A novel adjuvant, mixture of alum and the beta-adrenergic receptor antagonist propranolol, elicits both humoral and cellular immune responses for heat-killed Salmonella typhimurium vaccine

Immunomodulatory chitosan nanoparticles for Toxoplasma gondii infection: Novel application of chitosan in complex propranolol-hydrochloride as an adjuvant in vaccine delivery

The study aimed to investigate the immunomodulatory effects of propranolol hydrochloride (PRO) in combination with chitosan nanoparticles (CS NPs) as an adjuvant to develop an effective vaccine against T. gondii. A total of 105 BALB/c mice were randomly divided into seven equal groups including PBS alone, CS NPs, SAG1 (Surface antigen 1), CS-SAG1 NPs, CS-PRO NPs, SAG1-PRO, and CS-SAG1-PRO NPs. The immunostimulatory effect of each adjuvant used for vaccine delivery was evaluated in a mice immunization model. The results showed that the mice immunized with CS-SAG1-PRO NPs exhibited the highest lymphocyte proliferation rate, along with increased secretion of IFN-γ, TNF-α, IL-6, IL-12, IL-17, and IL-23, as well as elevated levels of protective cytokines such as TGF-β, IL-27, and IL-10. Although, the CS-SAG1-PRO NPs immunized mice showed the highest level of T. gondii specific IgG compared to the other groups, a significant production of IgG2a and IgG1 was observed in the sera of mice immunized with the CS-SAG1-PRO NPs compared to the other group (p <0.001). The higher IgG2a/IgG1 ratio observed in the CS-SAG1-PRO NPs group indicates a bias towards Th1 cell polarization, suggesting the promotion of Th1 cell-mediated immune responses. Considering the combination of the highest lymphocyte proliferation and survival rates, IgG2a/IgG1 ratio, and cytokine levels in the mice immunized with CS-SAG1-PRO NPs, this approach holds promise for immunostimulation and vaccine delivery against T. gondii infection.

Silver nanoparticles combat Salmonella Typhimurium: Suppressing intracellular infection and activating dendritic cells

Salmonella Typhimurium (ST) can hide inside cells, avoid antibiotic therapy and being killed by host's immune system to cause persistent infection in humans and animals. Metal nanoparticles are regarded as an alternative to overcome the above limitations, silver nanoparticles especially have been applied in combating drug-resistant bacteria. However, the therapeutic effects of silver nanoparticles against intracellular infection and their impacts on host immunity remain an area of further investigation. In this work, we synthesized Ganoderma extract-capped silver nanoparticles (Ag@Ge) and explored the therapeutic potential and immune adjuvant effects of Ag@Ge against intracellular ST. Firstly, Ag@Ge had a small particle size of 35.52±7.46 nm, good stability, and biocompatibility. Then, Ag@Ge effectively entered RAW 264.7 cells, suppressed intracellular ST infection. Furthermore, Ag@Ge activated mouse dendritic cells (DCs) in vitro, evidenced by increased phenotypic markers (CD80/CD86/CD40/major compatibility complex II (MHCII)) expression and cytokine and chemokine (interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand 2 (CCL-2), and chemokine (C-C motif) receptor-7 (CCR-7)) transcription. More notably, the combination of Ag@Ge with inactivated ST recruited intestinal DCs to mitigate ST infection in mice, evidenced by decreased body weight loss and bacterial loads in the tissues (liver, jejunum, and colon), and improved platelets count. The above findings indicate that Ag@Ge has the potential as an alternative nano-antibiotic against intracellular ST infection.

