Serum Hemagglutinin Research Articles

Long-lasting immunogenicity of a virosomal vaccine in older children and young adults with type I diabetes mellitus

To evaluate the long-lasting immunogenicity and reactogenicity of a virosomal influenza vaccine in subjects with type I diabetes, a trial was conducted during the 2007–2008 influenza season in Milan, Northern Italy. One hundred five subjects aged 9–30 years were randomized to receive by intramuscular injection vaccination by a single dose (0.5 ml) of either a virosomal (Inflexal V ®) ( n = 52) or a standard subunit (Influvac ®) ( n = 53) vaccine. Serum hemagglutinin inhibition antibody titres were determined against the three recommended influenza-like strains, A/H1N1, A/H3N2 and B, at pre-vaccination, and 1 and 6 months post-vaccination. Geometric mean titres were increased in the two groups 1 and 6 months post-vaccination ( P < 0.001). One month post-vaccination both vaccines met the CPMP requirement for immunogenicity with high seroprotection rates (>95%) for strains A/H1N1 and A/H3N2, and a seroprotection of 73% and 70% in the virosomal and subunit vaccine for strain B. Mean fold increase ranged 2.8 (A/H3N2)–6.2 (A/H1N1) in the virosomal group and 2.3 (A/H3N2)–4.8 (A/H1N1) in the subunit group. Immunogenicity declined 6 months post-vaccination in both groups, and the CPMP requirement for immunogenicity was satisfied only in the virosomal group. In subjects without pre-existing antibodies to strain B (titre <10), the virosomal vaccine showed higher immune response than the subunit vaccine 6 months post-vaccination, with a geometric mean titre (95% CI) of 40.2 (30.7–54.6) vs. 21.2 (14.6–30.8). Reactogenicity was similar in the two vaccines. All reactions were transient and not severe. The results indicate that in older children and young adults with type I diabetes influenza vaccination with a virosomal or a standard subunit vaccine is safe and adequately immunogenic against the three influenza vaccine strains. In addition, the virosomal vaccine may show better long-lasting immune response than the standard subunit vaccine, especially in subjects without pre-existing antibodies to influenza strains.

Arrestin-2 Interacts with the Ubiquitin-Protein Isopeptide Ligase Atrophin-interacting Protein 4 and Mediates Endosomal Sorting of the Chemokine Receptor CXCR4

The chemokine receptor CXCR4 is rapidly targeted for lysosomal degradation by the E3 ubiquitin ligase atrophin-interacting protein 4 (AIP4). Although it is known that AIP4 mediates ubiquitination and degradation of CXCR4 and that perturbations in these events contribute to disease, the mechanisms mediating AIP4-dependent regulation of CXCR4 degradation remain poorly understood. Here we show that AIP4 directly interacts with the amino-terminal half of nonvisual arrestin-2 via its WW domains. We show that depletion of arrestin-2 by small interfering RNA blocks agonist-promoted degradation of CXCR4 by preventing CXCR4 trafficking from early endosomes to lysosomes. Surprisingly, CXCR4 internalization and ubiquitination remain intact, suggesting that the interaction between arrestin-2 and AIP4 is not required for ubiquitination of the receptor at the plasma membrane but perhaps for a later post-internalization event. Accordingly, we show that activation of CXCR4 promotes the interaction between AIP4 and arrestin-2 that is consistent with a time when AIP4 co-localizes with arrestin-2 on endocytic vesicles. Taken together, our data suggest that the AIP4.arrestin-2 complex functions on endosomes to regulate sorting of CXCR4 into the degradative pathway.

HFE Modulates Transferrin Receptor 2 Levels in Hepatoma Cells via Interactions That Differ from Transferrin Receptor 1-HFE Interactions

