aqueous extract from Crassostrea sikamea in the splenocytes of Sprague-Dawley rats

Crassostrea sikamea (C. sikamea) is used as an important edible and medicinal seafood in China. In the present study, an aqueous extract of C. sikamea (AECs) was prepared, and its immunomodulatory effects on rat splenocytes were studied. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay revealed that AECs was able to promote splenocyte proliferation. Moreover, flow cytometry revealed that AECs treatment markedly altered the populations of splenic lymphocyte subtypes. Data from real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) showed that AECs promoted the mRNA expression and secretion of TNF-α, IL-2, IL-6, IL-12, and IFN-γ. Mechanistically, p38 MAPK phosphorylation in splenocytes was significantly upregulated under AECs treatment and p38 MAPK inhibitor reversed the promoting effect of AECs on the expression of inflammatory cytokines. Collectively, our novel evidence suggests that AECs exhibits immunomodulatory activity in vitro, supporting the further application of C. sikamea as a potential functional food.

Metabolomic Profiling and Immunomodulatory Activity of a Polyherbal Combination in Cyclophosphamide-Induced Immunosuppressed Mice

The study was aimed to develop a characterized polyherbal combination as an immunomodulator containing Phyllanthus emblica L., Piper nigrum L., Withania somnifera (L.) Dunal, and Tinospora cordifolia (Willd.) Miers. Through response surface methodology (RSM), the ratio of aqueous extracts of four plant materials was optimized and comprised 49.76% of P. emblica, 1.35% of P. nigrum, 5.41% of W. somnifera, and 43.43% of T. cordifolia for optimum immunomodulatory activity. The optimized combination showed antioxidant potential and contains more than 180 metabolites, out of which gallic acid, quercetin, ellagic acid, caffeic acid, kaempferitrin, and p-coumaric acid are some common and significant metabolites found in plant extracts and in polyherbal combination. Treatment with the polyherbal combination of different doses in cyclophosphamide-induced immunosuppressed mice significantly (p < 0.01) enhanced the subsets of immune cells such as natural killer (NK) cells (60%), B cells (18%), CD4 cells (14%), and CD8 cells (7%). The characterized polyherbal combination exhibited potent immunomodulatory activity, which can be further explored clinically for its therapeutic applicability.

Strain-Specific Identification and In Vivo Immunomodulatory Activity of Heat-Killed Latilactobacillus sakei K040706

We previously reported that the immunostimulatory activity of heat-killed Latilactobacillus sakei K040706 in macrophages and cyclophosphamide (CTX)-treated mice. However, identification of heat-killed L. sakei K040706 (heat-killed LS06) using a validated method is not yet reported. Further, the underlying molecular mechanisms for its immunostimulatory effects in CTX-induced immunosuppressed mice remain unknown. In this study, we developed strain-specific genetic markers to detect heat-killed L. sakei LS06. The lower detection limit of the validated primer set was 2.1 × 10⁵ colony forming units (CFU)/mL for the heat-killed LS06 assay. Moreover, oral administration of heat-killed LS06 (10⁸ or 10⁹ CFU/day, p.o.) effectively improved the body loss, thymus index, natural killer cell activity, granzyme B production, and T and B cell proliferation in CTX-treated mice. In addition, heat-killed LS06 enhanced CTX-reduced immune-related cytokine (interferon-γ, interleukin (IL)-2, and IL-12) production and mRNA expression. Heat-killed LS06 also recovered CTX-altered microbiota composition, including the phylum levels of Bacteroidetes, Firmicutes, and Proteobacteria and the family levels of Muribaculaceae, Prevotellaceae, Tannerellaceae, Christensenellaceae, Gracilibacteraceae, and Hungateiclostridiaceae. In conclusion, since heat-killed L. sakei K040706 ameliorated CTX-induced immunosuppression and modulated gut microbiota composition, they have the potential to be used in functional foods for immune regulation.