Novel naltrexone hydrochloride nanovaccine based on chitosan nanoparticles promotes induction of Th1 and Th17 immune responses resulting in protection against Toxoplasma gondii tachyzoites in a mouse model

This study was aimed to encapsulate and construct the Toxoplasma gondii surface antigen (SAG1) and naltrexone hydrochloride (NLT-HCL) as an adjuvant within chitosan nanoparticles (CS-NPs) to develop efficacious vaccine against T. gondii. Seven groups of BALB/c mice were immunized with SAG1, chitosan (CS), NLT-SAG1, CS-SAG1, CS-SAG1-NLT, CS-NLT and PBS. The efficiency of each approach was detected in vivo mouse immunization. Moreover, the immuno-induction effect of SAG1 recombinant protein and CS-NPs-based NLT-HCL as an adjuvant in a vaccine delivery was evaluated. Experimentally, Th1/Th17 biased cellular and humoral immune responses were activated in the mice immunized with CS-SAG1-NLT nanoparticles that were accompanied by considerable increased production of IFN-γ, IL-17, IL-12, IL-4, IFN-γ/IL-4 ratio, IgG, IgG2a. This group of mice also showed significantly increased survival time post-challenging. The successful encapsulated SAG1 recombinant protein and NLT-HCL, as an adjuvant, within CS-NPs can induce immune responses against toxoplasmosis. We could incorporate NLT-HCL adjuvant into the CS-NPs based delivery systems, which makes CS-NPs attractive as a colloidal carrier system for NLT-HCL as secondary adjuvant. This new approach or the simultaneous use of CS and NLT demonstrated that the co-administration of CS-NPs and NLT-HCL induce production of IL-17 cytokine. This approach can be used for vaccination purposes, in which Th17 and Th1 cellular immune are considered the key of the successful immune response.

Alum and metoclopramide synergistically enhance cellular and humoral immunity after immunization with heat-killed Salmonella typhimurium vaccine

Typically, the killed form of microorganisms in combination with alum does not produce strong cellular immune responses. A recent investigation has indicated the role of dopamine D2 receptor antagonists like metoclopramide in reducing the polarization of immune responses toward Th2 immunity. This study was performed to evaluate the effects of a combination of alum and metoclopramide on the induction of cellular and humoral immunity in response to a heat-killed preparation ofSalmonella typhimurium(HKST). Wistar rats were immunized with the HKST vaccine alone or in combination with alum, metoclopramide, or the alum-metoclopramide mixture twice with a two-week interval. Fourteen days after the last vaccination, immune responses against S. typhimurium and the protective potential of the vaccines were assessed. The combination of alum and metoclopramide as an adjuvant augmented the potential of the HKST vaccine to enhance lymphocyte proliferation, delayed-type hypersensitivity reaction, and antibody titer. These results were concurrent with the polarization of immune response towards the Th1 response and improving protective immunity against S. typhimurium. Overall, the combination of alum and metoclopramide as an adjuvant synergistically enhanced cellular and humoral immunity after immunization with the HKST vaccine.

Evaluation of Adjuvant Effectiveness of Alum-Propranolol Mixture on the Immunogenicity of Excreted/Secreted Antigens of Toxoplasma gondii RH Strain

Purpose: The introduction of novel adjuvants is an important step in attempts to develop a safe and more efficient vaccine. The present study was performed to determine whether the use of a mixed beta-adrenergic receptor antagonist propranolol (PRP) and aluminum (alum), as an adjuvant, have efficacy for Toxoplasma gondii vaccine to induce protective immunity in a mouse model. Methods: Female BALB/c mice divided into five groups were immunized with excretorys-ecretory antigens (ESA) vaccine, alum-ESA vaccine, PRP-ESA vaccine, and alum-PRP ESA vaccine, as well as with phosphate buffered saline (PBS), as a negative control group. The immune responses were evaluated by lymphocyte proliferation assay for measuring delayedtype hypersensitivity (DTH) response and by cytokine assay for evaluating IFN-γ and IL-5 levels. The survival rate of mice in all groups was assessed during a three-week monitoring period after an intraperitoneal challenge with T. gondii tachyzoites. Results: The results showed that mice immunized with PRP, as an adjuvant, could secret a higher level of IFN-γ, which was significant in comparison to other groups. However, mice vaccinated with alum-precipitated ESA antigen had ability to produce an elevated level of IL-5 compared to other mouse groups (P ≤ 0.05). Moreover, alum-PRP co-administration together with ESA vaccine resulted in the longer survival of mice. Conclusion: The findings of this study revealed that the combination of alum-PRP adjuvants and ESA vaccine of T. gondii elicits both humoral and cellular immune responses, which are comparable to either alum or PRP alone.