Mutations in the transmembrane glycoproteins transferrin receptor 2 (TfR2) and HFE are associated with hereditary hemochromatosis. Interactions between HFE and transferrin receptor 1 (TfR1) have been mapped to the alpha1- and alpha2-helices in HFE and to the helical domain of TfR1. Recently, TfR2 was also reported to interact with HFE in transfected mammalian cells. To test whether similar HFE residues are important for both TfR1 and TfR2 binding, a mutant form of HFE (W81AHFE) that has an approximately 5,000-fold lower affinity for TfR1 than HFE was employed. As expected, W81AHFE does not interact with TfR1. However, we found that the same mutation in HFE does not affect the TfR2/HFE interaction. This finding indicates that the TfR2/HFE and TfR1/HFE interactions are distinct. We further observed that, unlike TfR1/HFE, Tf does not compete with HFE for binding to TfR2 and that binding is independent of pH (pH 6-7.5). TfR2-TfR1 and HFE-HLA-B7 chimeras were generated to map the domains of the TfR2/HFE interaction. TfR1 and HLA-B7 were chosen because of their similar overall structures with TfR2 and HFE, respectively. We mapped the interacting domains to the putative stalk and protease-like domains of TfR2 located between residues 104 and 250 and to the alpha3 domain of HFE, both of which differ from the TfR1/HFE interacting domains. Furthermore, we found that HFE increases TfR2 levels in hepatic cells independent of holo-Tf.

Long-term immunogenicity of a virosomal subunit inactivated influenza vaccine in children with asthma

To evaluate long-term immunogenicity of a virosomal subunit inactivated influenza vaccine in children with asthma, a prospective study was conducted during 2005-2006 influenza season in six public pediatric clinics in Milan and surroundings, Northern Italy. A single dose (0.5 ml) of a virosomal subunit inactivated influenza vaccine (Inflexal V) was injected in 106 asthmatic children aged 3-9 years. Serum hemagglutinin inhibition antibody titers were determined against the recommended influenza strains A/New Caledonia (H1N1), A/California (H3N2), and B/Shanghai (B), at pre-vaccination and 1 and 6 months after vaccination. Seroconversion rate (95% CI) against the strains A/H1N1, A/H3N2 and B was, respectively, 78% (68.6-85.7), 57% (46.7-66.9) and 66% (55.8-71.2) at 1 month. Seroprotection (titer> or =40) rate for A/H1N1, A/H3N2 and B was, respectively, 87% (77.8-92.2), 82% (72.6-89.7) and 90% (82.6-94.8) at 1 month and 74% (64.3-82.3), 77% (67.5-84.8), and 77% (67.5-84.8) at 6 months. Seroprotection rate was high and persistent (>95%) in children with pre-existing antibodies (titer> or =10) at pre-vaccination for any specific strain. In children without pre-existing antibodies, seroprotection rate for A/H1N1, A/H3N2 and B was, respectively, 67.6%, 66.7% and 74.4% at 1 month, and 35.1%, 56.2% and 41.0% at 6 months after vaccination. Vaccine was well tolerated. These results indicate that in unvaccinated children with asthma vaccination with a single dose of virosomal-adjuvanted influenza vaccine is well tolerated and effective as a whole. However, while immunity response and persistence are excellently high in children with pre-existing antibodies, in children naive for the antigens the immune parameters are lower at 6 months after vaccination.

Abnormal humoral immune response to influenza vaccination in pediatric type-1 human immunodeficiency virus infected patients receiving highly active antiretroviral therapy

Given that highly active antiretroviral therapy (HAART) has been demonstrated useful to restore immune competence in type-1 human immunodeficiency virus (HIV-1)-infected subjects, we evaluated the specific antibody response to influenza vaccine in a cohort of HIV-1-infected children on HAART so as to analyze the quality of this immune response in patients under antiretroviral therapy. Sixteen HIV-1-infected children and 10 HIV-1 seronegative controls were immunized with a commercially available trivalent inactivated influenza vaccine containing the strains A/H1N1, A/H3N2, and B. Serum hemagglutinin inhibition (HI) antibody titers were determined for the three viral strains at the time of vaccination and 1 month later. Immunization induced a significantly increased humoral response against the three influenza virus strains in controls, and only against A/H3N2 in HIV-1-infected children. The comparison of post-vaccination HI titers between HIV-1+ patients and HIV-1 negative controls showed significantly higher HI titers against the three strains in controls. In addition, post vaccination protective HI titers (defined as equal to or higher than 1:40) against the strains A/H3N2 and B were observed in a lower proportion of HIV-1+ children than in controls, while a similar proportion of individuals from each group achieved protective HI titers against the A/H1N1 strain. The CD4+ T cell count, CD4/CD8 T cells ratio, and serum viral load were not affected by influenza virus vaccination when pre- vs post-vaccination values were compared. These findings suggest that despite the fact that HAART is efficient in controlling HIV-1 replication and in increasing CD4+ T cell count in HIV-1-infected children, restoration of immune competence and response to cognate antigens remain incomplete, indicating that additional therapeutic strategies are required to achieve a full reconstitution of immune functions.

