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T K Eisenstein

Publications and source records attributed to T K Eisenstein.

At least 19 recordsLinked to original sources
PubMed2001

Morphine inhibits mucosal antibody responses and TGF-beta mRNA in gut-associated lymphoid tissue following oral cholera toxin in mice.

In this study, we investigated the effect of morphine on the mucosal immune system using fragment cultures of ileal segments, Peyer's patches (PPs), and mesenteric lymph nodes. Mice were implanted s.c. with a morphine slow release pellet. Control groups received a naltrexone slow release pellet, a placebo pellet, or both a morphine and a naltrexone pellet. After 48 h, mice were orally immunized with cholera toxin (CT) and were boosted orally 1 wk later. Animals were sacrificed 1 wk after the booster immunization, and PPs, mesenteric lymph nodes, and ileal segments were cultured in 24-well plates for 12 days. Morphine resulted in a highly significant inhibition of CT-specific IgA and IgG production in fragment culture supernatants of all three tissues compared with placebo. Naltrexone blocked the reduction in Ab levels induced by morphine, indicating that the effect is opioid receptor mediated. Morphine did not significantly alter total IgA levels in any of the tissue culture supernatants. Morphine also inhibited CT-specific IgA and IgG levels in serum. By flow cytometry, morphine did not alter the lymphoid cell composition in PPs compared with placebo. The effect of morphine on TGF-beta, IL-5, and IL-6 mRNA expression in PPs and ileal segments was determined following oral immunization with CT. Morphine significantly decreased TGF-beta mRNA compared with that in the placebo group, and naltrexone blocked this effect. These results indicate that morphine inhibits Ag-specific IgA responses in gut-associated lymphoid tissue at least partially through the inhibition of TGF-beta, a putative IgA switch factor, in the gastrointestinal tract.

Administration, Oral↗
PubMed2001

Specific association of Type I c-Abl with Ran GTPase in lipopolysaccharide-mediated differentiation.

Each of several isoforms of c-Abl may be involved in different biological functions. Type I c-Abl has been shown to be involved in LPS-induced differentiation and Type IV c-Abl, apoptosis. Ran has recently been shown to be involved in LPS endotoxin signal transduction. Here we show that Type I c-Abl associates with Ran. Formation of this complex is specific, as Ran did not associate with the highly homologous Type IV c-Abl isoform. In non-stimulated lymphoid B cells, Type I c-Abl tyrosine kinase is inactive, whereas Type IV kinase is active. Formation of Type I c-Abl/Ran complex and activation of Type I c-Abl kinase activity are LPS dose-dependent. This complex is detectable in B cells of endotoxin-sensitive inbred mice but absent in B cells of endotoxin-resistant mice. These findings therefore suggest that Type I c-Abl and Ran are important targets in lipopolysaccharide-induced biological responses of hematopoietic cells.

Animals↗
PubMed2001

Opioids, opioid receptors, and the immune response.

It is now clear that opioid receptors participate in the function of the cells of the immune system, and evidence suggests that opioids modulate both innate and acquired immune responses. We review literature here which establishes that mu-, kappa-, and delta-opioid compounds alter resistance to a variety of infectious agents, including the Human Immunodeficiency Virus (HIV). The nature of the immunomodulatory activity of the opioids has been the subject of a great deal of research over the last ten years. There is increasing evidence that effects of opioids on the immune response are mediated at several levels. Modulation of the inflammatory response appears to be a target of these compounds, including effects on phagocytic activity, as well as the response of cells to various chemoattractant molecules. Moreover, findings from several laboratories have demonstrated the impact of opioid treatment on antibody responses, and the molecular basis for this effect is likely due, at least in part, to the modulation of both cytokine and cytokine receptor expression. Future research should provide a clearer understanding of the cellular and molecular targets of opioid action within the immune system.

Antibodies, Viral↗
PubMed2001

Administration of mu-, kappa- or delta2-receptor agonists via osmotic minipumps suppresses murine splenic antibody responses.

