Biomedical subjects

Jeffrey K Actor

Publications and source records attributed to Jeffrey K Actor.

At least 19 recordsLinked to original sources

PubMed2006

New enzyme-linked chemiluminescent immunosorbent digoxin assay is free from interference of Chinese medicine DanShen.

DanShen is a traditional Chinese medicine indicated for cardiovascular diseases. The potential interference of DanShen with serum digoxin measurement was investigated using a new enzyme-linked chemiluminescent immunosorbent (ECLIA) digoxin assay. Aliquots of drug-free serum were supplemented with ethyl acetate extract of DanShen (4 different brands studied), and apparent digoxin concentrations were measured by the ECLIA as well as fluorescence polarization immunoassay (FPIA) and a turbidimetric assay for comparison. Mice were also fed 4 DanShen preparations and apparent digoxin concentrations were subsequently measured. In another experiment, serum pools containing digoxin were further supplemented with DanShen extracts and digoxin concentrations were measured again by all 3 assays. No apparent digoxin concentration was observed when aliquots of drug-free serum pools were supplemented with DanShen and digoxin concentrations were measured by the ECLIA or the turbidimetric assay. In contrast, significant apparent digoxin concentrations were observed using FPIA, and the highest apparent digoxin concentration was observed with brand 4 of DanShen extract. Similarly, when mice were fed with this herb, significant apparent digoxin concentrations were also observed using FPIA, but neither ECLIA nor turbidimetric assay showed any apparent digoxin concentration. When aliquots of digoxin pool were further supplemented with various DanShen extract, the apparent digoxin concentrations were significantly increased when FPIA was used. In contrast, digoxin concentrations in the presence of DanShen extract compared well with the digoxin concentration of the original pool when ECLIA or turbidimetric assay was used. We conclude that DanShen does not interfere with serum digoxin measurement using a more recently released ECLIA digoxin assay.

Animals↗

PubMed2006

CD3+ cells transfer the hypersensitive granulomatous response to mycobacterial glycolipid trehalose 6,6'-dimycolate in mice.

The granulomatous response is the characteristic histological feature of Mycobacterium tuberculosis infection that is essential for organism containment. Trehalose 6,6-dimycolate (TDM), a cell-wall glycolipid present on most mycobacterial species, has been implicated in the pathogenesis of M. tuberculosis infection. TDM has potent immunoregulatory and inflammatory properties, and can be used to model granulomatous reactions that mimic, in part, pathology caused during active infection. This study examined the hypersensitive granulomatous response, focusing on cellular responses specific to TDM. Lungs from mice immunized with TDM emulsion demonstrated exacerbated histological damage, inflammation, and lymphocytic infiltration upon subsequent challenge with TDM. Splenocytes recovered from these mice demonstrated significant interferon (IFN)-gamma production during recall response to TDM, as well as increased production of proinflammatory mediators (tumour necrosis factor-alpha, interleukin-6 and macrophage inflammatory protein-1alpha). The exacerbated response could be adoptively transferred to naïve mice. Administration of non-adherent lymphocytes or purified CD3(+) cells from TDM-immunized mice led to increased inflammation, lymphocytic infiltration, and vascular endothelial cell damage upon challenge with TDM. Recipient mice that received immunized CD3(+) lymphocytes demonstrated significant increases in Th1-type cytokines and proinflammatory mediators in lung tissue following TDM challenge. When CD1d(-/-) mice were immunized with TDM, they failed to generate a specific IFN-gamma response, suggesting a role for this molecule in the generation of hypersensitivity. These experiments provide further evidence for the involvement of TDM-specific CD3(+) T cells in pathological damage elicited during M. tuberculosis infection.

Adoptive Transfer↗

PubMed2006

Proinflammatory cytokines in granulomas associated with murine cysticercosis are not the cause of seizures.

