Secretory IgA Levels Research Articles

A randomised, double-blind, placebo controlled cross-over study to determine the gastrointestinal effects of consumption of arabinoxylan-oligosaccharides enriched bread in healthy volunteers

BackgroundPrebiotics are food ingredients, usually non-digestible oligosaccharides, that are selectively fermented by populations of beneficial gut bacteria. Endoxylanases, altering the naturally present cereal arabinoxylans, are commonly used in the bread industry to improve dough and bread characteristics. Recently, an in situ method has been developed to produce arabinoxylan-oligosaccharides (AXOS) at high levels in breads through the use of a thermophilic endoxylanase. AXOS have demonstrated potentially prebiotic properties in that they have been observed to lead to beneficial shifts in the microbiota in vitro and in murine, poultry and human studies.MethodsA double-blind, placebo controlled human intervention study was undertaken with 40 healthy adult volunteers to assess the impact of consumption of breads with in situ produced AXOS (containing 2.2 g AXOS) compared to non-endoxylanase treated breads. Volatile fatty acid concentrations in faeces were assessed and fluorescence in situ hybridisation was used to assess changes in gut microbial groups. Secretory immunoglobulin A (sIgA) levels in saliva were also measured.ResultsConsumption of AXOS-enriched breads led to increased faecal butyrate and a trend for reduced iso-valerate and fatty acids associated with protein fermentation. Faecal levels of bifidobacteria increased following initial control breads and remained elevated throughout the study. Lactobacilli levels were elevated following both placebo and AXOS-breads. No changes in salivary secretory IgA levels were observed during the study. Furthermore, no adverse effects on gastrointestinal symptoms were reported during AXOS-bread intake.ConclusionsAXOS-breads led to a potentially beneficial shift in fermentation end products and are well tolerated.

Effects of heat-inactivatedLactobacillus gasseriTMC0356 on metabolic characteristics and immunity of rats with the metabolic syndrome

The present study investigated the potential health-promoting effects of heat-inactivated Lactobacillus gasseri TMC0356 (TMC0356) on the metabolic syndrome (MS) and the probable mechanisms underlying these effects using an MS rat model. For the purpose of the study, sixty Sprague-Dawley rats were randomly divided into five groups: a control group fed a conventional diet, an MS model group fed a high-fat and high-salt (HFS) diet and three TMC0356 test groups (low-, medium- and high-dose groups) fed an HFS diet supplemented with TMC0356 at 41.8, 83.5 and 167.0 mg/kg body weight (BW) per d, respectively. Food intake and BW were measured weekly. Fasting blood glucose (FBG), lipid profiles and blood pressure (BP) were measured at 0, 5, 10 and 15 weeks. Organ coefficients, immune cell counts and serum insulin, adiponectin, C-reactive protein (CRP), IL-6, TNF-α, IgG and secretory IgA levels were measured at the 15th week after diet intervention. The HFS diet increased the BW, liver or fat:BW ratio, FBG, homeostatic model assessment of insulin resistance, adiponectin, serum LDL-cholesterol and total cholesterol levels and BP (P< 0.01). Average food and energy intakes in the three TMC0356 groups were significantly lower than those of the MS model group. All the metabolic indices, except BP, were markedly improved (P< 0.05) by oral administration of low and medium doses of TMC0356. The thymus index in the medium-dose group and lymphocyte, CRP, IL-6, TNF-α and IgG levels in all the three TMC0356 groups were significantly increased (P< 0.05 or P< 0.01) compared with those in the MS model group. These results suggest that TMC0356 can improve the metabolic characteristics of MS rats by suppressing appetite. Additionally, the enhancement of inflammatory immune response may be, at least in part, the mechanism underlying the health-promoting effects of TMC0356 on the MS.