Previously, our laboratory has shown that morphine given by implantation of a 75-mg slow-release pellet for 48 h suppresses murine splenic antibody responses to sheep red blood cells (SRBCs) in a plaque-forming cell (PFC) assay. However, the use of slow-release pellets for such studies is limited, as these pellets are only available in fixed doses and similar pellets for kappa and delta agonists have not been developed. In the present study, we investigated the feasibility of administering opioids via Alzet osmotic minipumps to assess their immunomodulatory effects. Groups of mice received minipumps dispensing morphine sulfate, which has primary activity at the mu opioid receptor; U50,488H, which is a kappa-selective agonist; deltorphin II, which is a delta2-selective agonist; or DPDPE, which has greater selectivity for delta1 than delta, receptors. Morphine, U50,488H and deltorphin II were all immunosuppressive, with biphasic dose-response curves exhibiting maximal (approximately 50%) suppression of the PFC response at doses of 0.5 to 2 mg/kg/day 48 h after pump implantation. Further, immunosuppression by morphine sulfate, U50,488H or deltorphin II was blocked by simultaneous implantation of a minipump administering the opioid receptor-selective antagonists CTAP (1 mg/kg/day), nor-binaltorphimine (5 mg/kg/day), or naltriben (3 mg/kg/day), respectively. DPDPE was inactive at doses lower than 10 mg/kg/day. We conclude that osmotic minipumps are a practical and useful way of administering opioids to study their effects on the immune system, and give further evidence that immunosuppression induced in vivo by opioid agonists is mediated not only via mu, but also via kappa and delta2 opioid receptors.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed2000

Mu-opioid induction of monocyte chemoattractant protein-1, RANTES, and IFN-gamma-inducible protein-10 expression in human peripheral blood mononuclear cells.

Strong evidence for the direct modulation of the immune system by opioids is well documented. Mu-opioids have been shown to alter the release of cytokines important for both host defense and the inflammatory response. Proinflammatory chemokines monocyte chemoattractant protein-1 (MCP-1), RANTES, and IFN-gamma-inducible protein-10 (IP-10) play crucial roles in cell-mediated immune responses, proinflammatory reactions, and viral infections. In this report, we show that [D-Ala(2),N:-Me-Phe(4),Gly-ol(5)]enkephalin (DAMGO), a mu-opioid-selective agonist, augments the expression in human PBMCs of MCP-1, RANTES, and IP-10 at both the mRNA and protein levels. Because of the proposed relationship between opioid abuse and HIV-1 infection, we also examined the impact of DAMGO on chemokine expression in HIV-infected cells. Our results show that DAMGO administration induces a significant increase in RANTES and IP-10 expression, while MCP-1 protein levels remain unaffected in PBMCs infected with the HIV-1 strain. In contrast, we show a dichotomous effect of DAMGO treatment on IP-10 protein levels expressed by T- and M-tropic HIV-infected PBMCs. The differential modulation of chemokine expression in T- and M-tropic HIV-1-infected PBMCs by opioids supports a detrimental role for opioids during HIV-1 infection. Modulation of chemokine expression may enhance trafficking of potential noninfected target cells to the site of active infection, thus directly contributing to HIV-1 replication and disease progression to AIDS.

Cells, Cultured↗
PubMed2000

Morphine increases susceptibility to oral Salmonella typhimurium infection.

This study examined the effect of morphine on oral infection with virulent Salmonella typhimurium. Animals were treated with a 75-mg slow-release morphine pellet followed by inoculation with salmonellae. Morphine markedly sensitized mice to oral infection, as assessed by survival, mean survival time, and colony culture. By 24 h after Salmonella inoculation, morphine-treated mice had a 105-fold difference in number of organisms in the Peyer's patches, compared with controls. The opioid antagonist naltrexone significantly blocked Salmonella colonization in Peyer's patches and reduced Salmonella burden in other organs, indicating that morphine acts at least in part via an opioid receptor-mediated pathway. The data show that morphine markedly potentiates Salmonella infection at the gastrointestinal portal of entry and enhances subsequent dissemination of Salmonella organisms. The results have implications for potentiating gastrointestinal opportunistic infections in intravenous drug abusers and in opioid-medicated postsurgical patients.

Animals↗
PubMed2000

Morphine attenuates leukocyte/endothelial interactions.