Non-Selective Beta-Blockers Decrease Infection, Acute Kidney Injury Episodes, and Ameliorate Sarcopenic Changes in Patients with Cirrhosis: A Propensity-Score Matching Tertiary-Center Cohort Study

Background: Cirrhotic complications resulting from portal hypertension can be considerably reduced by non-selective beta-blockers (NSBBs); however, scarce studies have investigated therapeutic agents for other complications. We aimed to investigate the effects of NSBBs on common cirrhotic complications of infection, acute kidney injury (AKI), chronic renal function declination, and sarcopenic changes. Methods: Medical records of hospitalization for cirrhosis with at least a 4-year follow-up were analyzed and selected using propensity-score matching (PSM). Generalized estimating equation (GEE) was applied to assess the association of NSBBs with infection requiring hospitalization and AKI. Chronic renal function declination was evaluated by slope of regression lines derived from reciprocal of the serum creatinine level. The covariates of CT-measured skeletal muscle index (SMI) alterations were analyzed by generalized linear mixed model. Results: Among the 4946 reviewed individuals, 166 (83 NSBB group, 83 non-NSBB group) were eligible. Using GEE, Charlson comorbidity index, Child-Pugh score and non-NSBB were risk factors for infection; non-NSBB group revealed a robust trend toward AKI, showed no significant difference with chronic renal function declination of NSBB group, and was negatively associated with SMI alteration. Conclusion: Chronic NSBB use lowered the episodes of infection requiring hospitalization and AKIs, whereas non-NSBB was associated with sarcopenic changes.

Adrenergic Tone as an Intermediary in the Temperament Syndrome Associated With Flight Speed in Beef Cattle

The temperament of farm animals can influence their resilience to everyday variations within the managed production environment and has been under strong direct and indirect selection during the course of domestication. A prominent objective measure used for assessing temperament in beef cattle is the behavioral flight response to release from confinement in a crush or chute. This behavioral measure, termed flight speed (also known as escape velocity) is associated with physiological processes including body temperature, feeding behavior, growth rate, carcass composition, immune function, and health outcomes. This review examines the functional links between this suite of traits and adrenergic activity of the sympathetic nervous system and the adrenomedullary hormonal system. It is suggested that flight speed is the behavioral aspect of an underlying “flightiness” temperament syndrome, and that elevated adrenergic tone in animals with a high level of flightiness (i.e., flighty animals) tunes physiological activities toward a sustained “fight or flight” defense profile that reduces productivity and the capacity to flourish within the production environment. Nonetheless, despite a common influence of adrenergic tone on this suite of traits, variation in each trait is also influenced by other regulatory pathways and by the capacity of tissues to respond to a range of modulators in addition to adrenergic stimuli. It is suggested that tuning by adrenergic tone is an example of homeorhetic regulation that can help account for the persistent expression of behavioral and somatic traits associated with the flight speed temperament syndrome across the life of the animal. At a population level, temperament may modulate ecological fit within and across generations in the face of environmental variability and change. Associations of flight speed with the psychological affective state of the animal, and implications for welfare are also considered. The review will help advance understanding of the developmental biology and physiological regulation of temperament syndromes.

NY-ESO-1 Protein Vaccine Combining Alum, CpG ODN, and HH2 Complex Adjuvant Induces Protective and Therapeutic Anti-Tumor Responses in Murine Multiple Myeloma

Background

NY-ESO-1 is an ideal target for multiple myeloma immunotherapy. Alum, CpG ODN and HH2 complex is a safe and effective adjuvant for cancer vaccine.