Neurocysticercosis is a parasitic infection of the human central nervous system caused by the cestode Taenia solium. The most common clinical manifestations of neurocysticercosis are seizures. Taenia crassiceps cysticercosis in mice has been used as an experimental model for T. solium cysticercosis. Granulomas surrounding murine cysticerci have striking immunopathological resemblance to human neurocysticercosis; early stage granulomas were able to induce seizures in a rodent model. To assess the role of proinflammatory cytokines in early stage granulomas, we isolated RNA from murine cysticercal granulomas and checked for cytokine expression by reverse transcriptase-polymerase chain reaction (RT-PCR) and/or ribonuclease (RNase) protection assays. Cytokine expression was compared with histological stages. Interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist, and tumor necrosis factor (TNF-alpha) were the major cytokines detected in all granulomas. Signals for IL-12, IL-18, and IL-6 RNA were not consistently detected and, when detected, were barely demonstrable. Expression of migration inhibitory factor (MIF), IL-6, IL-1alpha, TNF-alpha, and IL-18 was not significantly different between early and late-stage granulomas. Expression of IL-1beta, IL-1 receptor antagonist, and IL-12 p40 were higher in late, compared with early, stages. Thus, we demonstrated a broad range of cytokines in these granulomas. However, we did not document preferential expression of any proinflammatory cytokines in early stage granulomas. Thus, proinflammatory cytokines are not responsible for the seizures in the rodent model of neurocysticercosis.

Animals↗

PubMed2006

Trehalose 6,6'-dimycolate and lipid in the pathogenesis of caseating granulomas of tuberculosis in mice.

Trehalose 6,6'-dimycolate (TDM) is the most abundant, most granulomagenic, and most toxic lipid extractable from the surface of virulent Mycobacterium tuberculosis (MTB). We further examined its toxicity, which requires activation by oily surfaces. Injections of MTB and/or TDM into sensitized mice induced caseating granulomas that centered on oil droplets. If large doses of MTB were injected in saline, caseating granulomas developed in adipose tissue, but MTB with surface TDM removed induced only acute inflammation that did not persist. Variations in protocols produced several variants of caseating granulomas, each with characteristics of human tuberculosis. In each instance, MTB were localized in fat cells or oil drops during initiation of caseating granulomas suggesting that necrosis was caused by activation of the toxicity of TDM toxicity. Evidence extending these findings to the lung was derived from the observation that in sensitized mice, as in humans, tuberculosis development stimulates accumulation of lipid selectively in alveoli. MTB preferentially associated with lipid droplets in developing necrotic foci in late-stage murine tuberculosis. This supports the hypothesis that pulmonary tuberculosis sequesters MTB in a protected environment that accumulates lipid until it is able to activate the toxicity of TDM and initiate necrosis that results in caseating granulomas.

Adipose Tissue↗

PubMed2006

Multiple roles of cord factor in the pathogenesis of primary, secondary, and cavitary tuberculosis, including a revised description of the pathology of secondary disease.

Tuberculosis, once thought to have been controlled, is now resurgent in many parts of the world. Many gaps exist in understanding the pathogenesis of tuberculosis, especially secondary and cavitary disease. Evidence presented here suggests that cord factor (trehalose 6,6'-dimycolate, TDM) is a key driver of these processes. It is the most abundant lipid released by virulent M. tuberculosis (MTB) and can switch between two sets of activities. On organisms, TDM is non-toxic and protects them from killing by macrophages. On lipid surfaces, it becomes antigenic and highly toxic. Caseating granulomas, the hallmark of primary tuberculosis, develop from interaction of TDM with lipid within granulomas. New evidence indicates that secondary tuberculosis begins as a lipid pneumonia that accumulates mycobacterial antigens and host lipids in alveoli before developing conditions for activation of the toxicity and antigenicity of TDM. This rapidly produces caseation necrosis that leads to cavities. Finally, virulent MTB release large amounts of TDM during growth as a pellicle within cavities. We propose that such growth results in activation of the toxicity and antigenicity of TDM at the air interface and that presence of the activated TDM perpetuates the cavity.

Adjuvants, Immunologic↗

PubMed2005

Interleukin-15 activates human natural killer cells to clear the intestinal protozoan cryptosporidium.

