In vitro effects of an immunostimulating bacterial lysate on human lymphocyte function

Promising Immunomodulatory Effects of Bacterial Lysates in Allergic Diseases

In light of an escalating prevalence of allergic disorders, it is crucial to fully comprehend their pathophysiology and etiology. Such knowledge would play a pivotal role in the search for new therapeutic approaches concerning not only diseases’ symptoms, but also their underlying causes. The hygiene hypothesis indicates a high correlation between limited exposure to pathogens in early childhood and the risk of developing allergic disorders. Bearing in mind the significance of respiratory and digestive systems’ mucous membrane’s first-line exposure to pathogens as well as its implications on the host’s immune response, a therapy targeted at aforesaid membranes could guarantee promising and extensive treatment outcomes. Recent years yielded valuable information about bacterial lysates (BLs) known for having immunomodulatory properties. They consist of antigen mixtures obtained through lysis of bacteria which are the most common etiologic agents of respiratory tract infections. They interact with dendritic cells located in the mucous membranes of the upper respiratory tract and the gastrointestinal tract by toll-like receptors. The dendritic cells present acquired antigens resulting in innate immune response development on the release of chemokines, both stimulating monocytes and NK cells maturation and promoting polymorphonuclear neutrophil migration. Moreover, they influence the adaptive immune system by stimulating an increase of specific antibodies against administered bacterial antigens. The significance of BLs includes not only an anti-inflammatory effect on local infections but also restoration of Th1/Th2 balance, as demonstrated mainly in animal models. They decrease Th2-related cytokine levels (IL-4, IL-13) and increase Th1-related cytokine levels (IFN-γ). The reestablishment of the balance of the immune response leads to lowering atopic reactions incidence which, in addition to reduced risk of inflammation, provides the alleviation and improvement of clinical manifestations of allergic disorders. In this review, we hereby describe mechanisms of BLs action, considering their significant immunomodulatory role in innate immunity. The correlation between local, innate, and adaptive immune responses and their impact on the clinical course of allergic disorders are discussed as well. To conclude our review, we present up-to-date literature regarding the outcomes of BLs implemented in atopic dermatitis, allergic rhinitis, and asthma prevention and treatment, especially in children.

A Case-Control Study on the Changes in Natural Killer Cell Activity following Administration of Polyvalent Mechanical Bacterial Lysate in Korean Adults with Recurrent Respiratory Tract Infection

Polyvalent mechanical bacterial lysate (PMBL) is used for the treatment and prevention of recurrent respiratory tract infections. Although PMBL is an immunostimulant, it remains unknown whether treatment with PMBL influences natural killer cell activity (NKA). Hence, this case-control study compared the changes in IFN-γ levels (surrogate index for NKA) following PMBL treatment or time passing between the PMBL-treated group and controls. The treatment group included adults who had a PMBL prescription for three months against recurrent respiratory tract infection from an outpatient clinic, while the control group had healthy adults visiting the health promotion center for periodic health check-ups. The control group (N = 506) showed no change in IFN-γ levels, while the treatment group (N = 301) showed a significant increase in mean from 462.8 to 749.3 pg/mL after PMBL treatment. In the subgroup with IFN-γ <500 pg/mL, IFN-γ levels significantly increased in both groups. However, the change in the treatment group (287 ± 822 pg/mL) was greater than that in the control group (58 ± 809 pg/mL), and the interaction between the visit and case/control was significant (p = 0.030) in a generalized estimating equation model. In conclusion, NKA increased in the subjects with recurrent respiratory tract infections with PMBL treatment.

Nasal carriage of Staphylococcus aureus in children with grass pollen‐induced allergic rhinitis and the effect of polyvalent mechanical bacterial lysate immunostimulation on carriage status: A randomized controlled trial

Background

Numerous studies indicate that Staphylococcus aureus (S. aureus) colonizing the nasal cavity plays a role in the pathogenesis of allergic rhinitis (AR). This bacterium is able to produce a variety of toxins with superantigenic properties that can exacerbate allergic inflammation.

Objective

The objective of the study was to evaluate the ability of polyvalent mechanical bacterial lysate (PMBL) to eliminate S. aureus nasal carriage in children with grass pollen‐induced AR.