Gram-negative sepsis and subsequent endotoxic shock after surgery remain problematic in the United States and throughout the world. While morphine is widely prescribed for postoperative trauma pain management, there are reports that morphine may compromise the immune system and contribute to postoperative sepsis. The current study tested the hypothesis that morphine attenuates leukocyte rolling and sticking in both arterioles and venules via nitric oxide production. Nude mice implanted with slow-release morphine pellets were used in this study. The dorsal skinfold chamber model for intravital fluorescence microscopy on awake mice was used. Leukocyte/endothelial interactions were evaluated after bolus injection of oxidized low density lipoprotein. Morphine was found to significantly attenuate leukocyte rolling and sticking in both the arterial and venular side of the microcirculation. This attenuation was reversed by simultaneous implantation of naloxone pellets. The mechanisms of this attenuation were further investigated by administration of the nitric oxide synthase inhibitors NG-nitro-l-arginine (NOLA) and aminoguanidine (AG) in drinking water. NOLA was found to significantly reverse this morphine-induced attenuation of leukocyte rolling and sticking in both arterioles and venules. However, AG did not have the same effect. The results indicate that morphine interferes with leukocyte/endothelial cell interactions via stimulation of nitric oxide production.

Analgesics, Opioid↗
PubMed2000

Morphine enhances interleukin-12 and the production of other pro-inflammatory cytokines in mouse peritoneal macrophages.

In this study we investigated the capacity of morphine to modulate expression of cytokines in peritoneal macrophages. Mice were implanted subcutaneously with a 75-mg morphine slow-release pellet, and 48 h later resident peritoneal macrophages were harvested. Control groups received placebo pellets, naltrexone pellets, or morphine plus naltrexone pellets. Adherent cells were stimulated with lipopolysaccharide (LPS: 10 microg/mL) plus interferon-gamma (IFN-gamma: 100 units/mL) to induce cytokine production. After 24 h RNA was extracted for analysis of cytokine mRNA levels by reverse transcriptase-polymerase chain reaction, or supernatants were collected after 48 h for determination of cytokine production by enzyme-linked immunosorbent assay (ELISA). Morphine enhanced mRNA expression of interleukin (IL)-12 p40 and tumor necrosis factor alpha (TNF-alpha) compared with controls, whereas IL-10 levels were unchanged by drug treatment. ELISA data showed that both IL-12 p40 and p70 were increased by morphine. The enhancement of IL-12 at both the mRNA and protein levels was antagonized by naltrexone, indicating that the modulation of this cytokine by morphine is via a classic opioid receptor. These results are particularly interesting in light of our previous observation that 48 h after morphine pellet implantation, the peritoneal cavity is colonized with gram-negative and other enteric bacteria. The enhancement of IL-12 by morphine might be related to morphine-induced sepsis.

Adjuvants, Immunologic↗
PubMed1999

In vivo blockage of nitric oxide with aminoguanidine inhibits immunosuppression induced by an attenuated strain of Salmonella typhimurium, potentiates Salmonella infection, and inhibits macrophage and polymorphonuclear leukocyte influx into the spleen.

Our laboratory has previously shown that after immunization with a strain of Salmonella typhimurium, SL3235, made avirulent by a blockage in the pathway of aromatic synthesis, murine splenocytes were profoundly suppressed in their capacity to mount an in vitro antibody plaque-forming cell (PFC) response to sheep erythrocytes. Evidence indicated that suppression was mediated by nitric oxide (NO), since the in vitro addition of NG-monomethyl-L-arginine blocked suppression. The present studies examined the effect of blocking NO production on Salmonella-induced immunosuppression by in vivo administration of aminoguanidine hemisulfate (AG). AG was administered to C3HeB/FeJ mice in their drinking water (2.5% solution) for 7 days prior to intraperitoneal inoculation with SL3235. AG treatment inhibited the increase in nitrate and nitrite levels in plasma and nitrite levels in the spleen seen in immunized mice. Importantly, AG treatment completely blocked suppression of the splenic PFC response and markedly attenuated the suppression of the response to concanavalin A in immunized mice, providing further evidence that Salmonella-induced immunosuppression is mediated by NO. AG treatment also alleviated the majority of the splenomegaly associated with SL3235 inoculation, which correlated with a blockage of influx of neutrophils and macrophages into spleens, as assessed by flow cytometry. AG treatment unexpectedly resulted in 90% mortality in mice injected with the highly attenuated vaccine strain of Salmonella, SL3235. Increased mortality in AG-treated mice correlated with inability to clear organisms from the spleen by day 15 postinoculation and with persistent bacteremia, compared with control mice. Collectively, these in vivo results underscore the dual biological consequences of NO production following Salmonella infection, with NO being necessary for host defense, but also having the potentially adverse effect of immunosuppression. A unifying hypothesis to explain how these seemingly paradoxical effects could both result from NO production is presented.

