جستجوی مقالات مرتبط با کلیدواژه « cellular immunity » در نشریات گروه « پزشکی »

Leptospirosis is an infectious zoonotic disease that can result in severe complications. It is widespread, especially in hot and humid climates such as the northern region of Iran. The immune responses to leptospirosis are multifaceted. Lipl41 is an outer membrane protein that is expressed during infection and is highly conserved among pathogenic species. This makes it a good candidate for diagnosis and induction of specific immune responses. The aim of the present study was to evaluate immune responses against recombinant Lipl41 in mice.

After immunizing of different groups of mice with recombinant Lipl41 (rLipl41), the levels of specific antibodies and cytokine profiles interferon-gamma/ interleukin-4 (IFN-γ/IL-4) were measured.

The results revealed that rLipl41 showed a significant increase in antibody levels compared with the control groups (P< 0.05). Although the level of IL-4 in the groups that received Lipl41 was similar to that in the other control groups, the IFN-γ levels showed a significant increase (P<0.05).

It has been concluded that recombinant Lipl41 protein could strongly stimulate specific immune responses and be considered a potential candidate for vaccine development and diagnostic research.

Necrotic enteritis (NE), an infection of the gastrointestinal tract of birds, is a major concern of the poultry industry due to its huge economic losses. The disease is caused by the Gram-positive bacterium Clostridium perfringens (C. perfringens). Due to the ban on antibiotic usage in the poultry industry, the incidence of NE has increased significantly in recent years. We have previously shown that immunization of chickens with a subunit chimeric antigen composed of the most effective C. perfringens toxins in NE pathogenesis (alpha toxin, B-like toxin (NetB), and zinc metallopeptidase (ZMP)) can protect birds against this disease. In the present study, the chickens were subcutaneously immunized by the recombinant protein. Then, the expression profile of cytokines in immunized birds was evaluated. For this purpose, following the immunization regimen, samples were taken from the intestines of the birds, mRNAs were extracted and the expression of four different cytokines (IFN-γ, IL-4, IL-17, and IL-22) was investigated using quantitative real-time PCR. The mentioned cytokines are representatives of helper T lymphocytes and have roles in several immune system activities, such as cellular, humoral, and mucosal immunity responses, as well as inflammation. According to the results of the cytokine assay, subcutaneously-administered recombinant protein elicited humoral and cellular immune systems but it could not stimulate the mucosal immune system. The candidate vaccine elicited the immune system so that the differences between the adjuvant recombinant protein (Adj-rNAM group) and the control group were significant (p <0.001). The results, in addition to our previous study outputs, indicate that our strategy, after completing adequate investigations, can provide an alternative solution to using antibiotics in NE treatment.

Probiotics are alive and beneficial microorganisms that affect the body’s microbial flora when consumed by humans or animals and have beneficial effects on the health of the host. Nowadays, probiotics are considered a factor in the prevention of many infectious diseases and cancers. Given the particular importance of probiotics, this study aimed to narratively review previous studies on the mode of action of probiotics and the beneficial effects of probiotics on enhancing intestinal immune responses. Articles on this topic were searched in Google Scholar, Springer, Science Direct, and Clinical Trial databases, and systematic review articles examining the effects of probiotics on the function of the intestinal immune response were included in the study. The results of the research showed that probiotics can boost the body’s immune system, break down food due to their ability to produce enzymes, lower the pH of the environment, and secrete bacteriocins. Furthermore, the effect of probiotics on the modulation mechanisms of the innate defense responses of the intestinal epithelium, including the stimulation of trefoil factor 3, induction of antimicrobial peptide (AMP) secretion, stimulation of secretory immunoglobulin production, and stimulation of toll-like receptors increase in heat shock protein production, modulation of P-glycoprotein (P-gp) and regulation of mucins by probiotics. Therefore, probiotics are expected to be used as an adjunct treatment for many digestive and infectious diseases.