Methods

This randomized, double‐blind, placebo‐controlled study included 80 children aged 5–17 years with seasonal AR (SAR). At the randomization visit and after 12 weeks of the study, a swab was taken from the region of the middle nasal meatus. Standard microbiology culture and identification techniques were used to analyze the swab contents.

Results

Nasal colonization by S. aureus was confirmed in 29 children (42%), with Moraxella catarrhalis in three participants (4.4%). Physiological flora was detected in 37 children. No statistically significant differences were observed between the two measurement points in both the PMBL and placebo groups with respect to the number of patients whose nasal swab cultures showed a growth of S. aureus (p = 1). Both groups also showed no significant changes in the mean number of S. aureus colonies in nasal swab cultures taken at baseline and after 12 weeks of the study (PMBL group p = .41; placebo group p = .16).

Conclusion

Almost every second child with SAR is S. aureus nasal carrier. Sublingual administration of PMBL in children with grass pollen‐induced AR did not affect S. aureus nasal colonization. Therefore, PMBL should not be used for the eradication of S. aureus from the nasal cavity.

Polyvalent Mechanical Bacterial Lysate Administration Improves the Clinical Course of Grass Pollen-Induced Allergic Rhinitis in Children: A Randomized Controlled Trial

BACKGROUND

Recent studies highlight the immunoregulatory potential of bacterial lysates, indicating their potential use in the prevention and treatment of allergic diseases.

OBJECTIVE

To investigate the clinical efficacy of polyvalent mechanical bacterial lysates (PMBLs) in children with grass pollen-induced allergic rhinitis.

METHODS

Seventy children with seasonal allergic rhinitis were enrolled to this study and were randomly assigned to the PMBL and placebo groups. Severity of seasonal allergic rhinitis symptoms was assessed by the total nasal symptom score, total ocular symptom score, and visual analogue scale. During 3 visits, peak nasal inspiratory flow was measured, and nasal smears for the presence of eosinophils and nasal lavage fluids for the presence of allergen-specific IgE against timothy grass pollen allergens were sampled.

RESULTS

A statistically significant decrease in total nasal symptom score (P = .001), total ocular symptom score (P = .04), and visual analogue scale score for nasal and eye symptoms (P < .001 and P < .001, respectively) and an increase in peak nasal inspiratory flow (P = .04) were observed in the PMBL group versus the placebo group. During the grass pollen season, an increase and then a decrease in the number of eosinophils in nasal smears was observed in both groups; however, the number of eosinophils was significantly lower in the PMBL group versus the placebo group. No significant changes in allergen-specific IgE concentrations were observed in the PMBL group, whereas in the placebo group a statistically significant increase in allergen-specific IgE concentration was observed.

CONCLUSIONS

Sublingual administration of PMBLs during the grass pollen season offers significant efficacy in alleviating seasonal allergic rhinitis symptoms in children sensitized to grass pollen allergens. PMBLs probably affect mucosal immunity, weakening the response of T_H2 cells.

Immunostimulants in respiratory diseases: focus on Pidotimod

Usefulness of Pidotimod and its role as immunostimulant, has been discussed, we know, for several decades. Nevertheless, there is still much to know. Understanding its mechanisms and its potential usefulness in airway infections and its prevention, asthma both Th2 and non Th2 type, bronchiectasis, as adjuvant in vaccination and in allergen immunotherapy still remains to clearly unveil. The aim of this paper was to provide a useful updated review of the role of the main available immunostimulants, giving particular focus on Pidotimod use and its potentials utility in respiratory diseases. Pidotimod showed its usefulness in reducing need for antibiotics in airway infections, increasing the level of immunoglobulins (IgA, IgM, IgG) and T-lymphocyte subsets (CD3+, CD4+) endowed with immunomodulatory activity that affect both innate and adaptive immune responses. Higher expression of TLR2 and of HLA-DR molecules, induction of dendritic cell maturation and release of pro-inflammatory molecules, stimulation of T lymphocyte proliferation and differentiation toward a Th1 phenotype, as well as an increase of the phagocytosis have been demonstrated to be associated with Pidotimod in in vitro studies. All these activities are potentially useful for several respiratory conditions such as asthma, COPD, and recurrent respiratory tract infections.

Nonspecific immunomodulators for recurrent respiratory tract infections, wheezing and asthma in children: a systematic review of mechanistic and clinical evidence

PURPOSE OF REVIEW

To provide an overview of the mechanistic and clinical evidence for the use of nonspecific immunomodulators in paediatric respiratory tract infection (RTI) and wheezing/asthma prophylaxis.