Adjuvant-free nanogel-based PspA nasal vaccine for the induction of protective immunity against Pneumococcus (166.7)

Abstract To establish strategically effective and attractive vaccine against pneumococcal respiratory infections, combining the current knowledge and technology for common antigen throughout pneumococcal strains and the new delivery system is essential. Here, we introduce a new pneumococcal nasal vaccine using the advantages of Pneumococcal surface protein A (PspA) antigen and a new adjuvant-free intranasal vaccine-delivery system with a nanometer-sized hydrogel (nanogel) consisting of a cationic type of cholesteryl group-bearing pullulan (cCHP). Nanogel-based PspA nasal vaccination induced high levels of antigen-specific serum IgG, and nasal and bronchial secretory IgA (SIgA) antibodies. The levels of PspA-specific antibodies were as high as those in mice nasally immunized with PspA and mucosal adjuvant, cholera toxin. The nanogel induced PspA-specific immune responses provided protective immunity against the lethal challenge with Streptococcus pneumoniae Xen10. Nanogel-PspA vaccinated group thus had less numbers of pneumococcus on the surface of the bronchial mucosa, and perfectly protected from the pneumococcal invasion of the lung parenchyma. These results demonstrate the effectiveness of the nanogel-based PspA nasal vaccine system as an adjuvant free mucosal vaccine against the respiratory infection of pneumococcus.

Oxidative Stress in Children with Intractable Epilepsy Reflected by Salivary Glands Anti-Oxidant Profile (P01.073)

Objective: To investigate anti- oxidant paradigm in children with intractable epilepsy, compare it with children in whom the seizures were controlled and also compare with a control group of age-matched children assessing the salivary anti-oxidant profile performing sialometry and sialochemistry. Background Oxidative stress has emerged as a possible important underlying direct and indirect mechanism that may play an important role in the etiology of seizure-induced cell death. Design/Methods: Saliva was collected from 49 children who suffered from intractable epilepsy (the study group), from 22 children after controlling the seizures (the study group) and 16 health age-matched children (the control group). Salivary flow rate and pH were measured as well as levels of calcium (Ca), phosphate (P), magnesium (Mg), total protein, albumin, amylase, lactate dehydrogenase (LDH), and secretory IgA were analysed. Salivary total antioxidant status (TAS), peroxidase activity, superoxide dismutase (SOD) activity, uric acid (UA) were also analyzed. Results: A significant decrease in the total anti-oxidant profile has been detected in children with intractable epilepsy compared with children with controlled seizures and healthy age-matched children. Marked increase of the SOD activity has been found in children with intractable epilepsy compared with the control group. LDH levels were decreased in the study group compared with seizure- controlled children. Ph levels were decreased remarkably in intractable epilepsy compared with control children. Conclusions: Our findings suggest that an oxidative stress may be a possible underlying mechanism in the evolution of epileptic disorders as has been demonstrated by a significant decrease in the total anti-oxidant prophile. As such, such a non- invasive method of saliva collection and performing sialomertry ans sialochmistry, may serve as a useful measure of possible imminent epileptic activity as well as a measure of seizure control. Disclosure: Dr. Shahar has nothing to disclose. Dr. Nagler has nothing to disclose.

Mo1984 Stool Secretory IgA Levels in Preterm Infants With and Without Necrotising Enterocolitis

Introduction Secretory Immunoglobulin A (SIgA) is the most prolific immunoglobulin of the GI tract, and high levels in preterm infants may prevent necrotising enterocolitis, the most devastating disease of the gut of early life. Our aim was to determine and compare the levels of SIgA in stool samples of preterm neonates and breast milk in their mothers. Design The NAPI Study (see abstract 1299049) sequentially recruited infants 0.05) within all the four weeks. A significant increase in mean stool sIgA concentration appeared from week 2 to week 3 (p=0.0485) in NEC infants and from week 1 to week 2 (p=0.005) for those without NEC. For all breastfed preterm neonates (n=6) in the first four weeks, the level of milk sIgA was significant higher on week 1 (colostrum) than week 2 (p=0.021) and week 3 (p=0.034). Conclusions Our study illustrates immunological adaptation of maternal milk sIgA level for the preterm newborn and that exclusive breast milk feeding may increase stool sIgA more than mixed breast milk and formula. Levels found in stool and milk are significantly higher than for infants and mothers at term.

