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At least 181 records · Page 10Linked to original sources
PubMed1984

Specific interactions of liposomes with PMN leukocytes upon incorporating tuftsin in their bilayers.

Incorporation of tuftsin derivatives, Thr-Lys-Pro-Arg-NH-C18H37 or Thr-Lys-Pro-Arg-NH-(CH2)2-NH-COC15H31, into an egg phosphatidylcholine/cholesterol liposome bilayer led to significantly enhanced binding of the liposomes to PMN leukocytes at 37 degrees C but not at 0 degree C. Under identical conditions, no such enhanced binding of the liposomes was observed with erythrocytes and lymphocytes. These results demonstrate that grafting of tuftsin on the liposome bilayer enables the liposome to recognize specifically the PMN leukocytes and to deliver its contents to these cells.

Cholesterol↗
PubMed1988

Tuftsin stimulates growth of HL60 cells.

Many functions of monocyte/macrophage and granulocyte are activated by tuftsin; principally phagocytosis, motility, immunogenic stimulation, antibacterial and antineoplastic activities. Here it is shown that tuftsin stimulates HL60 growth to twice the control rate. The uptake of [3H]uridine and [3H]leucine in a pulse of 30 min was also double that of the control. The uptake of thymidine was not stimulated.

Cell Division↗
PubMed1993

Tuftsin-bearing liposomes as drug vehicles in the treatment of experimental aspergillosis.

Encapsulation of amphotericin B in tuftsin-bearing liposomes greatly increased its efficacy in treatment of human aspergillosis in mice. Also, the drug efficacy was significantly increased by pretreating the animals with drug-free tuftsin-bearing liposomes. These results demonstrate that macrophage activation can considerably enhance the therapeutic efficacy of antifungal drugs, like amphotericin B.

Amino Acid Sequence↗
PubMed1984

Stimulating effect of tuftsin and its analogues on the defective monocyte chemotaxis in systemic lupus erythematosus.

Monocytes and macrophages are engaged at various levels of cellular immune reactivity. In addition to their function in the defensive mechanism directed at infective agents, they also play a basic role in immune complex elimination and antigen handling. Previous experiments revealed that systemic lupus erythematosus (SLE), the main representative of the autoimmune diseases, is associated with impaired monocyte chemotaxis. The endogenous basic tetrapeptide tuftsin and 6 of its analogues were examined in vitro for their stimulating capacity on the chemotactic responsiveness of monocytes derived from patients with SLE. The monocyte migration assay was carried out by a modified Boyden technique and quantified by the leading front distance method and by counting the total distance covered by the monocyte locomotion. Tuftsin and 3 of its analogues significantly increased the defective chemotaxis in SLE. The tetrapeptides effective on chemotaxis also stimulated random migration and phagocytosis of the monocytes, albeit to a lesser extent. Structure-activity relationships, as well as the influence of the clinical stage of the disease were also examined. Experimental evidence leads to a favourable prediction for the immunotherapeutic value of these oligopeptides for the control of infections and the progression of the disease in patients with systemic lupus erythematosus.

Adolescent↗
PubMed1987

In vitro effects of prostaglandin E1, prostaglandin E2, indomethacin, histamine, and tuftsin on chemiluminescence response of bovine polymorphonuclear leukocytes.

The in vitro effects of prostaglandin E1 (PGE1), prostaglandin E2 (PGE2), indomethacin, histamine, and tuftsin on the chemiluminescence response of bovine polymorphonuclear cells (PMN) were determined. Addition of PGE1, PGE2, indomethacin, and histamine in vitro significantly suppressed the chemiluminescence response of bovine PMN's, whereas tuftsin had no effect. Suppression was dependent upon the continued presence of PGE1, PGE2, and histamine in the culture media. However, indomethacin's suppressive effect remained even after it was removed from the culture media. Hydrogen peroxide generated chemiluminescence was suppressed by high concentrations of indomethacin and histamine. Results of this study suggest possible pharmacologic or regulatory mechanisms for certain of these immune modulators in the control of the oxidative burst reaction of bovine PMN's.

Alprostadil↗
PubMed2000

Tuftsin-bearing liposomes in treatment of macrophage-based infections.

The use of liposomes as drug carriers in treatment of various diseases has been explored extensively for more than 20 years. 'Conventional' liposomes, when administered in vivo by a variety of routes, rapidly accumulate in the mononuclear phagocyte system (MPS). The inherent tendency of the liposomes to concentrate in MPS can be exploited in enhancing the non-specific host defence against infections by entrapping in them the macrophage modulators, and as carriers of antibiotics in treatment of intracellular infections that reside in MPS. This must further be enhanced by grafting on the liposome surface the ligands, e.g. tuftsin, that not only binds specifically to the MPS cells but also enhances their natural killer activity. Keeping this in view, we designed and developed tuftsin-bearing liposomes as drug carriers for the treatment of macrophage-based infections and outline these studies in this overview.

