Mucosal vaccination with a recombinant OprF-I vaccine of Pseudomonas aeruginosa in healthy volunteers: comparison of a systemic vs. a mucosal booster schedule

We compared the immunogenicity of two vaccination schedules with either a systemic or a mucosal booster, both following a mucosal primary vaccination with a recombinant outer membrane fusion protein of Pseudomonas aeruginosa (OprF-I) in 12 healthy volunteers. The systemic booster induced higher levels of OprF-I-specific serum antibodies of IgG isotype, with a mean+/-S.E.M. of 32.6+/-7.8x10(7) enzyme-linked immunosorbent assay (ELISA) units (EU) as compared to the nasal booster with 14.6+/-2.1x10(7) EU (P=0.05). Specific serum IgA antibodies and antibodies in saliva did not differ between the two vaccination groups. We conclude that a combined mucosal/systemic vaccination with the OprF-I vaccine may offer an enhanced systemic immunogenicity. Further studies on the long-term immunogenicity and induction of antibodies on the respiratory airway surface are warranted.     

Anti-spike S1 IgA,anti-spike trimeric IgG,and anti-spike RBD IgG response after BNT162b2 COVID-19 mRNA vaccination in healthcare workers

BackgroundMost studies on immune response after coronavirus disease 2019 (COVID-19) vaccination focused on serum IgG antibodies and cell-mediated immunity, discounting the role of anti-SARS-CoV-2 neutralizing IgA antibodies in preventing viral infection. This study was aimed to quantify serum IgG and IgA neutralizing antibodies after mRNA COVID-19 vaccination in baseline SARS-CoV-2 seronegative healthcare workers.MethodsThe study population consisted of 181 SARSCoV-2 seronegative healthcare workers (median age 42 years, 59.7% women), receiving two doses of Pfizer COVID-19 vaccine BNT162b2 (Comirnaty). Serum samples were collected before receiving the first vaccine dose, 21 days (before the second vaccine dose) and 50 days afterwards. We then measured anti-spike trimeric IgG (Liaison XL, DiaSorin), anti-spike receptor binding domain (RBD) IgG (Access 2, Beckman Coulter) and anti-spike S1 subunit IgA (ELISA, Euroimmun). Results were presented as median and interquartile range (IQR).ResultsVaccine administration elicited all anti-SARS-CoV2 antibodies measured. Thirty days after the second vaccine dose, 100% positivization occurred for anti-spike trimeric IgG and anti-spike RBD IgG, whilst 1.7% subjects remained anti-spike S1 IgA negative. The overall increase of antibodies level ratio over baseline after the second vaccine dose was 576.1 (IQR, 360.7-867.8) for anti-spike trimeric IgG, 1426.0 (IQR, 742.0-2698.6) for anti-spike RBD IgG, and 20.2 (IQR, 12.5-32.1) for anti-spike S1 IgA. Significant inverse association was found between age and overall increase of anti-spike trimeric IgG (r=-0.24; p=0.001) and anti-spike S1 IgA (r=-0.16; p=0.028), but not with anti-spike RBD IgG (r=-0.05; p=0.497).ConclusionsmRNA COVID-19 vaccination elicits sustained serum levels of anti-spike trimeric IgG and anti-spike RBD IgG, while also modestly but significantly increasing those of anti-spike S1 IgA.     

Different Dynamics for IgG and IgA Memory B Cells in Adolescents following a Meningococcal Serogroup C Tetanus Toxoid Conjugate Booster Vaccination Nine Years after Priming: A Role for Priming Age?

Background

Antibody levels wane rapidly after Meningococcal serogroup C conjugate (MenCC) vaccination in young children, rendering the need for an adolescent booster dose. It is not clear whether circulating memory B cells are associated with persistence of MenC-specific antibody levels.

Methods

Measurement of MenC-specific IgG and IgA memory B cells and levels of serum and salivary MenC-specific IgG and IgA in healthy 10-, 12- and 15-year-olds prior to and one month and one year after a MenCC booster vaccination. All participants had received a primary MenCC vaccination nine years earlier.