Safety and Immunogenicity of a Baculovirus-Expressed Hemagglutinin Influenza Vaccine

A high priority in vaccine research is the development of influenza vaccines that do not use embryonated eggs as the substrate for vaccine production. To determine the dose-related safety, immunogenicity, and protective efficacy of an experimental trivalent influenza virus hemagglutinin (rHA0) vaccine produced in insect cells using recombinant baculoviruses. Randomized, double-blind, placebo-controlled clinical trial at 3 US academic medical centers during the 2004-2005 influenza season among 460 healthy adults without high-risk indications for influenza vaccine. Participants were randomly assigned to receive a single injection of saline placebo (n = 154); 75 microg of an rHA0 vaccine containing 15 microg of hemagglutinin from influenza A/New Caledonia/20/99(H1N1) and influenza B/Jiangsu/10/03 virus and 45 microg of hemagglutinin from influenza A/Wyoming/3/03(H3N2) virus (n = 153); or 135 microg of rHA0 containing 45 microg of hemagglutinin each from all 3 components (n = 153). Serum samples were taken before and 30 days following immunization. Primary safety end points were the rates and severity of solicited and unsolicited adverse events. Primary immunogenicity end points were the rates of 4-fold or greater increases in serum hemagglutinin inhibition antibody to each of the 3 vaccine strains before and 28 days after inoculation. The prespecified primary efficacy end point was culture-documented influenza illness, defined as development of influenza-like illness associated with influenza virus on a nasopharyngeal swab. Rates of local and systemic adverse effects were low, and the rates of systemic adverse effects were not different in either vaccine group than in the placebo group. Hemagglutinin inhibition antibody responses to the H1 component were seen in 3% of placebo, 51% of 75-microg vaccine, and 67% of 135-microg vaccine recipients, while responses to B were seen in 4% of placebo, 65% of 75-microg vaccine, and 92% of 135-microg vaccine recipients. Responses to the H3 component occurred in 11% of placebo, 81% of 75-microg vaccine, and 77% of 135-microg vaccine recipients. Influenza infections in the study population were due to influenza B and A(H3N2), and influenza A infections were A/California/7/2004-like viruses, an antigenically drifted strain. Seven cases of culture-confirmed CDC-defined influenza-like illness occurred in 153 placebo recipients (4.6%) compared with 2 cases (1.3%) in 150 recipients of 75 microg of vaccine, and 0 cases in recipients of 135 microg of vaccine. In this study, a trivalent rHA0 vaccine was safe and immunogenic in a healthy adult population. Preliminary evidence of protection against a drifted influenza A(H3N2) virus was obtained, but the sample size was small. Inclusion of a neuraminidase component did not appear to be required for protection. clinicaltrials.gov Identifier: NCT00328107.

Cold-pressed flaxseed oil reverses age-associated depression in a primary cell-mediated adaptive immune response in the mouse

The objective of this investigation was to determine the influence of flaxseed oil on responses representative of primary humoral and cell-mediated adaptive immune competence in immunosenescent mice. Male and female C57BL/6J mice, 85 weeks old, were randomized between two complete purified diets differing only in oil source (cold-pressed safflower or flaxseed). After 8 weeks, humoral competence was assessed in six mice per group as the serum haemagglutinin titre to sheep red blood cells (SRBC) and cell-mediated competence was assessed, in an additional six mice per group, as the delayed hypersensitivity response to SRBC. A zero-time control group (88 weeks old) and a young adult positive control group (12 weeks old) were each tested similarly (six per immune response), revealing age-related depression in both antibody and cell-mediated competence at 88 weeks of age. After the 8-week experimental period, the antibody response of the two test groups of geriatric mice remained below the young adult level (P=0.04) and the cell-mediated response of the safflower oil group also continued to exhibit age-related depression (20 % of young adult level, P=0.0002). By contrast, the anti-SRBC delayed hypersensitivity response of the flaxseed group no longer differed from the response of the young adults but exceeded that of the safflower and zero-time control senescent groups (P=0.0002). Depression in primary cell-mediated competence, the most outstanding aspect of immunosenescence, can be addressed by means of a dietary source of 18 : 3n-3 without longer-chain PUFA.