In humans, the immune system serves as a protective barrier against infection; however, when the immune system is out of balance, it can harm the host. Immunomodulators are chemicals or medications that have been employed in the clinic to treat an unbalanced immune response. The majority of immunological medicines in clinical use are cytotoxic. They harm the patient's quality of life by causing various side effects and being associated with higher production costs, longer lead times, and a high failure rate. Furthermore, obtaining single-compound chemicals with low toxicity, high efficacy, and selectivity for specified disorders is difficult for researchers. As a result, techniques based on alternative medicine are gaining traction in drug development, focusing on innovative natural compounds utilized to treat various disorders. Many plant molecules founded to have biologically beneficial properties. This review aimed to look at the immunomodulatory activity of plant-derived chemicals from widely used plants that treat a range of diseases worldwide.

Niclosamide, a STAT3 inhibitor, is widely under investigation due to its anti-cancer properties. STAT3 also exhibits an exciting role in the immune responses. This study aimed to evaluate the impact of niclosamide on immune response of mice. Niclosamide was administered to balb/c mice. To evaluate cell-mediated immune response, a contact-hypersensitivity (CHS) test, cyclophosphamide-induced neutropenic assay, and carbon clearance test were performed, whereas a humoral immune response was evaluated by hemagglutination assay (HA) and mice lethality test. The concentration of TGF-β1 was determined by enzyme-linked immunosorbent assay (ELISA) on murine peritoneal macrophages. In the CHS test, niclosamide caused a decrease in skin thickness, significantly exhibiting a decrease in inflammation. A highly significant decrease in overall leukocyte count (lymphocytes and neutrophils) was observed before and after cyclophosphamide injection as compared with the control group. However, only a highly significant decrease in the neutrophil percentage was observed. Niclosamide has decreased the phagocytic process immensely compared with the control. In the HA titer, niclosamide was found to reduce the antibodies' titer compared with the negative control group. In the mice lethality test, the treatment groups have shown an increase in the percentage of mortality. TGF-β1 elevated in peritoneal macrophages when treated with niclosamide, in a dose-dependent manner. Niclosamide exerts potent immunomodulatory effects by significantly suppressing cell-mediated and humoral immune responses and increasing the levels of TGF-β1 in mice. Niclosamide might be added as an adjuvant to immunosuppressive drugs for the treatment of autoimmune diseases.

Hemiscorpius lepturus is one of the most dangerous scorpions in Iran and the world. Numerous studies have been conducted on phospholipases, especially phospholipase D, in this scorpion’s venom, and the results have shown this protein to be the main cause of death. Therefore, one of the most effective ways of preventing fatalities is to produce a toxoid vaccine from the deadly toxin of the venom. The present study was conducted to assess the non-toxicity of this toxoid and the safety of the vaccine candidate in BALB/c mice.

The production of interferon-gamma and interleukin-4 cytokines in the spleen cells of the mice was measured using ELISpot assay 28 days following immunization with rPLD toxoid.

The unpaired t-test results showed a significant increase in the concentration of IFN-γ cytokine in the vaccinat ed mice (P= 0.001), indicating that the immune system is directed toward the Th1 pattern, while no significant differ ence was observed in the levels of IL-4 (P= 0.16) despite an increase in this cytokine. The in-vivo tests showed that the mice immunized with interval doses of 80µg of toxoid were completely protected against 10 × the LD100 of the venom. Moreover, the toxoid had no dermonecrotic effects and caused no necrotic and inflammatory complications in the rabbit skin.

As a vaccine, the toxoid has the potential to increase the Th1 cytokine response and, subsequently, in crease acquired cellular immunity. Thus, this toxoid appears to be able to provide an effective vaccine against the ven om of Hemiscorpius lepturus.

 Obstructive sleep apnea-hypopnea syndrome (OSAHS) can impact multiple organ systems in children.

 To investigate the effects of OSAHS on T-lymphocyte subgroups and natural killer (NK) cell activity in the peripheral blood of affected children.

 A total of 85 children with OSAHS were enrolled into an experimental group (OSAHS) and 76 healthy children were placed in a control group (CON) to compare peripheral blood levels of CD3+, CD4+, CD8+, and NK cell activity using flow cytometry. Meanwhile, their polysomnography results were monitored to analyze the correlation between T-lymphocyte subgroups/NK cell activity and lowest pulse oxygen saturation (LSaO2)/apnea-hypopnea index (AHI).