Enhancing CCL28 expression through the gene transfer to salivary glands for controlling cariogenic microbe

The chemokine CCL28 participates in direct antimicrobial activities as well as homing of certain types of lymphocytes. The present study was conducted to harness these properties of the chemokine for the prevention of dental caries. The gene encoding CCL28 was transferred to salivary glands to enhance the production of this chemokine locally. First, a recombinant eukaryotic plasmid expressing CCL28 was constructed. Then, the CCL28 protein from 293 cells transfected with the recombinant plasmid was verified to inhibit the caries pathogen Streptococcus mutans (S. mutans) in a biofilm. Finally, the recombinant plasmid was retrogradely administered to the parotid glands of rats through the secretory ducts. The successful transfer of the gene encoding CCL28 to rat parotid acinar cells was confirmed by immunofluorescence and real-time PCR. Increases in both CCL28 and secretory IgA (SIgA) in the rat saliva were tested by ELISA. It was revealed that the CCL28 protein obtained from the study was able to strongly inhibit S. mutans living in biofilm in vitro. The delivery of the recombinant plasmid to the rat parotid glands was able to induce high levels of CCL28 and SIgA in saliva, and the increased levels of CCL28 and SIgA in saliva were maintained for 2weeks. Notably, the dental plaque from the rats treated with the delivery of the recombinant plasmid in the study harbored significantly less S. mutans. These data indicated that the present strategy may hold hope for the effective prevention of dental caries.

Effects of the antimicrobial peptide cecropin AD on performance and intestinal health in weaned piglets challenged with Escherichia coli

This study was conducted to determine the effects of the antimicrobial peptide cecropin on performance and intestinal health in piglets. Newly weaned barrows were randomly assigned to one of three treatments (n=8), including a corn-soybean basal diet or similar diets supplemented with antibiotics (100mg/kg kitasamycin plus 800mg/kg colistin sulfate) or 400mg/kg cecropin AD. On day 13, all piglets were orally challenged with 109CFU/mL of Escherichia coli K88. On day 19, all piglets were euthanized and sampled. Before challenge, piglets fed antibiotics had greater weight gain, feed efficiency, nitrogen and energy retention than the control (P<0.05). E. coli challenge decreased weight gain, feed intake and feed efficiency for the control piglets (P<0.05) but not for the antibiotic or cecropin AD treated piglets. The incidence of diarrhea post-challenge in the antibiotic and cecropin AD treatments decreased compared with the control piglets. The total viable counts of cecal E. coli were lower while the Lactobacilli counts were higher in the antibiotic and cecropin AD treatments compared with the control (P<0.05). Cecropin AD treatment decreased total aerobes while increasing total anaerobes in the ileum (P<0.05). A higher villus height to crypt depth ratio in the jejunum and ileum as well as a deeper crypt depth in the jejunum and higher villus height in the ileum were observed in piglets fed antibiotics or cecropin AD compared with control piglets (P<0.05). Piglets fed the control diet had lower levels of secretory IgA in their jejunum and lower serum IgA, IgG, interleukin-1β and interleukin-6 compared with the other treatments (P<0.05). Overall, these data suggest that cecropin AD enhances pig performance through increasing immune status and nitrogen and energy retention as well as reducing intestinal pathogens in weaned piglets.