RECENT FINDINGS

Nonspecific immunomodulators have a long history of empirical use for the prevention of RTIs in vulnerable populations, such as children. The past decade has seen an increase in both the number and quality of studies providing mechanistic and clinical evidence for the prophylactic potential of nonspecific immunomodulators against both respiratory infections and wheezing/asthma in the paediatric population. Orally administered immunomodulators result in the mounting of innate and adaptive immune responses to infection in the respiratory mucosa and anti-inflammatory effects in proinflammatory environments. Clinical data reflect these mechanistic effects in reductions in the recurrence of respiratory infections and wheezing events in high-risk paediatric populations. A new generation of clinical studies is currently underway with the power to position the nonspecific bacterial lysate immunomodulator OM-85 as a potential antiasthma prophylactic.

SUMMARY

An established mechanistic and clinical role for prophylaxis against paediatric respiratory infections by nonspecific immunomodulators exists. Clinical trials underway promise to provide high-quality data to establish whether a similar role exists in wheezing/asthma prevention.

Improvement of Clinical Response in Allergic Rhinitis Patients Treated with an Oral Immunostimulating Bacterial Lysate: In Vivo Immunological Effects

Allergic rhinitis is known to be one of the most common chronic diseases in the industrialized world. According to the concept that allergic rhinitis patients generally suffer from an immune deficit, in order to stimulate specifically or aspecifically their immune system, immunomodulating agents from various sources, such as synthetic compounds, tissue extracts or a mixture of bacterial extracts, have been used. The aim of the present trial is to evaluate the efficacy of the treatment with an immunostimulating vaccine consisting of a polyvalent mechanical bacterial lysate (PMBL) in the prophylaxis of allergic rhinitis and subsequently to analyze its in vivo effects on immune responses. 41 allergic rhinitis patients were enrolled: 26 patients were randomly assigned to the group for PMBL sublingual treatment and 15 others to the group for placebo treatment. For all 26 patients blood samples were drawn just before (T0) and after 3 months of PMBL treatment (T3) to evaluate plasma IgE levels (total and allergen-specific) and the cytokine production involved in the allergic response (IL-4, IFN-γ). The results of our study indicate that PMBL is effective in vivo in the reduction or in the elimination of the symptoms in rhinitis subjects during the treatment period in comparison to a non-immunostimulating treatment. A significant and clinically relevant improvement was found in 61.5%, a stationary clinical response was registered in 38.4% and no negative side effects associated with the medication or worsening were recorded. At the end of a 3-month follow up period the clinical picture remained the same as that observed at T3. PMBL treatment did not affect the serum IgE levels (either total or allergen-specific) and did not induce significant changes in IFN-γ concentration. In contrast, PMBL therapy may be accompanied, in some patients, by a potential immunomodulating activity by decreasing IL-4 cytokine expression.

Effectiveness of Polyvalent Bacterial Lysate and Autovaccines Against Upper Respiratory Tract Bacterial Colonization by Potential Pathogens: A Randomized Study

BACKGROUND

Polyvalent bacterial lysate (PBL) is an oral immunostimulating vaccine consisting of bacterial standardized lysates obtained by lysis of different strains of bacteria. Autovaccines are individually prepared based on the results of smears obtained from the patient. Both types of vaccine can be used to treat an ongoing chronic infection. This study sought to determine which method is more effective against nasal colonization by potential respiratory tract pathogens.

MATERIAL AND METHODS

We enrolled 150 patients with aerobic Gram stain culture and count results indicating bacterial colonization of the nose and/or throat by potential pathogens. The participants were randomly assigned to each of the following groups: 1. administration of PBL, 2. administration of autovaccine, and 3. no intervention (controls).

RESULTS

Reduction of the bacterial count in Streptococcus pneumoniae-colonized participants was significant after the autovaccine (p<0.001) and PBL (p<0.01). Reduction of the bacterial count of other β-hemolytic streptococcal strains after treatment with the autovaccine was significant (p<0.01) and was non-significant after PBL. In Haemophilus influenzae colonization, significant reduction in the bacterial count was noted in the PBL group (p<0.01). Methicillin-resistant Staphylococcus aureus colonization did not respond to either treatment.

