• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1539-1545
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• 2007

An experiment was conducted using 20 male buffalo calves to study the effect of vitamin E and selenium supplementation on their immune response and plasma ${\alpha}$-tocopherol and selenium status. These buffalo calves (10-12 months old, average body weight $75.30{\pm}2.20 $ kg) were randomly allotted to four treatments on the basis of their body weights and were fed on wheat straw and concentrate mixture to meet their nutrient requirements of 500 g/d body weight gain. The buffalo calves were fed either a control diet (neither supplemented with Se nor VE) or diets supplemented with Se at 0.3 ppm (+Se), DL-alpha tocopheryl acetate at 300 IU (+VE), and both DL-alpha tocopheryl acetate at 300 IU and Se at 0.3 ppm (+Se+VE). These experimental diets were fed for 180 days. Blood samples were collected at day 0 and subsequently at 45 day intervals up to 180 days of experimental feeding to monitor plasma ${\alpha}$-tocopherol and Se concentrations. To assess humoral immune response, all calves were sensitized with formalin inactivated Pasteurella multocida antigen at 135 days of experimental feeding and blood was collected on 0, 7, 14, 21 and 28 days post vaccination (DPV) to measure antibody production using indirect ELISA. Cell mediated immune response of calves was assessed after 180 days of experimental feeding by in vivo delayed type hypersensitivity (DTH) reaction using phytohaemaglutinin-P (PHA-P) as a mitogen. Results revealed that feeding of VE and Se improved the plasma levels of these nutrients. Plasma levels of Se were affected by supplementation of both VE (p<0.001) and Se (p<0.001); however, no interaction ($Se{\times}VE$) was observed. Supplementation of Se improved the humoral immune response (p<0.008), whereas, VE showed a tendency towards improvement in cell mediated immune response (p<0.064). It was concluded that vitamin E and Se supplementation improved the status of these micronutrients and humoral immune response in buffalo calves.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.175-184
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• 1987

The use of alkylating agent cyclophosphamide(CY), a widely used antitumor drug is well known as a potent immunosuppressant and has been used as a probe for investigating the functional capabilities of lymphocyte subsets of both T and B cells that play an important role in the regulation of the immune response. The present study was undertaken in an effort to assess the effects of CY on immunological memory in murine model. CY, given as a single dose of CY(250mg/kg) before sensitization with sheep red blood cells(SRBC) enhanced the primary response of Arthus and delayed-type hypersensitivity(DTH), as measured by footpad swelling reaction, but suppressed their tertiary DTH response. The similar CY pretreatment enhanced both the primary and tertiary hemagglutinin(HA) responses to SRBC, and the tertiary antibody response against polyvinylpyrroridone(PVP), a thymus-independent antigen but not the primary response against PVP. CY, given as a single dose of 250mg/kg 2 days before the primary immunization and two doses of 100mg/kg 2 days before the secondary and tertiary immunization, markedly suppressed the tertiary DTH and HA responses to SRBC. However, CY, given as small multiple daily doses(10mg/kg) over 4 days before sensitization but not after sensitization, enhanced the secondary HA response to SRBC. Contact sensitivity to dinitrofluorobenzene(DNFB) was suppressed by the drug, given either as a single large dose(300mg/kg) or as multiple dose(10mg/kg) administered 2 days before, together with or after DNFB sensitization. This suppression was more pronounced and more significant when CY was given as multiple dose. However, the enhancement of the secondary contact sensitivity to DNFB by CY was not clear-cut. The splenectomy appears to increase the enhancing effect of CY on contact sensitivity. These results suggest that CY selectively influences the immune response depending on the time of the drug administration relative to immunization and that the secondary or tertiary immune response involve memory cells with different susceptibilities to CY. Moreover, these results suggest that multiple low doses may sesectivley inhibit suppressor T cell proliferation involving DTH, HA or contact sensitivity without effecting helper T cells, but high doses presumably inhibit helper T cells and suppressor T cells with effecting B cells.

• IMMUNE NETWORK
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• v.8 no.1
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• pp.21-28
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• 2008

