CTLA4-Ig alleviates the allogeneic immune responses against insulin-producing cells in a murine model of cell transplantation.

The adoptive transfer of insulin-producing cells (IPCs) is one of the promising treatments for insulin-dependent diabetes mellitus. While the use of allogeneic cell resources is inevitable in the case of a series of patients, alloimmune responses are a major barrier ahead of the successful implementation of allogeneic therapeutic cells. This study is aimed at evaluating the potential of CTLA4-Ig, as an approved immunomodulatory biologic, in protecting the IPCs against allogeneic immune responses. The C57BL/6 and BALB/c mice were used to establish a murine model of allogeneic cell transplantation. The mouse bone-marrow-derived mesenchymal stem cells were in vitro differentiated into IPCs, and the in vitro as well as the in vivo immune responses against IPCs were evaluated in the presence and absence of CTLA4-Ig. The allogeneic IPCs induced the in vitro activation of CD4+ T-cells, IFN-γ release, and the proliferation of lymphocytes, which all were controlled by CTLA4-Ig. Upon in vivo transfer of IPC into an allogeneic host, the splenic CD4+ and CD8+ T-cells exhibited a significant activation, and there was a significant donor-specific antibody response. Either of the mentioned cellular and humoral responses were modulated by a CTLA4-Ig regimen. This regimen also reduced the infiltration of CD3+ T-cells into the IPC injection site along with the improved overall survival of diabetic mice. CTLA4-Ig could be a complementary therapy for improving the efficacy of allogeneic IPC therapy through modulating the cellular and humoral responses that can lead to prolonged durability of IPCs within an allogeneic host.

Effect of melatonin on stress-induced hyperglycemia and insulin resistance in critically-ill patients: A randomized double-blind, placebo-controlled clinical trial.

BACKGROUND: Hyperglycemia is a common finding which is associated with increased mortality and morbidity among critically ill patients. There is currently no evidence that melatonin could improve stress induced hyperglycemia (SIH). In this study, we evaluated the effect of melatonin on blood sugar and insulin resistance (IR) in critically-ill patients. METHODS: 104 critically-ill patients with SIH divided into two groups, receiving melatonin (6 mg BD for 3 days) or placebo. Changes of blood sugar, IR indices including homeostasis model assessment for insulin resistance and homeostasis model assessment adiponectin (HOMA-AD) ratios, Glasgow coma scale (GCS) were evaluated on the 4th day of melatonin prescription. On the 7Th day of study, changes of ventilator dependency and delirium were considered. Mortality and intensive care unit (ICU) stay were also compared between groups. RESULTS: On day 4, patients in the melatonin group had significantly lower blood glucose and HMOA-IR level compared with the placebo group (P=0.04 and P=0.03, respectively) whereas HOMA-AD level did not differ significantly from placebo group (p>0.2). Also, we did not observe any significant difference in GCS level at this time between groups (p>0.2). On day 7, melatonin could not improve ventilator dependency and delirium significantly (p>0.2) and also could not reduce mortality and ICU stay in comparison with placebo (p>0.2, P=0.2, respectively). CONCLUSION: Melatonin supplementation showed positive effect on blood sugar and somehow insulin resistance whereas it could not improve ICU complications.

Immunological evaluation of a DNA cocktail vaccine with co-delivery of calcium phosphate nanoparticles (CaPNs) against the Toxoplasma gondii RH strain in BALB/c mice.

Many recent studies have been conducted to evaluate protective immunity mediated by DNA vaccines against toxoplasmosis. Cocktail DNA vaccines showed better immune responses compared to single vaccines. The objective of the current study was to evaluate the protective efficacy of rhomboid 4 (ROM4) and cocktail DNA vaccines (ROM4 + GRA14) of the Toxoplasma gondii RH strain with or without coated calcium phosphate nanoparticles (CaPNs) as the adjuvant to improve the immunogenicity against the T. gondii RH strain in BALB/c mice. Cocktail DNA vaccines of pcROM4 + pcGRA14 of the T. gondii RH strain were constructed. CaPNs were synthesized and the cocktail DNA vaccine was coated with the adjuvant of CaPNs. Immunogenicity and the protective effects of cocktail DNA vaccines with or without CaPNs against lethal challenge were evaluated in BALB/c mice. pcROM4 and cocktail DNA vaccine coated with CaPNs significantly enhanced cellular and humoral immune responses against Toxoplasma compared to pcROM4 and cocktail DNA vaccine without CaPNs (p < 0.05). These findings indicate that the survival time of immunized mice after challenge with the RH strain of T. gondii was increased compared to that of controls and the DNA vaccine provided significant protection in mice (p < 0.05). The CaPN-based cocktail DNA vaccine of pcROM4 + pcGRA14 showed the longest survival time compared to the other groups. Co-immunization with CaPN-based cocktail DNA vaccine (pcROM4 + pcGRA14) boosted immune responses and increased the protective efficacy against acute toxoplasmosis in BALB/c mice compared to both single gene and bivalent DNA vaccine without nano-adjuvants.