Intracellular protozoans of the genus Cryptosporidium are a major cause of diarrheal illness worldwide, but little is known about the mechanisms that control intestinal infection. We have previously demonstrated interleukin (IL)-15 expression in the intestinal mucosa of seronegative symptomatic volunteers after oral challenge with C. parvum, which suggests a role for IL-15 in the control of acute infection. We hypothesize that IL-15 activates an innate cytolytic cell response that contributes to the clearance of initial C. parvum infection. We report here that IL-15 activates peripheral blood mononuclear cells to lyse Cryptosporidium-infected epithelial cells in a dose-dependent manner. Lysis was due to CD3(-)CD16(+)CD56+ cells (i.e., natural killer [NK] cells). Furthermore, flow cytometry revealed that IL-15 increased expression of the activation receptor NKG2D on NK cells, particularly among the CD16Hi cytolytically active cells. Major histocompatibility complex class I-related molecules A and B (MICA and MICB), ligands for NKG2D, were increased after infection of epithelial cell lines and human ileal tissue. These data suggest that IL-15 has an important role in activating an NK cell-mediated pathway that leads to the elimination of intracellular protozoans from the intestines, which is a previously unrecognized feature of NK cell function.

Animals↗

PubMed2005

Lactoferrin augments BCG vaccine efficacy to generate T helper response and subsequent protection against challenge with virulent Mycobacterium tuberculosis.

The ability to control intracellular Mycobacterium tuberculosis (MTB) infection relies on cellular immunity and generation of a strong T-cell helper 1 (T(H)1) response. Lactoferrin, an iron-binding protein with immune regulatory functions, was investigated as an adjuvant to boost Mycobacterium bovis Bacillus Calmette-Guerin (BCG) efficacy. Lactoferrin was initially shown to augment IL-12(p40) production from macrophages stimulated with LPS. A single immunization of mice with Lactoferrin as an adjunct adjuvant resulted in amplified splenocyte proliferative response to heat-killed BCG, and elevated IL-12(p40) production with increased relative ratios of IL-12/IL-10. Furthermore, splenocyte recall response to HK-BCG was augmented for proinflammatory mediators, TNF-alpha, IL-1beta, and IL-6, approaching responses generated to complete Freund's adjuvant (CFA) immunized controls. Specific responses were identified, with significant elevation of IFN-gamma generated during antigenic recall. Subsequent aerosol challenge of Lactoferrin adjuvant immunized mice with virulent M. tuberculosis revealed decreased mycobacterial loads in the lung, and limitation of organism dissemination to a peripheral organ (spleen). These studies indicate that Lactoferrin can act as an adjunct adjuvant to augment cellular immunity and boost BCG efficacy for protection against subsequent challenge with virulent MTB.

Animals↗

PubMed2005

Peptide nucleic acid antisense oligomer as a therapeutic strategy against bacterial infection: proof of principle using mouse intraperitoneal infection.

Antisense oligodeoxynucleotides (ODNs) and their analogs have been successfully utilized to inhibit gene expression and bacterial growth in vitro or in cell culture. In this study, acpP-targeting antisense peptide nucleic acid (PNA) and its peptide conjugate were tested as potential antibacterial agents in two groups of experiments using a mouse model. In the first group, Escherichia coli mutant strain SM101 with a defective outer membrane was used to induce bacteremia and peritonitis in BALB/c mice by intraperitoneal (i.p.) injection. The resulting bacteremia was fatal within 48 h. A single i.p injection of 5 nmol (or more) of PNA administered 30 min before bacterial challenge significantly reduced the bacterial load in mouse blood. Reductions in serum concentrations of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-1beta (IL-1beta), IL-6, and IL-12 were also observed. PNA treatment was effective in rescuing 100% of infected animals. In the second group, bacteremia in BALB/c mice was induced by i.p. injection of E. coli wild-type strain K-12. The infected mice were treated by a single intravenous injection of peptide-PNA conjugate 30 min after bacterial challenge. Treatment with the peptide-PNA conjugate significantly reduced the K-12 load, with modest reduction in cytokine concentrations. The conjugate treatment was also able to rescue up to 60% of infected animals. This report is the first demonstration of ODNs' antibacterial efficacy in an animal disease model. The ability of PNA and its peptide conjugate to inhibit bacterial growth and to prevent fatal infection demonstrates the potential for this new class of antibacterial agents.