Results

The number of circulating MenC-specific IgG memory B cells prior to booster was low and not predictive for MenC-specific IgG responses in serum or saliva post-booster, whereas the number of MenC-specific IgA memory B cells pre-booster positively correlated with MenC-specific IgA levels in saliva post-booster (R = 0.5, P<0.05). The booster induced a clear increase in the number of MenC-specific IgG and IgA memory B cells. The number of MenC-PS-specific IgG memory B cells at 1 month post-booster was highest in the 12-year-olds. The number of MenC-specific memory B cells at one month post-booster showed no correlation with the rate of MenC-specific antibody decay throughout the first year post-booster.

Conclusions

Circulating MenC-specific IgA memory B cells correlate with IgA responses in saliva, whereas circulating MenC-specific IgG memory B cells are not predictive for MenC-specific IgG responses in serum or saliva. Our results are suggestive for age-dependent differences in pre-existing memory against MenC.     

Human immune responses elicited by an intranasal inactivated H5 influenza vaccine

Intranasally administered influenza vaccines could be more effective than injected vaccines, because intranasal vaccination can induce virus-specific immunoglobulin A (IgA) antibodies in the upper respiratory tract, which is the initial site of infection. In this study, immune responses elicited by an intranasal inactivated vaccine of influenza A(H5N1) virus were evaluated in healthy individuals naive for influenza A(H5N1) virus. Three doses of intranasal inactivated whole-virion H5 influenza vaccine induced strong neutralizing nasal IgA and serum IgG antibodies. In addition, a mucoadhesive excipient, carboxy vinyl polymer, had a notable impact on the induction of nasal IgA antibody responses but not on serum IgG antibody responses. The nasal hemagglutinin (HA)-specific IgA antibody responses clearly correlated with mucosal neutralizing antibody responses, indicating that measurement of nasal HA-specific IgA titers could be used as a surrogate for the mucosal antibody response. Furthermore, increased numbers of plasma cells and vaccine antigen-specific Th cells in the peripheral blood were observed after vaccination, suggesting that peripheral blood biomarkers may also be used to evaluate the intranasal vaccine-induced immune response. However, peripheral blood immune cell responses correlated with neutralizing antibody titers in serum samples but not in nasal wash samples. Thus, analysis of the peripheral blood immune response could be a surrogate for the systemic immune response to intranasal vaccination but not for the mucosal immune response. The current study suggests the clinical potential of intranasal inactivated vaccines against influenza A(H5N1) viruses and highlights the need to develop novel means to evaluate intranasal vaccine-induced mucosal immune responses.     

The utility of saliva for the assessment of anti-pneumococcal antibodies: investigation of saliva as a marker of antibody status in serum

Context: Salivary antibodies may act as non-invasive marker of systemic immunity enabling assessment of vaccination and protection against bacterial infections.

Objective: To assess if levels of anti-pneumococcal (Pn) antibodies in saliva reflect concentrations in serum and determine whether saliva can accurately identify protective concentrations in serum.

Methods: IgG, IgA and IgM antibody levels in paired saliva and serum samples were measured against 12 Pn polysaccharide antigens in 72 healthy adults.

Results: Antibody levels in saliva correlated positively with serum across immunoglobulin classes, most strongly for IgA. Individuals who had protective antibody levels in serum demonstrated significantly higher IgG and IgA salivary antibody concentrations/secretion rates. Salivary IgG and IgA Pn antibodies were able to distinguish between those with/without protective levels in serum for the majority of serotypes. Salivary IgM antibodies were not able to differentiate protective status. Median IgG and IgA Pn salivary parameters were able to identify individuals who had protective levels in serum on ≥8/12 serotypes with moderate accuracy: median IgA secretion rates provided the best sensitivity (73%) and specificity (71%).

Conclusions: These findings suggest that IgG and IgA Pn specific antibodies in saliva may be useful surrogate markers of antibody status in serum.     

Induction of systemic and mucosal immune response and decrease in Streptococcus pneumoniae colonization by nasal inoculation of mice with recombinant lactic acid bacteria expressing pneumococcal surface antigen A

