Protection of palmitic acid treatment in RAW264.7 cells and BALB/c mice during Brucella abortus 544 infection.

BACKGROUND: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. OBJECTIVES: We aimed to investigate the efficacy of PA against B. abortus infection using a murine cell line and a murine model. METHODS: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O2⁻) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. RESULTS: PA did not affect the growth of B. abortus. PA treatment in macrophages did not change B. abortus uptake but it did attenuate the intracellular survivability of B. abortus. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression. Compared to control cells, reduced nitrite accumulation, augmented O2⁻, and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus-infected cells. Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. CONCLUSIONS: Our results suggest that PA participates in the control of B. abortus within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus infection by fatty acids.

Nanoparticle-Based Vaccines for Brucellosis: Calcium Phosphate Nanoparticles-Adsorbed Antigens Induce Cross Protective Response in Mice.

INTRODUCTION: Vaccine formulation with appropriate adjuvants is an attractive approach to develop protective immunity against pathogens. Calcium phosphate nanoparticles (CaPNs) are considered as ideal adjuvants and delivery systems because of their great potential for enhancing immune responses. In the current study, we have designed nanoparticle-based vaccine candidates to induce immune responses and protection against B. melitensis and B. abortus. MATERIALS AND METHODS: For this purpose, we used three Brucella antigens (FliC, 7α-HSDH, BhuA) and two multi-epitopes (poly B and poly T) absorbed by CaPNs. The efficacy of each formulation was evaluated by measuring humoral, cellular and protective responses in immunized mice. RESULTS: The CaPNs showed an average size of about 90 nm with spherical shape and smooth surface. The CaPNs-adsorbed proteins displayed significant increase in cellular and humoral immune responses compared to the control groups. In addition, our results showed increased ratio of specific IgG2a (associated with Th1) to specific IgG1 (associated with Th2). Also, immunized mice with different vaccine candidate formulations were protected against B. melitensis 16M and B. abortus 544, and showed same levels of protection as commercial vaccines (B. melitensis Rev.1 and B. abortus RB51) except for BhuA-CaPNs. DISCUSSION: Our data support the hypothesis that these antigens absorbed with CaPNs could be effective vaccine candidates against B. melitensis and B. abortus.

A Carbonic Anhydrase Pseudogene Sensitizes Select Brucella Lineages to Low CO2 Tension.

Brucella spp. are intracellular pathogens that cause a disease known as brucellosis. Though the genus is highly monomorphic at the genetic level, species have animal host preferences and some defining physiologic characteristics. Of note is the requirement for CO2 supplementation to cultivate particular species, which confounded early efforts to isolate B. abortus from diseased cattle. Differences in the capacity of Brucella species to assimilate CO2 are determined by mutations in the carbonic anhydrase gene, bcaA Ancestral single-nucleotide insertions in bcaA have resulted in frameshifted pseudogenes in B. abortus and B. ovis lineages, which underlie their inability to grow under the low CO2 tension of a standard atmosphere. Incubation of wild-type B. ovis in air selects for mutations that "rescue" a functional bcaA reading frame, which enables growth under low CO2 and enhances the growth rate under high CO2 Accordingly, we show that heterologous expression of functional Escherichia coli carbonic anhydrases enables B. ovis growth in air. Growth of B. ovis is acutely sensitive to a reduction in CO2 tension, while frame-rescued B. ovis mutants are insensitive to CO2 shifts. B. ovis initiates a gene expression program upon CO2 downshift that resembles the stringent response and results in transcriptional activation of its type IV secretion system. Our study provides evidence that loss-of-function insertion mutations in bcaA sensitize the response of B. ovis and B. abortus to reduced CO2 tension relative to that of other Brucella lineages. CO2-dependent starvation and virulence gene expression programs in these species may influence persistence or transmission in natural hosts.IMPORTANCEBrucella spp. are highly related, but they exhibit differences in animal host preference that must be determined by genome sequence differences. B. ovis and the majority of B. abortus strains require high CO2 tension to be cultivated in vitro and harbor conserved insertional mutations in the carbonic anhydrase gene, bcaA, which underlie this trait. Mutants that grow in a standard atmosphere, first reported nearly a century ago, are easily selected in the laboratory. These mutants harbor varied indel polymorphisms in bcaA that restore its consensus reading frame and rescue its function. Loss of bcaA function has evolved independently in the B. ovis and B. abortus lineages and results in a dramatically increased sensitivity to CO2 limitation.