Methods

We constructed NY-ESO-1 protein vaccine combined with alum, CpG ODN, and HH2 complex adjuvant to immunize the BALB/c mice inoculated with NS-1 murine multiple myeloma cells. Then, we determined the immunogenicity and anti-tumor effects in prophylactic and therapeutic models by analyzing the NY-ESO-1 antibody titer, evaluating IL4/INF-γ expression, and assessing cytotoxic T lymphocytes activities. The side-effects of vaccines were also evaluated.

Results

The group of NY-ESO-1 protein vaccine combining alum, CpG ODN, and HH2 complex adjuvant is more capable of stimulating both humoral and cellular tumor-specific immune responses to prolong the survival of the mice and inhibit tumor growth in prophylactic and therapeutic immunotherapy. The marked side-effects were not detected in immunized mice.

Discussion

The results suggest that alum, CpG ODN, and HH2 complex as a novel immune adjuvant combined cancer vaccine could improve the immunity efficiency in a murine multiple myeloma model.

Evaluation of the efficacy of isopathic immunotherapy in the treatment of allergic asthma in BALB/C mice

Introduction: Homeopathy is a therapeutic method based on the fundamental principle of "like cures like." Homeopathic remedies are extremely dilute but involve vigorous shaking at each dilution. Isopathy is one approach of homeopathy, in which the causative agents or products of a disease are used to treat the same disease. Allergen immunotherapy is the only potential disease-modifying treatment for allergic patients. Subcutaneous immunotherapy is more effective than sublingual immunotherapy. However, subcutaneous immunotherapy is ineffective at a low dose, whereas at high doses it can result in an unacceptably high frequency of systemic reactions. In the current study, we evaluated the efficacy of isopathic immunotherapy with highly diluted ovalbumin (HD OVA) in the treatment of OVA-induced allergic asthma in BALB/c mice.Methods: BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received HD OVA on days 21, 22, 32 and 41 (8 h after the last challenge) of the treatment. The mice were challenged with OVA (5%) aerosols on days 35, 38 and 41 for 20 minutes using an ultrasonic nebulizer and sacrificed the next day.Results: Isopathic immunotherapy significantly reduced lung tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and interleukin-4 production. It also insignificantly increased the production of transforming growth factor-beta and proliferation of regulatory T cells against the allergen.Conclusion: Isopathic immunotherapy may be a good candidate treatment for allergic asthma.

An overview of the role of sympathetic regulation of immune responses in infectious disease and autoimmunity

Stress in patients and pre-clinical research animals plays a critical role in disease progression Activation of the sympathetic nervous system (SNS) by stress results in secretion of the catecholamines epinephrine (Epi) and norepinephrine (NE) from the adrenal gland and sympathetic nerve endings. Adrenergic receptors for catecholamines are present on immune cells and their activity is affected by stress and the accompanying changes in levels of these neurotransmitters. In this short review, we discuss how this adrenergic stress impacts two categories of immune responses, infections and autoimmune diseases. Catecholamines signal primarily through the β2-adrenergic receptors present on innate and adaptive immune cells which are critical in responding to infections caused by pathogens. In general, this adrenergic input, particularly chronic stimulation, suppresses lymphocytes and allows infections to progress. On the other hand, insufficient adrenergic control of immune responses allows progression of several autoimmune diseases.

Nicotine, as a novel tolerogenic adjuvant, enhances the efficacy of immunotherapy in a mouse model of allergic asthma