Amphotericin B↗
PubMed1986

Prophylaxis of Candida albicans infection with tuftsin.

The efficacy of tuftsin, a naturally-occurring immunomodulating peptide, in the prophylaxis of disseminated Candida albicans infections in mice was studied. The intravenous administration of tuftsin caused prolonged survival at all concentrations tested.

Animals↗
PubMed1985

Anti-writhing activity of some peptides related to neurotensin and tuftsin.

Several small peptides related to neurotensin (NT) and tuftsin were synthesized and tested for analgesic activity against acetic acid induced writhing in mice. None of the peptides approached the activity shown by NT or NT hexapeptide. Tuftsin itself was found to be weakly active. An isosteric dipeptide related to a cobra venom peptide was found to have considerable anti-writhing activity at a high intracerebroventricular dose.

Analgesics↗
PubMed1993

Suppression of tuftsin activity by the partial sequences of adenovirus type 2 proteins.

The synthesis of tuftsin inhibitor-like partial sequences of adenovirus type 2 proteins: TVPPR (1), TRPPR (2), TGPPT (3), PRPPT (4), FVPPR (5), ARPPA (6) and YGPPK (7) are described. The choice of peptides for synthesis was performed by using a simple computer-aided method for predicting antigenic determinants of proteins. For all these peptides an inhibitory activity against tuftsin was found.

Adenoviruses, Human↗
PubMed1983

The antineoplastic effects of tuftsin and tuftsinyltuftsin on B16/5B melanoma and L1210 cells.

The intraperitoneal (i.p.) injection of tuftsin, Thr-Lys-Pro-Arg, into C57BL/6 mice that were injected with B16/5B melanoma cells, resulted in a considerable suppression and elimination of solid tumor growth. While 100% of control animals exhibited tumor growth, 38% of the treated animals failed to show tumor formation for the duration of the experiment, 60-80 days. The octapeptide, tuftsinyltuftsin, was effective at 3 ng per mouse as was a dose of 2 and 20 micrograms per mouse. In each case there was a significant number of mice free of tumors. The octapeptide was also quite effective against L1210 cells resulting in the survival of 35-40% of the treated animals. The lethal effect of increased superoxide, O X 2, production by tuftsin treatment may explain the antineoplastic effect of the tetrapeptide. This may result not only from higher concentrations of O X 2 but also from the potentially lethal effects of H2O2 and OH X radical, both of which are products of O X 2 metabolism.

Animals↗
PubMed1984

Antibacterial properties of tuftsin and its analogs.

The antibacterial properties of tuftsin and its 11 analogs on 20 bacterial strains were investigated. Tuftsin showed a definite antibacterial effect at a minimal effective concentration of 62.5 micrograms/ml. All analogs were either less effective or lacked any activity. The bacteria used included some highly pathogenic organisms.

Bacteria↗
PubMed1999

Theoretical study of conformational flexibility of tuftsin in vacuum and in aqueous environment.

Conformational flexibility of tuftsin molecule is studied using all-atom based atom-atom potential and systematic search, simulated annealing molecular dynamics (SAMD) and molecular dynamics (MD) techniques. Latter was carried out for 650 pico seconds (ps) using AMBER 4.0 with explicit water in TIP3P model. Number of inter-atomic distances and torsional angles were monitored during SAMD and MD simulation. We found that tuftsin molecule, irrespective of any starting conformation, assumes highly folded structure with strong electrostatic interaction between Lys-2 NH3 and Arg-4 carboxylic group and weak hydrogen bond between Lys-2 CO and Arg-4 NH atoms. It had distorted but stable conformation close to inverse gamma turn.

Amino Acid Sequence↗
PubMed1992

The influence of tuftsin partial sequences on histamine level in guinea pig and rat tissues.

We investigated the influence of tuftsin partial sequences (Thr-Lys, Lys-Pro, Lys-Pro-Arg and Pro-Arg) on histamine concentration in selected tissues (lungs, kidneys, liver, duodenal wall and arterial blood) of guinea-pigs and rats. The peptides were administered in 1 mg/kg dose intravenously (single dose) or intraperitoneally (single dose or three doses at one-hour intervals). Histamine concentration was determined spectrofluorimetrically. Tissues used in the determination were taken 1 hour after the last injection. It was found that Pro-Arg and Lys-Pro-Arg (similarly to tuftsin), lower histamine concentration in lungs, and elevate it in kidneys.

Amino Acid Sequence↗
PubMed1992

[The effect of the calf spleen and calf thymus extracts, thymopentin and tuftsin, on the phagocytosis activity of neutrophilic granulocytes].