CONCLUSIONS

The autovaccine is more effective than PBL for reducing bacterial count of Streptococcus pneumoniae and β-hemolytic streptococci, while PBL was more effective against Haemophilus influenzae colonization.

Bacterial vaccines in chronic obstructive pulmonary disease: effects on clinical outcomes and cytokine levels

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity worldwide. Exacerbation episodes impair lung function leading to disease progression. Levels of inflammation markers correlate with disease severity. Bacterial immunomodulators have shown a beneficial effect in COPD, improving symptoms and reducing the rate of exacerbations. This is an observational prospective study on 30 patients diagnosed with bronchiectasis and COPD, who received bacterial autogenous vaccine for 12 months. The rate of exacerbation, severity of symptoms and lung function were studied at baseline and after treatment. In addition, plasma levels CRP, IL6, IL8, and TNFα were measured. After treatment we found a reduction in mean acute respiratory infections and signs of lung disease. Acute phase proteins IL6 and CRP increased in blood and IL8 decreased. These changes may be related to the repeated injection of inactivated bacteria. Given the implication of these factors in the pathogenesis of COPD, particularly the production of IL8, the causes and consequences of cytokine modulation by bacterial vaccines should be investigated. Vaccination with autogenous vaccines for 1 year can produce a significant clinical improvement in COPD patients, reducing the frequency of exacerbations associated to changes in the profile of markers of inflammation.

Clinical efficacy and tolerability of an immune-stimulant(*) constituted by inactivated bacterial bodies in the prophylaxis of infectious episodes of airways: a double blind, placebo-controlled, randomized, multicentre study

Background

(Buccalin ®) is a Bacterial Lysates (BL) that belongs to a family of immune-stimulators, developed more than 30 years ago and it still has a role in the prophylaxis of Recurrent Respiratory Tract Infections (RRTI). However, original studies were conducted with an approach that does not seem to be aligned with the present methodologies. In addition, concomitant therapies substantially improved in the last decades. These two reasons strongly suggested to update our knowledge on the capacity of this bacterial lysate (Buccalin ®) to reduce the number of days with infectious episodes in patients with RRTI.

Methods

A double blind, placebo-controlled, randomized, multicentre study was programmed (EudraCT code: 2011-005187-25). The reduction of the number of days with infectious episodes (IE) was the primary endpoint. Secondary endpoints were the number of IE, the use of concomitant drugs, the efficacy on signs and symptoms of RRTI and the safety of the drug. Patients were treated according to the registered schedule and were followed up for a period of 6 months.

Results

From a cohort of 188 patients eligible for the study, 90 were included in the active group and 88 in the placebo group. The study was completed in 170 patients. A significant reduction of the number of days with IE was observed (6.57 days in the active group and 7.47 in the placebo group). Secondary endpoints were only partially achieved. No virtual adverse events related to the treatment were recorded.

Conclusion

The administration of bacterial lysate (Buccalin ®) in patients with RRTI had the capacity to significantly reduce the number of days with IE in a multicentre, randomized, placebo controlled, clinical study. The treatment was safe. Of note, all patients were free to be treated with the best concomitant therapies. In these conditions, the positive results observed demonstrated that this bacterial lysate has maintained its capacity of reducing the days with infections in patients with RRTI, also in association to the concomitant therapies available nowadays.

Non-specific immune stimulation in respiratory tract infections. Separating the wheat from the chaff

Parents of children suffering from recurrent respiratory infections can be persuaded by advertisements to pressure their family physicians and pediatricians for "immune-stimulating enhancements". However, the evidence base behind these immune stimulants is usually lacking. Often there is no peer-reviewed studies available that support claims made by "immune-booster" supplements. In this review, we critically analyze most of the marketed immuno-active drugs (including vitamin preparations, dietary supplements, homeopathic remedies, Ecchinacea, bacterial lysates, and probiotics) and identify the necessity to exclude an immunodeficiency in every child suffering from recurrent respiratory tract infections.