Cordyceps sinensis aqueous extract regulates the adaptive immunity of mice subjected to 60 Co γ irradiation

Cordyceps sinensis (CS) is a traditional Chinese medicine that is known for treating various diseases, and particularly for exerting therapeutic effects in immune disorders. The adaptive immunoregulatory effects of CS aqueous extract (CSAE) on γ-irradiated mice have not been reported previously. The study aimed to evaluate the therapeutic effects of CSAE in mice immunosuppressed by irradiation. We observed that CSAE administration significantly increased body weight and spleen index, as well as the number of white blood cells, lymphocytes, and platelets in peripheral blood, T and B lymphocytes in spleen tissue, and total serum immunoglobulins in irradiated mice, whereas total serum pro-inflammatory cytokine levels were decreased. Collectively, CSAE maintained the structural integrity of spleen tissue and repaired its damage in irradiated mice as shown by hematoxylin and eosin staining, and decreased the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive splenocytes. Mechanistically, CSAE upregulated Bcl-2, and downregulated Bax and cleaved caspase-3 in spleen of irradiated mice. However, there were no significant differences in red blood cells and neutrophils in different groups. The results revealed that CSAE had protective effects against irradiation-induced immunosuppression, which was likely associated with an antiapoptotic effect and the regulation of adaptive immunity.

Human Leukemia T-Cell Lines as Alternatives to Animal Use for Detecting Biologically Active Staphylococcal Enterotoxin Type B

Staphylococcal enterotoxin type B (SEB) is associated with food poisoning. Current methods for the detection of biologically active SEB rely upon its ability to cause emesis when administered to live kittens or monkeys. This technique suffers from poor reproducibility and low sensitivity and is ethically disfavored over concerns for the welfare of laboratory animals. The data presented here show the first successful implementation of an alternative method to live animal testing that utilizes SEB super-antigenic activity to induce cytokine production for specific novel cell-based assays for quantifiable detection of active SEB. Rather than using or sacrificing live animals, we found that SEB can bind to the major histocompatibility complex (MHC) class II molecules on Raji B-cells. We presented this SEB–MHC class II complex to specific Vβ5.3 regions of the human T-cell line HPB-ALL, which led to a dose-dependent secretion of IL-2 that is capable of being quantified and can further detect 10 pg/mL of SEB. This new assay is 100,000 times more sensitive than the ex vivo murine splenocyte method that achieved a detection limit of 1 µg/mL. The data presented here also demonstrate that SEB induced proliferation in a dose-dependent manner for cells obtained by three different selection methods: by splenocyte cells containing 22% of CD4⁺ T-cells, by CD4⁺ T-cells enriched to >90% purity by negative selection methods, and by CD4⁺ T-cells enriched to >95% purity by positive selection methods. The highly enriched and positively isolated CD4⁺ T-cells with the lowest concentration of antigen-presenting cells (APC) (below 5%) provided higher cell proliferation than the splenocyte cells containing the highest concentration of APC cells.

Immunostimulatory Effects of Live Lactobacillus sakei K040706 on the CYP-Induced Immunosuppression Mouse Model

Our previous studies have shown that heat-killed Lactobacillus sakei K040706 exerts immunostimulatory and anti-inflammatory activities in macrophages, cyclophosphamide (CYP)-treated mice, and dextran sulfate sodium–induced colitis mice. However, the immunostimulatory effects of live Lactobacillus sakei K040706 (live K040706) against CYP-induced immunosuppression and its underlying molecular mechanisms remain unknown. Therefore, we investigated the immunostimulatory effects of live K040706 (10⁸ or 10⁹ colony forming unit (CFU)/day, p.o.) in CYP-induced immunosuppressed mice. Oral administration of live K040706 prevented the CYP-induced decreases in body weight, thymus index, natural killer (NK) cell activity, T and B cell proliferation, and cytokine (interferon (IFN)-γ, interleukin (IL)-2, and IL-12) production. The administration of live K040706 also exerted positive effects on the gut microbiota of CYP-induced mice, resulting in a microbiota composition similar to that of normal mice. Moreover, live K040706 significantly enhanced IL-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) production in the splenocytes and Peyer’s patch (PP) cells of mice and increased bone marrow (BM) cell proliferation. Taken together, our data indicate that live K040706 may effectively accelerate recovery from CYP-induced immunosuppression, leading to activation of the immune system. Therefore, live K040706 may serve as a potential immunomodulatory agent against immunosuppression.