Seasonal variation in the innate immune parameters of the Asian catfish Clarias batrachus

To determine if the innate immunity of Asian catfish ( Clarias batrachus) raised in captivity are affected by the rearing temperature or seasons, various indices of the humoral and cellular innate immune functions were measured in fish reared at a wide range of water temperatures over a period of 2 years. Measures of humoral immunity included the estimation of serum myeloperoxidase, lysozyme, haemagglutinin and alternative complement activities. Cellular assay quantified the ability of blood phagocytes to mount superoxide production. Fish were sampled during different periods of two consecutive years, maintained at similar prevailing ranges of water temperature. Experiments were performed at mean temperatures of 19, 24, 28, 31, 32.5 °C during the same time of 2 years. The kinetics of the temperature or season mediated immunomodulation in the innate immune parameters was remarkably fluctuated among the individuals and at different periods or temperatures. Although a clear seasonal variation was marked in the innate immune parameters of this species, the fluctuations of all the parameters are not consistent to any of the temperatures except for lysozyme levels that remained significantly lower during summer compared to other seasons. The probable compensatory mechanism among the innate defence molecules might be playing role to protect from infections during different water temperatures or seasons.

Immunogenicity and tolerability of a trivalent virosomal influenza vaccine in a cohort of HIV-infected children.

Twenty-three children infected with the human immunodeficiency virus (HIV) were vaccinated with a trivalent inactivated virosomal influenza vaccine. Serum haemagglutinin inhibition antibody titres were determined for the three viral strains at the time of vaccination and 1 month later. CD4 cell counts and HIV viral loads were measured to evaluate the effect of vaccination on HIV status. Adverse reactions were monitored during the first hour following vaccination by an investigator and then on a continuous basis by the parents. Seroconversion rates against the three viral strains A/H3N2, A/H1N1 and B were 73.9%, 56.5% and 52.2%, respectively. Geometric mean antibody titres increased after 1 month compared with baseline values (A/H3N2: 70.9 versus 13.5; A/H1N1: 24.7 versus 5.8; B: 34.4 versus 9.1). No significant changes were observed in either HIV viral load or CD4 cell count following vaccination. Vaccination was well tolerated with only a few mild, transient symptoms.

A comparison of the capacity of six cold-pressed plant oils to support development of acquired immune competence in the weanling mouse: superiority of low-linoleic-acid oils

The objective of this investigation was to compare, at several levels of intake, the capacity of diverse cold-pressed plant oils to support development of acquired immune competence assessedin vivoin the weanling mouse. Safflower, maize, soyabean, rapeseed, flaxseed and olive oils were selected to represent widely differing 18: 1n-9, 18: 2n-6 and 18: 3n-3 contents, and each oil was fed at three dietary levels (40, 80 and 160 g/kg) as the exclusive source of fat. C57BL/6J mice, ten males and ten females, had free access to each diet for 28 d beginning at 19 d of age. The primary serum haemagglutinin response to sheep red blood cells and the primary cutaneous delayed hypersensitivity response to dinitrochlorobenzene were used to assess humoral and cell-mediated competence respectively, on day 28. A zero-time control group, assessed immunologically at 19 d of age, was also included (n32). Independently of dietary oil level, flaxseed, rapeseed, olive and soyabean oils supported development of a more vigorous antibody response than safflower (a useful point of reference, being rich in 18: 2n-6 but low in 18: 1n-9 and 18: 3n-3), whereas only flaxseed oil supported development of cell-mediated responsiveness exceeding that of safflower-fed mice. Independently of oil type, development of both immunological indices correlated negatively with intake of 18: 2n-6, and development of humoral competence varied inversely with dietary oil level. A low content of 18: 2n-6, perhaps less than 20 g/100 g fatty acids, appears important to the capacity of a plant oil to support development of acquired immune competence in the young.

Protein Kinase Cζ Phosphorylates Nuclear Factor of Activated T Cells and Regulates Its Transactivating Activity

