Naloxone can improve the anti-tumor immunity by reducing the CD4+CD25+Foxp3+ regulatory T cells in BALB/c mice

Effects of perioperative low-dose naloxone on the immune system in patients undergoing laparoscopic-assisted total gastrectomy: a randomized controlled trial

BACKGROUND

Low immune function after laparoscopic total gastrectomy puts patients at risk of infection-related complications. Low-dose naloxone (LDN) can improve the prognosis of patients suffering from chronic inflammatory diseases or autoimmune diseases. The use of LDN during perioperative procedures may reduce perioperative complications. The purpose of this study was to examine the effects of LDN on endogenous immune function in gastric cancer patients and its specific mechanisms through a randomized controlled trial.

METHODS

Fifty-five patients who underwent laparoscopic-assisted total gastrectomy were randomly assigned to either a naloxone group (n = 23) or a nonnaloxone group (n = 22). Patients in the naloxone group received 0.05 µg/kg-1.h- 1naloxone from 3 days before surgery to 5 days after surgery via a patient-controlled intravenous injection (PCIA) pump, and patients in the nonnaloxone group did not receive special treatment. The primary outcomes were the rates of postoperative complications and immune function assessed by NK cell, CD3+ T cell, CD4+ T cell, CD8+ T cell, WBC count, neutrophil percentage, and IL-6 and calcitonin levels. The secondary outcomes were the expression levels of TLR4 (Toll-like receptor), IL-6 and TNF-α in gastric cancer tissue.

RESULTS

Compared with the nonnaloxone group, the naloxone group exhibited a lower incidence of infection (in the incision, abdomen, and lungs) (P < 0.05). The numbers of NK cells and CD8+ T cells in the naloxone group were significantly greater than those in the nonnaloxone group at 24 h after surgery (P < 0.05) and at 96 h after surgery (P < 0.05). Compared with those in the nonnaloxone group, the CD3 + T-cell (P < 0.05) and CD4 + T-cell (P < 0.01) counts were significantly lower in the naloxone group 24 h after surgery. At 24 h and 96 h after surgery, the WBC count (P < 0.05) and neutrophil percentage (P < 0.05) were significantly greater in the nonnaloxone group. The levels of IL-6 (P < 0.05) and calcitonin in the nonnaloxone group were significantly greater at 24 h after surgery. At 24 h following surgery, the nonnaloxone group had significantly greater levels of IL-6 (P < 0.05) and calcitonin than did the naloxone group. Compared with those in the naloxone group, the expression levels of TLR4 (P < 0.05) in gastric cancer tissue in the naloxone group were greater; however, the expression levels of IL-6 (P < 0.01) and TNF-α (P < 0.01) in the naloxone group were greater than those in the nonnaloxone group.

CONCLUSION

Laparoscopic total gastrectomy patients can benefit from 0.05 ug/kg- 1. h- 1 naloxone by reducing their risk of infection. It is possible that LDN alters the number of cells in lymphocyte subpopulations, such as NK cells, CD3 + T cells, and CD4 + T cells, and the CD4+/CD8 + T-cell ratio or alters TLR4 receptor expression in immune cells, thereby altering immune cell activity.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trial Registry on 24/11/2023 (ChiCTR2300077948).

Low MxA Expression Predicts Better Immunotherapeutic Outcomes in Glioblastoma Patients Receiving Heat Shock Protein Peptide Complex 96 Vaccination

Heat shock protein peptide complex 96 (HSPPC-96) has been proven to be a safe and preliminarily effective therapeutic vaccine in treating newly diagnosed glioblastoma multiforme (GBM) (NCT02122822). However, the clinical outcomes were highly variable, rendering the discovery of outcome-predictive biomarkers essential for this immunotherapy. We utilized multidimensional immunofluorescence staining to detect CD4+ CD8+ and PD-1+ immune cell infiltration levels, MxA and gp96 protein expression in pre-vaccination GBM tissues of 19 patients receiving HSPPC-96 vaccination. We observed low MxA expression was associated with longer OS than high MxA expression (48 months vs. 20 months, p=0.038). Long-term survivors (LTS) exhibited significantly lower MxA expression than short-term survivors (STS) (p= 0.0328), and ROC curve analysis indicated MxA expression as a good indicator in distinguishing LTS and STS (AUC=0.7955, p=0.0318). However, we did not observe any significant impact of immune cell densities or gp96 expression on patient outcomes. Finally, we revealed the association of MxA expression with prognosis linked to a preexisting TCR clone (CDR3-2) but was independent of the peripheral tumor-specific immune response. Taken together, low MxA expression correlated with better survival in GBM patients receiving HSPPC-96 vaccination, indicating MxA as a potential biomarker for early recognition of responsive patients to this immunotherapy.