Topical Application of KAJD Attenuates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis Symptoms Through Regulation of IgE and MAPK Pathways in BALB/C Mice and Several Immune Cell Types

Atopic dermatitis (AD) is a frequent skin complication that is caused by unknown reasons. KHU-ATO-JIN-D (KAJD) is a new drug aimed at AD composed of a mixture of extracts from six plants known to have anti-inflammatory and antiallergic effects. This study investigated whether KAJD alleviates 2,4-dinitrochlorobenzene (DNCB)-induced AD in BALB/c mice and several immune cell types. We applied KAJD to DNCB-induced AD-like skin lesions in BALB/c mice, phorbol myristate acetate/ionomycin-stimulated human mast cells (HMC-1), and lipopolysaccharide (LPS)-stimulated macrophages and splenocytes. Histological, ELISA, PCR, and Western blot experiments were performed. The application of KAJD significantly attenuated the lesion severity and skin thickness and inhibited the infiltration of inflammatory cells, mast cells, and CD4+ T cells into the sensitized skin of mice. Reduced leukocyte numbers and proinflammatory cytokine and IgE levels were also observed in the sera of KAJD-treated mice. Moreover, in vitro studies demonstrated that KAJD treatment reduced the LPS-induced expression of proinflammatory cytokines and nitric oxide (NO) production in RAW 264.7 cells. The regulation of IL-4 and IL-6 mRNA and MAPK pathways was also detected in agonist-induced isolated splenocytes and HMC-1 cells by the addition of KAJD. Taken together, our results demonstrate that KAJD inhibits the development of DNCB-induced AD in BALB/c mice and in several immune cell types, suggesting that KAJD might be a useful therapeutic drug for the treatment of AD.

The effect of chronic supplementation of Nigella sativa on splenocytes response in rats following treadmill exercise

Nigella sativa (N. sativa) was shown to recover fatigue and imbalanced immune system. Therefore, effect of chronic administration of N. sativa hydroethanolic extract on splenocytes response in sedentary and exercised animals, was evaluated. Male Wistar rats were randomly divided into non-treated (control sedentary (C), moderately trained (MT; Velocity 20 m/min, 30 min/day 8 weeks), and over-trained (OT; Velocity 25 m/min, 60 min/day 11 weeks)), and N. sativa-treated animals (Nisa, 200 mg/kg, orally) (control (Nisa-C), moderately trained (Nisa-MT) and over-trained (Nisa-OT)). Finally, cell viability and proliferation, as well as interleukin 4 (IL-4) and interferon-γ (IFN-γ) secretion in non-stimulated and concanavalin A (Con A)-stimulated splenocytes, were evaluated. In the absence of the mitogen, cell viability in Nisa-C and Nisa-OT, cell proliferation in Nisa-C and Nisa-MT, IFN-γ concentration in Nisa-MT and Nisa-OT and IFN-γ/IL-4 ratio in Nisa C, Nisa-MT and Nisa-OT were higher compared to non-treated groups; but, IL-4 level in Nisa-MT was lower than non-treated groups. In the presence of the mitogen, cell viability in Nisa-C and Nisa-OT, IL-4 concentration in Nisa-C and Nisa-OT groups, and IFN-γ concentration and IFN-γ/IL-4 ratio in Nisa-MT were higher, while IFN-γ/IL-4 ratio was lower in Nisa-C group compared to non-treated groups. Moreover, IFN-γ/IL-4 ratio in stimulated and non-stimulated splenocytes supernatant was higher in Nisa-MT compared to Nisa-C and Nisa-OT groups. N. sativa chronic administration may shift Th1/Th2 cytokines profile of splenocytes towards Th1, especially in over-trained and non-stimulated condition. Moderate exercise and N. sativa supplementation may improve disorders associated with elevated Th2 such as overtraining syndrome.

Suppression of IFN-γ Production in Murine Splenocytes by Histamine Receptor Antagonists

Accumulating evidence suggests that histamine synthesis induced in several types of tumor tissues modulates tumor immunity. We found that a transient histamine synthesis was induced in CD11b⁺Gr-1⁺ splenocytes derived from BALB/c mice transplanted with a syngeneic colon carcinoma, CT-26, when they were co-cultured with CT-26 cells. Significant levels of IFN-γ were produced under this co-culture condition. We explored the modulatory roles of histamine on IFN-γ production and found that several histamine receptor antagonists, such as pyrilamine, diphenhydramine, JNJ7777120, and thioperamide, could significantly suppress IFN-γ production. However, suppression of IFN-γ production by these antagonists was also found when splenocytes were derived from the Hdc-/- BALB/c mice. Suppressive effects of these antagonists were found on IFN-γ production induced by concanavalin A or the combination of an anti-CD3 antibody and an anti-CD28 antibody in a histamine-independent manner. Murine splenocytes were found to express H₁ and H₂ receptors, but not H₃ and H₄ receptors. IFN-γ production in the Hh1r-/- splenocytes induced by the combination of an anti-CD3 antibody and an anti-CD28 antibody was significantly suppressed by these antagonists. These findings suggest that pyrilamine, diphenhydramine, JNJ7777120, and thioperamide can suppress IFN-γ production in activated splenocytes in a histamine-independent manner.

