Formulation of a recombinant HIV-1 polytope candidate vaccine with naloxone/alum mixture: induction of multi-cytokine responses with a higher regulatory mechanism.

The potency of a vaccine highly depends upon the nature of the adjuvant used. There are a variety of ineffective vaccines, such as HIV-1 vaccine candidates, that need to be optimized with new adjuvant formulations to improve vaccine potency and efficacy. Studies show the potency of naloxone (NLX)/alum mixture in the induction of Th1/Th2 response for vaccine. However, other immunologic patterns inducing by this adjuvant and its immunoregulatory effect is unclear. In this regard, the aim of the present study was to investigate the effect of the NLX/alum mixture, as an adjuvant, on cytokine networks and immunoregulatory activity for an HIV-1 polytope vaccine. BALB/c mice were divided into six groups (n = 6) and immunized subcutaneously with 10 µg of the vaccine formulated with NLX/alum, NLX, alum, and Freund's adjuvants. At the same time, the mice in the control groups received an equal volume of PBS or NLX. The lymphocyte proliferation assay was carried out using the BrdU method. ELISA was used to measure the levels of IFN-γ, IL-2, IL-4, IL-10, IL-12, and IL-17 cytokines, total IgG, as well as IgG1 and IgG2a subtypes in serum samples. Our findings showed that mice receiving the NLX/alum-adjuvanted vaccine exhibited increased antibody levels compared with other groups. In addition, there was a considerable difference in the levels of IgG1, IgG2a, IFN-γ, IL-2, IL-10, IL-12, and IL-17 in mice receiving the NLX/alum-adjuvanted vaccine as compared with other groups. The NLX/alum mixture, as an adjuvant, may have a positive effect on the induction of multi-cytokine responses, as well as the increased level of IL-10, showing its higher immunogenicity with a higher immunoregulatory mechanism.

The anti-inflammatory effect of opioids.

The anti-inflammatory activity of two novel opioids PM and PO as well as of pethidine was studied. The mouse paw edema, induced by various phlogistic agents, was significantly inhibited after the administration of opioids, fact that was independent of their antioxidant properties. The anti-inflammatory action of the above opioids was not reversed by naloxone. These results suggest that a variety of complex regulatory activities may be performed by opioid agonists via naloxone-sensitive or naloxone insensitive receptors on inflammatory cells, directly or indirectly by the inhibition of cytokines and mediators involved in inflammation.

Anti-angiotensin antibodies cross-reactive with nonpeptide angiotensin antagonists as angiotensin receptor model.

Anti-angiotensin II (Ang) antibodies could become important receptor mimicking tools if an antibody with binding properties identical to a particular Ang receptor could be generated. For this purpose, anti-Ang sera from mice were screened for antibodies with structure-affinity relationships similar or identical to a particular Ang receptor. Mice were immunized with BSA-coupled [Sar1]Ang and the sera were screened in ELISA for crossreactivity with the Ang analogues saralasin, L158,809, EXP 3147, DuP 753, DuP 532, PD 123177, PD 123319 and the non-related compounds ACTH, naloxone, and CP 96,345. All sera had at least some cross-reactivity with saralasin and some also with L158,809, a potent non-peptide Ang antagonist, selective for the AT1 site. One serum out of eight recognized most Ang analogues except the AT2 selective PD 123177 and PD 123319. ELISA detection antigens were prepared by two different BSA conjugations: [Sar1]Ang was N-terminally attached and [Sar1,Lys8]Ang was C-terminally attached. Against both detection antigens, the peptide antagonists saralasin and [Sar1,Phe(Br5)8]Ang displaced in a sigmoidal manner the antibodies with an IC50-value of 0.4 mM. L158,809 and EXP 3147 displaced also in a parallel manner, suggesting an apparently homogenous population of binding sites. The selectivity profile of the serum has some resemblance to the AT1 selectivity profile but the observed affinities are too low to suggest AT1 receptor mimicry.

Molecular and biochemical analyses of combining sites of monoclonal anti-morphine antibodies.

V region nucleotide sequences were determined by mRNA sequencing for 11 monoclonal anti-morphine antibodies with slightly different specificities for morphine-related opiates. The VH region nucleotide sequences of the antibodies MOR8, MOR33, MOR35, MOR44, MOR83, and MOR76 were classified into the VH-5 (7183) family, while the antibodies MOR39, MOR115, MOR131, MOR158 and MOR180 used VH-1 (J558) family genes. MOR39, MOR115 and MOR131 used the V lambda-1 gene for their L chain V region. MOR158 and MOR180 used the Vk-10 gene. MOR8, MOR33, OR35, MOR44, MOR76 and MOR83 used VK-21D. The antibody sets MOR158 and MOR180; MOR39 and MOR131; and MOR8, MOR33, MOR35, MOR44, MOR76 and MOR83 appeared to be somatic mutants derived from the same clones since they showed the same VH/VL usage and V(D)J recombination pattern. The pH-reactivity profiles for these antibodies revealed that the binding of morphine to the antibodies is highly dependent on the pH value of the assay solution, suggesting the importance of the electrostatic interaction between the positive charge of morphine and the negative charges at or near the combining sites. Direct UV-photoaffinity labeling with 3H-morphine was carried out in order to estimate the orientation of morphine in the combining sites. The H chains were preferentially labeled in MOR8, MOR33, MOR35, MOR76, and MOR83, whereas most of the crosslinked hapten was found in the L chains in MOR39, MOR115, MOR131, MOR158 and MOR180. Thus, these 11 antibodies were classified into two types in terms of reactivity in the photoaffinity labeling.