Inhibitory Effect of the Ethanol Extract of a Rice Bran Mixture Comprising Angelica gigas, Cnidium officinale, Artemisia princeps, and Camellia sinensis on Brucella abortus Uptake by Professional and Nonprofessional Phagocytes.

In this study, we evaluated the inhibitory effect of a rice bran mixture extract (RBE) on Brucella abortus pathogenesis in professional (RAW 264.7) and nonprofessional (HeLa) phagocytes. We fermented the rice bran mixture and then extracted it with 50% ethanol followed by gas chromatography-mass spectrometry to identify the components in RBE. Our results clearly showed that RBE caused a significant reduction in the adherence of B. abortus in both cell lines. Furthermore, analysis of phagocytic signaling proteins by western blot assay revealed that RBE pretreatment resulted in inhibition of phosphorylation of JNK, ERK, and p38, leading to decline of internalization compared with the controls. Additionally, the intensity of F-actin observed by fluorescence microscopy and FACS was remarkably reduced in RBE-pretreated cells compared with control cells. However, the intracellular replication of B. abortus within phagocytes was not affected by RBE. Taken together, these findings suggest that the phagocytic receptor blocking and suppressive effects of RBE on the MAPK-linked phagocytic signaling pathway could negatively affect the invasion of B. abortus into phagocytes.

The host immune enhancing agent Korean red ginseng oil successfully attenuates Brucella abortus infection in a murine model.

ETHNOPHARMACOLOGICAL RELEVANCE: Panax ginseng Meyer (Araliaceae), is one of the most valuable traditional Chinese medicines and is used for the treatment of various human diseases. In this study, we elucidated the protective mechanism of the essential oil from Korean red ginseng (RGO) against Brucella infection. MATERIALS AND METHODS: The effects of RGO on Brucella abortus viability, NO production, uptake and intracellular growth in macrophages were investigated. Mice were intraperitoneally infected with B. abortus and orally treated with RGO for 14 days. The weights and bacterial numbers from each spleen were monitored, and the sera were evaluated for cytokine production. RESULTS: B. abortus viability was not affected, whereas NO production, internalization and intracellular replication were inhibited in RGO-treated macrophages. Bacterial adherence, F-actin polymerization and MAPK signaling protein phosphorylation (ERK1/2, JNK and p38α) were reduced and the co-localization of B. abortus-containing phagosomes with LAMP-1 was augmented in RGO-treated cells compared to untreated cells. RGO displayed protective effects against cell damage by inhibiting nitrite production during B. abortus infection in macrophages. Moreover, the spleen weight and bacterial burden were lower in the RGO-treated group than in the control group. The uninfected RGO-treated mice displayed increased TNF-α and IFN-γ production, whereas the B. abortus-infected RGO-treated mice showed reduced IL-10 production compared to the control. CONCLUSION: RGO exhibits protective effects against B. abortus infection in vitro and in vivo, which emphasize the beneficial effects of RGO in the prevention and treatment of brucellosis.

Intravenous Iron Carboxymaltose as a Potential Therapeutic in Anemia of Inflammation.