Mucosal epithelia constitute the first barriers to be overcome by pathogens during infection. The induction of protective IgA in this location is important for the prevention of infection and can be achieved through different mucosal immunization strategies. Lactic acid bacteria have been tested in the last few years as live vectors for the delivery of antigens at mucosal sites, with promising results. In this work, Streptococcus pneumoniae PsaA antigen was expressed in different species of lactic acid bacteria, such as Lactococcus lactis, Lactobacillus casei, Lactobacillus plantarum, and Lactobacillus helveticus. After nasal inoculation of C57Bl/6 mice, their ability to induce both systemic (IgG in serum) and mucosal (IgA in saliva, nasal and bronchial washes) anti-PsaA antibodies was determined. Immunization with L. lactis MG1363 induced very low levels of IgA and IgG, possibly by the low amount of PsaA expressed in this strain and its short persistence in the nasal mucosa. All three lactobacilli persisted in the nasal mucosa for 3 days and produced a similar amount of PsaA protein (150-250 ng per 10(9) CFU). However, L. plantarum NCDO1193 and L. helveticus ATCC15009 elicited the highest antibody response (IgA and IgG). Vaccination with recombinant lactobacilli but not with recombinant L. lactis led to a decrease in S. pneumoniae recovery from nasal mucosa upon a colonization challenge. Our results confirm that certain Lactobacillus strains have intrinsic properties that make them suitable candidates for mucosal vaccination experiments.     

One-year follow-up of anti-Leishmania antibody concentrations in serum and saliva from experimentally infected dogs

The quantification of anti-Leishmania antibodies in serum and saliva by a time-resolved immunofluorometric assay is useful for the diagnosis and treatment monitoring of dogs with clinical leishmaniasis. We compared the kinetics of anti-Leishmania IgG2 and IgA antibodies in serum and saliva from 11 Beagle dogs experimentally infected with Leishmania infantum. Most dogs showed detectable concentrations of anti-Leishmania IgG2 earlier in serum (between 3 and 4 months p.i.) than in saliva (between 4 and 6 months p.i.). Overall, a high correlation between concentrations of anti-Leishmania IgG2 in serum and saliva (r = 0.853; P < 0.0001) was observed. The quantification of anti-Leishmania IgA showed less diagnostic value than IgG2, since detectable amounts of IgA were not observed in the saliva of four dogs and in the serum of one dog. In addition, a very low correlation between anti-Leishmania IgA in serum and saliva (r = 0.289; P < 0.001) was observed. Our results indicate that the antibodies against L. infantum in saliva appear approximately 1 month later than in serum, and suggest that there is a threshold for the passing of immunoglobulins from serum to saliva in dogs. These facts should be taken into consideration for a proper interpretation of saliva assays for quantification of antibodies.     

Antimicrobial Effect of Human Serum IgA

Serum IgA, IgG and colostrum secretory IgA prepared from specimens pooled from a large number of human beings were shown to have measurable levels of antibodies against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, poliovirus, Coxsackie B virus, echovirus and influenza virus. Serum IgA exerted a bacteriostatic effect in vitro on E. coli and P. aeruginosa, which increased in the presence of the iron-binding proteins lactoferrin and transferrin. This bacteriostasis was reduced when the iron-binding proteins were saturated with iron. Similar results were obtained with IgG and secretory IgA. The bacteriostatic effect of serum IgA was also shown in vivo, in the peritoneal cavity of mice. The effect was suppressed by iron. Iron-chelating substances, siderophores, excreted by E. coli diminished the cosoperative bacteriostatic effect of serum IgA and transferrin. Siderophore production by E. coli was inhibited in the presence of serum IgA, but not when serum IgA was deprived of specific antibody by absorption with E. coli. These results indicate that serum IgA has a potent bacteriostatic effect in cooperation with transferrin or lactoferrin because of the inhibitory effect of the specific antibody on siderophore production by E. coli.     

The relationship between airway immunoglobulin activity and eosinophils in COPD

In chronic obstructive pulmonary disease (COPD), the effects of inhaled corticosteroids are predicted by blood eosinophil counts. We previously briefly reported increased immunoglobulin (Ig)A and IgM levels in bronchoalveolar lavage (BAL) of COPD patients with higher (eosinophil^high) compared to lower (eosinophil^low) blood eosinophils (>250/μL versus < 150/μL), suggesting differences in adaptive immune function. An inverse relationship exists between eosinophil counts and airway pathogenic bacteria levels. The mechanistic reasons for these associations between eosinophils, corticosteroids and pathogenic bacteria are unclear. IgA, IgM and IgG levels were assessed in BAL, bronchial biopsies and epithelium collected from eosinophil^high (n = 20) and eosinophil^low (n = 21) patients. Bronchial B-cell numbers were measured by immunohistochemistry. B-cell activity was assessed in bronchial samples and following exposure to BAL from eosinophil^high and eosinophil^low patients. BAL levels of non-typeable Haemophilus influenza (NTHi)-specific immunoglobulins were quantified. Results showed airway expression of IgA, IgG1 and IgM were lower in eosinophil^low compared to eosinophil^high patients, with lower levels of NTHi-specific IgA and IgM. Bronchial B-cell numbers were similar in both groups, but B-cell activity was lower in eosinophil^low patients. In conclusion, COPD eosinophil^low patients show differences in adaptive immune function compared to COPD eosinophil^high patients. These differences may cause different microbiomes in these COPD phenotypes.     