Acyl Carrier Protein↗

PubMed2004

Cytokine production by non-adherent mouse splenocyte cultures to Echinacea extracts.

BACKGROUND: Echinacea is commonly used in oral dosage as an immune stimulant to increase resistance to viral, bacterial and fungal infections of the upper respiratory tract. It has been suggested that Echinacea is able to stimulate innate immune responses, including those regulated by macrophages and natural killer cells. Indeed, macrophages respond to purified polysaccharide and alkylamide preparations. However, the mechanisms for stimulation of cells responsible for adaptive immunity have not been fully elucidated for other molecules present in Echinacea purpurea preparations. METHODS: Adherent and non-adherent mouse splenocyte populations were incubated in vitro with Echinacea, or with water or alcohol soluble Echinacea extract preparations. Supernatants were collected at 48-h post-incubation, and tested by standard ELISA for presence of secreted cytokines and proinflammatory mediators. RESULTS: Whole splenocyte populations were capable of producing significant amounts IL-6 (1014 pg/ml) in response to Echinacea preparations. The response was primarily contained towards products isolated to the water extract preparation; no IL-6 was produced upon challenge with the alcohol extract. The IL-6 response was produced by the non-adherent cellular population, which made 4912 pg/ml IL-6 when treated with water soluble extract at 1 mg/ml. Likewise, the water soluble extract of Echinacea was able to stimulate non-adherent splenocyte populations to produce TNF-alpha (2082 pg/ml), IL-10 (892 pg/ml) and MIP-1alpha (6486 pg/ml) from non-adherent splenocytes, but only significant concentrations of TNF-alpha and MIP-1alpha mediators were produced from adherent populations at similar dose concentrations. Neither population of splenocytes was capable of stimulating significant production of IFN-gamma, IL-2 or IL-12 to any preparation of Echinacea examined. CONCLUSIONS: The immune stimulatory ability of components contained within E. purpurea extracts offer insight into possible therapeutic potential of this product to regulate non-adherent lymphocytes in immune responses and activation events.

Alcohols↗

PubMed2004

Failure of CD1D-/- mice to elicit hypersensitive granulomas to mycobacterial cord factor trehalose 6,6'-dimycolate.

The present study defines pathologic differences in acute and hypersensitive responses to Mycobacterium tuberculosis glycolipid trehalose-6,6'-dimycolate (TDM, cord factor) in normal BALB/c mice and those deficient in group II CD1 molecule CD1d1. Mice immunized against TDM demonstrate hypersensitive responses, yet the mechanisms for TDM presentation remain elusive. Mice lacking CD1d (CD1D(-/-)) demonstrate dysregulated granulomatous response to TDM, compared with CD1D(+/-) heterozygous controls. Because CD1d-restricted T cells can regulate macrophage immune functions at mucosal surfaces, we hypothesized that CD1D(-/-) mice would show deficient TDM-induced hypersensitive pulmonary granulomatous response in which T cells play a central role. Control CD1D(+/+) mice sensitized and subsequently challenged with TDM demonstrated aggressive inflammation defined by monocytic lesions contained by CD3(+) lymphocytic cuffing. CD1D(-/-) mice demonstrated distinctly different pathologies, with edema present concurrent with extended, nonfocal mononuclear cell-based granulomatous reactions. Furthermore, CD1D(-/-) mice did not demonstrate destructive lesions, and CD3(+) lymphocytes were only loosely organized in proximity to reactive pathology. The CD1d-deficient mice demonstrated rapid increases in proinflammatory mRNAs, with significant differences in interferon-gamma (IFN-gamma) compared to the wild-type group. IFN-gamma, interleukin-6 (IL-6), and IL-12 proteins were significantly elevated in the CD1D(-/-) group compared with wild-type mice (p < 0.05) 2 days after TDM challenge. However, by 7 days postadministration, similar production for all cytokines and proinflammatory molecules examined was present in both groups of mice. These experiments provide evidence for a role for CD1d in mediation of pathology during hypersensitive responses to the mycobacterial glycolipid TDM.

Adjuvants, Immunologic↗

PubMed2004

A mutant of Mycobacterium tuberculosis H37Rv that lacks expression of antigen 85A is attenuated in mice but retains vaccinogenic potential.