Alternative to Animal Use for Detecting Biologically Active Staphylococcal Enterotoxin Type A

Staphylococcal enterotoxins (SEs) are a food safety concern. Existing methods for biologically active SE detection rely on the emetic response in live kittens or monkeys. This method suffers from low sensitivity, poor reproducibility, and causes ethical concerns regarding the use of experimental animals. The Lautenberg Chemical Safety Act encourages the development and adoption of alternatives to testing on animals for chemical toxicity methodologies. In this study, we utilized the superantigenic effect of SE type A (SEA) and used an ex vivo bioassay as an alternative to live animal testing. We found that interleukin-2 (IL-2) secreted by splenocyte can be utilized for quantifiable detection of SEA in food products. To avoid food matrix interference and attenuation of signal, we separated SEA from spiked food products by employing immunomagnetic beads that were coated with an anti-SEA antibody. This ex vivo method has achieved the detection of 1 ng mL⁻¹ of SEA, which is 10⁷ times more sensitive than the existing live animal testing methods. However, this ex vivo bioassay requires sacrificing of mice. To overcome this limitation, we established a cell based in vitro assay using CCRF-CEM, a human CD4⁺ T-cell line, for the quantitative detection of SEA. Incubation of SEA with CCRF-CEM human T-cells and Raji cells led to quantifiable and dose dependent secretion of IL-2. This novel cell-based assay is highly specific to biologically active SEA, compared with the related SE toxin subtypes B, D, and E or heat inactivated SEA, which produce no secretion of IL-2. This is the first demonstration of an alternative assay that completely eliminates the use of animals for quantitative detection of active SEA.

Splenocyte proliferation and anaphylaxis induced by BSA challenge in a D-galactose-induced aging mouse model

We previously found a cross-reactive autoantibody that bound to bovine serum albumin generated in a D-galactose-induced aging mouse model. Also, we confirmed that other reducing sugars (glucose and fructose) could induce the formation of autoantibody, and only following subcutaneous injection, not oral or intraperitoneal administration. Mice that had never been exposed to bovine serum albumin produced an anti-bovine serum albumin autoantibody following repeated subcutaneous injection of D-galactose (D-gal). In this study, we investigated the involvement of the adaptive immune system in the production of this autoantibody. In particular, we examined bovine serum albumin-induced splenocyte proliferation and bovine serum albumin-induced active cutaneous and systemic anaphylaxis in D-gal-treated mice. We find our results particularly interesting: bovine serum albumin stimulates splenocyte proliferation and induces both active cutaneous and systemic anaphylaxis in D-gal-treated mice. In summary, our results suggest that adaptive immune response participates in the autoantibody formation against bovine serum albumin in D-gal-treated mice.

Sensitive, Rapid, Quantitative and in Vitro Method for the Detection of Biologically Active Staphylococcal Enterotoxin Type E

Staphylococcus aureus is a major bacterial cause of clinical infections and foodborne illnesses through its production of a group of enterotoxins (SEs) which cause gastroenteritis and also function as superantigens to massively activate T cells. In the present study, we tested Staphylococcal enterotoxin type E (SEE), which was detected in 17 of the 38 suspected staphylococcal food poisoning incidents in a British study and was the causative agent in outbreaks in France, UK and USA. The current method for detection of enterotoxin activity is an in vivo monkey or kitten bioassay; however, this expensive procedure has low sensitivity and poor reproducibility, requires many animals, is impractical to test on a large number of samples, and raises ethical concerns with regard to the use of experimental animals. The purpose of this study is to develop rapid sensitive and quantitative bioassays for detection of active SEE. We apply a genetically engineered T cell-line expressing the luciferase reporter gene under the regulation of nuclear factor of activated T-cells response element (NFAT-RE), combined with a Raji B-cell line that presents the SEE-MHC (major histocompatibility complex) class II to the engineered T cell line. Exposure of the above mixed culture to SEE induces differential expression of the luciferase gene and bioluminescence is read out in a dose dependent manner over a 6-log range. The limit of detection of biologically active SEE is 1 fg/mL which is 10⁹ times more sensitive than the monkey and kitten bioassay.