Influence of postpartum supplementation with vitamin A on the levels of immunoglobulin A in human colostrum

To evaluate the influence of supplementation with retinyl palmitate in the immediate postpartum period on the levels of secretory immunoglobulin A (SIgA) in colostrum. A clinical trial was conducted among 96 recently-delivered mothers treated at a public maternity hospital, divided into control group, which was not supplemented (n = 44), and test group, supplemented on the first day postpartum (n = 52). Samples of 2 mL of colostrum were collected on the first 2 days postpartum. SIgA was measured by turbidimetry and data were analyzed by the Student t test. Before supplementation, the average SIgA was 829.1±337.6 mg/dL in the control group and 827.3±249.8 mg/dL in the test group (p = 0.52). After supplementation, the average SIgA was 343.9±177.2 mg/dL in the unsupplemented group and 501.2±54.5 mg/dL in the supplemented group (p < 0.00001). The colostrum of women supplemented with retinyl palmitate has higher levels of SIgA, which suggests that the production of antibodies is modulated by vitamin A.

Characterization of a Novel Inactivated Salmonella enterica Serovar Enteritidis Vaccine Candidate Generated Using a Modified cI857/λ PR/GeneEExpression System

A new strategy to develop an effective vaccine is essential to control food-borne Salmonella enterica serovar Enteritidis infections. Bacterial ghosts (BGs), which are nonliving, Gram-negative bacterial cell envelopes, are generated by expulsion of the cytoplasmic contents from bacterial cells through controlled expression using the modified cI857/λ P(R)/gene E expression system. In the present study, the pJHL99 lysis plasmid carrying the mutated lambda pR37-cI857 repressor and PhiX174 lysis gene E was constructed and transformed in S. Enteritidis to produce a BG. Temperature induction of the lysis gene cassette at 42°C revealed quantitative killing of S. Enteritidis. The S. Enteritidis ghost was characterized using scanning and transmission electron microscopy to visualize the transmembrane tunnel structure and loss of cytoplasmic materials, respectively. The efficacy of the BG as a vaccine candidate was evaluated in a chicken model using 60 10-day-old chickens, which were divided into four groups (n = 15), A, B, C, and D. Group A was designated as the nonimmunized control group, whereas the birds in groups B, C, and D were immunized via the intramuscular, subcutaneous, and oral routes, respectively. The chickens from all immunized groups showed significant increases in plasma IgG and intestinal secretory IgA levels. The lymphocyte proliferation response and CD3(+) CD4(+) and CD3(+) CD8(+) T cell subpopulations were also significantly increased in all immunized groups. The data indicate that both humoral and cell-mediated immune responses are robustly stimulated. Based on an examination of the protection efficacy measured by observations of gross lesions in the organs and bacterial recovery, the candidate vaccine can provide efficient protection against virulent challenge.

Induction and maintenance of anti‐influenza antigen‐specific nasal secretory IgA levels and serum IgG levels after influenza infection in adults

To determine the induction and changes in anti-influenza virus secretory IgA (s-IgA) levels in nasal washes and serum IgG levels in patients with influenza. The study recruited 16 patients with influenza aged 35.6 ± 9.6 years in 2007/2008 and 2008/2009 seasons. Nasal washes and serum were obtained throughout the first year. Anti-viral s-IgA levels and neutralization activities in nasal washes, and serum anti-viral IgG levels and hemagglutination inhibition (HI) titers were measured. Anti-viral(H1N1) s-IgA to total IgA ratio and neutralizing antibody titer were low in nasal washes of all patients, whereas serum levels of anti-viral IgG and HI titers varied widely at day 1.4 ± 1.0 postinfection. Both nasal s-IgA and serum IgG levels later increased significantly, reaching peak levels at day 9.6 ± 3.3 postinfection. The induced nasal s-IgA then returned toward the initial levels within 300 days, although the levels at day 143 ± 70 were 3.03-fold of the initial. Individual serum IgG levels also returned toward the initial levels within 300 days, although the mean levels remained high probably because of re-infection in a subgroup of patients. Although influenza A (H3N2) was a minor epidemic subtype in both flu seasons, a significant rise in nasal anti-viral (H3N2) s-IgA levels and a slightly increase in serum IgG levels were noted. Low levels of nasal anti-viral s-IgA and neutralizing antibody were noted compared with a wide range of serum anti-viral IgG and HI titers at the onset of infection. Elevated s-IgA and IgG returned toward the initial levels within 300 days of infection with minor exceptions.