An increasing trend in the incidence of allergic diseases including asthma and related morbidity and mortality is observed worldwide during the last decades. Allergen-specific immunotherapy is suggested for the treatment of some allergic diseases; nevertheless, there is always a menace of uncommon, but life-treating reactions due to increasing the administration of allergen extract doses. Hence, improving its efficacy may reduce the required doses as well as the risk of such reactions. The current study aimed at examining the effects of nicotine (NIC), as a tolerogenic adjuvant, on the improvement of immunotherapy efficacy in a mouse model of allergic asthma. BALB/c mice were sensitized using alum and ovalbumin (OVA) on the days 0 and 7. Mice received OVA either alone or together with NIC (1 or 10 mg/kg) on the days 21, 23, and 25. Then, the mice were challenged with OVA 5% using a nebulizer on the days 35, 38, and 41 and sacrificed the next day. Co-administration of OVA and NIC decreased the inflammation of the lung tissue, eosinophils count in the bronchoalveolar lavage (BAL) fluid, the serum level of OVA-specific immunoglobulin E, as well as interleukin (IL)-4 production, while increasing the population of antigen-specific regulatory T-cells (Treg cells) and transforming growth factor-β/IL-4 (TGF-β/IL-4) ratio compared to the OVA and control groups in a dose-dependent manner. Collectively, the findings suggest that administration of NIC plus the allergen increased immunotherapy efficacy through decreasing allergic inflammation and allergic responses intensity, and increasing Treg cells population.

Propranolol efficacy as a novel adjuvant for immunization against Toxoplasma gondii tachyzoites

Severe or lethal damages, caused by Toxoplasma gondii infection in congenital cases and immunocompromised patients implies the necessity for development of a vaccine and an appropriate adjuvant would be needed to elicit a protective Th1 biased-immune response. The adjuvant activity of propranolol was surveyed and compared with alum by immunization of BALB/c mice with protein components of T. gondii tachyzoites. Five groups of BALB/c mice were immunized with phosphate buffered saline (negative control), Toxoplasma lysate antigen (TLA), alum plus TLA, Propranolol plus TLA, and alum, propranolol and TLA. Immunization efficacy was evaluated by lymphocyte proliferation and DTH tests, challenge with live tachyzoites, IFN-γ production by spleen cells, serum TNF-α concentration and anti- Toxoplasma total IgG, IgG1 and IgG2a measurements. Mice of the PRP-TLA group induced significantly more IFN-γ and TNF-α production and lymphocyte proliferation than other groups. This group of mice also showed more anti-T. gondii IgG2a and DTH responses and showed a significantly increased survival time after challenge. These findings indicate that propranolol as an adjuvant in combination with TLA, may enhance cellular immunity against T. gondii.

Evaluation of the efficacy of nicotine in treatment of allergic asthma in BALB/c mice

Nicotine, an nAChR agonist, shows prominent anti-inflammatory properties, and some studies have illustrated its suppressive effects on inflammation. Here, we have examined whether nicotine as a medicine may have beneficial effects on the treatment of asthma in a mouse model of allergic asthma. BALB/c mice were sensitized with OVA and alum. Two weeks later, the mice received nicotine with concentrations of 1 and 10 mg/kg three times every other day. After 10 days, the mice were challenged with OVA (5%) using an ultrasonic nebulizer and died the next day. Our results showed that the administration of nicotine reduced lung-tissue inflammation, the number of eosinophils in bronchoalveolar fluid, allergen-specific IgE and IL-4 production, while it increased the TGF-β/IL-4 ratio and the number of Treg cells. Our results showed that nicotine applies its suppressive effects in a dose-dependent manner: administration of 10 mg/kg of nicotine showed more suppressive effects than 1 mg/kg. Such data suggested that nicotine might be a good candidate to be used as a medicine in the treatment of allergic asthma by decreasing allergic inflammation severity and potentiating Treg cells proliferation against the allergen.

Anti-tumor effects of propranolol: Adjuvant activity on a transplanted murine breast cancer model

Propranolol (Pro), a non-specific β-adrenergic blocking drug, competitively prevents the binding of catecholamines to receptors and suppresses cancer cells. The anti-tumor activity of propranolol has been proved in different kinds of cancers. In this study, we assessed the adjuvant activity of propranolol combined with a tumor vaccine model on the immunological parameters of breast tumor-bearing mice. Breast tumor pieces were implanted into the flank of inbred BALB/C female mice from stock mice. Tumor-bearing mice were treated with tumor antigen lysate vaccine and propranolol/Vaccine (Pro/Vac) combination (as treatment groups), propranolol and PBS (as control groups) for 5 consecutive days, every 12 h. Moreover, all experimental groups received vaccine for three times with one-week interval via s.c injection. After immunization courses, spleens of tumor-bearing mice were removed and dissected, cell suspension was stimulated in vitro, and the cytokine levels in supernatant of splenocytes were measured via commercial ELISA kits. Compared with the vaccine group, immunization with tumor lysate in combination with propranolol significantly increased IL-2, IL-4, IL-12, IL-17, and IFN-γ cytokines. Considering the suppression of tumor growth, propranolol seems to be a potent immunomodulator capable of inducing cellular immune responses against breast cancer.