Animals↗
PubMed1998

Characterization of kappa-opioid receptor transcripts expressed by T cells and macrophages.

We have found that the immature T cell lines R1.1 and DPK and the macrophage lines P388D1 and WEHI-3 also express kappa-opioid receptor (KOR) mRNA. Characterization of the KOR transcripts in both brain tissue and these T cells has revealed both the normal full-length as well as a truncated form of the mRNA. Our results show that the truncated transcript lacks the second exon. Primary macrophages express this truncated form of the transcript in the absence of detectable levels of the full-length form. These results suggest a degree of heterogeneity in the expression of the opioid receptors which has not previously been reported.

Animals↗
PubMed1998

Involvement of C-Abl tyrosine kinase in lipopolysaccharide-induced macrophage activation.

LPS endotoxin-induced macrophage activation is recognized to be important in both nonspecific immunity and endotoxin-induced sepsis when excessive macrophage stimulation occurs. In this study, we showed that reduction of c-Abl in macrophages prevented LPS-induced growth arrest, nitric oxide production and TNF-alpha secretion by ANA-1 macrophages. These cells continued to grow but later underwent apoptosis. Reduction of c-Abl in these cells led to reduced c-Abl kinase activity associated with Ran, which recently has been shown to be an LPS-responsive gene product. Our data suggest that c-Abl tyrosine kinase is one of the intermediates downstream of the initial signal transduction event related to activation of macrophages by LPS.

Animals↗
PubMed1998

Opioid modulation of immune responses: effects on phagocyte and lymphoid cell populations.

The literature describing effects of morphine on cells of the immune system points to the clear conclusion that morphine given in vivo suppresses a variety of immune responses that involve the major cell types in the immune system, including natural killer (NK) cells, T cells, B cells, macrophages and polymorphonuclear leukocytes (PMNs). Depression of NK cell activity has been reported in humans, monkeys and rodents. Similarly, responses of T cells are depressed by morphine, as assessed by inhibition of induction of delayed-type hypersensitivity reactions and cytotoxic T-cell activity, modulation of T-cell antigen expression, and depression of responses to T-cell mitogens. Effects on T cells have been reported in humans, monkeys and rodents. Effects of morphine on B-cell activity have mainly been tested in rodents using assays of antibody formation, which also require macrophages and T cells, preventing a conclusion as to the cell type being affected. Consistent effects on phagocytic cell function have been reported in rodents given morphine. In contrast, studies on immunomodulatory effects of morphine added to cells of the immune system in vitro have shown robust effects on some of these cell types, but not others. There is a rich literature demonstrating downregulation of phagocytic cell function by morphine, particularly for human peripheral blood mononuclear cells (PBMCs) and PMNs. Phagocytosis, chemotactic responses, interleukin production, and generation of activated oxygen intermediates and arachidonic acid products have all been reported to be inhibited. On the contrary, the literature does not support direct effects of morphine on NK cell function, is inconclusive concerning effects on B cells, and provides limited evidence for effects on T cells. The divergence between the in vivo and in vitro data suggests that effects on some cells in the immune system observed after in vivo morphine are probably not direct, but mediated. In aggregate, the literature supports the existence of an in vivo neural-immune circuit through which morphine acts to depress the function of all cells of the immune system. Further, there is strong evidence that morphine can directly depress the function of macrophages and PMNs, and modulate expression of one type of T-cell surface marker. There is, however, little evidence for direct effects of morphine on NK cells and B cells. A further complication emerges from reports of immunopotentiation of immune function in in vitro assays using endogenous opioids. The possibility of different receptors for endogenous and exogenous opioids or of interactions among the activated opioid receptors may account for these opposing effects.