Impact of a mixed bacterial lysate (OM-85 BV) on the immunogenicity, safety and tolerability of inactivated influenza vaccine in children with recurrent respiratory tract infection

It is known that the immunogenicity and efficacy of conventional inactivated influenza vaccines (IIVs) are not completely satisfactory in children. The aim of this prospective, randomised, single-blind study was to compare the immune response to, and the effectiveness and safety of, an IIV (Fluarix, GlaxoSmithKline Biologicals, Rixensart, Belgium) administered to 68 children aged 36-59 months affected by recurrent respiratory tract infections (RRTIs) who were vaccinated with (n=33) or without (n=35) the mixed bacterial lysate OM-85 BV (Broncho-vaxom, Vifor Pharma, Geneva, Switzerland). OM-85 BV had no effect on seroconversion or seroprotection rates, geometric mean titres, or dendritic cells, which were not significantly different between the two groups. Moreover, OM-85 BV did not significantly increase the pool of the memory B cells that produce IgG and IgM antibodies against the influenza antigens. However, respiratory morbidity was significantly lower in the children treated with OM-85 BV (p<0.05), thus confirming its positive effect on the incidence of RRTIs. There was no difference in the incidence of adverse events between the two groups. These findings show that the immune response of children to influenza vaccine is not significantly influenced by the administration of OM-85 BV. However, the use of OM-85 before and at the same time as IIV seems to reduce respiratory morbidity, and seems to be safe and well tolerated.

Effects of hepatitis B virus X protein on human T cell cytokines

Chronic infection with hepatitis B virus (HBV) plays a significant role in hepatocellular carcinoma development. To investigate the effect of hepatitis B virus X protein (HBx) on inflammatory cytokines of human T cell, a eukaryotic expression vector, HBx-pEGFP-C1, was constructed and transfected into the Jurkat human T-cell line. Jurkat cells were transfected transiently using Lipofectamine 2000 and activated by phytohemagglutinin (PHA). Interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), IL-4, IL-10, IL-13, and IL-14 mRNA was measured. The results showed that the vector HBx-pEGFP-C1 was successfully constructed, and HBx was expressed in Jurkat cells. Compared with a control group, mRNA of IL-1β and TNF-α was significantly elevated in the HBx-pEGFP-C1 group (p < 0.05), while IL-4, IL-10, IL-13, and IL-14 mRNA was decreased (p < 0.05). Therefore, transient overexpression of HBx promoted PHA-induced pro-inflammatory cytokine secretion and repressed anti-inflammatory cytokine secretion in human T cells.

The administration of a polyvalent mechanical bacterial lysate in elderly patients with COPD results in serological signs of an efficient immune response associated with a reduced number of acute episodes

The administration of a polyvalent mechanical bacterial lysate (PMBL) in elderly patients with COPD has been shown to reduce the number of exacerbation. This is largely related to the involvement of cells belonging to the innate and the adaptive immune system (including dendritic cells, granulocytes, T and B lymphocytes and NK cells) that actively cooperate inducing the production of specific opsonizing antibodies directed to the antigens of PMBL. We have evaluated the production of antibodies directed to respiratory and systemic pathogens in a group of elderly COPD patients, recruited in a clinical trial, ancillary to a larger multicenter double blind, placebo-controlled, parallel-designed clinical trial in which patients were randomized to daily receive either PMBL or placebo. The treated group not only experienced a reduced number of seroconversion, but also, better controlled the number of infectious episodes and COPD exacerbations. It was thus evident that the administration of PMBL resulted not only effective in inducing the secretion of specific antibodies, but also effective in reducing the infectious episodes trough the potentiation of the antibody-mediated arm of the immune response.

Administration of a polyvalent mechanical bacterial lysate to elderly patients with COPD: Effects on circulating T, B and NK cells

The modifications of the subsets of circulating lymphocytes were evaluated in a group of patients with COPD undergoing treatment with a polyvalent mechanical bacterial lysate (PMBL), a drug that is able to significantly modify the natural history of these patients. Using multicolor immune-florescence and flow cytometry, T, B subsets and NK cells were extensively studied both in the group of treated patients and in a disease and age matched controls. Despite the age, in treated patients, T and NK cells were significantly increased in numbers of circulating cells, but not in percentages, while B cells remained unmodified. CD3+4+T cells were increased in treated patients, while CD3+CD8T cells were unmodified by the treatment. Activated T cells were increased but Treg, resulted reduced both in percentage than in absolute numbers. Transitional B cells resulted increased (in percentage and in absolute numbers) in their late maturation step (T3), while only early Naïve B cells were increased by the treatment, while other naïve subpopulations were unmodified. Memory B cells were reduced in percentage (but remained unmodified as absolute numbers), while the most immature form of memory B cells was significantly increased. Finally, both switch memory B cells and plasma cells resulted unmodified by the PMBL treatment. These results clearly indicated that the administration of the PMBL, even in elderly patients with COPD, was able to induce a significant immune-stimulation and these results, at cellular level, clearly support the evidence that the mechanism of action of PMBL is strictly related to a direct effect on immune-competent cells.