The fbpA and fbpB genes encoding the 85A and 85B proteins of Mycobacterium tuberculosis H37Rv, respectively, were disrupted, the mutants were examined for their ability to survive, and the strain lacking 85A (DeltafbpA) was tested for its ability to immunize mice. The DeltafbpA mutant was attenuated in mice after intravenous or aerosol infection, while replication of the DeltafbpB mutant was similar to that of the wild type. Complementation of the fbpA gene in DeltafbpA restored its ability to grow in the lungs of mice. The DeltafbpA mutant induced a stronger expression of pulmonary mRNA messages in mice for tumor necrosis factor alpha, interleukin-1 beta (IL-1beta), gamma interferon, IL-6, IL-2, and inducible nitric oxide (NO) synthase, which led to its decline, while H37Rv persisted despite strong immune responses. H37Rv and DeltafbpA both induced NO in macrophages and were equally susceptible to NO donors, although DeltafbpA was more susceptible in vitro to peroxynitrite and its growth was enhanced by NO inhibitors in mice and macrophages. Aerosol-infected mice, which cleared a low-dose DeltafbpA infection, resisted a challenge with virulent M. tuberculosis. Mice subcutaneously immunized with DeltafbpA or Mycobacterium bovis BCG and challenged with M. tuberculosis also showed similar levels of protection, marked by a reduction in the growth of challenged M. tuberculosis. The DeltafbpA mutant was thus attenuated, unlike DeltafbpB, but was also vaccinogenic against tuberculosis. Attenuation was incomplete, however, since DeltafbpA revived in normal mice after 370 days, suggesting that revival was due to immunosenescence but not compensation by the fbpB or fbpC gene. Antigen 85A thus affects susceptibility to peroxynitrite in M. tuberculosis and appears to be necessary for its optimal growth in mice.

Acyltransferases↗

PubMed2003

Substance P expression correlates with severity of diarrhea in cryptosporidiosis.

Cryptosporidiosis, caused by Cryptosporidium parvum, is self-limited in immunocompetent hosts but may cause chronic diarrhea in patients with acquired immunodeficiency syndrome (AIDS). Substance P (SP), a neuropeptide belonging to the tachykinin family, is expressed in gastrointestinal tract and can cause electrogenic chloride anion secretion. Therefore, we studied SP mRNA and protein expression in jejunal tissue samples of patients with AIDS with naturally occurring chronic cryptosporidiosis and healthy volunteers with mild cryptosporidiosis or asymptomatic infection after experimental C. parvum challenge. SP mRNA was associated with symptoms in cryptosporidiosis. SP protein levels were greater in symptomatic than asymptomatic volunteers. Similarly, greater expression of SP mRNA and protein were noted in patients with AIDS with chronic cryptosporidiosis versus immunocompetent volunteers with self-limited infection. This study demonstrates a direct correlation between SP levels and disease severity and may imply that SP plays a role in diarrhea mediation.

AIDS-Related Opportunistic Infections↗

PubMed2003

Asian and Siberian ginseng as a potential modulator of immune function: an in vitro cytokine study using mouse macrophages.

BACKGROUND: Ginseng is a widely used herbal product in China, other Asian countries, and in the Unites States. There is a traditional belief that ginseng stimulates immune functions. In this study, the innate effects of Asian and Siberian ginsengs on cytokines and chemokines produced by cultured macrophages were examined. MATERIALS AND METHODS: The effects of Asian and Siberian ginseng on cytokines and chemokines produced by cultured macrophages were examined. Mouse macrophages (J774A.1) were incubated with Asian or Siberian ginseng at varying concentrations (1, 10, 100, and 1000 microg/ml) for 24 h and then harvested for RNA isolation. The expression levels of IL-1beta, IL-12, TNF-alpha, MIP-1 alpha, and MIP-2 mRNA were measured by quantitative PCR. RESULTS: Our data showed that Asian ginseng induced a statistically significant increase in IL-12 expression at both mRNA and protein levels. However, the minor twofold increase is probably biologically insignificant. No significant increase of IL-12 by Siberian ginseng was observed at any dose level studied. No significant change in IL-1beta, IL-15, TNF-alpha, or MIP-1alpha mRNA was observed by either Asian or Siberian ginseng treatment. CONCLUSIONS: Our data showed statistically significant differential regulation of IL-12 by Asian ginseng. Siberian ginseng did not show a statistically significant increase. We conclude that both Asian ginseng and Siberian ginseng cannot significantly stimulate innate macrophage immune functions that influence cellular immune responses. Therefore, contrary to the popular belief, Asian and Siberian ginseng may not stimulate immune function.