Clinical Trial Registration: ClinicalTrials.gov (NCT02122822) http://www. chictr.org.cn/enindex.aspx (ChiCTR-ONC-13003309).

Naloxone Diminishes the Virulence and Modifies the Cellular Immune Responses of BALB/c Mice Infected with Leishmania major

PURPOSE

Leishmania major-infected BALB/c mice display strong susceptibility to the infection due to the induction of Th2 response. The aim of this study was to assess the effects of naloxone on virulence of L. major in BALB/c mice and the ensued cellular immune response.

METHODS

The effects of injection of a single dose of naloxone in the footpad of L. major-infected BALB/c mice were investigated by evaluating the lesion sizes, the parasite burden, cell proliferation, secreted cytokines (IFN-γ, IL-4, IL-10 and IL-12) and their genes expressions due to naloxone treatment while the untreated mice were used as a control.

RESULTS

Significantly lower lesion sizes and less parasite burden were measured in the treated mice. Significantly decreased productions of IFN-γ, IL-12, IL-4, and IL-10 were also observed in the treated mice at week 4 post-infection while the production IL-10 remained significantly hindered till 8 weeks post-infection.

CONCLUSION

Our data indicated that although the treatment of L. major-infected BALB/c mice with a single dose of naloxone was unable to improve the cellular immune response, it led to lower virulence, confirmed by significantly reduced lesions and parasite load.

A review of combination adjuvants for malaria vaccines: a promising approach for vaccine development

It is obvious that there is a critical need for an efficient malaria vaccine to accelerate malaria eradication. Currently, recombinant subunit vaccination against malaria using proteins and peptides is gaining attention. However, one of the major drawbacks of this approach is the lack of an efficient and durable immune response. Therefore, subunit vaccines require adjuvants to make the vaccine sufficiently immunogenic. Considering the history of the RTS,S vaccine, it seems likely that no single adjuvant is capable of eliciting all the protective immune responses required in many malarial subunit vaccines and the use of combination adjuvants will be increasingly important as the science of malaria vaccines advances. In light of this, it appears that identifying the most effective mixture of adjuvants with minimal adverse effects offers tremendous opportunities in improving the efficacy of vaccines against malaria. Owing to the importance of a multi-adjuvanted approach in subunit malaria vaccine development, this review paper outlines some of the best known combination adjuvants used in malaria subunit vaccines, focusing on their proposed mechanisms of action, their immunological properties, and their notable results. The aim of the present review is to consolidate these findings to aid the application of these combination adjuvants in experimental malaria vaccines.

A Survey on the Adjuvant Role of Naloxone Alone or Combined with Alum in Vaccination Against Fasciolosis in BALB/c Mice

BACKGROUND

Fasciolosis is a zoonotic parasitic disease imposing a heavy load of livestock losses worldwide.

PURPOSE

We aimed to evaluate immune-stimulatory effects of naloxone (NLX), an opioid receptor antagonist, in combination with alum in mice vaccinated with excretory-secretory antigens (E/S) of Fasciola hepatica.

METHODS

8-week-old female BALB/c mice were subcutaneously vaccinated using E/S antigens of F. hepatica. Experimental groups (14 mice per group) included: vaccine (E/S antigen), alum vaccine (E/S antigen plus alum), NLX vaccine (E/S antigen plus NLX), and alum-NLX vaccine (E/S antigen plus a mixture of alum-NLX). The control group was infused with PBS. Lymphocyte proliferation and the levels of IFN-γ, IL-4, IgG2a, IgG1, and total IgG were measured.

RESULTS

Mice vaccinated with NLX or alum-NLX adjuvants showed significantly higher rates of lymphocyte proliferation, IFN-γ, total IgG, and IgG2a levels. The mice that were injected with alum showed a significantly higher concentration of IL-4. Ratios of IFN-γ/Il-4 and IgG2a/IgG1 were significantly higher in the NLX and alum-NLX groups in comparison with the groups vaccinated either with alum or without any adjuvant. A significantly higher protection rate (62.5%) was seen in mice vaccinated with the alum-NLX adjuvant compared to the other groups.

CONCLUSION

NLX can be effective in conferring cellular immunity and protection against F. hepatica. It is recommended to consider this agent as a potential adjuvant in vaccines against fasciolosis.