Physiological concentrations of trans-11 18:1 vaccenic acid suppress pro-inflammatory markers under acute inflammation in isolated ICR mice splenocytes

Direct influences of dietary trans-11 18:1 vaccenic acid (TVA) at physiological concentrations of 50-200 μM were evaluated for cell growth, cytotoxic activity, and cytokine production in leukocytes isolated from the mouse spleen. TVA supplementation for 24 h induced growth of splenocytes at concentrations of 50-200 μM, except for 100 μM. The cytokines TNFα, IFNγ, and IL-10 of splenocytes were stimulated by 100 μM TVA. Induced production of TNFα in splenocytes challenged with lipopolisaccharides was suppressed by 100 μM TVA. Physiological levels of TVA had direct effects on growth and cytokine production in splenocytes. Further in vivo studies are needed to improve understanding of the precise influence of trans fatty acids on production of pro-inflammatory markers under acute inflammation conditions.

Immune-modulating activities of polysaccharides extracted from brown algae Hizikia fusiforme

The immuno-modulating activities of seaweed (Hizikia fusiforme) extracts on murine macrophage and splenocyte were studied in vitro. Polysaccharide (HFP) exhibited the potential macrophage stimulating effects than water extract (HFW) such as NO production and enhanced pro-inflammatory cytokines on the Raw 264.7 cells and splenocytes. From the mono-sugar composition, HFP-associated fucose based on HFP of H. fusiforme acts as immune modulator.

Immunosuppressive potential of Botryosphaeria dothidea, an endophyte isolated from Kigelia africana

CONTEXT

For years, natural products from microbes have been used as drugs. Endophytes are the most important fungi that produce many novel metabolites for potential use in pharmacology and agriculture.

OBJECTIVE

The objective of the present study was to explore new endophytes for novel natural products.

MATERIALS AND METHODS

An endophyte BAK-I was isolated from the bark of Kigelia africana (Lam.) Beneth (Bignoniaceae). BAK-I was characterized morphologically and on the basis of ITS-5.8S rDNA sequences. BAK-I was fermented to yield an extract, which was evaluated for its anticancer, antimicrobial, and immunomodulatory activities, using MTT, agar well-diffusion, tube dilution method, lymphocyte proliferation, and pro-inflammatory cytokines (TNF-α) (by macrophages) evaluation assays. For lymphocyte proliferation and pro-inflammatory cytokines studies, four concentrations were evaluated 10, 30, 100, and 1000 µg/mL and the experiments were conducted for 72 and 48 h, respectively.

RESULTS AND DISCUSSION

The BAK-I showed pink cottony growth. SEM studies showed smooth fusoid-oblong conidia with a truncated base. Furthermore, ITS-5.8S rDNA sequence showed 99% homology with the Botryosphaeria dothidea strain suggesting that the endophyte is a strain of the genus Botryosphaeria. Less than 50% growth inhibition of SF295, Lung A-549, and THP-1 cancer cell lines after treatment with BAK-I extract suggested that it did not have significant cytotoxic potential, whereas it is bactericidal for Gram-positive pathogens MRSA and VRE with MIC value 200 and 250 µg/mL, respectively. To elucidate its immunomodulation potential, splenocyte proliferation studies showed that BAK-1 suppressed the T cell proliferation by 50%. TNF-α evaluation studies also showed that the extract inhibited TNF-α production in a concentration-dependent manner suggesting that it had immunosuppressive potential. Inhibition at 10 µg/mL was found to be 55% as against 48% using β-methasone.

CONCLUSION

The results suggested that BAK-I extract can be used as a potential immunosuppressive agent.

Mesoporous silica particles potentiate antigen-specific T-cell responses

AIM

To study the adjuvant effect of mesoporous silica particles and their capability of modifying an already existing allergic Th2-like immune response.

MATERIALS & METHODS

The adjuvant effect of Santa Barbara Amorphous-15 (SBA-15) mesoporous silica particles was studied in an antigen-specific ovalbumin (OVA) system in vitro and in vivo. The capacity of the OVA-loaded SBA-15 particles (SBA-15-OVA) to modify an existing immune response was assessed in a murine allergy model.