Distinct immunoregulatory cytokine pattern in Egyptian patients with occult Hepatitis C infection and unexplained persistently elevated liver transaminases

Background/Aim:

The immunopathogenesis of occult Hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro- and anti-inflammatory activity. This work aimed at studying the serum Th1 and Th2 cytokine production in patients with occult HCV infection.

Materials and Methods:

Serum levels of cytokines of Th1 (interleukin [IL]-2, INF-γ) and Th2 (IL-4) were measured in 27 patients with occult HCV infection and 28 patients with chronic hepatitis C infection.

Results:

The levels of IL-2 and interferon-γ were highly significantly increased in patients with chronic HCV infection (P<0.001). IL-4 was highly significantly increased in occult HCV infection (P<0.001). Significant increases were noted in chronic HCV infection regarding bilirubin (P<0.001), ALT (P = 0.009), AST (P = 0.013), AFP (P<0.001), while serum albumin was significantly higher in occult HCV infection (P<0.001). Necroinflammation (P<0.001), fibrosis (P<0.001), and cirrhosis (P = 0.03) were significantly increased in chronic HCV infection.

Conclusion:

Our data revealed a high prevalence of occult HCV infection (25%) in patients with unexplained persistently abnormal liver function test results. Those patients exhibited a distinct immunoregulatory cytokine pattern, favoring viral persistence and explaining the less aggressive course of this disease entity than chronic HCV infection.

May we strengthen the human natural defenses with bacterial lysates?

During the last twenty years bacterial lysates have gained a new interest and their use has obtained a progressively larger consensus in the medical practice. They are commonly used as immunomodulators, in order to up-regulate immune responses against infectious damages. As a matter of fact, the role of these lysate seems relevant in upper and lower respiratory tract infections prevention, frequently observed both in paediatric and elder ages, and which represent a relevant problem also in terms of socio-economical implications. The effects of bacterial lysates as immunostimulatory agents have become the central point of many studies. The aim of those in vivo and in vitro studies was to understand and evaluate the capacity of this kind of treatments to create a better answer of the immune system against microbial infections, eventually leading to a reduction in their number. All the in vivo and in vitro findings analyzed support the evidence that bacterial lysates are powerful inducers of a specific immune response against bacterial infections. Both in paediatric and adult clinical trials, a positive trend has been found in terms of overall reduction of infection rates and duration, beneficial effect on symptoms, reduction in antibiotics use and possibility to improve the patient's quality of life in several diseases. Further well-designed trials in terms of blinding and randomization procedures and including a higher number of patients, selected according to the disease and its severity, are needed.

Effects of FR-91 on immune cells from healthy individuals and from patients with non-Hodgkin lymphoma

The immune system is subject to destruction and dysfunction as a result of attacks by pathogenic and environmental agents. In addition, many clinical situations exist in which it is desirable to stimulate or suppress the immune system. The present study evaluated the screening efficacy of flow cytometric lymphocyte subset typing in peripheral blood mononuclear cells from healthy individuals (HI) and from patients with non-Hodgkin lymphoma (NHL) treated with different concentrations of FR-91, a standardized lysate of microbial cells belonging to the Bacillus genus, and in vitro cytokine production. Increased expression of subset markers (CD3, CD4, CD8) in NHL and CD3 in HI suggests an immunomodulating effect of FR-91. In addition the results of cytokine production also demonstrated a clear effect of FR-91 on both populations. A significant increase of IL-6, IL-12, IFN-gamma and TNF-alpha was observed in the HI group after treatment with FR-91. In a similar manner an increase of IL-2, IL-6, IL-12, IFN-gamma and TNF-alpha was also observed in the NHL group. In conclusion FR-91 seems to affect lymphocyte subpopulations, in vitro cytokine production, as well as mitogen-induced lymphocyte activation in a dose-dependent manner in both healthy individuals and NHL patients.