How to Monitor the Neuroimmune Biological Response in Patients Affected by Immune Alteration-Related Systemic Diseases

The clinical management of patients affected by systemic diseases, including cancer and autoimmune diseases, is generally founded on the evaluation of the only markers related to the single disease rather than the biological immuno-inflammatory response of patients, despite the fundamental role of cytokine network in the pathogenesis of cancer and autoimmunity is well known. Cancer progression has appeared to be associated with a progressive decline in the blood levels of the main antitumor cytokines, including IL-2 and IL-12, in association with an increase in those of inflammatory cytokines, including IL-6, TNF-alpha, and IL-1-beta, and immunosuppressive cytokines, namely TGF-beta and IL-10. On the other hand, the severity of the autoimmune diseases has been proven to be greater in the presence of high blood levels of IL-17, TNF-alpha, IL-6, IL-1-beta, IFN-gamma, and IL-18, in association with low levels of TGF-beta and IL-10. However, because of excessive cost and complexity of analyzing the data regarding the secretion of the single cytokines, the relation between lymphocyte-induced immune activation and monocyte-macrophage-mediated immunosuppression has been recently proven to be expressed by the simple lymphocyte-to-monocyte ratio (LMR). The evidence of low LMR values has appeared to correlate with a poor prognosis in cancer and with a disease control in the autoimmune diseases. Moreover, since the in vivo immunoinflammatory response is physiologically under a neuroendocrine modulation, for the evaluation of patient biological response it would be necessary to investigate the function of at least the two main neuroendocrine structures involved in the neuroendocrine modulation of the immune responses, consisting of the hypothalamic-pituitary-adrenal axis and the pineal gland, since the lack of physiological circadian rhythm of cortisol and pineal hormone melatonin has appeared to be associated with a worse prognosis in the human systemic diseases.

Naltrexone; as an efficient adjuvant in induction of Th1 immunity and protection against Fasciola hepatica infection

Toxic effects of available therapeutics are major drawbacks for conventional management approaches in parasitic infections. Vaccines have provided a promising opportunity to obviate such unwanted complications. In present study, we examined immune augmenting capacities of an emerging adjuvant, Naltrexone, against Fasciola hepatica infection in BALB/c mice. Seventy BALB/c mice were divided into five experimental groups (14 mice per group) including 1- control (received PBS), 2- vaccine (immunized with F. hepatica E/S antigens), 3- Alum-vaccine (immunized with Alum adjuvant and E/S antigens), 4- NLT-vaccine (immunized with NLT adjuvant and E/S antigens), and 5- Alum-NLT-vaccine (immunized with mixed Alum-NLT adjuvant and E/S antigens). Lymphocyte stimulation index was assessed by MTT assay. Production of IFN-γ, IL-4, IgG2a and IgG1 was assessed by ELISA method. Results showed that NLT, either alone or in combination with alum, can induce immune response toward production of IFN-γ and IgG2a as representatives of Th1 immune response. Also, using this adjuvant in immunization experiment was associated with significantly high proliferative response of splenocytes/lymphocytes. Utilization of mixed Alum-NLT adjuvant revealed the highest protection rate (73.8%) in challenge test of mice infected with F. hepatica. These findings suggest the potential role of NLT as an effective adjuvant in induction of protective cellular and Th1 immune responses against fasciolosis.

The effects of naloxone on human breast cancer progression: in vitro and in vivo studies on MDA.MB231 cells

Background

Naloxone is viewed as a specific competitive opioid antagonist acting at the level of opioid receptors (μ, δ, and κ) with blended agonist-adversary or agonist action. The role of naloxone in tumor cell growth has been poorly studied in human cancer cell lines.

Materials and methods

In the present study, we report findings from in vitro and in vivo experiments performed to evaluate the effects of naloxone on human breast cancer cell growth and progression. In vitro assays were conducted on estrogen receptor-negative human breast carcinoma cells, MDA.MB231, treated with naloxone at different concentrations (10-100 μM). In vivo experiments were performed on a mouse model of human triple-negative breast cancer generated by using MDA.MB231 injected subcutaneously in mice. Naloxone was daily intraperitoneally injected in mice at 0.357 mg/kg for 2 weeks and at 0.714 mg/kg for the next 2 weeks. Microvessels formation was detected by fluorescein isothiocyanate-dextran (100 μL) injected into the tail vein of mice and confirmed by immunohistochemistry with CD31 on mice tumor sections.

Results

In vitro tests showed that the cell proliferation of MDA.MB231 was inhibited by naloxone in a dose-dependent manner, whereas the cell death was increased. In vivo studies demonstrated that tumors of mice treated with naloxone were significantly smaller than those observed in the control groups, as long as naloxone was administered. Finally, naloxone was not able to impair the microvessel formation in tumors of treated mice.