Rheumatoid arthritis–associated autoantibodies in non–rheumatoid arthritis patients with mucosal inflammation: a case–control study

IntroductionRheumatoid arthritis–associated autoantibodies (RA-AAB) can be present in serum years before clinical onset of rheumatoid arthritis (RA). It has been hypothesized that initiation of RA-AAB generation occurs at inflamed mucosal surfaces, such as in the oral cavity or lungs. The aim of this study was to assess systemic presence of RA-AAB in patients without RA who had oral or lung mucosal inflammation.MethodsThe presence of RA-AAB (immunoglobulin A [IgA] and IgG anti-cyclic citrullinated peptide 2 antibodies (anti-CCP2), IgM and IgA rheumatoid factor (RF), IgG anti-carbamylated protein antibodies and IgG and IgA anti-citrullinated peptide antibodies against fibrinogen, vimentin and enolase) were determined in sera of non-RA patients with periodontitis (PD, n = 114), bronchiectasis (BR, n = 80) or cystic fibrosis (CF, n = 41). Serum RA-AAB levels were compared with those of periodontally healthy controls (n = 36). Patients with established RA (n = 86) served as a reference group. Association of the diseases with RA-AAB seropositivity was assessed with a logistic regression model, adjusted for age, sex and smoking.ResultsLogistic regression analysis revealed that IgG anti-CCP seropositivity was associated with BR and RA, whereas the association with PD was borderline significant. IgA anti-CCP seropositivity was associated with CF and RA. IgM RF seropositivity was associated with RA, whereas the association with BR was borderline significant. IgA RF seropositivity was associated with CF and RA. Apart from an influence of smoking on IgA RF in patients with RA, there was no influence of age, sex or smoking on the association of RA-AAB seropositivity with the diseases. Anti-CarP levels were increased only in patients with RA. The same held for IgG reactivity against all investigated citrullinated peptides.ConclusionAlthough overall levels were low, RA-AAB seropositivity was associated with lung mucosal inflammation (BR and CF) and may be associated with oral mucosal inflammation (PD). To further determine whether mucosal inflammation functions as a site for induction of RA-AAB and precedes RA, longitudinal studies are necessary in which RA-AAB of specifically the IgA isotype should be assessed in inflamed mucosal tissues and/or in their inflammatory exudates.     

Prime-Boost Vaccination with Toxoplasma Lysate Antigen,but Not with a Mixture of Recombinant Protein Antigens,Leads to Reduction of Brain Cyst Formation in BALB/c Mice

IntroductionInfection with the ubiquitous parasite Toxoplasma gondii is a threat for immunocompromised patients and pregnant women and effective immune-prophylaxis is still lacking.MethodsHere we tested a mixture of recombinant T. gondii antigens expressed in different developmental stages, i.e., SAG1, MAG1 and GRA7 (SMG), and a lysate derived from T. gondii tachyzoites (TLA) for prophylactic vaccination against cyst formation. Both vaccine formulations were applied systemically followed by an oral TLA-booster in BALB/c mice.ResultsSystemic priming with SMG and oral TLA-booster did not show significant induction of protective immune responses. In contrast, systemic priming and oral booster with TLA induced higher levels of Toxoplasma-specific IgG, IgG1 and IgG2a in sera as well as high levels of Toxoplasma-specific IgG1 in small intestines. Furthermore, high levels of Toxoplasma-specific Th1-, Th17- and Th2-associated cytokines were only detected in restimulated splenocytes of TLA-vaccinated mice. Importantly, in mice orally infected with T. gondii oocysts, only TLA-vaccination and booster reduced brain cysts. Furthermore, sera from these mice reduced tachyzoites invasion of Vero cells in vitro, indicating that antibodies may play a critical role for protection against Toxoplasma infection. Additionally, supernatants from splenocyte cultures of TLA-vaccinated mice containing high levels of IFN-γ lead to substantial production of nitric oxide (NO) after incubation with macrophages in vitro. Since NO is involved in the control of parasite growth, the high levels of IFN-γ induced by vaccination with TLA may contribute to the protection against T. gondii.ConclusionIn conclusion, our data indicate that prime-boost approach with TLA, but not with the mixture of recombinant antigens SMG, induces effective humoral and cellular Toxoplasma-specific responses and leads to significant reduction of cerebral cysts, thereby presenting a viable strategy for further vaccine development against T. gondii infection.     