Evaluation of immunogenicity and protective efficacy of combination heat-killed immunogens from three entero-invasive bacteria in rabbit model

Diarrhea is a very common health problem in both developing and developed countries. Among the major entero-invasive bacteria, Shigella, Salmonella and Campylobacter cause serious problems in different geographic regions. Recently we have shown immunogenicity and protective efficacy of heat killed multi-serotype Shigella immunogen in different animal models. In our present study, we have advanced our research by preparing a combination heat-killed immunogen of three different entero-invasive bacteria, Shigella, Salmonella and Campylobacter. After three doses on 0th, 14th and 28th day of oral immunization with tri-valent heat-killed (TVHK) immunogen in rabbit model, the immunogenicity was determined by differential count of white blood cells and immunoglobulin assay at various time points. During oral immunization differential count of lymphocytes increased where as polymorphonuclear leucocytes (PMN) count decreased. Serum IgG and IgA showed significant elevation during oral immunization and remained at a detectable value upto 120 days. Protection study was performed in both, in vitro and in vivo conditions, using bacteriocidal assay and rabbit ligated ileal loop model, respectively, which conferred protection against homologous bacteria. Moreover, immunoblot assay against whole cell lysate and lipopolysaccharide exhibited significant amount of antigen-specific immunoglobulins raised against three different bacteria which proved that proteins along with lipopolysaccharides played a pivotal role in immunogenicity and protective efficacy. This trivalent heat-killed immunogen could be a low-cost, simple, oral, non-living vaccine candidate for future use against invasive diarrhea.

Mixture of Alum--Naloxone and Alum--Naltrexone as a novel adjuvant elicits immune responses for Toxoplasma gondii lysate antigen in BALB /c mice

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. Treatment of the infection induced by this parasite is not straightforward due to the toxic side effects of the available drugs. Vaccine development could be a solution to this problem. In the present study, T.gondii Lysate Antigen (TLA), as a model vaccine, in combination with the Alum-NLT (Aluminum phosphate-Naltrexone) and Alum-NLX (Aluminum phosphate-Naloxone) were evaluated for immunization BALB/c. 147 female BALB/c mice which were divided into seven groups of 21, were allocated to immunization experiments. The first group was selected as the negative control group, followed by the second, third, fourth, fifth, sixth and seventh groups which were immunized with Vac, Vac-Alum, Vac-NLX, Vac-NLT, Vac-Alum-NLX, Vac-Alum-NLT, respectively. Ten days after the final immunization, mice in all groups were divided into three groups for evaluating cellular immune responses, measuring the delayed-type hypersensitivity responses (DTHs) and evaluating survival. The DTH and cellular immune responses showed that in mice immunized with the TLA vaccine combined with the Alum-NLT mixture, the efficacy improved by increasing the production of Interleukin-5(IL-5) and Interferon gamma. This consequently shifted the immune responses toward a Th1 profile by increasing the IFN-γ/IL-5 ratios. In challenge experiments, immunized mice with the Alum-NLT-Vac mixture survived for a longer period of time which indicated an improvement in protective immunity against T. gondii. Administration of the Alum-NLT mixture adjuvant in combination with TLA vaccine enhanced the cellular immunity by shifting the immune response to a Th1 pattern. This shift to the Th1 pattern plays an important role in the induction of cellular.