Conclusion

Our data showed, for the first time, that naloxone reduced breast cancer progression without affecting angiogenesis.

Naloxone/alum mixture a potent adjuvant for HIV-1 vaccine: induction of cellular and poly-isotypic humoral immune responses

In the present study we used a fusion peptide from HIV-1 p24 and Nef as vaccine model and adjuvant activity of Naloxone/alum mixture was evaluated in a peptide vaccine model. HIV-1 p24-Nef fusion peptide was synthesized. Female BALB/c mice were divided into five groups. The first group immunized subcutaneously with the p24-Nef fusion peptide adjuvanted with Naloxone/alum mixture and boosted with same protocol. The second was immunized with fusion peptide adjuvanted in alum. The control groups were injected with NLX (Group 3), Alum (Group 4), or PBS (Groups 5) under the same conditions. To determine the type of induced immune response, sera and splenocytes were analyzed by commercial ELISA method for total IgG and isotypes and cytokine secretion (IL-4 & IFN-γ), respectively. We have also used the ELISPOT assay to monitor changes in the frequency of IFN-γ-producing T cells. The proliferation of T cells was assessed using Brdu method and T-cell cytotoxicity was assessed with CFSE method. Immunization of mice with HIV-1 p24-Nef fusion peptide formulated in Naloxone/alum mixture significantly increased lymphocyte proliferation and shifted cytokine responses toward Th1 profile compared to all other groups. Analysis of humoral immune responses revealed that administration of HIV-1 p24-Nef fusion peptide with Naloxone/alum mixture significantly increased specific IgG responses and also increased IgG1,IgG2a, IgG2b, IgG3, and IgM vs. alum-adjuvanted vaccine groups. Naloxone/alum mixture as an adjuvant could improve cellular and humoral immune response for HIV vaccine model and this adjuvant maybe useful for HIV vaccine model in human clinical trial.

Evaluation of the alum-naloxone adjuvant activity against experimental murine leishmaniasis due to L. major

Leishmaniasis is caused by intracellular parasites of Leishmania species, which are transmitted by the bite of the sandfly. Recovery and protection against the infection depends on the induction of a strong Th1 type of immune response. Vaccination of mice with the opioid antagonist naloxone can promote the activation of the Th1 responses. We studied the efficacy of the mixture of naloxone and alum, as an adjuvant, to enhance immune responses and induce protection against Leishmania major infection in BALB/c as a susceptible mouse model. BALB/c mice were immunized with Ag-naloxone-alum, Ag-alum, Ag-naloxone or PBS subcutaneously three times at 2-week intervals. The humoral and cellular specific immune responses were assessed 2 weeks after the last immunization and compared with the control mice. Our results indicated that the administration of alum-naloxone as an adjuvant increased the capability of L. major promastigote antigens to enhance lymphocyte proliferation, the levels of IFN-γ, and the IFN-γ/IL-5 ratio. The results of DTH showed that there were no significant differences in footpad swelling between the groups of immunized mice as compared with the non-vaccinated control group; however, no significant differences were observed in the survival rate among groups. It can be concluded that although immunization with the alum-naloxone mixture in combination with the autoclaved L. major promastigote antigens could enhance cellular immunity and shift the immune response to a Th1 pattern, it could not protect the mice against Leishmania major infection.

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.

Administration of naloxone in combination with recombinant Plasmodium vivax AMA-1 in BALB/c mice induces mixed Th1/Th2 immune responses

Naloxone (NLX) has the ability to shift the immune response to a Th1 profile. Therefore, the adjuvant efficacy of NLX with recombinant P. vivax apical membrane antigen-1(rPvAMA-1) in BALB/c mice was evaluated. Mice were immunized subcutaneously with purified rPvAMA-1 formulated with NLX (doses of 5 mg/kg body weight) alone or in combination with IFA. A significant increase in anti-PvAMA-1 IgG antibody after the second boost (mean OD₄₉₀  = 2·08 and 2·17, in groups received, rPvAMA-1/NLX and rPvAMA-1/NLX/IFA, respectively) was detected. IgG1 and IgG2b were the predominant isotypes in all immunized mouse groups. In immunized mice with rPvAMA-1/NLX (mean: 1036 pg/mL) and with rPvAMA-1/NLX/IFA (mean: 1024 pg/mL), IFN-γ was elicited in response to rPvAMA-1 after the second boost. No detectable IL-4 secretion was determined in all tested groups. In conclusion, the administration of NLX alone or NLX/IFA with rPvAMA-1 in BALB/c mice, which induced mixed Th1/Th2 immune responses, was comparable with that of the same recombinant antigen with CFA/IFA adjuvant. The results indicate that NLX alone may possibly not be considered as a potent Th1 adjuvant in PvAMA-1-based vaccine. However, in order to modulate immune responses from mixed Th1/Th2 to strong and protective Th1 response, further study is warranted on combination of NLX with other adjuvants such as CpG motifs or MPL in proper vaccine formulation. Additionally, dose-response study is necessary to determine the effect of different doses of antigen combined with NLX (at various doses) in Balb/c mice.