Intravenous iron supplementation is an effective therapy in iron deficiency anemia (IDA), but controversial in anemia of inflammation (AI). Unbound iron can be used by bacteria and viruses for their replication and enhance the inflammatory response. Nowadays available high molecular weight iron complexes for intravenous iron substitution, such as ferric carboxymaltose, might be useful in AI, as these pharmaceuticals deliver low doses of free iron over a prolonged period of time. We tested the effects of intravenous iron carboxymaltose in murine AI: Wild-type mice were exposed to the heat-killed Brucella abortus (BA) model and treated with or without high molecular weight intravenous iron. 4h after BA injection followed by 2h after intravenous iron treatment, inflammatory cytokines were upregulated by BA, but not enhanced by iron treatment. In long term experiments, mice were fed a regular or an iron deficient diet and then treated with intravenous iron or saline 14 days after BA injection. Iron treatment in mice with BA-induced AI was effective 24h after iron administration. In contrast, mice with IDA (on iron deficiency diet) prior to BA-IA required 7d to recover from AI. In these experiments, inflammatory markers were not further induced in iron-treated compared to vehicle-treated BA-injected mice. These results demonstrate that intravenous iron supplementation effectively treated the murine BA-induced AI without further enhancement of the inflammatory response. Studies in humans have to reveal treatment options for AI in patients.

Inhibitory effect of red ginseng acidic polysaccharide from Korean red ginseng on phagocytic activity and intracellular replication of Brucella abortus in RAW 264.7 cells.

Korean red ginseng (KRG) has long been used in traditional Korean and Oriental medicine. However, the anti-bacterial mechanism and therapeutic efficiency of KGR for intracellular Brucella infection are still unclear. In this study, the bactericidal activity of Korean red ginseng acidic polysaccharide (RGAP) on Brucella (B.) abortus and its cytotoxic effects on RAW 264.7 cells were evaluated. In addition, B. abortus internalization and intracellular replication in macrophages were investigated after RGAP treatment. RGAP-incubated cells displayed a marked reduction in the adherence, internalization and intracellular growth of B. abortus in macrophages. Furthermore, decreased F-actin fluorescence was observed relative to untreated B. abortus-infected cells. Western blot analysis of intracellular signaling proteins revealed reduced ERK, JNK and p38α phosphorylation levels in B. abortus-infected RGAP-treated cells compared to the control. Moreover, elevated co-localization of B. abortus-containing phagosomes with lysosome-associated membrane protein 1 (LAMP-1) were observed in RGAP-treated cells compared with the control. Overall, the results of this study suggest that RGAP can disrupt phagocytic activity of B. abortus via suppression of mitogen-activated protein kinases (MAPKs) signaling proteins ERK, JNK and p38 levels and inhibit intracellular replication of B. abortus by enhancing phagolysosome fusion, which may provide an alternative control of brucellosis.

Inhibitory effect of red ginseng acidic polysaccharide from Korean red ginseng on phagocytic activity and intracellular replication of Brucella abortus in RAW 264.7 cells

Korean red ginseng (KRG) has long been used in traditional Korean and Oriental medicine. However, the anti-bacterial mechanism and therapeutic efficiency of KGR for intracellular Brucella infection are still unclear. In this study, the bactericidal activity of Korean red ginseng acidic polysaccharide (RGAP) on Brucella (B.) abortus and its cytotoxic effects on RAW 264.7 cells were evaluated. In addition, B. abortus internalization and intracellular replication in macrophages were investigated after RGAP treatment. RGAP-incubated cells displayed a marked reduction in the adherence, internalization and intracellular growth of B. abortus in macrophages. Furthermore, decreased F-actin fluorescence was observed relative to untreated B. abortus-infected cells. Western blot analysis of intracellular signaling proteins revealed reduced ERK, JNK and p38α phosphorylation levels in B. abortus-infected RGAP-treated cells compared to the control. Moreover, elevated co-localization of B. abortus-containing phagosomes with lysosome-associated membrane protein 1 (LAMP-1) were observed in RGAP-treated cells compared with the control. Overall, the results of this study suggest that RGAP can disrupt phagocytic activity of B. abortus via suppression of mitogen-activated protein kinases (MAPKs) signaling proteins ERK, JNK and p38 levels and inhibit intracellular replication of B. abortus by enhancing phagolysosome fusion, which may provide an alternative control of brucellosis.

The effects of red ginseng saponin fraction-A (RGSF-A) on phagocytosis and intracellular signaling in Brucella abortus infected RAW 264.7 cells.