A genetically engineered derivative of Salmonella Enteritidis as a novel live vaccine candidate for salmonellosis in chickens

To construct a novel live Salmonella Enteritidis (SE) vaccine candidate, SE was genetically engineered using the allelic exchange method to delete two virulence genes, lon and cpxR. The lon gene deletion is essential to impair Salmonella replication and avoid overwhelming systemic disease in the host. The cpxR gene deletion is needed to enhance the ability of bacteria to adhere and invade the host cell. Scanning electron microscopy revealed that the derivatives JOL917 (Δlon), JOL918 (ΔcpxR), and JOL919 (Δlon/ΔcpxR) had increased surface fimbrial filamentous structures. Significant elevations of extracellular polysaccharide and FimA expression were observed for the derivatives compared to the parental wild type JOL860, while biochemical properties of the derivatives were not altered. In the safety examination by inoculation of the derivatives in chickens, gross lesion scores of the liver, spleen, kidney, small intestine and caecal tonsils were moderate in the JOL917 and JOL918 groups, and significantly lower in the JOL919 group than those of the JOL860. Bacterial counts from the spleen and caeca of the JOL917 and JOL918 groups were moderate, and significantly reduced in the JOL919 group compared to the JOL860 group. In addition, only the JOL919 group showed significantly lower bacterial counts in the faecal samples than those of the JOL860 group. Significant elevations of IgG and secretory IgA levels observed in the derivative groups, while the JOL919 and JOL860 groups showed a potent lymphocyte proliferation response as compared to those of the control group. In the protection efficacy examination, JOL919 immunized group showed significantly lower depression, lower gross lesion in the liver and spleen, and lower number of the SE positive internal organs than those of the control group against a virulent wild type SE challenge.

Levels of lactoferrin, secretory IgA and serum albumin in the tear film of people with keratoconus

Keratoconus is a degenerating disease of the eye which causes an irregularly shaped cornea leading to severe impairment of vision. Tear proteomics in keratoconus has been a topic of substantial discussion and speculation over many years. This study was designed to examine the levels of total protein, lactoferrin, secretory IgA and serum albumin in the tear film of people with keratoconus. Basal tears were collected using a capillary tube and corneal curvature was mapped using a topographer. Total protein in tears was estimated. The amount of regulated protein lactoferrin, constitutive protein sIgA and serum protein albumin was measured using specific ELISAs. The changes in protein concentrations in tears were correlated to the degree of corneal asphericity. There was a two-fold (p<0.0001) decrease in total protein levels between keratoconus (3.86 ± 1.62 mg/ml) and normal (7.00 ± 1.58 mg/ml) tears. The amount of lactoferrin (0.67 ± 0.28 vs. 1.13 ± 0.29 mg/ml) and secretory IgA (0.78 ± 0.36 vs. 1.70 ± 0.66 mg/ml) were significantly (p<0.0001) reduced in keratoconus tears. Variation in serum albumin levels between keratoconus (8.18 ± 4.72 μg/ml) and normal tears (11.66 ± 8.20 μg/ml) were not significant. The differences in total protein, lactoferrin and secretory IgA were not associated with contact lens wear, age, gender or atopy of subjects. The keratometry reading was negatively correlated to tear levels of total protein (r = −0.59, p < 0.01) lactoferrin (r = −0.40, p < 0.05) and secretory IgA (r = −0.34, p < 0.05). The tears of keratoconus subjects appear to have an altered protein profile, and one that might change with the severity of the disease. These findings may lead the way to understanding or monitoring disease progression.