Background: A co-inhibitory molecule, B7-H4, is believed to negatively regulate T cell immunity by suppressing T cell proliferation and inhibiting cytokine production. However, the mechanism behind B7-H4-mediated tolerance remains unclear. Methods: Balb/c $(H-2^d)$ mice were fed with dendritic cell line, DC2.4 $(H-2^d)$ every day for 10 days. Meantime, mice were hydrodynamically injected with recombinant plasmid expressing B7-H4 fusion protein (B7-H4.hFc) or hFc via tail vein. One day after last feeding, mice were immunized with allogeneic B6 spleen cells. 14 days following immunization, mice were challenged with B6 spleen cells to ear back and the ear swelling was determined the next day. Subsequently, a mixed lymphocyte reaction (MLR) was also performed and cytokines profiles from the reaction were examined by sandwich ELISA. Frequency of immunosuppressive cell population was assayed with flow cytometry and mRNA for FoxP3 was determined by RT-PCR. Results: Tolerant mice given plasmid expressing B7-H4.hFc showed a significant reduction in ear swelling compared to control mice. In addition, T cells from mice given B7-H4.hFc plasmid revealed a significant hyporesponsiveness of T cells against allogeneic spleen cells and showed a significant decrease in Th1 and Th2 cytokines such as IFN-${\gamma}$, IL-5, and TNF-${\alpha}$. Interestingly, flow cytometric analysis showed that the frequency of CD4+CD25+FoxP3+ Tregs in spleen was increased in tolerant mice given recombinant B7-H4.hFc plasmid compared to control group. Conclusion: Our results demonstrate that B7-H4 synergistically potentiates oral tolerance induced by allogeneic cells by increasing the frequency of FoxP3+ CD4+CD25+ Treg and reducing Th1 and Th2 cytokine production.

• Journal of Life Science
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• v.30 no.10
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• pp.905-911
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• 2020

The adjuvant effect of PAMAM dendrimer G4 (PAMAM) on the induction of humoral and cellular immune responses against keyhole limpet hemocyanin (KLH) was examined. Mice were immunized subcutaneously twice at two-week intervals with KLH, with or without PAMAM dendrimer (100 ㎍/mouse), and the mice immunized with KLH+PAMAM showed significantly higher antibody titers against KLH than those immunized with KLH alone. The assay for determining the isotypes of the antibodies showed that PAMAM augmented the KLH-specific antibody titers of IgG1, IgG2a, IgG2b, IgG3, and IgM. In addition, mice immunized twice with KLH+PAMAM followed by a subcutaneous injection of KLH (20 ㎍/site) 7 weeks after the primary immunization exhibited a higher delayed-type hypersensitivity (DTH) reaction than those treated with KLH alone. In an in vitro analysis of T lymphocyte proliferation in response to KLH in week 8, the splenocytes of mice treated with KLH+PAMAM showed significantly higher proliferating activity than those treated with KLH alone, and the culture supernatants of cell cultures from mice immunized with added PAMAM dendrimer showed higher levels of KLH-specific cytokine (IL-4 and IFN-r) production. These results suggest that PAMAM dendrimer G4 possesses a potent immune-adjuvant activity for enhancing both humoral and cell-mediated immunity specific to foreign antigens.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.1026-1038
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• 1995

Although aloe lost a lot of its previous popularity in modern clinical uses as medicine numerous scientific researches still have claimed the beneficial properties(curing and general tonic effect) of aloe gel. Whereas considerable contradictory reports have helped to confuse the aloe gel issue and continually aroused controversy about aloe gel efficacy. However health food, cosmetic and medicinal products made from aloe gel are widely available in the world market especially in U.S.A. so the growing of Aloe plant and the processing of A. vera gel have become big industries in some countries. In some previous papers the salicylic acid, one of the common trace gel components, was thought to have an analgetic and antinflammatory effect. Large amount of Mg ion in the gel was suggested to act as anesthetic, Mg-lactate as antihistamic, and Aloctin A(a glycoprotein) as wound healer by promoting the cell growth. The carboxypeptidase and bradykinase activity in the gel were proposed to have the pain relieving and antiinflammatory effect. But any of thes etheories concerining the physiological action of the trace gel components has not been demonstrated by modern pharmacology, and failed to be supported by clinical research. It was suggested by some research workers that trace amount of anthraquinone compounds in the gel play an important role to act as false substrate inhibitors for PG and TX production(antiprostanoid effect), by which, they believed, inflammation, burn and frostbite, and infected wound could be healed. This hypothesis has not been substantiated. Butthe suggested antimicrobial action, antidiabetic, and antidotic effect of aloe gel are likely to be attributed to the trace anthraquinone compounds. In a lot of recent experimental reports it has been claimed that aloe gel polysaccharides(acetylglucomannan, acetylmannan, and glycoprotein) have the antimicrobial, antinflammatory, antitumour, and infected wound healing effect by immunoenhancement. It is hoped that these effects will be soon documented in clinical studies, then the controversy on aloe gel beneficial effect will cease. In the 30 days subchronic toxicity test the lowest observed adverse effect level of acemannan(acetylmannan) on dog was 5.0 mg/kg, IP. But the aloe gel is generally agreed to be harmless and non toxic even for the internal use such as health food. In the case of idiosynrasy one must keep the delayed type hypersensitivity reaction of aloe gel in mind. In conclusion it seem to be impossible to simply refuse a lot of evidences made by research workers who have claimed aloe gel's beneficial effects and to deny the fact that there had been long therapeutic histories of Aloe plants.