Although several isoforms of protein kinase C (PKC) have been implicated in T lymphocyte activation events, little is known about their mode of action. To address the role of PKCzeta in T cell activation, we have generated Jurkat T cell transfectants expressing either the wild type (J-PKCzeta) or "kinase-dead" mutant (J-PKCzeta(mut)) versions of this protein. Expression of PKCzeta but not PKCzeta(mut) increased transcriptional activation mediated by the NF-kappaB or nuclear factor of activated T cells (NFAT). PKCzeta cooperates with calcium ionophore and with NFAT1 or NFAT2 proteins to enhance transcriptional activation of a NFAT reporter construct. However, neither NFAT nuclear translocation nor DNA binding were in J-PKCzeta cells. Our results show that PKCzeta enhanced transcriptional activity mediated by Gal4-NFAT1 fusion proteins containing the N-terminal transactivation domain of human NFAT1. Interestingly, PKCzeta synergizes with calcineurin to induce transcriptional activation driven by the NFAT1 transactivation domain. Co-precipitation experiments showed physical interaction between PKCzeta and NFAT1 or NFAT2 isoforms. Even more, PKCzeta was able to phosphorylate recombinant glutathione S-transferase-NFAT1 (1-385) protein. These data reveal a new role of PKCzeta in T cells through the control of NFAT function by modulating the activity of its transactivation domain.

The role of live influenza vaccines in children

Live attenuated cold-adapted influenza vaccines (CAIVs) have been developed over the past two decades by taking advantage of the segmented RNA genome of influenza and creating attenuated reassortants containing contemporary hemagglutinin (HA) and neuraminidase (NA) genes. These vaccines have been shown to be easily administered, safe and immunogenic in adults and children. Recent trials of a trivalent live attenuated CAIV (CAIV-T, tradename FluMist™, Aviron, Mt. View, CA) in children have demonstrated greater than 85% efficacy against culture positive H3N2 and B influenza illness and complications, such as otitis media. CAIV-T also prevented shedding of H1N1 virus in 83% of vaccinated subjects after a monovalent CAIV challenge. Nasal IgA and serum HA inhibition (HAI) antibody produced by these vaccines have been associated with protection against infection, but protection may exist even in the absence of identifiable antibody response. Work to date documenting phenotypic and genetic stability, low likelihood of reactogenicity, infrequent transmissibility and attenuating properties of reassortants heralds promise for the broad use of this vaccine. Targeting children to receive this vaccine may now prove practical and may serve to reduce overall influenza morbidity, given the significant contribution of the pediatric age group of children to influenza illness burden and community spread. Studies of vaccine use in community settings will aid in determining the public health future of this approach.

A TritonX-100-split Virion Influenza Vaccine is Safe and Fulfills the Committee for Proprietary Medicinal Products (CPMP) Recommendations for the European Community for Immunogenicity, in Children, Adults and the Elderly

Influenza epidemics are an important cause of morbidity and mortality throughout the world. Current recommendations from Health Authorities emphasize annual immunization of people who are particularly at risk from an influenza virus infection; however, vaccination of working adults and of school children also has been shown to provide public health benefits. To give it a more advantageous reactogenicity profile than the diethylether-split influenza vaccines available previously, a split virion influenza vaccine has been produced with TritonX-100. In a series of clinical trials, Aventis Pasteur (formerly, Pasteur Mérieux Connaught) tested both the safety and immunogenicity of this TritonX-100-split virion influenza vaccine in 566 subjects (42 children, 296 adults, and 228 elderly adults) during three influenza seasons (1991, 1993, and 1995). The TritonX-100-split virion vaccine was well tolerated: no serious adverse events were recorded during the 21 days following immunization. Among the local reactions observed, mild pain, redness, or induration at the injection site were the most frequently reported. Fever (38·0 to 38·5°C) was noted in five adults or elderly subjects (1%), and in two children (5%). Immunogenicity was determined by measuring serum haemagglutinin antibody titres specific to each vaccine virus strain. In each of the three vaccination campaigns, the TritonX-100-split virion influenza vaccine fulfilled the Notes for Guidance on Harmonization of Requirements for Influenza Vaccines outlined by the Committee for Proprietary Medicinal Products (CPMP) of the European Community for an influenza virus vaccine (i.e., seroprotection, seroconversion, or increase of geometric mean titre) in all age groups.

Epidemiology of influenza-associated encephalitis-encephalopathy in Hokkaido, the northernmost island of Japan.