Humans↗
PubMed1998

Nitric oxide mediates immunosuppression induced by Listeria monocytogenes infection: quantitative studies.

Our laboratory has shown that immunization of mice with an attenuated strain of Salmonella typhimuriuminduces profound suppression in the capacity of splenocytes to mount an in vitro antibody plaque-forming cell (PFC) response to sheep red blood cells (SRBC) and to proliferate in response to mitogens. In vitro addition of NG-monomethyl-L-arginine (NMMA), an inhibitor of nitric oxide (NO) synthase, to cell cultures from Salmonella-immunized mice completely blocked suppression of the PFC responses, implicating that NO is the suppressor factor. The present study quantified the role of nitric oxide in immunosuppression induced by Listeria monocytogenes, a gram positive intracellular pathogen of macrophages. Listeria infection resulted in suppression of the PFC assay at inoculating doses of greater than 6.5x10(3)colony forming units, with no suppression observed at lower doses. Suppression correlated with increased nitrite production. Addition of NMMA to spleen cell cultures taken from Listeria-infected mice completely blocked suppression of the PFC response, and returned nitrite production to baseline levels. In regard to Listeria-induced suppression of responses to the mitogen, Concanavalin A (Con A), the parameters were different from those observed for the PFC response. There was a direct correlation between the log10of the inoculating dose of Listeria and degree of immunosuppression, with suppression observed at doses as low as 1x10(3)cells. Addition of NMMA to the Con A-stimulated cultures resulted in reduced nitrite levels, but only partial restoration of the proliferative responses. Co-culture of splenocytes from Listeria inoculated mice with normal splenocytes in media with NMMA and reduced levels of L-arginine resulted in complete reversal of suppressed responses to Con A. Similar differences in ease of reversing suppression of the PFC response, as compared with responses to Con A, were previously noted using cells taken from Salmonella-infected mice. The present results show that a gram positive intracellular pathogen of macrophages, L. monocytogenes, induces immunosuppression in mouse spleen cells by a nitric oxide mediated mechanism that closely parallels that induced by the gram negative pathogen, S. typhimurium.

Animals↗
PubMed1998

Immunosuppression and nitric oxide production induced by parenteral live Salmonella vaccines do not correlate with protective capacity: a phoP::Tn10 mutant does not suppress but does protect.

Previous work from our laboratory showed that an aroA mutant strain of S. typhimurium, SL3235, induces profound immunosuppression 7 days post-parenteral inoculation, and that the suppression is mediated by nitric oxide. Suppression was measured by the capacity of spleen cells to mount a primary in vitro plaque-forming cell response to sheep red blood cells in Mishell-Dutton cultures. In the present studies, the capacity of a panel of strains of attenuated Salmonella with various genetic lesions was tested. Most of the strains were S. typhimurium, but several were S. dublin. It was found that a variety of Salmonella strains induced suppression, demonstrating that suppressive capacity is not unique to SL3235 or to S. typhimurium. A strong correlation was obtained between the log10 of the microbial burden (cfu spleen-1) on the seventh day post-vaccine inoculation and the degree of immunosuppression. Strains that gave high spleen counts gave greater suppression. Microbial burden also correlated with the size of the spleen and the amount of nitrite produced by spleen-cell cultures, a measure of nitric oxide. Finally, the degree of immunosuppression was found to be linearly related to the log10 of the amount of nitrite produced. The capacity of the various strains of Salmonella to protect against challenge with virulent S. typhimurium, strain W118-2, was also tested. No correlation was found between suppressive and protective capacities of the various strains. Two strains suppressed, but did not protect. While most strains that protected grew or persisted in vivo, a phoP::Tn10 mutant of S. typhimurium did not grow or persist; this phoP mutant did not cause immunosuppression, but gave 100% protection against challenge with wild type S. typhimurium, suggesting that such mutants have advantageous properties as live vaccines.

Animals↗