Slow Salivary Secretory IgA Maturation May Relate to Low Microbial Pressure and Allergic Symptoms in Sensitized Children

It is unknown why allergic symptoms do not develop in all sensitized children. We analyzed prospectively the postnatal secretory IgA (SIgA) development and whether high SIgA levels would protect sensitized infants from developing allergic symptoms. Salivary total IgA and SIgA levels were determined by ELISA, and allergy development was investigated at 3, 6, and 12 mo and at 2 and 5 y in two birth cohorts in Estonia (n = 110) and Sweden (n = 91), two geographically adjacent countries with different living conditions and allergy incidence. Total and SIgA levels increased with age, reaching adult levels at the age of 5. Virtually, all salivary IgA in Estonian children was in the secretory form, while a major part of IgA in Swedish saliva lacked the secretory component up to 2 y of age. In Sweden, high levels of salivary IgA without secretory component correlated inversely with house dust endotoxin levels. High SIgA levels were associated with less development of allergic symptoms in sensitized Swedish children. In conclusion, postnatal maturation of the salivary SIgA system proceeds markedly slower in Swedish than Estonian children, possibly as a consequence of low microbial pressure. SIgA may limit allergy-mediated tissue damage at mucosal surfaces in sensitized individuals.

The effect of black soybean tempe and it’s ethanol extract on lymphocyte proliferation and IgA secretion in Salmonella typhimurium induced rat

Children patient suffering from malnutrition and chronic diarrhea, who had been treated with tempe formula improved their health status, recovered from the diarrhea in a relatively shorter period, and gained weight. It is perceived that the quick recovery was due to improvement of the body’s immune system. The aim of the research was to observe the effect of black soybean tempe and it’s ethanol extract on T and B cells proliferation and level of secretory IgA (sIgA) in rat induced with Salmonella typhimurium . A total of 48 rats were divided into four groups, 12 rats each assigned to standard diet, diet plus black soybean tempe flour, diet plus tempe ethanol extract, and diet plus mixture from tempe ethanol extract and flour of black soybean tempe. Body weights were recorded during 35 days of diet treatment, and index stimulation on T and B cells as well as level of secretory IgA were measured after S. typhimurium induction. Result indicated that diet with tempe, diet with ethanol extract and combination of both increased body weight better than that of control. Treatments with tempe and mixture of tempe with its ethanol extract were significantly different from the control in the proliferation of T cell; however, the treatment with tempe ethanol extract did not. The three treatments did not improved proliferation of B cell. Diet with tempe alone significantly increased secretory IgA in the intestinal tract fluid of rats, but the other treatments did not show significant difference with the control (without Salmonella induction).

Adjuvanted, antigen loaded N-trimethyl chitosan nanoparticles for nasal and intradermal vaccination: Adjuvant- and site-dependent immunogenicity in mice

N-trimethyl chitosan (TMC) nanoparticles have been shown to increase the immunogenicity of subunit antigens after nasal and intradermal administration. This work describes a second generation of TMC nanoparticles containing ovalbumin as a model antigen (TMC/OVA nanoparticles) and an immunopotentiator (TMC/OVA/immunopotentiator nanoparticles). The selection of immunopotentiators included Toll-like receptor (TLR) ligands lipopolysaccharide (LPS), PAM3CSK4 (PAM), CpG DNA, the NOD-like receptor 2 ligand muramyl dipeptide (MDP) and the GM1 ganglioside receptor ligand, cholera toxin B subunit (CTB). The TMC/OVA/immunopotentiator nanoparticles were characterised physico-chemically and their immunogenicity was assessed by determining the serum IgG, IgG1, IgG2a titres and secretory IgA levels in nasal washes after intradermal and nasal vaccination in mice.After nasal vaccination, TMC/OVA nanoparticles containing LPS or MDP elicited higher IgG, IgG1 and sIgA levels than non-adjuvanted TMC/OVA particles, whereas nanoparticles containing CTB, PAM or CpG did not. After intradermal vaccination, the TMC/OVA/CpG and TMC/OVA/LPS nanoparticles provoked higher IgG titres than plain TMC/OVA particles.Altogether, our results show that co-encapsulation of an additional immunopotentiator with the antigen into TMC nanoparticles can further improve the immunogenicity of the vaccine. However, the strength and quality of the response depends on the immunopotentiator as well as the route of administration.