It is well known that acute onset brain dysfunction, which usually is diagnosed as encephalitis or encephalopathy, occurs in association with influenza. However, this may have been underestimated as a rather infrequent event. Sixty-four infants and children developed encephalitis-encephalopathy during the five recent influenza seasons in Hokkaido, the northernmost island of Japan. Inquiries were sent at the end of each season, from October 1994 to March 1999, to 94 hospitals and institutes in Hokkaido which accept pediatric age patients, asking if there were any admitted cases of encephalitis or encephalopathy. The patients were 42 boys and 22 girls and 47 (73.4%) were 4 years of age or younger. None of them had received an influenza vaccine nor had an oral administration of aspirin. Most of the patients became comatose with or without convulsions within a few days of the onset of fever. Twenty-eight (43.8%) patients died and 13 (20.3%) had neurological sequelae. Patients with clotting disorders, elevations of serum creatine kinase and/or aspartate aminotransferase and alanine aminotransferase, and brain CT abnormalities had a poor prognosis compared with patients without. Among these affected patients, the influenza genome (H3) was detected by polymerase chain reaction in nine cerebrospinal fluid samples, influenza virus A (H3N2) was isolated in 18 nasopharyngeal swab samples and a four-fold or greater rise in serum hemagglutinin inhibition antibody titer against H3N2 was observed in seven patients. It appears urgent to promote vaccination against influenza in young children to prevent these devastating disease conditions.

Sorbitan monostearate/polysorbate 20 organogels containing niosomes: a delivery vehicle for antigens?

Multi-component organogels formed using the non-ionic surfactant sorbitan monostearate as gelator have been formulated to contain niosomes. The purpose of this study was to evaluate the potential of these vesicle-in-water-in-oil (v/w/o) gels as delivery vehicles for vaccines. Bovine serum albumin (BSA) and haemagglutinin (HA) were used as model antigens in depot and immunogenicity studies respectively. The complex gels were prepared by the addition of a hot (60°C) aqueous niosome suspension (v/w) to the sol phase ( o, an organic solution of the gelator); a vesicle-in-water-in-oil (v/w/o) emulsion was produced which cools to an opaque, semi-solid, thermoreversible v/w/o gel. Light microscopy of the organogel revealed that the microstructure consists of a tubular network of surfactant aggregates in the organic medium, the niosome suspension being dispersed in these surfactant tubules. Therefore, in such gels, the vaccine is thought to be entrapped in the niosomes, themselves located within the sorbitan monostearate tubular network in the organic medium. In vivo, a depot effect was observed following intramuscular administration of the gel containing the entrapped bovine serum albumin, cleared from the injection site over a period of days. The relatively short-lived nature of the depot was thought to arise due to interactions between the gel and the local interstitial fluid which results in gel disintegration in situ. Thus, the niosomes containing antigens are believed to be released from the organic gel. Immunogenicity studies showed that the v/w/o gel as well as one of the controls, the water-in-oil (w/o) gel, possess immunoadjuvant properties and enhance the primary and secondary antibody titres (of total IgG, IgG 1, IgG 2a and IgG 2b) to haemagglutinin antigen. As far as humoral immunity is concerned, the w/o gel showed stronger immunoadjuvant properties compared to the v/w/o gel, being effective at a lower antigen dose i.e 0.1μg HA.

Effects of levamisole, DTC and low-dose mechlorethamine on humoral response of SRBC-immunized rabbits exposed to cold stress.

The experiments were carried out on normothermal rabbits and rabbits exposed to cold stress (hypothermia). The animals of the latter group were submerged in ice-water for 20 s and then placed in a freezer at -15 degrees C for 8 min until their body temperature dropped by 3 degrees C. Both the normothermal and hypothermal rabbits were immunized i.p. with 3 ml of 10% sheep red blood cells (SRBC). Levamisole (2 mg/kg), DTC (sodium diethyldithiocarbamate, 20 mg/kg) or mechlorethamine (mustine; 5 micrograms/kg) were injected i.v. three times at 24-h intervals. The number of PFC, total (19S + 7S) and 2-mercapthoethanol resistant (7S) serum haemagglutination titres were determined. It was found that, in normothermal rabbits, all three agents potentiated the number of plaque-forming cells (PFC); the impact of DTC was the strongest, while the weakest influence was observed for mechlorethamine. Furthermore, DTC increased anti-SRBC haemagglutinin titre, whereas mechlorethamine did not. Levamisole, on the other hand, reduced total serum haemagglutinin titre. Cold stress reduced humoral response to SRBC, which was reflected in the decreased number of PFC and serum haemagglutination titres (19S + 7S and 7S). Each agent showed a different way of action. Pretreatment with DTC prevented the immunosuppression caused by cold stress, while levamisole and mechlorethamine only reduced the immunosuppressive effect.

