Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “immune modulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources

Influence of age on the ability of thymic adherent cells to produce factors in vitro which modulate immune responses of thymocytes.

Thymic adherent cells from BALB/c mice ranging in age from 1 day to 20 months were cultured in vitro for 1 month. The supernatants, collected at weekly intervals, were assessed for their ability to augment the antigen/mitogen responses of thymocytes from 2- or 4-week-old BALB/c mice and spleen cells from 3-month-old nude BALB/c mice. The results indicate that (a) the ability of thymic adherent cells to produce an augmenting factor(s) declines sharply between 2.5 and 5 months of age; (b) thymic adherent cells of 1-day-old mice synthesize an inhibitory factor(s) in addition to the augmenting factor, while those of young adult mice synthesize only the augmenting factor, and those of 20-month-old mice synthesize primarily the inhibitory factor; (c) supernatants containing the augmenting factor can be neutralized by mixing them with supernatants containing the inhibitory factor; (d) thymocytes which are responsive to the augmenting factor are immature as judged by their sensitivity to dexamethasone and by their ability to bind macrophages; and (e) spleen cells of normal and nude mice are not responsive to either the augmenting or the inhibitory factor of the supernatant.

Aging↗

Nonspecific immune modulating effects of ascites fluid and hyperimmune sera in vivo.

To determine whether the appearance of interferon (IFN) and the modulation of humoral responses observed following injection of irradiated tumor cells were mediated by suppressor cells, the effects of in vivo injection of I-Js specific antibodies were studied. We found that anti-I-J-containing, as well as normal ascites fluids, obtained after repeated ip injection of complete Freund's adjuvant, contain a factor which (a) induces the appearance of serum IFN, (b) enhances the response to SRBC, and (c) suppresses the response to TNP-Ficoll, when injected 1 day before antigen. This effect is not immunologically specific, is probably not caused by intact Ig, and does not appear to be mediated by T cells. Although the nature of the factor(s) responsible for the observed results has not been fully clarified, we report these findings now as a cautionary note for the interpretation of studies where in vivo injection of unfractionated ascites fluids containing monoclonal antibodies are used.

Animals↗

Soluble extracts from larval Ostertagia ostertagi modulating immune function.

BALB/c mice were immunized with Ostertagia ostertagi antigens and keyhole limpet hemocyanin (KLH) or sheep erythrocytes (SR) for evaluation of antibody production by enzyme linked immunosorbent assay (ELISA) or modified Jerne plaque assay. One semi-purified larval antigen caused both decreased anti-KLH serum antibody levels and fewer anti-SR IgM-secreting B cells. This antigen was shown to depress lymphocyte blastogenesis to Concanavalin A when added to cultured BALB/c splenic lymphocytes.

Animals↗

Low calcium diet and 1,25-dihydroxyvitamin D(3) infusion modulate immune responses during Mycobacterium paratuberculosis infection in beige mice.

A 12-month study was conducted to evaluate the effects of feeding a low calcium (Ca) diet or 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3) infusion on the persistence of Mycobacterium paratuberculosis infection using a mouse model. Male beige mice 6-8 weeks of age were assigned to one of the following treatments: (1) non-infected, (2) infected,(3) non-infected/1,25(OH)(2)D(3), (4) infected/1,25(OH)(2)D(3), and (5) infected/low Ca (0.15 percent) diet. Infected mice were inoculated intravenously with live M. paratuberculosis. At 1, 6 and 12 months postinfection, mice in Treatments 3 and 4 were implanted subcutaneously with mini-osmotic pumps to deliver 1,25(OH)(2)D(3). Infusion with 1,25(OH)(2)D(3) exacerbated M. paratuberculosis infection in most tissues at all time points. Mice infused with 1,25(OH)(2)D(3) had higher bacterial counts in spleen, liver, and ileum compared with control infected mice after 1 month of infection. In contrast, feeding a low Ca diet reduced the number of viable organisms cultured from the liver and ileum of infected mice. Plasma Ca and 1,25(OH)(2)D(3) were increased in mice infused with 1,25(OH)(2)D(3) at all time points but values for low Ca mice were not different than for non-infused mice. Splenocyte production of TNF, IL-1 and IL-6 was higher for mice fed the low Ca diet compared with control infected mice after 1 month of infection. Inducible IL-6 activity remained higher for this treatment at 6 months postinfection. These results suggest that feeding a low Ca diet to mice chronically infected with M. paratuberculosis appears to enhance their ability to clear the infection in a manner distinct from any effect of 1,25(OH)2D3.