Mucosal Immunization of Lactating Female Rhesus Monkeys with a Transmitted/Founder HIV-1 Envelope Induces Strong Env-Specific IgA Antibody Responses in Breast Milk

We previously demonstrated that vaccination of lactating rhesus monkeys with a DNA prime/vector boost strategy induces strong T-cell responses but limited envelope (Env)-specific humoral responses in breast milk. To improve vaccine-elicited antibody responses in milk, hormone-induced lactating rhesus monkeys were vaccinated with a transmitted/founder (T/F) HIV Env immunogen in a prime-boost strategy modeled after the moderately protective RV144 HIV vaccine. Lactating rhesus monkeys were intramuscularly primed with either recombinant DNA (n = 4) or modified vaccinia virus Ankara (MVA) poxvirus vector (n = 4) expressing the T/F HIV Env C.1086 and then boosted twice intramuscularly with C.1086 gp120 and the adjuvant MF59. The vaccines induced Env-binding IgG and IgA as well as neutralizing and antibody-dependent cellular cytotoxicity (ADCC) responses in plasma and milk of most vaccinated animals. Importantly, plasma neutralization titers against clade C HIV variants MW965 (P = 0.03) and CAP45 (P = 0.04) were significantly higher in MVA-primed than in DNA-primed animals. The superior systemic prime-boost regimen was then compared to a mucosal-boost regimen, in which animals were boosted twice intranasally with C.1086 gp120 and the TLR 7/8 agonist R848 following the same systemic prime. While the systemic and mucosal vaccine regimens elicited comparable levels of Env-binding IgG antibodies, mucosal immunization induced significantly stronger Env-binding IgA responses in milk (P = 0.03). However, the mucosal regimen was not as potent at inducing functional IgG responses. This study shows that systemic MVA prime followed by either intranasal or systemic protein boosts can elicit strong humoral responses in breast milk and may be a useful strategy to interrupt postnatal HIV-1 transmission.     

Commensal Streptococcus mitis is a unique vector for oral mucosal vaccination

The development of vaccine approaches that induce mucosal and systemic immune responses is critical for the effective prevention of several infections. Here, we report on the use of the abundant human oral commensal bacterium Streptococcus mitis as a delivery vehicle for mucosal immunization. Using homologous recombination we generated a stable rS. mitis expressing a Mycobacterium tuberculosis protein (Ag85b). Oral administration of rS. mitis in gnotobiotic piglets resulted in efficient oral colonization and production of oral and systemic anti-Ag85b specific IgA and IgG antibodies. These results support that the commensal S. mitis is potentially a useful vector for mucosal vaccination.     

Intranasal immunization with a lipooligosaccharide-based conjugate vaccine from nontypeable Haemophilus influenzae enhances bacterial clearance in mouse nasopharynx

Nontypeable Haemophilus influenzae (NTHi) is a major cause of otitis media in children. We investigated whether intranasal immunization with a detoxified lipooligosaccharide-tetanus toxoid (dLOS-TT) conjugate vaccine would generate protective immunity against NTHi in a mouse model of nasopharyngeal clearance. The results demonstrated that intranasal immunization with dLOS-TT plus adjuvant cholera toxin (CT) significantly induced LOS-specific IgA antibodies in mouse external secretions, especially in nasal wash (90-fold), bronchoalveolar lavage fluid (25-fold), saliva (13-fold) and fecal extract (three-fold). LOS-specific IgA antibody-forming cells were also found in mucosal and lymphoid tissues with their highest numbers in the nasal passage (528 per 10(6) cells). In addition, the intranasal immunization elicited a significant rise in LOS-specific IgG (32-fold) and IgA (13-fold) in serum. For the immunized mice which had been challenged through the nose with 10(7) live NTHi strain 9274 cells, the vaccine group showed a significant reduction (74-77%) of NTHi, compared to that of control groups with CT alone or dLOS plus CT (P<0.05). Negative correlations were found between bacterial counts and the levels of nasal wash IgA or IgG, saliva IgA and serum IgG. The clearance of five heterologous strains was investigated and revealed a significant clearance of strains 3198, 5657 and 7502 but not of strains 1479 and 2019. These data suggest that intranasal immunization with dLOS-TT vaccine elicits both mucosal and systemic immunity against NTHi and enhances bacterial clearance from nasopharynx in mice. Such a vaccine and vaccination regime may be applicable to humans with an appropriate formulation.     