Immunorestorative Effect of Triiodothyronine Supplementation on the Primary Antibody Response to Sheep Red Blood Cells Following the Development of Immunodepression in Protein-Energy Malnourished Weanling Mice

Abstract The objective of the present investigation was to determine whether acquired immunity can be restored in weanling protein-energy malnutrition (PEM) despite continued wasting disease. Weanling CBA/J mice were subjected to wasting PEM by means of restricted daily intake of a complete diet. The experimental design included ad libitum-fed positive controls. After 9 days all mice were immunized with sheep red blood cells (SRBC). A subgroup of malnourished mice was then given supplements of the endocrine hormone, triiodothyronine (T3), by way of the diet for the remaining 5 days of the experiment. Comparable wasting was achieved, throughout the 14-day experimental period, in the T3-supplemented and -unsupplemented malnourished groups. The latter group exhibited profound depression in primary anti-SRBC antibody response according to the criteria of splenic direct plaque-forming cell count and serum hemagglutinin titer. By contrast, despite extreme splenic atrophy, the T3-supplemented group generated an ...

A High α-Linolenate Diet Suppresses Antigen-Induced Immunoglobulin E Response and Anaphylactic Shock in Mice

Mice were fed for 2 mo diets having ratios of alpha-linolenate [18:3 (n-3)] to linoleate [18:2(n-6)] of < 0.01, 0.36, 1.0 and 3.9. Proportions of safflower seed oil and perilla seed oil were adjusted to obtain these ratios. The dietary alpha-linolenate to linoleate balance was reflected in the proportion of (n-3) and (n-6) highly unsaturated fatty acids with 20- and 22-carbon chains in spleen phospholipids, but the ratio did not affect the proportion of T lymphocyte subsets expressing CD4 and CD8 antigens in splenic leukocytes. The immunoglobulin (Ig) G and IgM responses against sheep red blood cells when estimated as plaque-forming cells present in spleen, were not affected significantly by the diets. However, the serum hemagglutinin titer was slightly but significantly higher in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the dietary group with 18:3(n-3) to 18:2(n-6) ratios of 0.36 and < 0.01. In contrast, the IgE antibody response against egg albumin, as well as the mortality from anaphylactic shock induced by a second challenge with antigen, was significantly lower in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the high linoleate diet [18:3(n-3)/18:2(n-6) < 0.01] group. These results, together with the reported suppressive effects of a high alpha-linolenate diet on the formation of lipid-derived allergic mediators, support the hypothesis that raising the (n-3) to (n-6) ratios of diets would be effective in reducing the severity of immediate-type allergic hypersensitivity.

Characterization of a natural hemagglutinin in the serum of a freshwater crab Parathelphusa hydrodromus (Herbst).

A naturally occurring hemagglutinin (HA) was detected in the serum of the freshwater crab Parathelphusa hydrodromus using mammalian erythrocytes (RBC) as indicator cells. The serum gave the highest HA titer with rabbit RBC. In cross adsorption tests, this RBC type completely adsorbed all HA activities from serum. An analysis of the physico-chemical properties of HA showed it to be specifically dependent on the presence of Ca2+ for its activity, irreversibly sensitive to EDTA, stable between pH 7.5 and 10.0, and heat-labile. Further studies demonstrated that the HA is proteinaceous as it was precipitable by conventional deproteinizing agents, and susceptible to the action of proteases and 2-mercaptoethanol. HA-inhibition assays performed with 44 carbohydrates revealed that the serum HA was specific for non-reducing terminal glucose with alpha 1-2 glycosidic linkage. Thus this agglutinin appears to be unique among all the known crustacean agglutinins.

Enhancing effects of pertussis toxin B oligomer on the immunogenicity of influenza vaccine administered intranasally

Influenza vaccines together with pertussis toxin B oligomer (PTB) purified from a culture supernatant of Bordetella pertussis were administered intranasally into mice to test for an adjuvant effect of the PTB. An inactivated virus vaccine and an ether-treated HA vaccine prepared from influenza virus A/Yamagata/120/86 (H1N1) and formulated with PTB, stimulated production of serum haemagglutinin inhibition (HI) antibody and pulmonary and endotracheal secretory IgA antibody to high titres. In addition, mice immunized with the influenza vaccines formulated with PTB were protected against exposure with a challenge virus. These results demonstrate that PTB can enhance the immunogenicity of influenza vaccines administered intranasally.