 Compared to the CON group, the CD3+ percentage in the OSAHS group showed no significant difference (65.98 ± 6.54 vs 64.36 ± 5.32; P > 0.05), but the CD4+ percentage, CD4+/CD8+ ratio, and NK cell activity decreased markedly (33.52 ± 3.04 vs 35.26 ± 3.68,1.29 ± 0.14 vs 1.43 ± 0.26, and 11.47 ± 4.58 vs 12.69 ± 2.36, respectively; P < 0.05). In addition, the CD8+ percentage increased significantly (26.18 ± 4.76 vs 24.36 ± 2.32; P < 0.05). Linear regression analysis indicated that the CD3+ percentage was not related to LSaO2/AHI (P > 0.05), but the CD4+ and CD8+ percentages, CD4+/CD8+ ratio, and NK cell activity were linearly related to LSaO2 and AHI (P < 0.05).

 OSAHS can affect the cellular immunity of children. The AHI and LSaO2 may be involved in cellular immunity function.

Exercise-related studies do not agree on changes in blood parameters regarding anemia and serum immunoglobulin concentration as adaptive immunity.

The current study aimed to investigate exercise-induced variations in hematological and immunological parameters in response to one bout of intensive judo exercise in adolescent elite judoka.

Venipuncture was performed on ten adolescent male Iranian elite judoka (age: 15.60 ± 0.69 years; body mass index: 24.15 ± 2.80 kg/m2) before and immediately after one bout of intensive judo protocol. Erythrocyte variables [red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), red distribution width (RDW), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC)], platelets variables [platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), plateletcrit (PCT)], cellular immune variables [white blood cell (WBC), neutrophil (NEU), lymphocyte (LYM)], and humoral immune variables (IgM, IgA, IgG, IgE) were measured. Data were analyzed using Wilcoxon and paired-samples t-test, and P < 0.05 was considered significant.

After the plasma volume was corrected using the Dill and Costill equation, the results showed that RBC, HGB, HCT, MCHC, IgA, and IgM decreased significantly immediately after exercise. However, MCH, RDW, PLT, PDW, MPV, PCT, WBC, LYM, NEU, IgG, and IgE did not change significantly.

According to the findings, it can be concluded that intensive judo exercise results in transient anemia and suppression of humoral immune response among adolescent elite judoka.

In recent years attention has been paid to develop effective adjuvant systems for DNA vaccines. Co-formulation of a gene delivery vector with an immunostimulator can enhance therapeutic efficiency of DNA vaccine. To investigate the efficacy of chitosan as a nanodelivery system to enhance antitumor effects of human papilloma virus (HPV)-16 DNA vaccine with IL-12 gene for protection against TC-1 tumor using an animal model. The mice were challenged by subcutaneous injection of TC-1 cells and immunized intramuscularly with DNA vaccine thrice at seven-day intervals. One week after the last immunization, mice were sacrificed and antitumor effects were assessed through measuring lymphocyte proliferation, cytotoxicity, cytokines production, and tumor regression. We found that co-formulation and co-administration of chitosan nanoparticles and IL-12 with HPV-16 E7 DNA vaccine induced higher antitumor effects compared with chitosan or IL-12 alone. E7-specific lymphocyte proliferation index and CTL activity were found to be significantly higher in combination group in comparison to single vaccination with either chitosan or IL-12. Co-formulation of chitosan and IL-12 resulted in higher IFN-γ and IL-4, and decreased IL-10 production. Furthermore, combined vaccination highly inhibited the tumor progression compared with chitosan or IL-12 alone. Chitosan nanoparticle is a promising delivery system for DNA vaccine and IL-12 is an effective genetic adjuvant for the induction of strong antitumor immune response.

Hydatid cyst is the larval stage of the tape worm parasite, Echinococcus granulosus. Human is infected by ingestion of parasite ova excreted in dog feces. The anticancer activity of different antigens of hydatid cyst has been reported in the previous works. In this research, the role of immune system in induction of this anticancer activity has been investigated. Spleen cells of mice immunized with hydatid cyst antigens were transferred to the recipient mice that had already been challenged with melanoma cells. Also, mice with melanoma cancer were injected with antisera raised against hydatid cyst antigens. In all above mice, tumor growth was measured using a caliper. Passive transfer of spleen cells resulted in significant inhibition of melanoma cancer growth. However passive transfer of antisera did not affect cancer growth in the recipient mice. According to the results of this work, cellular immunity but not humoral immunity may be involved in induction of anticancer activities of hydatid cyst.