RESULTS

SBA-15-OVA induced significantly stronger OVA-specific splenocyte proliferation compared with OVA alone. Significantly higher IFN-γ production was observed in ex vivo OVA-stimulated splenocytes from SBA-15-OVA-immunized mice compared with mice injected with only SBA-15 or OVA. Treatment of OVA-sensitized mice with SBA-15-OVA modified the immune response with significantly lower serum levels of OVA-specific IgE and higher IgG levels compared with the alum-OVA-treated group.

CONCLUSION

The results are promising for the continued development of mesoporous silica materials for therapeutic applications.

Donor-specific tolerance induction in organ transplantation via mixed splenocytes chimerism

We have shown previously that donor-derived splenocytes can replace recipients' bone marrow and induce donor-specific tolerance (DST). We have also shown the usefulness of the chimeric state for the induction of DST. Further analysis of mixed splenocytes chimera, especially the role of each T cells in mixed splenocytes chimera, is indispensable issue for its clinical use. A chimeric state has been shown to achieve long-term survival in major histocompatibility complex (MHC)-mismatched grafts. The donor-derived splenocytes can replace recipients' bone marrow and induce DST. The long-term survival of allogeneic skin grafts was achieved without immunosuppressants. In this study we show the role of each T cell type in a splenocyte mixed chimera. This review provides a short summary of our original work, adding some supplemental interpretations. Mixed chimerism is thus considered an attractive approach for the induction of DST without the use of immunosuppressants. In this paper, we summarize some of the findings on mixed splenocyte chimeras and review mixed chimerism in recent organ transplantation.

Wound trauma alters ionizing radiation dose assessment

BACKGROUND

Wounding following whole-body γ-irradiation (radiation combined injury, RCI) increases mortality. Wounding-induced increases in radiation mortality are triggered by sustained activation of inducible nitric oxide synthase pathways, persistent alteration of cytokine homeostasis, and increased susceptibility to bacterial infection. Among these factors, cytokines along with other biomarkers have been adopted for biodosimetric evaluation and assessment of radiation dose and injury. Therefore, wounding could complicate biodosimetric assessments.

RESULTS

In this report, such confounding effects were addressed. Mice were given 60Co γ-photon radiation followed by skin wounding. Wound trauma exacerbated radiation-induced mortality, body-weight loss, and wound healing. Analyses of DNA damage in bone-marrow cells and peripheral blood mononuclear cells (PBMCs), changes in hematology and cytokine profiles, and fundamental clinical signs were evaluated. Early biomarkers (1 d after RCI) vs. irradiation alone included significant decreases in survivin expression in bone marrow cells, enhanced increases in γ-H2AX formation in Lin+ bone marrow cells, enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood, and concomitant decreases in γ-H2AX formation in PBMCs and decreases in numbers of splenocytes, lymphocytes, and neutrophils. Intermediate biomarkers (7 - 10 d after RCI) included continuously decreased γ-H2AX formation in PBMC and enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood. The clinical signs evaluated after RCI were increased water consumption, decreased body weight, and decreased wound healing rate and survival rate. Late clinical signs (30 d after RCI) included poor survival and wound healing.

CONCLUSION

Results suggest that confounding factors such as wounding alters ionizing radiation dose assessment and agents inhibiting these responses may prove therapeutic for radiation combined injury and reduce related mortality.

Study on the immunomodulation effect of Isodon japonicus extract via splenocyte function and NK anti-tumor activity

Here we investigated the potential immune-enhancing activity of Isodon japonicus on murine splenocyte and natural-killer (NK) cells in vitro. The ethanol extract of I. japonicus significantly enhanced the proliferation of splenocyte and induced the significant enhancement of NK cells' activity against tumor cells (YAC-1). In addition, I. japonicus increased the production of interferon (IFN)-γ and tumor necrosis factor (TNF)-α, suggesting that the increase in NK cell cytotoxicity could be due to the enhancement of the NK cell production of both cytokines. Taken together, I. japonicus extract inhibited the growth of human leukemia cells (K562) by 74%. Our observation indicated that the anti-tumor effects of I. japonicus may be attributed to its ability to serve as a stimulant of NK anti-tumor activity. In addition, our results support the development of functional food studies on I. japonicus.