Adjuvants, Immunologic↗

PubMed2003

Cord factor trehalose 6,6'-dimycolate (TDM) mediates trafficking events during mycobacterial infection of murine macrophages.

The persistence of tuberculosis within pulmonary granulomatous lesions is a complex phenomenon, with bacterial survival occurring in a focal region of high immune activity. In part, the survival of the organism may be linked to the ability of the surface glycolipid trehalose 6,6'-dimycolate (TDM; cord factor) to inhibit fusion events between phospholipid vesicles inside the host macrophage. At the same time, TDM contributes to macrophage activation and a cascade of events required for initiation and maintenance of granulomatous responses. This allows increased sequestration of organisms and further survival and persistence within host tissues. Bacterial viability, macrophage cytokine and chemokine response, and intracellular trafficking were investigated in Mycobacterium tuberculosis from which TDM had been removed. Removal of surface lipids led to enhanced trafficking of organisms to acidic compartments; reconstitution of delipidated organisms with either pure TDM or the petroleum ether extract containing crude surface lipids restored normal responses. Use of TDM-coated polystyrene beads demonstrated that TDM can mediate intracellular trafficking events, as well as influence macrophage production of pro-inflammatory molecules. Thus, the presence of TDM may be an important determinant for successful infection and survival of M. tuberculosis within macrophages.

Animals↗

PubMed2002

In vivo digoxin-like immunoreactivity in mice and interference of Chinese medicine Danshen in serum digoxin measurement: elimination of interference by using a chemiluminescent assay.

BACKGROUND: Danshen, a traditional Chinese medicine used in the management of cardiovascular diseases, is available without prescription in the US. Because Danshen is used to treat cardiovascular diseases, we studied the potential interference of Danshen with serum digoxin measurement using various immunoassays. METHODS: Blood was collected 1 day before and then 1 and 2 h after feeding mice with Danshen. The apparent digitoxin activities were measured by the fluorescence polarization immunoassay (FPIA). We also added microliter amounts of Danshen extract to digoxin pools prepared from patients receiving digoxin. The digoxin concentrations were measured using the fluorescence polarization immunoassay (FPIA), microparticle enzyme immunoassay (MEIA) and chemiluminescent assay (CLIA). The observed values were compared with original values. We also fed mice with Danshen. RESULTS: We observed measurable digoxin-like immunoreactivity in sera of mice after feeding with Danshen. We also observed falsely lower digoxin concentrations (negative interference) when MEIA was used for digoxin measurement. However, serum digoxin concentrations were falsely elevated with FPIA. We observed no interference of Danshen in serum digoxin measurement using the CLIA. CONCLUSION: Danshen appears to contain digoxin-like immunoreactivity but does not interfere with serum digoxin measurement when CLIA was used.

Animals↗

PubMed2002

Activated charcoal is more effective than equilibrium dialysis in removing Chinese medicines Chan Su and Dan Shen from serum and activated charcoal also prevents further absorption of these agents from G.I. tract in mice: monitoring the effect in clinical laboratory by measuring digoxin activity in serum.