This study indicated that RGSF-A caused a marked reduction in the adherence, internalization and intracellular growth of Brucella abortus in RGSF-A-treated cells. Furthermore, a decline in the intensity of F-actin fluorescence was observed in RGSF-A-treated cells compared with untreated B. abortus-infected cells. In addition, an evaluation of phagocytic signaling proteins by Western blot analysis revealed an apparent reduction of ERK and p38α phosphorylation levels in B. abortus-infected RGSF-A-treated cells compared with the control. Upon intracellular trafficking of the pathogen, a higher number of B. abortus-containing phagosomes colocalized with LAMP-1 in RGSF-A-treated cells compared with control cells. These results strongly suggest that inhibition of B. abortus uptake could be mediated by suppression in the activation of MAPKs signaling proteins phospho-ERK 1/2, and p38 levels. On the other hand, inhibition of intracellular replication results from the enhancement of phagolysosome fusion in host macrophages. This study highlights the phagocytic and intracellular modulating effect of RGSF-A and its potential as an alternative remedy to control B. abortus infection.

Foodborne outbreak of human brucellosis caused by ingested raw materials of fetal calf on Jeju Island.

Since the first reported case of human brucellosis in 2002 in South Korea, its incidence has been increasing nationally. However, bovine brucellosis has not been present from 2005 to date on Jeju Island. Despite Jeju Island being considered a clean area for bovine brucellosis, we experienced an outbreak of human brucellosis between 2012 and 2013. Herein, we report cases with human brucellosis after ingestion of raw materials of fetal calf at a restaurant. Patients were identified by isolation of the Brucella abortus in their blood and joint tissue. Because all patients developed zoonosis by a faulty folk remedy, we emphasize the importance of educational programs to increase the awareness of zoonosis, and the need for active surveillance and detection of illegal distribution channels of the infected animal. After the outbreak, we took control of the involved restaurant and its illegal distribution channel, and there have been no further outbreaks.

Use of S-[2,3-bispalmitoyiloxy-(2R)-propyl]-R-cysteinyl-amido-monomethoxy polyethylene glycol as an adjuvant improved protective immunity associated with a DNA vaccine encoding Cu,Zn superoxide dismutase of Brucella abortus in mice.

This study was conducted to evaluate the immunogenicity and protective efficacy of a DNA vaccine encoding Brucella abortus Cu,Zn superoxide dismutase (SOD) using the Toll-like receptor 2/6 agonist S-[2,3-bispalmitoyiloxy-(2R)-propyl]-R-cysteinyl-amido-monomethoxy polyethylene glycol (BPPcysMPEG) as an adjuvant. Intranasal coadministration of BPPcysMPEG with a plasmid carrying the SOD-encoding gene (pcDNA-SOD) into BALB/c mice elicited antigen-specific humoral and cellular immune responses. Humoral responses were characterized by the stimulation of IgG2a and IgG1 and by the presence of SOD-specific secretory IgA in nasal and bronchoalveolar lavage fluids. Furthermore, T-cell proliferative responses and increased production of gamma interferon were also observed upon splenocyte restimulation with recombinant SOD. Cytotoxic responses were also stimulated, as demonstrated by the lysis of RB51-SOD-infected J774.A1 macrophages by cells recovered from immunized mice. The pcDNA-SOD/BPPcysMPEG formulation induced improved protection against challenge with the virulent strain B. abortus 2308 in BALB/c mice over that provided by pcDNA-SOD, suggesting the potential of this vaccination strategy against Brucella infection.

Immunization of mice with recombinant protein CobB or AsnC confers protection against Brucella abortus infection.

Due to drawbacks of live attenuated vaccines, much more attention has been focused on screening of Brucella protective antigens as subunit vaccine candidates. Brucella is a facultative intracellular bacterium and cell mediated immunity plays essential roles for protection against Brucella infection. Identification of Brucella antigens that present T-cell epitopes to the host could enable development of such vaccines. In this study, 45 proven or putative pathogenesis-associated factors of Brucella were selected according to currently available data. After expressed and purified, 35 proteins were qualified for analysis of their abilities to stimulate T-cell responses in vitro. Then, an in vitro gamma interferon (IFN-γ) assay was used to identify potential T-cell antigens from B. abortus. In total, 7 individual proteins that stimulated strong IFN-γ responses in splenocytes from mice immunized with B. abortus live vaccine S19 were identified. The protective efficiencies of these 7 recombinant proteins were further evaluated. Mice given BAB1_1316 (CobB) or BAB1_1688 (AsnC) plus adjuvant could provide protection against virulent B. abortus infection, similarly with the known protective antigen Cu-Zn SOD and the license vaccine S19. In addition, CobB and AsnC could induce strong antibodies responses in BALB/c mice. Altogether, the present study showed that CobB or AsnC protein could be useful antigen candidates for the development of subunit vaccines against brucellosis with adequate immunogenicity and protection efficacy.