Morphine suppresses primary humoral immune responses by a predominantly indirect mechanism.

Morphine suppresses humoral immune responses, causes thymic hypoplasia and suppresses NK (natural killer) activity in animal models. There is evidence that thymic hypoplasia and NK suppression are predominantly mediated by indirect mechanisms. The mechanism of morphine-induced humoral immunosuppression is less certain. Recent reports suggest that morphine and other opioids can directly act on cells of the immune system to suppress the generation of antibody-forming cells (AFC) in Mishell-Dutton cultures. The present study was designed to assess the roles of direct and indirect mechanisms in morphine-induced suppression of humoral immunity. Splenocytes from mice treated with morphine by s.c. implantation of a slow-release 75 mg pellet were dysfunctional in Mishell-Dutton cultures. Exposure to morphine in vivo for 12 or 24 hr caused significant suppression of the AFC production stimulated by sheep erythrocytes in Mishell-Dutton cultures. In contrast, direct addition of morphine or the kappa selective opioid agonist U50,488H to Mishell-Dutton cultures under a variety of conditions had little or no effect on AFC generation. These results indicate that suppression of humoral responses by morphine is not primarily mediated by direct action of morphine on the immune system. Suppression of AFC responses by administration of morphine in vivo was substantially blocked by treating mice with the glucocorticoid antagonist RU 38486, suggesting that glucocorticoids may be involved in the indirect mechanism by which morphine causes splenocyte dysfunction.

Methylnaloxonium diffuses out of the rat brain more slowly than naloxone after direct intracerebral injection.

The value of intracerebral injections as a means of relating brain structure and function is dependent on the degree of site specificity of the injection. The purpose of this study was to compare the distribution over time of naloxone and its quaternary derivative, methylnaloxonium, after intracerebral microinjection. One microliter of tritiated naloxone (NAL) or methylnaloxonium (MN 10.0 ng, 12.8 nCi for both drugs) was infused directly into the n. raphe pontis. Each animal was then decapitated at a specific time (2.5, 5.0, 15, 30, or 60 min), the brain was removed and dissected into hindbrain, cerebellum, midbrain and cortex. Tritium beta emissions of brain homogenates were measured 1 day later, MN remained better localized to the injection site than did the same volume of the more lipophilic NAL. Within 15 minutes, less than 5% of the NAL remained in the hindbrain compared with nearly 40% of the MN. These results that MN may be a better probe than NAL for investigating the relationship of opioid receptor anatomy and function, particularly for dependent variables requiring sustained time courses.

Rabbit anti-idiotypic antibodies raised against monoclonal anti-morphine IgG block mu & delta opiate receptor sites.

Rabbit antibodies have been raised against murine monoclonal anti-morphine Fab fragments. Following affinity purification, these antibodies competitively inhibit morphine binding to anti-morphine monoclonal antibodies, yet do not recognize normal mouse IgGs, suggesting that the antibodies produced are anti-idiotypic with respect to the anti-morphine IgG. More importantly, the purified antibodies competitively inhibit binding of morphine, naloxone, and D-ala-2-D-leu-5-enkephalin to rat brain opiate receptors.

Effect of morphine on resistance to infection.

Morphine was demonstrated to exacerbate infections. Experiments were performed to evaluate variations of phagocytic physiology during morphine treatment. In mice, morphine drastically reduced reticuloendothelial system activity, phagocyte count, phagocytic index, killing properties, and superoxide anion production in polymorphonuclear leukocytes and macrophages. Similar effects on alveolar macrophage count, phagocytosis, and killing were found in rabbits, a result which suggested a lack of species specificity. Additional experiments demonstrated that morphine (1) induces a reduction of lymphoid organ weight, (2) impairs the ability to eradicate infections and (3) is counteracted in its depressing activity on phagocytic physiology by small amounts of Corynebacterium parvum. The results suggest that there is a close relationship between the fact that morphine exacerbates infections and the fact that morphine depresses phagocytic functions; therefore, the negative effect of morphine on phagocytosis is at least one of the reasons for its negative effect on the development of infections.

Disposition of naloxone: use of a new radioimmunoassay.

Understanding of the pharmacology of the narcotic antagonist naloxone has been limited by the lack of a convenient and sensitive method of assay. A radioimmunoassay for naloxone has been developed and is described. It is applicable for drug analysis in either serum or brain. The limit of sensitivity of the assay was 0.1 ng. Naloxone glucuronide, noroxymorphone (nor-naloxone) and morphine were not recognized by the antibody whereas naltrexone and 6-hydroxynaloxone were able to displace naloxone-3H from the antibody. The assay was of sufficient sensitivity to follow the serum levels of naloxone in man for up to 2 hours after an i.v. injection of 0.4 mg. In animal studies, the biologic half-lives of naloxone or morphine (5 mg/kg) were compared after s.c. injection in rats. The peak serum levels A (1 mu/mo), time to peak serum levels (less than 1/2 hour), and serum half-life (40 minutes) were comparable. However, the brain entry and egress of the two compounds differed markedly. Peak brain levels of naloxone occurred within 15 minutes and had declined by 50% within 1 hour, whereas the peak brain levels of morphine were sustained for up to 2 hours. At peak serum levels, the brain/serum ratio for morphine was 0.1 whereas for naloxone it was 15 times greater. We suggest the high brain/serum ratio of naloxone contributes to its potency whereas the rapid egress from the brain is important in the short duration of action of naloxone.