This study demonstrates the effectiveness of a novel self-adjuvanting vaccine delivery system for multiple different synthetic peptide immunogens by use of lipid core peptide (LCP) technology. An LCP formulation incorporating two different protective epitopes of the surface antiphagocytic M protein of group A streptococci (GAS)-the causative agents of rheumatic fever and subsequent rheumatic heart disease-was tested in a murine parenteral immunization and GAS challenge model. Mice were immunized with the LCP-GAS formulation, which contains an M protein amino-terminal type-specific peptide sequence (8830) in combination with a conserved non-host-cross-reactive carboxy-terminal C-region peptide sequence (J8) of the M protein. Our data demonstrated immunogenicity of the LCP-8830-J8 formulation in B10.BR mice when coadministered in complete Freund's adjuvant and in the absence of a conventional adjuvant. In both cases, immunization led to induction of high-titer GAS peptide-specific serum immunoglobulin G antibody responses and induction of highly opsonic antibodies that did not cross-react with human heart tissue proteins. Moreover, mice were completely protected from GAS infection when immunized with LCP-8830-J8 in the presence or absence of a conventional adjuvant. Mice were not protected, however, following immunization with an LCP formulation containing a control peptide from a Schistosoma sp. These data support the potential of LCP technology in the development of novel self-adjuvanting multi-antigen component vaccines and point to the potential application of this system in the development of human vaccines against infectious diseases.To induce effective immunostimulation and protective immunity, vaccines comprising a particular antigen or fragment thereof require a suitable adjuvant in addition to a carrier system. This is a critical issue with newer-generation vaccines such as subunit, recombinant, and synthetic vaccines, which, despite containing purer antigens, tend to be poorly immunogenic compared to live attenuated vaccine formulations (3, 43). The efficacy of conventional vaccine formulations, administered parenterally and mucosally in experimental animal models, has required the use of adjuvants such as complete Freund's adjuvant (CFA) (7) and cholera toxin (20), respectively, which are not suitable for use in humans due to their toxicity. Current vaccine formulations licensed for human use mainly contain alum-based adjuvants (such as aluminum hydroxide or aluminum phosphate) (18). This limited choice of adjuvants for human vaccination reflects a compromise between a requirement for adjuvanticity and an acceptably low level of toxicity.Development of novel human vaccine delivery strategies for both existing and reemerging infections faces significant hurdles, particularly with regard to development of safe, effective, nontoxic adjuvants, in addition to the number of antigens that can be included in any one formulation, as multiple antigens may be required for successful vaccination against certain pa...
u.9., Hungary 1 Somatostatin (6.11 nmol kg 71 i.p.) inhibited neurogenic plasma extravasation evoked by 1% mustard oil and non-neurogenic oedema induced by 5% dextran in the rat skin. 2 Cyclic synthetic octapeptide (TT-248 and TT-250) and heptapeptide (TT-232) somatostatin analogues proved to be more e ective in reducing neurogenic and non-neurogenic in¯ammatory reactions but octreotide had no in¯uence on either neurogenic or non-neurogenic in¯ammation.
Implicit sequence learning is a fundamental mechanism that underlies the acquisition of motor, cognitive and social skills. The relationship between implicit learning and executive functions is still debated due to the overlapping fronto-striatal networks. According to the framework of competitive neurocognitive networks, disrupting specific frontal lobe functions, such as executive functions, increases performance on implicit learning tasks. The aim of our study was to explore the nature of such a relationship by investigating the effect of long-term regular alcohol intake on implicit sequence learning. Since alcohol dependency impairs executive functions, we expected intact or even better implicit learning in patient group compared to the healthy controls based on the competitive relationship between these neurocognitive networks. To our knowledge, this is the first study to examine the long-term effects of alcohol dependency both on implicit learning and on executive functions requiring different but partly overlapping neurocognitive networks. Here, we show weaker executive functions but intact implicit learning in the alcohol-dependent group compared to the controls. Moreover, we found negative correlation between these functions in both groups. Our results confirm the competitive relationship between the fronto-striatal networks underlying implicit sequence learning and executive functions and suggest that the functional integrity of this relationship is unaltered in the alcohol-dependent group despite the weaker frontal lobe functions.