Protection of mice from respiratory Sendai virus infections by recombinant vaccinia viruses.

Mechanisms of protection of mice from Sendai virus, which is exclusively pneumotropic and causes a typical respiratory disease, by immunization with recombinant vaccinia viruses (RVVs) were investigated. Although the RVV carrying a hemagglutinin-neuraminidase gene of Sendai virus (Vac-HN) propagated in the noses and lungs of mice by either intranasal (i.n.) or intraperitoneal (i.p.) inoculation, no vaccinia virus antigens were detected in the mucosal layer of upper and lower airways of the i.p.-inoculated mice. The mice immunized i.n. with Vac-HN or Vac-F (the RVV carrying a fusion protein gene of Sendai virus) demonstrated the strong resistance to Sendai virus challenge both in the lung and in the nose, whereas the i.p.-immunized mice showed almost no resistance in the nose but showed a partial resistance in the lung. Titration of Sendai virus-specific antibodies in the nasal wash (NW), bronchoalveolar lavage (BAL), and serum collected from the Vac-F-immunized mice showed that the NW from the i.n.-immunized mice contained immunoglobulin A (IgA) antibodies but no IgG and the BAL from the mice contained both IgA and IgG antibodies. On the other hand, neither IgA nor IgG antibodies were detected in the NW from the i.p.-immunized mice and only IgG antibodies were detected in the BAL, although both i.n.- and i.p.-immunized mice exhibited similar levels of serum IgG, IgA, and neutralizing antibodies. The resistance to Sendai virus in the noses of i.n.-immunized mice could be abrogated by the intranasal instillation of anti-mouse IgA but not of anti-IgG antiserum, while the resistance in the lung was not significantly abrogated by such treatments. These results demonstrate that IgA is a major mediator for the immunity against Sendai virus induced by the RVVs and IgG is a supplementary one, especially in the lung, and that the RVV should be intranasally inoculated to induce an efficient mucosal immunity even if it has a pantropic nature.     

Generation and Characterization of Antibodies against Asian Elephant (Elephas maximus) IgG,IgM, and IgA

Asian elephant (Elephas maximus) immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV), which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV.     

老年支气管哮喘患者血清 MC-CP、S1P水平与 T细胞免疫分子及气道基底膜厚度的关系

摘要 目的：探讨老年支气管哮喘患者血清肥大细胞羧肽酶（MC-CP）、1-磷酸鞘氨醇（S1P）水平,并分析与 T细胞免疫分子及气道基底膜厚度的关系。方法：选择 2016年 8月至 2018年 12月我院收治的老年支气管哮喘患者 86例,根据哮喘控制情况分为急性发作期组 48例和缓解期组 38例,选择同期医院体检的健康老年人 40例作为对照组,检测并比较各组血清 MC-CP、S1P水平、肺功能、T细胞免疫分子、支气管黏膜网状基底膜厚度（BMT）,并分析血清 MC-CP、S1P水平与肺功能指标、T细胞免疫分子及BMT的相关性。结果：急性发作组、缓解组患者血清 MC-CP、S1P水平及 BMT、CD8⁺均高于对照组,且急性发作组患者血清MC-CP、S1P、CD8+水平高于缓解期组（P＜0.05）。急性发作期组和缓解期组 FEV1%pred、CD4⁺、CD4⁺/ CD8⁺,血清免疫球蛋白 A（IgA）、免疫球蛋白 M（IgM）、免疫球蛋白 G（IgG）水平低于对照组,且急性发作期组上述指标低于缓解期组（P＜0.05）。老年支气管哮喘患者血清 MC-CP、S1P与 CD8⁺、BMT呈正相关（P＜0.05）,与 FEV1%pred、CD4⁺、CD4⁺/CD8⁺、IgA、IgM、IgG呈负相关（P＜0.05）。结论：老年支气管哮喘患者的血清 MC-CP、S1P水平显著升高,其水平与与肺功能、免疫功能和气道重塑相关,且血清MC-CP与 S1P水平密切相关。     