Intracellular replication inhibitory effects of Galla Rhois ethanol extract for Brucella abortus infection.

ETHNOPHARMACOLOGICAL RELEVANCE: Galla Rhois (GR) has long been applied in traditional Korean and Oriental medicine. Although GR has an anti-bacterial effect, the anti-bacterial mechanism and therapeutic efficiency of GR for intracellular parasitic Brucella infection are still unclear. AIM OF THE STUDY: The objective of this study was to investigate the antibacterial and therapeutic effects of GR ethanol extract (GRE), which is a natural antibacterial component for the treatment of Brucella abortus infection. MATERIALS AND METHODS: The antibacterial activity of GRE towards Brucella abortus was evaluated by incubating Brucella abortus with GRE. Following treatment with GRE, Brucella abortus adherence, uptake, intracellular growth, and intracellular trafficking in macrophages were monitored. Mice were infected intraperitoneally with Brucella abortus and treated orally with GRE for 14 days, and then the weight and CFUs from each spleen were monitored. RESULTS: The viability of Brucella abortus was markedly decreased in a dose-dependent manner. Moreover, Brucella abortus internalization and intracellular growth within macrophages were reduced in GRE-treated cells. The number of bacteria that adhered to GRE-pretreated cells was significantly lower than that of untreated cells. With regards to intracellular trafficking, treatment with GRE augmented the colocalization of Brucella abortus-containing phagosomes with LAMP-1. GRE-treated mice showed considerably decreased weight and bacterial burdens in the spleen compared to untreated mice. CONCLUSION: GRE exhibits antibacterial and protective effects on Brucella abortus in vitro and in vivo. These results highlight the beneficial effects of GRE in the prevention and treatment of brucellosis.

Co-immunization with interlukin-18 enhances the protective efficacy of liposomes encapsulated recombinant Cu-Zn superoxide dismutase protein against Brucella abortus.

Brucellosis is a worldwide zoonotic disease caused by Brucella abortus and a number of closely related species. Brucellosis has severe impact on the health and economic prosperity of the developing countries due to the persistent nature of infection and unavailability of effective control measures. The Cu-Zn superoxide dismuatse (SOD) protein of Brucella have been extensively studied as a major antigen involved in bacterial evading mechanism of host defence. Being a critical pro-inflammatory cytokine interleukin-18 (IL-18) plays key role in induction of immune mediated protection against intracellular pathogens. In the present study, we aimed to investigate the immunogenic potential of fusogenic liposomes (escheriosomes) encapsulated recombinant Cu-Zn SOD (rSOD) protein alone or in combination with recombinant IL-18 (rIL-18). Escheriosomes encapsulated rSOD mediated immune responses were further increased upon co-immunization with rIL-18. Furthermore, immunization with escheriosomes encapsulated rSOD alone or in combination with rIL-18, increased resistance in mice against challenge with B. abortus 544.

Brucellosis in domestic water buffalo (Bubalus bubalis) of Trinidad and Tobago with comparative epidemiology to cattle.