The study reported here investigated the immunogenicity and protective potential of a lipid core peptide (LCP) construct containing a conserved region determinant of M protein, defined as peptide J8. Parenteral immunization of mice with LCP-J8 led to the induction of high-titer serum immunoglobulin G J8-specific antibodies when the construct was coadministered with complete Freund's adjuvant (CFA) or administered alone. LCP-J8 in CFA had significantly enhanced immunogenicity compared with the monomeric peptide J8 given in CFA. Moreover, LCP-J8/CFA and LCP-J8 antisera opsonized four different group A streptococcal (GAS) strains, and the antisera did not cross-react with human heart tissue proteins. These data indicate the potential of an LCP-based M protein conserved region GAS vaccine in the induction of broadly protective immune responses in the absence of a conventional adjuvant.
We report a series of new in vitro and in vivo data proving the selective antitumor activity of our somatostatin structural derivative, TT-232. In vitro, it inhibited the proliferation of 20 different human tumor cell lines in the range of 50-95% and induced a very strong apoptosis. In vivo was not toxic at a dose of 120 mg/kg of b.w. in mice. Long-term incubation (24 h) of tumor cells with TT-232 caused significant inhibition of tyrosine kinases in good correlation with the apoptosis-inducing effect. The level of p53 or KU86 did not change following TT-232 treatment, suggesting a p53-independent apoptotic effect. Preincubation of human breast cancer cells (MDA-MB-453) with TT-232 for 2 h decreased the growth factor receptor autophosphorylation. All of these data suggest that TT-232 is a promising and selective antitumor agent.
Using native chemical ligation, we synthesized a group A streptococcal (GAS) vaccine that contained three different GAS M protein peptide epitopes in a chemically well-characterized construct in high purity. Two of the peptide epitopes represented variable amino terminal serotype determinants, and the third represented a carboxyl terminal conserved region determinant of the GAS M protein. We also synthesized a lipid core peptide (LCP) construct containing the same three peptides. Upon immunization of mice, the non-LCP construct only elicited antibody responses to all three epitopes with the use of adjuvant. The LCP construct, however, elicited excellent antibody responses to all three epitopes without the need for any additional adjuvant or carrier. We have synthesized the LCP synthetic vaccine system with good reproducibility.
The putative anti-inflammatory and anti-nociceptive activity of the heptapeptide somatostatin analogue TT-232 ( D-Phe-Cys-Tyr- D-Thr-Lys-Cys-Thr-NH(2)) was investigated in the rat and mouse, as well as its effect on neuropathic hyperalgesia, gastric ulceration and the release of sensory neuropeptides. In the rat, carrageenin-induced paw oedema was inhibited dose dependently by TT-232 (3x2.5-20 microg/kg i.v.). Evans blue accumulation induced by intraarticular bradykinin injection (0.5 nmol in 0.1 ml) was slightly, but significantly inhibited by a single TT-232 dose (5-20 microg/kg). Cutaneous neutrophil accumulation over a 3-h period after intradermal (i.d.) injection of carrageenin (1 mg/site) or interleukin 1beta (IL-1beta, 3 pmol/site) was inhibited significantly by TT-232 (3x80 microg/kg i.v.), while diclofenac (3x10 mg/kg i.v.) elicited significant inhibition only in the IL-1beta test. In the mouse, TT-232 potently decreased oedema formation induced by 2.5% capsaicin applied topically to the ear. Mechano-nociception in the rat hind-paw during neuropathic pain induced by partial sciatic nerve injury (model of Seltzer) was measured using the Randall-Selitto test. TT-232 (5-20 microg/kg i.p. on the 7th day after the operation) dose-dependently inhibited the mechano-nociceptive hyperalgesia. In vitro release of substance P (SP), calcitonin gene-related peptide (CGRP) and somatostatin from the isolated rat trachea in response to electrical field stimulation (40 V, 0.1 ms, 10 Hz, 120 s) of its nervous elements was inhibited significantly by 500 nM TT-232. The role of G protein-coupled receptors in the effect of TT-232 was indicated by the prevention of its inhibitory action on the release of sensory neuropeptides by incubation the tissue for 1 or 6 h with pertussis toxin (100 ng/ml). The release of sensory neuropeptides to in response to electrical nerve stimulation was not inhibited by a potent tyrosine kinase inhibitor, genistein (50 microM). TT-232 (up to 5 mg/kg i.p.) did not induce mucosal lesions in either the stomach or the duodenum. These data suggest that TT-232, a somatostatin analogue devoid of endocrine effects, is a promising lead molecule in the search for novel, broad-spectrum anti-inflammatory and analgesic agents.
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