Social stress is a factor involved in the etiology of many diseases. Also, gender is another factor which predisposes individuals to certain disease. Results from animal and human studies suggest that socially-stressed men are more vulnerable to catching diseases compared to socially-stressed women.

The role of chronic social stress and gender were examined in the present study through implementing food deprivation, food intake inequality, and unstable social status (cage-mate change every three days) for a period of 14 days on 96 male and female mice. Then, vital activity of peritoneal macrophages and spleen’s lymphocytes were measured using MTT test as well as the concentration of Tumor Necrosis Factor-alpha (TNF-α) by ELISA technique.

Our results showed that cell viability of peritoneal macrophages and spleen’s lymphocytes as well as serum concentration of TNF-α in all female and male stressed animals increased compared to the controls (P

The results suggest that social factors have significant effects on immunity and should be considered in the studies of gender differences for evaluating possible effective mechanisms.

Some evidence suggests that chronic uptake of estragole and methyl-eugenol, found in the essential oil of Artemisia dracunculus (tarragon), may be associated with an increased risk of hepato-carcinogenicity. The present study was conducted to investigate the immumodulatory and anti-inflammatory potentials of estragole and methyl-eugenol free extract of tarragon.
Aqueous, hydroalcoholic, methanol and hexane extracts of dried and milled tarragon was prepared and analyzed by GC-MS. The estragole and methyl-eugenol free extract was characterized and used for evaluation of immunity in NMRI mice after challenging with sheep red blood cells.
It was shown that the aqueous extract of tarragon was free from potentially harmful estragole or methyl-eugenol. Moreover, the immunomodulatory effect of the aqueous extract of tarragon (100 mg/kg for 21 consecutive days) was investigated. The extract significantly increased the level of anti-sheep red blood cells (SRBC (antibody and simultaneously decreased the level of cellular immunity in the treatment group. Moreover, tarragon caused a significant reduction in the production of pro-inflammatory IL-17 and IFN-γ in parallel with a reduction in the ratio of INF-γ to Il-10 or IL-17 to IL-10 in the splenocytes. In addition, the levels of the respiratory burst and nitric oxide production in peritoneal macrophages were significantly decreased. Additionally, the phagocytosis potential of macrophages was significantly increased in treated mice.
These data showed that the aqueous extract of tarragon may be used as a natural source to modulate the immune system, because it can inhibit pro-inflammatory cytokines and induce anti-inflammatory macrophages.

The aim of the present study was to investigate immunotoxic effect of safranal (SAF), a main component of Crocus sativus essential oil, using Balb/c mice. SAF was administered intraperitoneally at doses of 0.1, 0.5 and 1 ml/kg for 3 weeks. Hystopathological examination of spleen and bone marrow, cellularity of spleen, delayed type of hypersensitivity (DTH) response, hemagglutination titer (HA), cytokine production and lymphocyte proliferation assay were studied in various groups of animals. Spleen cellularity for SAF groups (0.1 ml/kg SAF: 6.68 [± 0.88] × 107, 0.5 ml/kg SAF: 8.16 [± 1.33] × 107, 1 ml/kg SAF: 6.12 [± 0.59] × 107) did not significantly differ as compared to vehicle control (8.52 [± 1.36] × 107; p > 0.05). In addition, SAF at all doses could not produce any significant changes in hematological parameters, HA titer, DTH and lymphoproliferation responses, as well as in release of cytokines by isolated splenocytes (p > 0.05). Despite a few studies demonstrating some immunomodulatory effects for saffron extract, SAF as a major constituent of saffron did not induce any marked effects in immune system parameters of mice. Contrary to the toxicological studies which have indicated that SAF is more toxic than other active constituents in saffron stigma, at least it was found to be safe to mice immune system and has no toxicity on humoral and cellular immune responses.