The water buffalo is an important domestic animal worldwide, and the local Buffalypso variety was developed in Trinidad to have improved beef qualities. Brucellosis was diagnosed in Trinidad and Tobago during 1998 in both cattle and domestic water buffalo (Bubalus bubalis) populations. Brucellosis in the latter species is caused by infection with Brucella abortus, similar to bovine brucellosis. Control of brucellosis is of paramount importance to preservation of the genetic diversity of these animals in Trinidad, and this has been complicated by differences in the epidemiology of water buffalo and bovine brucellosis. Some diagnostic tests do not have comparable accuracy between the two species, and the RB51 vaccine does not adequately protect against infection in water buffalo. The water buffalo in Trinidad may also be more resistant to infection than cattle. Development of effective vaccination protocols is key to brucellosis control in Buffalypso in Trinidad, and prohibitions on import of virulent B. abortus strains for vaccine efficacy studies has impeded progress in this area. These Trinidadian strains are of variable virulence; some might be effective for challenge in vaccine efficacy studies, while other, of lower virulence, may be vaccine candidates for use in water buffalo.

Resveratrol improves hippocampal atrophy in chronic fatigue mice by enhancing neurogenesis and inhibiting apoptosis of granular cells.

Neuroimaging evidence showed structural and/or functional abnormalities existing in the central nervous system, especially the hippocampus, in chronic fatigue syndrome (CFS) patients. However, its pathophysiologic mechanisms are unclear in part due to the lack of an applicable animal model. We established a chronic fatigue murine model by six repeated injections of Brucella abortus antigen to mice, which was manifested as reduced daily running activity and hippocampal atrophy. Thereafter, resveratrol, a polyphenolic activator of sirtuin 1, was used for treatment in this model. Daily running activity was increased by more than 20%, and the hippocampus was enlarged after 4-week resveratrol therapy. Furthermore, resveratrol inhibited neuronal apoptosis and expression of hippocampal acetylated p53 in the fatigue mice. Resveratrol also improved neurogenesis and expression of brain-derived neurotrophic factor mRNA in the hippocampus. We concluded that repeated injection of B. abortus antigen could induce hypoactivity and hippocampal atrophy in mice. Resveratrol may be effective for improving fatigue symptoms and enlarging the atrophic hippocampus by repressing apoptosis and promoting neurogenesis.

Thioredoxin 80-activated-monocytes (TAMs) inhibit the replication of intracellular pathogens.

BACKGROUND: Thioredoxin 80 (Trx80) is an 80 amino acid natural cleavage product of Trx, produced primarily by monocytes. Trx80 induces differentiation of human monocytes into a novel cell type, named Trx80-activated-monocytes (TAMs). PRINCIPAL FINDINGS: In this investigation we present evidence for a role of TAMs in the control of intracellular bacterial infections. As model pathogens we have chosen Listeria monocytogenes and Brucella abortus which replicate in the cytosol and the endoplasmic reticulum respectively. Our data indicate that TAMs efficiently inhibit intracellular growth of both L. monocytogenes and B. abortus. Further analysis shows that Trx80 activation prevents the escape of GFP-tagged L. monocytogenes into the cytosol, and induces accumulation of the bacteria within the lysosomes. Inhibition of the lysosomal activity by chloroquine treatment resulted in higher replication of bacteria in TAMs compared to that observed in control cells 24 h post-infection, indicating that TAMs kill bacteria by preventing their escape from the endosomal compartments, which progress into a highly degradative phagolysosome. SIGNIFICANCE: Our results show that Trx80 potentiates the bactericidal activities of professional phagocytes, and contributes to the first line of defense against intracellular bacteria.

Modulatory effects of two levels of dietary Alliums on immune response and certain immunological variables, following immunization, in White Leghorn chickens.

This study aimed at investigating the effects of dietary Allium sativum (garlic, G) and Allium cepa (onion, O) on immune functions in White Leghorn chicken. One-week-old chicks, were fed diets without (control) or with Alliums (GL and OL, 10 g or GH and OH, 30 g/kg diet). Chickens were immunized with Newcastle disease virus (NDV), sheep red blood cells (SRBC) and Brucella abortus (BA). Antibodies, lymphocyte proliferation, and ratios of CD4(+) , CD8(+) and CD4⁻ CD8⁻ lymphocytes were investigated. Histology and weights of the spleen, thymus and bursa (BF), and white blood cell (WBC) counts were studied as well. Alliums at 10 g/kg diet enhanced anti-NDV, anti-SRBC and anti-BA antibody productions, whereas 30 g/kg diet had less stimulatory effects. Histology of the lymphoid organs and proliferation of peripheral blood lymphocytes (PBL) were not influenced. However, splenocyte and thymocyte proliferations were augmented with garlic. Flow cytometry analysis showed reduction in CD4(+) and increase in CD4⁻ CD8⁻ lymphocyte ratios in GH and OH groups. Garlic-supplemented chickens had heavier spleen and thymus, and higher WBC counts, whereas BF weight increased with both Alliums at 30 g/kg diet. These results suggest that dietary Alliums have a potential to enhance the immune functions in White Leghorn chickens.