In vitro end points for the assessment of cellular immune response-modulating drugs

BACKGROUND

The concept of immunotoxicology and the development of a battery of immune-function assays to screen potential immunotoxic compounds have been increasingly used in the past. Immunotoxic outcome generally seems appropriate to evaluate the risk in drug development. Improving this approach is possible, by using methods now available, to study the effect of a chemical compound on the immune system.

OBJECTIVE

The goal of this review is to provide an overview of the current and recent methodologies for testing the immunological effect and immunotoxic risks in drug candidates.

METHODS

The methodological details here discussed include a synthetic description of the immunocompetent cells in cell-mediated immunity and the choice of the most appropriate assay (bioassays, immunoassays, molecular biology techniques, flow cytometry).

CONCLUSION

This review offers an assessment of in vitro models to study the toxic impact of (bio)pharmaceuticals on cellular immune system and aid drug scientists in understanding the significance and the methods to approach immunotoxicology.

Immunomodulatory activity of shikimic acid and quercitin in comparison with oseltamivir (Tamiflu) in an in vitro model

The risk of an avian influenza pandemic has put oseltamivir (Tamiflu) in the spotlight and has given rise to rumors that shikimic acid (SK), which is used for the synthesis of Tamiflu, possesses therapeutic activity. This study was undertaken to determine whether SK, either alone or in combination with quercitin (QT) is able to modulate the release of IL-6 and IL-8 from peripheral blood mononuclear cells (PBMCs). The experiments were conducted comparing the properties of SK, both alone and in combination, with those of Tamiflu. The incubation of PBMCs with 100 nM Tamiflu or SK at two concentrations (10 nM; 100 nM) did not produce any change in IL-6 and IL-8 baseline levels (data expressed as incremental change vs. baseline). On the contrary, incubation with SK and QT at both concentrations (10 and 100 nM) produced a significant increase in the release of IL-8 as compared to other groups (4.19 +/- 0.82, SK-QT 10 nM; 3.83 +/- 1.17 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.10, Tamiflu 100 nM 1.35 +/- 0.16, SK 10 nM 1.68 +/- 0.15 and SK 100 nM 1.80 +/- 0.48). The SK-QT combination also proved to be effective in the upregulation of IL-6 (3.08 +/- 0.46, SK-QT 10 nM; 3.60 +/- 0.74 SK-QT 100 nM, P < 0.05 vs. baseline 1.00 +/- 0.26). According to these findings SK alone is not able to modulate innate immunity in antiviral terms. However, the data show that the SK + QT combination, even at low doses, may be effective for the modulation of innate immunity.

IL-1beta induces alkaline phosphatase in human phagocytes

BACKGROUND

Alkaline phosphatase (ALPase) is found in blood plasma or serum and leukocytes and regulates intercellular processes, maintaining phosphoryl metabolites in a steady state, as well as synthesizing and hydrolyzing phosphate esters on membranes. ALPase supervises the active transport of inorganic phosphates, fats, proteins, carbohydrates and the sodium/potassium pump mechanisms. The formed elements of blood such as polymorphonuclear (PMNs) leucocytes, macrophages (MP) and some lymphocytes are high in ALPase concentrations.

METHODS

In this study we have tested whether the interleukin-1 receptor antagonist (IL-lra) could influence ALPase generation in IL-1beta or lipopolysaccharide (LPS)-stimulated neutrophils and MP. Human neutrophils were isolated from heparin-anticoagulated blood drawn from healthy individuals by centrifugation in a two-step gradient, Ficoll-Hypaque. ALPase activity was assessed spectrophotometrically in test tubes containing isolated neutrophils and adherence PBMCs treated with LPS, IL-1beta and IL-1ra, alone or in combination.

RESULTS

IL-lbeta or LPS enhanced ALPase in both PMNs and MP, whereas IL-1ra could not inhibit ALPase activity. We performed time course experiments at 0 min, 5 min, 1 h, 24 h, and 43 h (LPS 20 microg/mL, IL-1beta 10 ng/mL). No significant increase in ALPase activity was seen until 1 h; however, there was a rapid rise over the next few hours. In another set of experiments using IL-1ra (500 ng/mL), there was no difference between treated cells and control cells. The combination of IL-1beta plus IL-1ra did not reduce the ability of IL-1beta to induce ALPase activity.