β-Adrenergic blockade protects BALB/c mice against infection with a small inoculum of Leishmania mexicana mexicana (LV4)

In order to test the influence of the sympathetic nervous system on Leishmania mexicana infection, groups of female BALB/c mice were treated (i.p.) with the non-selective β-adrenergic receptor (β-AR) antagonist (S)-propranolol (5mg/kg thrice a day), the β2-AR agonist clenbuterol (1mg/kg once a day) or the α2-AR antagonist yohimbine (2mg/kg twice a day) during 5days. During the second day of treatments, mice were inoculated in the footpad with 1×10(6) or 1×10(3) metacyclic promastigotes of L. mexicana mexicana (LV4). The lesion size was measured weekly, and parasite burden on week 12. In mice treated with (S)-propranolol, the percentage of splenic T lymphocytes producing IFN-γ after antigen challenge was determined by flow cytometry. In mice infected with 1×10(6) parasites, only (S)-propranolol caused a reduction of footpad swelling (p<0.05, weeks 11-12), without effects on parasite burden, or in the percentage of IFN-γ-immunopositive CD4(+) or CD8(+) T lymphocytes. In mice infected with 1×10(3) parasites, the effects of treatments vs. control group were as follows: (a) inhibition of footpad swelling by (S)-propranolol (p<0.01, weeks 3-12), clenbuterol (p<0.05, weeks 7-10), and yohimbine (p<0.01, week 7); (b) a decrease of the parasite burden by (S)-propranolol (p<0.01) and yohimbine (p<0.05); (c) in control mice the percentage of CD4(+) T-cells producing IFN-γ was 6.2±0.5%, while in those treated with (S)-propranolol it increased to 8.7±0.6% (p<0.01); (d) in control mice the percentage of CD8(+) T-cells producing IFN-γ was 3.1±0.4%, while in those treated with (S)-propranolol it increased to 10.4±0.2% (p<0.01). These results indicate that the blockade of β-ARs during infection of BALB/c mice with an inoculum of L. mexicana mexicana similar to that delivered by the bite of a sand fly produces a Th1 bias in the immune response, favoring an increment of T lymphocytes secreting IFN-γ, which correlated with a reduced parasite burden (p<0.05, Spearman's test). We suggest that β-AR antagonists could be of therapeutic value, either as treatment or as adjuvant of vaccines for L. mexicana.

Effective inhibition of melanoma tumorigenesis and growth via a new complex vaccine based on NY-ESO-1-alum-polysaccharide-HH2

Background

A safe and effective adjuvant plays an important role in the development of a vaccine. However, adjuvants licensed for administration in humans remain limited. Here, for the first time, we developed a novel combination adjuvant alum-polysaccharide-HH2 (APH) with potent immunomodulating activities, consisting of alum, polysaccharide of Escherichia coli and the synthetic cationic innate defense regulator peptide HH2.

Methods

The adjuvant effects of APH were examined using NY-ESO-1 protein-based vaccines in prophylactic and therapeutic models. We further determined the immunogenicity and anti-tumor effect of NY-ESO-1-APH (NAPH) vaccine using adoptive cellular/serum therapy in C57/B6 and nude mice. Cell-mediated and antibody-mediated immune responses were evaluated.

Results

The APH complex significantly promoted antigen uptake, maturation and cross-presentation of dendritic cells and enhanced the secretion of TNF-α, MCP-1 and IFN-γ by human peripheral blood mononuclear cells compared with individual components. Vaccination of NAPH resulted in significant tumor regression or delayed tumor progression in prophylactic and therapeutic models. In addition, passive serum/cellular therapy potently inhibited tumor growth of NY-ESO-1-B16. Mice treated with NAPH vaccine produced higher antibody titers and greater antibody-dependent/independent cellular cytotoxicity. Therefore, NAPH vaccination effectively stimulated innate immunity, and boosted both arms of the adaptive humoral and cellular immune responses to suppress tumorigenesis and growth of melanoma.

Conclusions

Our study revealed the potential application of APH complex as a novel immunomodulatory agent for vaccines against tumor refractory and growth.