Animals↗

Immune modulation within the brain: recruitment of inflammatory cells and increased major histocompatibility antigen expression following intracerebral injection of interferon-gamma.

Intracerebral injections of interferon-gamma (IFN-gamma) have multiple immunological effects on rat brain, affecting all anatomic compartments. Lymphocytes and other inflammatory cells are recruited to the injection site: CD4+ T-cells into the perivascular space, OX42+ monocytes/macrophages into brain parenchyma. IFN-gamma also recruits OX8+ cells into brain parenchyma. These OX8+ cells are not stained by 'pan' T-cell antibodies, however, suggesting that they may be natural killer cells. IFN-gamma also causes increased major histocompatibility complex expression on brain cells: class I antigen on local endothelial and ependymal cells, and class II antigen on microglial, ependymal, and perivascular cells throughout both hemispheres of the brain.

Animals↗

Rapid tumor regression and induction of tumor-regressing activity in serum by various immune-modulating agents.

A rapid decrease in the number of tumor cells from S180 tumors was caused by several antitumor polysaccharides including the beta (1-3)glucans lentinan and TAK-N and a mannoglucan MGA, but not by those lacking antitumor activity. MGA was demonstrated to induce potent tumor-regressing activity in the serum of tumor-bearing mice similar to that reported previously to be induced after an injection of CM-TAK, a carboxymethylated beta (1-3)glucan. It is probable that the induction of rapid regression of established tumors is a phenomenon common to antitumor polysaccharides and some microbiological products and that the tumor-regressing factor in the serum underlies a common mechanism.

Animals↗

Immune modulation by Ostertagia ostertagi and the effects of diet.

IgG1 antibody responses to Ostertagia ostertagi third stage larvae (L3) and the third party antigen, keyhole limpet haemocyanin (KLH), and faecal egg counts were determined in calves infected with a single dose of O. ostertagi and in uninfected, pair-fed calves. The infected and uninfected calves were given diets either high (H) or low (L) in protein and energy. The diets were within the normal range of husbandry practice in the UK. IgG1 antibody responses to L3 antigen were significantly greater from 6 weeks post-infection in infected calves given the L diet than in infected calves given the H diet (P less than 0.05). The effects of diet and infection on anti-KLH IgG1 responses were independent of each other. IgG1 responses to KLH were decreased by infection and by the L diet compared with the H diet.

Animals↗

Transplanting stem cells: potential targets for immune attack. Modulating the immune response against embryonic stem cell transplantation.

The curative promise of stem cells and their descendants for tissue regeneration and repair is currently the subject of an intense research effort worldwide. If it proves feasible to differentiate stem cells into specific tissues reliably and safely, this approach will be invaluable in the treatment of diseases that lead to organ degeneration or failure, providing an alternative or supplementary source of tissue for transplantation. Embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of a pre-implantation blastocyst that can produce all cells and tissues of the foetus. In recent years, several laboratories have described the directed differentiation of ES cells into multiple mature cell types including: cardiomyocytes; haemopoietic cells; hepatocytes; neurones; muscle cells and both endocrine and exocrine cells of the pancreas. How the immune system of the host will respond when these ES cell-derived mature cells are transplanted is ill defined. This review will focus on the potential mechanisms that the immune system could use to target ES cell-derived transplants and how unwanted responses might be prevented.

Animals↗

Potent S1P receptor agonists replicate the pharmacologic actions of the novel immune modulator FTY720.

Alteration in lymphocyte trafficking and prevention of graft rejection in rodents observed on exposure to FTY720 (1) or its corresponding phosphate ester 2 can be induced by the systemic administration of potent sphingosine-1-phosphate receptor agonists exemplified by 19. The similar S1P receptor profiles of 2 and 19 coupled with their comparable potency in vivo supports a connection between S1P receptor agonism and immunosuppressive efficacy.

Animals↗

Immune modulation by probiotic strains: quantification of phagocytosis of Aeromonas salmonicida by leukocytes isolated from gut of rainbow trout (Oncorhynchus mykiss) using a radiolabelling assay.