CONCLUSIONS

These data suggest that IL-1beta stimulates ALPase through other mechanisms than the release of arachidonic acid products, which are inhibited by IL-lra.

Expression and secretion of RANTES (CCL5) in granulomatous calcified tissue before and after lipopolysaccharide treatment in vivo

RANTES (regulated on activation, normal T cell-expressed and secreted) is a CC chemokine appearing to be involved in the recruitment of leukocytes at inflammation sites. RANTES is produced by CD8(+) T cells, epithelial cells, fibroblasts, and platelets. It acts in vitro in leukocyte activation and human immunodeficiency virus suppression, but its role in vivo is still uncertain. In our study, we established the involvement of RANTES in an in vivo model of chronic inflammation induced by potassium permanganate, leading to calcified granulomas. In our rat model, RANTES expression (mRNA and protein) was significantly upregulated in granulomatous tissue; RANTES expression was further increased upon i.p. injection of lipopolysaccharide (LPS), while it was kept at basal levels by dexamethasone (Dex) given 18 hours before sacrifice. LPS and Dex increased and decreased, respectively, the recruitment of mononuclear cells in granulomatous tissue compared with control granulomas from phosphate-buffered saline (PBS)-treated animals. In granuloma tissue, levels of RANTES were higher in LPS-treated rats and lower in the Dex group compared to controls. RANTES was also found in the conditioned medium of granuloma tissue from treated (LPS or Dex) and untreated (PBS) rats. When LPS was added in vitro for 18 hours, RANTES was further increased, except in the Dex group (P > 0.05). On serum analysis, RANTES levels were higher in the LPS group and lower in the Dex group compared to controls. This study shows for the first time that RANTES is produced in vivo in chronic, experimental inflammatory states, an effect increased by LPS and inhibited by Dex.

In vivo effect of an immunostimulating bacterial lysate on human B lymphocytes

The aim of the present study is to investigate in humans the mechanism by which the oral vaccine Polyvalent Mechanical Bacterial Lysate (PMBL) can rapidly mobilize specific immune response and evaluate the efficacy of its immunostimulating activity in preventing recurrent infections of the upper respiratory tract (URTIs) in a group of patients with a medical history of URTI recurrence. Patients received, by sublingual route, PBML, an immunostimulating lysate obtained by mechanical lysis of the most common bacteria responsible for upper respiratory tract infections. The treatment was administered for 10 consecutive days/month for 3 consecutive months. After the end of the treatment period the patients were followed up for an additional 3 months. The frequency of IgM memory B cells and the expression of the activation marker CD25 in peripheral blood lymphocytes were measured using the flow cytometric method before the start and at days 30 and 90 of the treatment cycle. To correlate clinical results to immunological parameters, the patients were monitored at different time-points during the treatment and at the end of follow-up period. The results showed that PMBL exerts a therapeutic and preventing effect in acute and recurrent infections of the upper respiratory tract and that this effect correlated with the activation and enhancement of both IgM memory B lymphocytes (CD24+/CD27+ cells) and IL2 receptor-expressing lymphocytes (CD25+ cells) involved either in humoral or cellular immunity.

Inhibitory effect of quercetin on tryptase and MCP-1 chemokine release, and histidine decarboxylase mRNA transcription by human mast cell-1 cell line

Mast cells are important in reactions of allergic disease and are also involved in a variety of neuroinflammatory diseases. Mast cells can be immunologically activated by IgE through their Fc receptors, as well as by neuropeptides and cytokines to secrete mediators. Here we used a human mast cell-1 (HMC-1) cell line cultured and treated with a physiological activator, anti-IgE, and a nonphysiological activator, calcium ionophore A23187, for tryptase and MCP-1 generation and transcription of histidine decarboxylase. We used quercetin, a potent antioxidant, cytoprotective and anti-inflammatory compound capable of inhibiting histamine and some cytokines released from several cell types, as an inhibitor of immunological and nonimmunological stimulus for mast cells. In this study quercetin inhibits, in a dose-response manner, tryptase and MCP-1. Moreover, using RT-PCR quercetin inhibited the transcription of histidine decarboxylase, the rate-limiting enzyme responsible for the generation of histamine from histidine, and MCP-1. Our data suggest that quercetin is an important and good candidate for reducing the release of pro-inflammatory mast cell mediators activated by physiological and nonphysiological stimulators.