A novel adjuvant, the mixture of alum and naltrexone, augments vaccine-induced immunity against Plasmodium berghei

We previously showed that the mixture of naltrexone (NLT), a general opioid antagonist, and alum, acts as an effective adjuvant in enhancing vaccine-induced T helper 1 (TH1) humoral immune responses against Toxoplasma gondii. Here, we tested the efficacy of the mixture of NLT and alum in the induction of immunity in response to blood stages of Plasmodium berghei (BSPb) as a model vaccine. BALB/c mice were divided into five vaccination groups. Mice in the experimental groups received the BSPb vaccine alone or in combination with the adjuvant alum, NLT or the alum-NLT mixture. Mice in the control group received PBS. All mice were immunized on days 0, 7 and 14. Two weeks after the last immunization, immune responses to Plasmodium berghei were assessed. Our results indicated that including the alum-NLT mixture as an adjuvant during vaccination increased the ability of the BSPb vaccine to enhance lymphocyte proliferation, shifted the immune response towards a TH1 profile and increased Plasmodium berghei-specific IgG2a. This resulted in improved protective immunity against Plasmodium berghei. In conclusion, administering alum-NLT mixture in combination with the BSPb vaccine enhanced the vaccine-induced immunity, and shifted the immune response toward TH1 pattern.

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

OBJECTIVE

To determine the efficacy of the mixture of propranolol (PRP), a beta-adrenergic receptor antagonist, and alum, as a new adjuvant, in the induction of humoral and cellular immunity in response to heat-killed Salmonella typhimurium (S. typhimurium) (HKST) as a model vaccine.

METHODS

BALB/c mice were divided into five groups. Mice in the experimental groups received either the HKST vaccine alone or in combination with the adjuvant alum, PRP or the alum-PRP mixture. Mice in the negative control group received phosphate-buffered saline. All mice were immunized two times on days 0 and 14. Two weeks after the last immunization, immune responses to S. typhimurium were assessed.

RESULTS

Administration of the alum-PRP mixture as an adjuvant increased the ability of the HKST vaccine to enhance lymphocyte proliferation, shifted the immune response towards a T-helper (Th) 1 pattern and increased S. typhimurium specific IgG, IgG2a and IgG1. This resulted in improved protective immunity against S. typhimurium.

CONCLUSION

Administration of the alum-PRP mixture as an adjuvant in combination with the HKST vaccine, can enhance both humoral and cellular immunity and shift the immune responses to a Th1 pattern.

Naloxone and alum synergistically augment adjuvant activities of each other in a mouse vaccine model of Salmonella typhimurium infection

Alum is the most commonly used adjuvant for human vaccination but is a poor inducer of cell mediated immunity and T helper 1 (Th1) responses. We have previously shown that naloxone (NLX), which is a general opioid antagonist, acts as an effective adjuvant in enhancing vaccine-induced cellular immunity and Th1 immune responses. Here, we tested the efficacy of an alum-NLX mixture, as a new adjuvant, in the induction of humoral and cellular immunity in response to endotoxin-removed lysate (ERL) of Salmonella typhimurium (S. typhimurium) as a model vaccine. BALB/c mice were divided into five vaccination groups. Mice in the experimental groups received either the ERL vaccine alone or in combination with the adjuvant alum, NLX or the alum-NLX mixture. Mice in the negative control group received phosphate-buffered saline. All mice were immunized on days 0 and 7. Two weeks after the last immunization, immune responses to S. typhimurium were assessed. Our results indicate that including the alum-NLX mixture as an adjuvant during vaccination increased the ability of the ERL vaccine to enhance lymphocyte proliferation, shifted the immune response toward a Th1 profile and increased S. typhimurium-specific IgG, IgG2a and the ratio of IgG2a to IgG1. This resulted in improved protective immunity against S. typhimurium. In conclusion, administering an alum-NLX mixture adjuvant in combination with the ERL vaccine enhances both humoral and cellular immunity, and shifts the immune response to a Th1 pattern.