Development and characterization of chitosan coated poly-(ɛ-caprolactone) nanoparticulate system for effective immunization against influenza

In this study surface coated poly-(ɛ-caprolactone) (PCL) nanoparticles with chitosan (CS) were developed as a carrier system for nasal immunization using recombinant Influenza A virus (A/California/07/2009) H1N1 hemagglutinin (HA) protein, for the induction of humoral, cellular and mucosal immunity. CS coated PCL (CS-PCL) nanoparticles were characterized in vitro for their percent yield, size, shape, entrapment efficiency, loading capacity and zeta potential. The in vitro release and antigen integrity were also evaluated. Particles were prepared by an emulsion-diffusion-solvent evaporation method. The coated cationic nanoparticles of average size 125.64±6.51 nm with a narrow size distribution (pdi: 0.185±0.032) and a positive surface charge (+22.88 mV) were obtained. HA antigen was efficiently entrapped in CS-PCL nanoparticles (entrapment efficiency 74.84±4.51%, loading capacity 14±2% (w/w)). The molecular weight and antigenicity of the entrapped HA was maintained as shown by polyacrylamide gel electrophoresis and Western blotting, respectively. In vitro release study of antigen showed that about 66.47% of entrapped antigen was released within 63 days. The immune-stimulating activity was studied by measuring hemagglutination inhibition (HAI) titer, IgG, IgG1 and IgG2a titer, secretory IgA level in nasal and lung lavage (mucosal secretions) following nasal administration of modified CS-PCL nanoparticles in Balb/c mice and compared with soluble HA antigen administered intramuscular (IM) and with PCL (uncoated) nanoparticles administered intranasal (IN). The numbers of IFN-γ or IL-4 secreting cells in spleen homogenates were also measured 21 day after third immunization. Single IN or IM immunization with antigen-loaded CS-PCL nanoparticles resulted in strong HAI and total IgG responses. These responses were higher than those achieved after booster IM administration of the subunit antigen, whereas the IgG1/IgG2a profile did not change substantially. The IN administered antigen-CS-PCL nanoparticles induced higher immune responses compared to the other IN antigen formulations, and these responses were enhanced by IN booster vaccinations. Moreover, IM administered soluble HA antigen did not elicit s-IgA in mucosal secretions as it was induced and measured in the case of nasal administration of CS-PCL nanoparticles. In contrast to IM administered antigen CS-PCL nanoparticles induced a balanced Th1 and Th2 response. CS-PCL nanoparticles (cationic nanoparticles) thus produced humoral (both systemic and mucosal) and cellular immune responses upon nasal administration. These findings demonstrate high potential of CS-PCL nanoparticles for their use as a carrier adjuvant for nasal administered influenza antigens.

Lactobacillus plantarum strain YU from fermented foods activates Th1 and protective immune responses