In Vitro Infectivity Assessment by Drug Susceptibility Comparison of Recombinant Leishmania major Expressing Enhanced Green Fluorescent Protein or EGFP-Luciferase Fused Genes with Wild-Type Parasite.

Leishmaniasis is a worldwide uncontrolled parasitic disease due to the lack of effective drug and vaccine. To speed up effective drug development, we need powerful methods to rapidly assess drug effectiveness against the intracellular form of Leishmania in high throughput assays. Reporter gene technology has proven to be an excellent tool for drug screening in vitro. The effects of reporter proteins on parasite infectivity should be identified both in vitro and in vivo. In this research, we initially compared the infectivity rate of recombinant Leishmania major expressing stably enhanced green fluorescent protein (EGFP) alone or EGFP-luciferase (EGFP-LUC) with the wild-type strain. Next, we evaluated the sensitivity of these parasites to amphotericin B (AmB) as a standard drug in 2 parasitic phases, promastigote and amastigote. This comparison was made by MTT and nitric oxide (NO) assay and by quantifying the specific signals derived from reporter genes like EGFP intensity and luciferase activity. To study the amastigote form, both B10R and THP-1 macrophage cell lines were infected in the stationary phase and were exposed to AmB at different time points. Our results clearly revealed that the 3 parasite lines had similar in vitro infectivity rates with comparable parasite-induced levels of NO following interferon-γ/lipopolysaccharide induction. Based on our results we proposed the more reporter gene, the faster and more sensitive evaluation of the drug efficiency.

Evaluating the effect of four extracts of avocado fruit on esophageal squamous carcinoma and colon adenocarcinoma cell lines in comparison with peripheral blood mononuclear cells.

Most patients with gastrointestinal cancers refer to the health centers at advanced stages of the disease and conventional treatments are not significantly effective for these patients. Therefore, using modern therapeutic approaches with lower toxicity bring higher chance for successful treatment and reduced adverse effects in such patients. The aim of this study is to evaluate the effect of avocado fruit extracts on inhibition of the growth of cancer cells in comparison with normal cells. In an experimental study, ethanol, chloroform, ethyl acetate, and petroleum extracts of avocado (Persea americana) fruit were prepared. Then, the effects if the extracts on the growth of esophageal squamous cell carcinoma and colon adenocarcinoma cell lines were evaluated in comparison with the control group using the MTT test in the cell culture medium. Effects of the four extracts of avocado fruit on three cells lines of peripheral blood mononuclear cells, esophageal squamous cell carcinoma, and colon adenocarcinoma were tested. The results showed that avocado fruit extract is effective in inhibition of cancer cell growth in comparison with normal cells (P<0.05). Avocado fruit is rich in phytochemicals, which play an important role in inhibition of growth of cancer cells. The current study for the first time demonstrates the anti-cancer effect of avocado fruit extracts on two cancers common in Iran. Therefore, it is suggested that the fruit extracts can be considered as appropriate complementary treatments in treatment of esophageal and colon cancers.

Determination of trace elements in patients with chronic hepatitis B.

Chronic hepatitis B virus (HBV) infection is a major liver disease worldwide and its clinical manifestations are linked to immune response. The purpose of this study was to evaluate the relationship between selenium, copper, and zinc in comparison with transaminase level in chronic HBV patients. Serum samples of the HBV infected patients were obtained from Tooba medical center, Sari, Iran. Sixty patients were enrolled in this study (36 men and 24 women), mean age: 39.6 ± 12.2 years. The concentration of zinc, selenium, copper and transaminases were determined using an autoanalyzer system. Concentrations of selenium (0.273 ± 0.056 µg/dl) and zinc (2.1 ± 0.037) was elevated in patients with low transaminase levels as were significantly different in comparison with patients with high transaminase level (P<0.05). Serum copper concentration was similar in two groups of patients. Elevated levels of transaminase concentrations were independently associated with low zinc and selenium concentrations in chronic HBV patients. It is concluded that serum zinc and selenium levels are associated with less hepatic damage in chronic HBV patients and might have a protective role during liver injury.