A method is described for the rapid and sensitive assay of phagocytosis that utilizes radioactively labelled bacteria. With this method, we observed that phagocytosis of heat-inactivated Aeromonas salmonicida by leukocytes isolated from gut of rainbow trout fed with different viable probiotics (Lactococcus lactis subsp. lactis, Lactobacillus sakei, and Leuconostoc mesenteroides) was significantly higher (P<0.05) after 2 weeks of probiotic-feeding than the control group. However, only phagocytosis of live A. salmonicida by the leukocytes isolated from gut of rainbow trout fed with L. lactis subsp. lactis was significantly higher (P<0.05) than the control group.

Aeromonas salmonicida↗

New therapies: oral inhibitors and immune modulators.

Several new classes of antiviral drugs are undergoing development and should change the way that hepatitis C virus infection is treated in the future. It is likely that combinations of drugs that target different points in the viral replication and disease processes will prove most successful. It is hoped that such combinations will improve the efficacy, tolerability, and duration of antiviral treatment for this disease.

Antibodies, Viral↗

Low molecular weight fraction of shark cartilage can modulate immune responses and abolish angiogenesis.

Shark cartilage has proven to have inhibitory effects on angiogenesis. In this research, we studied the effects of shark cartilage on the immune system. Firstly, we isolated and purified a shark cartilage protein fraction with the most immunostimulatory effects. Our fraction was composed of two proteins with molecular weights of about 14 and 15 kDa. This fraction highly augments delayed-type hypersensitivity response against sRBC in mice, and decreases the cytotoxic activity of Natural Killer cells. Furthermore, intraperitoneal injection of this fraction to tumor-bearing mice could increase T-cell infiltration into the tumor, and decrease the tumor lesion size. Also, this fraction has strong inhibitory effect on HBMEC proliferation and migration in fibrin matrix. According to these results, we suppose that this fraction is a good candidate for further studies in cancer therapy.

Adjuvants, Immunologic↗

Immune modulation for prevention of type 1 diabetes mellitus.

Prevention of type 1 diabetes mellitus requires early intervention in the autoimmune process directed against beta cells of the pancreatic islets of Langerhans. This autoimmune inflammatory process is thought to be caused by the effect of Th1 cells and their secreted cytokines (e.g. interferon) and to be suppressed by Th2-secreted anti-inflammatory cytokines (e.g. IL-4, IL-10). Various methods aimed specifically at halting or modulating this response have been attempted. An alternative method is the re-induction of tolerance towards the putative self antigen that causes the disease. Proposed antigens such as insulin, glutamic acid decarboxilase (GAD) and the heat shock protein 60 (Hsp60)-derived peptide 277 have been used successfully in murine diabetes models and in initial clinical trials in early diabetes patients. Here, we review the results of these trials.

Animals↗

Neuroendocrine-immune modulation may be useful for allograft-specific immunosuppression in small bowel transplantation.

PURPOSE: The authors have previously demonstrated that the neuropeptide bombesin (BBS) prevented allograft mucosal atrophy under tacrolimus (TRL) immunosuppression for rats small bowel transplantation (SBT). The present study investigated whether BBS had immunosuppressive effects on small bowel allografts. METHODS: Allogeneic SBT was performed heterotopically in rats (n = 12) that received daily administration of 0.1 mg/kg/d TRL from postoperative day 0 to day 14. Rats divided into two groups of six rats each were administered BBS or normal saline as a control. Biopsy of the allograft was performed from the stomal site on postoperative days 6, 10, and 14. The state of the graft mucosal villi was evaluated by H & E staining and TUNEL immunohistochemistry. RESULTS: By postoperative day 14, extensive mucosal destruction accompanied by heavy transmural cellular infiltration had developed in the control group. Lymphocytes and plasma cells infiltrated the lamina propria of the allograft without the distorting villous architecture in the BBS group. The TUNEL index of graft mucosa in the control group was 1.26% +/- 0.37% (mean +/- SD) and that in the BBS group, 0.59% +/- 0.20%, respectively (p < .001). CONCLUSION: This study demonstrated an immunosuppressive effect of bombesin on transplanted allografts, which might dramatically reduce the dose of TRL required for postoperative immunosuppression.

Amino Acids↗