Select phytochemicals suppress human T-lymphocytes and mouse splenocytes suggesting their use in autoimmunity and transplantation

We have considered a novel "rational" gene targeting approach for treating pathologies whose genetic bases are defined using select phytochemicals. We reason that one such potential application of this approach would be conditions requiring immunosuppression such as autoimmune disease and transplantation, where the genetic target is clearly defined; i.e., interleukin-2 and associated T-cell activation. Therefore, we hypothesized that select phytochemicals can suppress T-lymphocyte proliferation both in vitro and in vivo. The immunosuppressive effects of berry extract, curcumin, quercetin, sulforaphane, epigallocatechin gallate (EGCG), resveratrol, alpha-tocopherol, vitamin C and sucrose were tested on anti-CD3 plus anti-CD28-activated primary human T-lymphocytes in culture. Curcumin, sulforaphane, quercetin, berry extract and EGCG all significantly inhibited T-cell proliferation, and this effect was not due to toxicity. IL-2 production was also reduced by these agents, implicating this important T-cell cytokine in proliferation suppression. Except for berry extract, these same agents also inhibited mouse splenic T-cell proliferation and IL-2 production. Subsequent in vivo studies revealed that quercetin (but not sulforaphane) modestly suppressed mouse splenocyte proliferation following supplementation of BALB/c mice diets. This effect was especially prominent if corrected for the loss of supplement "recall" as observed in cultured T-cells. These results suggest the potential use of these select phytochemicals for treating autoimmune and transplant patients, and support our strategy of using select phytochemicals to treat genetically-defined pathologies, an approach that we believe is simple, healthy, and cost-effective.

Chondroitin sulphate structure affects its immunological activities on murine splenocytes sensitized with ovalbumin

Chondroitin sulphate (CS) is a glycosaminoglycan widely distributed in animal tissues, which has anti-inflammatory and chondroprotective properties. We reported previously that chondroitin 4-sulphate (CS-A) up-regulates the antigen-specific Th1 immune response of murine splenocytes sensitized with ovalbumin in vitro, and that CS suppresses the antigen-specific IgE responses. We now demonstrate that a specific sulphation pattern of the CS polysaccharide is required for the Th1-promoted activity, as other polysaccharides such as dextran and dextran sulphate do not significantly induce this activity. While the presence of some O-sulpho groups appear to be essential for activity, CS-A, and synthetically prepared, partially O-sulphonated CS, induce higher Th1-promoted activity than synthetically prepared, fully O-sulphonated CS. CS-A induces an activity greater than chondroitin sulphate B (CS-B) or chondroitin 6-sulphate (CS-C). In addition, chondroitin sulphate E (CS-E) induces greater activity than CS-A or CS-D. These results suggest that the GlcA(beta1-3)GalNAc(4,6-O-disulpho) sequence in CS-E is important for Th1-promoted activity. Furthermore, rat anti-mouse CD62L antibody, an antibody to L-selectin, inhibits the Th1-promoting activity of CS. These results suggest that the Th1-promoted activity could be associated with L-selectin on lymphocytes. These findings describe a new mechanism for the anti-inflammatory and chondroprotective properties of CS that may be useful in designing new therapeutic applications for CS used in the treatment of immediate-type hypersensitivity.

Comparison of lymphokine-activated killer activities between thymocytes and splenocytes in rats with brain tumors

We studied the lymphokine-activated killer (LAK) activity in splenocytes and thymocytes of rats with brain tumors chronologically from the early stage to the late stage, in order to clarify how much LAK activity would be developed at each stage. Simultaneously the natural killer (NK) activity in splenocytes, as one aspect of the host immunocompetence, was also determined. The splenic NK activity was significantly depressed in rats with brain tumors during the 2nd and 3rd weeks after tumor transplantation, as compared with normal controls. On the other hand, the splenocytes incubated with interleukin-2 showed the same killer activity in rats with brain tumors as in normal rats at all times. The LAK activity in thymocytes from rats with brain tumors was significantly higher than that of controls in the 1st and 2nd weeks and became equal to that of the controls during the 3rd week. The killer activity after incubation with interleukin-2 in thymocytes was superior to that in splenocytes throughout the experiment in both tumor-bearing rats and controls, which suggested that the precursor of LAK cells was not NK cells.