In vivo immunomodulatory effects of dietary purple sweet potato after immunization in chicken.

This study was intended to determine the modulatory effects of dietary supplementation of purple sweet potato (Ipomoea batats Poir., PSP) on the immune response of chickens. PSP was included in a basal starter diet by 1% (PSP(L)) or 3% (PSP(H)) and continually fed. Newcastle disease (NDV) vaccine, Brucella abortus (BA) and sheep red blood cells (SRBC) were used for chicken immunization. Antibody titers against these antigens were used to estimate humoral immunity. Concanavalin A (Con A)-induced proliferations of splenocytes, thymocytes and peripheral blood lymphocytes (PBL), ratios of CD4- and CD8-single positive and CD4-CD8-double negative (DN) cells in splenocytes, were both used to indicate cellular immunity. Relative weights of spleen, thymus and bursa and white blood cell (WBC) counts were studied. PSP(H) increased anti-NDV (P < 0.05), anti-BA (P < 0.01) and anti-SRBC titers (P < 0.05) in response to secondary immunization, whereas PSP(L) increased titers of anti-BA (P < 0.05) and anti-SRBC (P < 0.01). Proliferations of splenocytes and thymocytes were augmented with PSP(L) (P < 0.05). PSP(H)-treated chickens had lower (P < 0.05) ratios of CD4-single positive lymphocytes. Proliferation of PBL, weights of lymphoid organs and WBC counts were not affected. These results suggest that dietary PSP supplementation could enhance the immune response after immunization in chickens.

Effect of dose and source of supplemental zinc on immune response and oxidative enzymes in lambs.

An experiment of 150 days was conducted on 42 male Nellore lambs (28.3 +/- 0.64 kg) to determine the effect of zinc (Zn) supplementation (0,15, 30 and 45 ppm) in diet from inorganic (ZnSO(4)) and organic (Zn proteinate) sources on immune response and antioxidant enzyme activities by allotting them randomly to 7 groups in completely randomized design. The basal diet (BD) contained 29.28 ppm Zn. The humoral immune response assessed at 75 d against B. abortus was higher (P<0.01) with 15 or 30 ppm Zn supplementation from organic source. The dose and source had no effect on titres against chicken RBC antigen. The cell mediated immune response assessed as delayed type hypersensitivity (DTH) response against phytohaemagglutinin-P and in vitro lymphocyte proliferative response against concanavalin A at 150 d was higher (P<0.05) at 15 ppm Zn supplementation compared to BD fed lambs. Supplementation of 45 ppm Zn had no positive effect on immune response. The DTH response and antibody titres against B.abortus were higher (P< 0.05) on Zn proteinate compared to ZnSO(4) at 15 ppm Zn supplementation. The lipid peroxidase activity was lower (P < 0.01), while the RBC superoxide dismutase and catalase activities were higher (P < 0.01) in lambs at 15 ppm Zn supplementation compared to BD diet fed lambs, assessed at 75 d of feeding. Serum globulin concentration and alkaline phosphatase (ALP) activity (75 d of experiment) was higher in Zn supplemented lambs. The ALP activity increased (P < 0.01) with increase in Zn supplementation and being higher when supplementation was from Zn proteinate compared to ZnSO(4). The study indicated that 15 ppm zinc supplementation was required for obtaining higher immune response in lambs when fed a basal diet containing 29.28 ppm Zn and supplementation as Zn proteinate had higher antioxidant enzyme activities and immune response compared to ZnSO(4).