Class IgG,IgM and IgA antibodies againstStaphylococcus aureus antigens in human serum and saliva

Using the ELISA method antibodies against the sonicate, teichoic acid (TA) and exoproducts ofStaphylococcus aureus were determined in sera and saliva of healthy individuals. Main serum antibodies against all the antigens used were shown to be class IgG antibodies. However, antigens of the sonicate stimulated significantly even the systemic IgA response. In the saliva class IgA antibodies predominated, but IgG antibody levels against TA and exoproducts approached the level of IgA antibodies. Levels of IgM antibodies against all antigens tested were low in both the serum and saliva which corresponds with the anamnestic type of response. On the basis of these results one may assume that not only IgG, but also IgA antibodies are important in the systemic immunity against staphylococcal infection and in the immunity of mucous membranes; besides IgA, even class IgG antibodies play an important role.     

Mucosal adjuvant activity of oligomannose-coated liposomes for nasal immunization

In the present study, we investigated the effectiveness of liposomes coated with a neoglycolipid consisting of mannotriose and dipalmitoylphosphatidylcholine (Man3-DPPE) as an adjuvant for induction of mucosal immunity. Immunization of BALB/c mice with ovalbumin (OVA)-encapsulated Man3-DPPE-coated liposomes (oligomannose-coated liposomes; OMLs) by a nasal route produced high levels of OVA-specific IgG and IgA antibodies in serum of immunized mice 1 week after the last nasal immunization, whereas no significant serum antibody responses were observed in mice that received OVA in uncoated liposomes or OVA alone. Seven weeks after the last nasal immunization, nasal challenge with an excess amount of OVA in mice that had received OVA/OMLs led to an anamnestic response to the antigen that resulted in 5- to 10-fold increases of antigen-specific serum IgG and IgA antibodies. Only mice immunized nasally with OML/OVA secreted antigen-specific secretory IgA in nasal washes and produced interferon-gamma secreting cells in nasopharyngeal-associated lymphoreticular tissue. Taken together, these results show that nasal administration of OMLs induces mucosal and systemic immunity that are specific for the entrapped antigen in the liposomes. Thus, liposomes coated with synthetic neoglycolipids might be useful as adjuvants for induction of mucosal immunity.     

Salivary Immune Responses to the 7-Valent Pneumococcal Conjugate Vaccine in the First 2 Years of Life

Background

The CRM197-conjugated 7-valent pneumococcal vaccine (PCV7) is protective against vaccine serotype disease and nasopharyngeal carriage. Data on PCV7-induced mucosal antibodies in relation to systemic or natural anticapsular antibodies are scarce.

Methods

In a randomized controlled setting, children received PCV7 at age 2 and 4 months (2-dose group), at age 2, 4 and 11 months (2+1-dose group) or no PCV7 (control group). From 188 children paired saliva samples were collected at 12 and 24 months of age. From a subgroup of 15 immunized children also serum samples were collected. IgG and IgA antibody-levels were measured by multiplex immunoassay.

Results

At 12 months, both vaccine groups showed higher serum and saliva IgG-levels against vaccine serotypes compared with controls which sustained until 24 months for most serotypes. Salivary IgG-levels were 10–20-fold lower compared to serum IgG, however, serum and saliva IgG-levels were highly correlated. Serum and salivary IgA-levels were higher in both vaccine groups at 12 months compared with controls, except for serotype 19F. Higher salivary IgA levels remained present for most serotypes in the 2+1-dose group until 24 months, but not in the 2-dose group. Salivary IgA more than IgG, increased after documented carriage of serotypes 6B, 19F and 23F In contrast to IgG, salivary IgA-levels were comparable with serum, suggesting local IgA-production.

Conclusions

PCV7 vaccination results in significant increases in salivary IgG and IgA-levels, which are more pronounced for IgG when compared to controls. In contrast, salivary anticapsular IgA-levels seemed to respond more to natural boosting. Salivary IgG and IgA-levels correlate well with systemic antibodies, suggesting saliva might be useful as potential future surveillance tool.