In the present in vitro study, the influence of proteolytic as well as untreated spleen and thymus extracts and, as a comparison, of biologically active peptides tuftsin and thymopentin on the phagocytic activities of human polymorphonuclear leukocytes was investigated. At a chosen concentration of 200 micrograms/ml, all products studied exhibited a significant stimulation of polymorphonuclear leukocyte activity, when lucigenin-amplified chemiluminescence was measured. This effect was considerably enhanced with tuftsin, thymopentin and spleen extract, compared to the thymus preparations. No difference in chemiluminescence was obvious between hydrolyzed and untreated thymus extracts. In parallel experiments, phagocytosis of opsonized zymosan was investigated by light microscopy. Using identical substrate concentrations, only spleen extract showed significant stimulation. This observation indicates that the investigated polymorphonuclear leukocyte activities may be caused by substrate-specific mechanism on the cellular level.

Adult↗
PubMedDate not supplied

Influence of long-term treatment with tuftsin analogue TP-7 on the anxiety-phobic states and body weight.

TP-7 is a synthetic analogue of tuftsin. It has a structure of tuftsin, to which three natural L-amino-acids Pro-Gly-Pro are attached. This heptapeptide improves learning and memorization and causes antidepressant and anxiolytic effect. It is possible to use TP-7 in the future to optimize cognitive functions and as a potential new anxioselective, fast-acting and easy-dosed drug. Therefore, it was purposeful to study such properties of the heptapeptide as its influence on anxiety-fear and body weight under a long-term treatment regimen. The experiment was performed on 24 preselected Wistar rats with the use of Rodina's method. There were three experimental groups of animals with high initial emotional reactivity: passive control group (P), active control group (A, receiving distilled water) and group treated with TP-7 at the dose of 0.3 mg/kg (T). The rats of A and T groups received intraperitoneal injections every day. The experiments were conducted 15 min after the administration of the drug, one and two days after initial testing day, then 1, 2, 3 and 4 weeks after that. The heptapeptide reduced the anxiety-phobic states significantly starting from the second day of drug application. The observed effects persisted throughout four weeks of the experiment, which confirmed effective long-term anxiolytic properties of the heptapeptide. TP-7 did not cause any changes in the body mass by itself.

Animals↗
PubMed1991

Effect of tuftsin and its partial sequences on the arterial blood pressure in guinea-pigs.

The effect of tuftsin (Thr-Lys-Pro-Arg) and its partial sequences: Thr-Lys-Pro, Lys-Pro-Arg, Thr-Lys, Lys-Pro and Pro-Arg on arterial blood pressure was studied in experiments on guinea-pigs anesthetized with urethane. The peptides were administered intravenously in a dose of 1 mg/kg. The blood pressure was measured directly in the carotid artery. Tuftsin and peptides: Thr-Lys-Pro, Thr-Lys and Pro-Arg, after longer period of latency, caused protracted rise in arterial blood pressure. Such action was not shown by Lys-Pro-Arg and Lys-Pro.

Amino Acid Sequence↗
PubMedDate not supplied

Further investigations on the antinociceptive activity of tuftsin analogs.

C-Terminal dipeptide fragment of tuftsin, Pro-Arg, substituted by D-amino acids, and tuftsin analogs with n-hexyl- and n-heptylamine coupled to their C-termini were synthesized by a classical method in solution and their antinociceptive activity was measured by tail flick immersion test (0.4 microM/icv). D-Pro-D-Arg and D-Pro-L-Arg showed an analgesic activity, with the duration of 60 and 40 min, respectively. The strong behavioral effects observed after injection of D-Pro-D-Arg were decreased by naloxone. L-Pro-D-Arg and Thr-Lys-Pro-Arg-HxA display no antinociceptive effect; the tetrapeptide amide showed some toxicity effects. Thr-Lys-Pro-Arg-HpA was very toxic and caused death of all experimental animals. This effect was not influenced by previous injection of naloxone.

Amino Acid Sequence↗
PubMed1991

[A cytochemical study of the effect of tuftsin on the enzyme activity in functionally different formations of the brain in rats].

Quantitative cytochemical methods in functionally different rat brain formations (sensomotor cortex, visual cortex, nucleus caudatus, hippocampus) showed the peculiarities of the effect of tuftsin on the activity of some enzymes (the oxidative, neurotransmitter and protein metabolism enzymes) 15 min and 3 days after its single administration. No changes of activity of neurotransmitter metabolism enzymes (monoamine oxidase, acetylcholinesterase) were registered cytochemically. The specificity of the neuro-tropical effect of tuftsin on protein (activity of aminopeptidase and acid phosphatase) and oxidative (activity of glutamate dehydrogenase and glucose-6-phosphate dehydrogenase) metabolism in different functional brain systems is discussed.

Animals↗