BACKGROUND: Chinese medicines are freely available without prescription and are widely used by the general population. Chan Su and Dan Shen are both indicated for the treatment of cardiac diseases. Severe toxicity from Chan Su has been reported. We studied the possibility of removing Chan Su and Dan Shen from human sera using activated charcoal and equilibrium dialysis, and also examined the potential benefit of preventing absorption of these agents from the G.I. tract in the mouse model. METHODS: For in vitro studies, drug-free serum pools were supplemented with Chan Su or Dan Shen and then either treated with activated charcoal (10 and 25 mg/ml), or passed through a column packed with activated charcoal. Serum pools supplemented with Chan Su or Dan Shen were also subjected to equilibrium dialysis against phosphate buffer (pH 7.4) using dialysis membrane with molecular cut-off of 25,000 Da. Removal of Chan Su or Dan Shen from the serum was monitored by measuring the apparent digoxin concentration using the fluorescence polarization immunoassay (FPIA) for digoxin (Abbott Laboratories). RESULTS: We observed the fast and effective removal of both Chan Su and Dan Shen from the serum by activated charcoal. We also observed significant removal of both Chan Su and Dan Shen when the serum pools containing these Chinese medicines were passed through columns packed with activated charcoal. Although equilibrium dialysis was also effective in removing these Chinese medicines from the serum, 24 h was required for complete removal of Dan Shen activity, and for Chan Su, complete removal was not achieved even after 24 h. In our in vivo model, we observed significantly less digoxin activity in the group of mice that received activated charcoal compared to the control group. CONCLUSIONS: Activated charcoal is effective in preventing absorption of these Chinese medicines from the G.I. tract and can also remove these agents from the serum.

Animals↗

PubMed2002

Lactoferrin immunomodulation of DTH response in mice.

Improved nontoxic adjuvants, especially adjuvants capable of inducing cell-mediated immunity (CMI), are needed for research in immunology and for development of human and veterinary vaccines. Bovine Lactoferrin, an effector molecule shown to directly participate in host defense, was assessed at various concentrations as an adjuvant component for induction of DTH responses to sheep red blood cells (SRBC). Subcutaneous immunization with Lactoferrin enhanced delayed type hypersensitivity (DTH) in CBA mice in a dose-dependent fashion; DTH responses were most significantly increased when sensitization was accomplished using Lactoferrin at 50 microg/dose and 250 microg/dose. Furthermore, Lactoferrin admixed with suboptimal dose of SRBC enhanced DTH responses by over 17-fold. Peritoneal cells collected from mice intraperitoneally injected with a 100 microg/dose of Lactoferrin demonstrated modest, but significant, production of TNF-alpha, IL-12 and MIP-1alpha when cultured in vitro, compared to saline-injected controls. J774A.1 murine macrophages stimulated with Lactoferrin resulted in increased TNF-alpha protein production, and upregulated IL-12 and IL-15 mRNA. Levels of message for chemokines MIP-1alpha and MIP-2 were also increased in a dose-dependent way. Taken together, these results indicate that Lactoferrin as an adjuvant may stimulate macrophages to generate a local environment likely to push immune responses towards development and maintenance of CMI.

Adjuvants, Immunologic↗

PubMed2002

Influence of trehalose 6,6'-dimycolate (TDM) during mycobacterial infection of bone marrow macrophages.

The relative role of surface lipids in the innate macrophage response to infection with mycobacteria remains unknown. Trehalose 6,6'-dimycolate (TDM), a major component of the mycobacterial cell wall, can elicit hypersensitive as well as T-cell-independent foreign body responses. The T-cell-independent contribution of TDM to the primary macrophage response to mycobacterial infection was investigated. Bone-marrow-derived macrophages isolated from C57BL/6 mice were infected with native Mycobacterium tuberculosis (MTB) or with MTB delipidated using petroleum ether extraction methods. The removal of surface lipids caused decreased bacterial survival in macrophages, but there was no loss of bacterial growth in broth culture. Bacterial survival within macrophages was restored upon reconstitution of the bacteria with purified TDM. The cytokine and chemokine parameters of the macrophage responses were also investigated. The amounts of IL-1beta, TNF-alpha, IL-6 and MIP-1alpha produced were significantly reduced following delipidation, but were restored upon reconstitution with TDM. The amount of IL-12 produced, but not the amount of IL-10 produced, was also significantly reduced upon macrophage infection with delipidated MTB. Furthermore, nitric oxide responses were not impaired upon infection with delipidated MTB, suggesting that intracellular survival and macrophage secretion of cytokines and chemokines are differentially controlled. These studies indicate that TDM is a major component contributing to the innate macrophage responses to MTB infection.

Animals↗