Lactic acid bacteria (LAB) are known to have effects on immune function. From 203 strains of LAB isolated from fermented foods, we selected a beneficial strain, Lactobacillus plantarum strain YU (LpYU), which has high interleukin (IL)-12-inducing activity in mouse peritoneal macrophages. This activity of LpYU was partially mediated by Toll-like receptor (TLR) 2, but not TLR4 or TLR9. Oral administration of LpYU to ovalbumin (OVA)-immunized mice caused suppression of serum OVA-specific immunoglobulin E (IgE) levels, enhancing interferon (IFN)-γ production from spleen cells in response to OVA. Furthermore, LpYU enhanced natural killer cell activity in spleen cells and the production of IgA from Peyer's patch cells. Because activation of Th1 immune responses and IgA production induce antiviral effects, we evaluated the inhibitory effects of LpYU against the influenza A virus (A/NWS/33, H1N1) (IFV). Oral administration of LpYU suppressed viral proliferation in the lungs and in bronchoalveolar lavage fluids (BALFs). Both levels of IFV-specific secretory IgA in BALF and feces and titers of IFV-specific neutralizing antibody in BALFs and sera were increased. These results indicate that LpYU has a protective effect against IFV replication. We conclude that this strain has a beneficial effect in activating Th1 immune responses and preventing viral infection.

Immunogenicity of a Salmonella Enteritidis mutant as vaccine candidate and its protective efficacy against salmonellosis in chickens

A novel Salmonella Enteritidis (SE) vaccine candidate strain, JOL919 was constructed by deleting the lon and cpxR genes from a wild-type SE using an allelic exchange method. The study was carried out to evaluate the strain as a vaccine candidate against salmonellosis. The strain showed the enhanced macrophage invasion, early bacterial clearance and higher immune responses as compared to the other mutants, JOL917 ( Δlon) and JOL918 ( ΔcpxR), and the wild type. In further analysis, the chickens immunized with JOL919 showed a significant increase in plasma IgG and intestinal secretory IgA levels, which was an indication of robust humoral and mucosal immune responses induced by the candidate. The lymphocyte proliferation response and CD45 +CD3 + T cells, associated with an activation of T helper and cytotoxic cells, were also significantly increased in the immunized group, which indicated that the candidate also induced cellular immune responses. The immune cell influx into caecal tissues analyzed by immunohistochemistry showed that CD8 + T cells were predominated in the immunized group, suggesting that the candidate can clear the invaded pathogen in the intestines by a more direct way involving cytotoxic activity. By the examination of the protection efficacy measured by observations of gross lesions in the organs and bacterial recovery, the candidate can provide an efficient protection upon virulent challenge.

Downregulation of the immune system in low-quality child care: The case of Secretory Immunoglobulin A (SIgA) in toddlers

Does the experience of stress during child care lead to downregulation of the immune system, in particular in low-quality care? Saliva was collected from 68 toddlers attending center or family child care at home and at child care, and assayed for secretory IgA (SIgA). Caregiver sensitivity was used as an index of quality of care and was observed during three videotaped episodes of 10min. Diurnal patterns of SIgA showed a steep fall in the morning followed by a flattening out. SIgA was not associated with type of care, but lower caregiver sensitivity was associated with lower SIgA levels in both types of care. Quality of child care is associated with a non-specific secretory component of children's mucosal immunity with well established protective effects against upper respiratory infections.

Ocular toxoplasmosis: evaluation of lacrimal - specific secretory IgA levels in both patients with active and inactive phases of the disease

Ocular toxoplasmosis can result in recurrent uveitis. Studies have shown that a correlation between active ocular toxoplasmosis and the presence of anti-Toxoplasma gondii secretory IgA (SIgA) in tears. This study compares anti-T. gondii SIgA levels in patients' tears during the acute and inactive phases of toxoplasmic uveitis. Twenty-nine positive tear specific SIgA for T. gondii patients with acute toxoplasmic uveitis were selected and were followed-up for at least two years, when the anti-T. gondii SIgA tears levels were determined. Specific SIgA for T. gondii was negative in 22 patients (75.86%) and positive in seven patients (24.13%) of whom six (85.7%) were followed over three years. Average SIgA levels during the acute phase are 1.54 and decrease significantly to 0.72 (p = 0.0001) during the inactive phase of disease. Because anti-T. gondii SIgA in the tear is negative in 75.86% of patients after the acute phase of infection, T. gondii SIgA levels may be used as a complementary diagnostic marker for active ocular toxoplasmosis.