High Serum IgA Levels Research Articles

Serum IgA/C3 ratio: a useful marker of disease activity in patients with IgA nephropathy.

High serum IgA and low serum C3 levels resulting from lectin and alternative pathway activation might be related to IgA nephropathy (IgAN) progression and exacerbation. This study examined whether the serum IgA/C3 ratio can serve as an IgAN progression marker. (1) This nationwide multicenter retrospective study in Japan included 718 patients with biopsy-confirmed IgAN. The patients whose serum creatinine levels at the time of renal biopsy had doubled were defined as having disease progression. (2) Furthermore, to investigate the pathological significance of a reduction in serum IgA/C3 ratio, we reviewed 63 patients whose serum IgA and C3 data at the end of the observation period were obtained. (1) A Kaplan-Meier analysis of the patients with IgAN revealed that the group with a high serum IgA/C3 (≥ 3.3) had a significantly worse renal outcome. In a multivariate analysis of eGFR ≥ 60mL/min per 1.73m2 at the time of biopsy, poor renal outcome was significantly predicted by a serum IgA/C3 ratio of ≥ 3.3. (2) A 15% reduction in the change of serum IgA/C3 ratio was associated with a significantly higher percentage of complete remission of proteinuria. Among the four groups divided by treatment, both the serum IgA/C3 ratio and proteinuria were reduced only in the tonsillectomy and steroid pulse group. The serum IgA/C3 level might reflect the disease activity and be a potent surrogate marker of therapeutic efficacy in patients with IgAN.

Intrahepatic IgA complex induces polarization of cancer-associated fibroblasts to matrix phenotypes in the tumor microenvironment of HCC.

Cancer-associated fibroblasts (CAFs) play key roles in the tumor microenvironment. IgA contributes to inflammation and dismantling antitumor immunity in the human liver. In this study, we aimed to elucidate the effects of the IgA complex on CAFs in Pil Soo Sung the tumor microenvironment of HCC. CAF dynamics in HCC tumor microenvironment were analyzed through single-cell RNA sequencing of HCC samples. CAFs isolated from 50 HCC samples were treated with mock or serum-derived IgA dimers in vitro. Progression-free survival of patients with advanced HCC treated with atezolizumab and bevacizumab was significantly longer in those with low serum IgA levels ( p <0.05). Single-cell analysis showed that subcluster proportions in the CAF-fibroblast activation protein-α matrix were significantly increased in patients with high serum IgA levels. Flow cytometry revealed a significant increase in the mean fluorescence intensity of fibroblast activation protein in the CD68 + cells from patients with high serum IgA levels ( p <0.001). We confirmed CD71 (IgA receptor) expression in CAFs, and IgA-treated CAFs exhibited higher programmed death-ligand 1 expression levels than those in mock-treated CAFs ( p <0.05). Coculture with CAFs attenuated the cytotoxic function of activated CD8 + T cells. Interestingly, activated CD8 + T cells cocultured with IgA-treated CAFs exhibited increased programmed death-1 expression levels than those cocultured with mock-treated CAFs ( p <0.05). Intrahepatic IgA induced polarization of HCC-CAFs into more malignant matrix phenotypes and attenuates cytotoxic T-cell function. Our study highlighted their potential roles in tumor progression and immune suppression.

Long-Term Analysis of Anti-CD20mab + HDMP for the Treatment of Patients with Chronic Lymphocytic Leukemia

Background: The addition of an anti-CD20 monoclonal antibody (mAB) to high dose methylprednisolone (HDMP) has been demonstrated to be an effective, non-myelosuppressive treatment (Tx) regimen for patients (Pts) with chronic lymphocytic leukemia (CLL). (Castro et al., 2009) We performed a single institution retrospective analysis of Pts treated with an anti-CD20 mAB and HDMP evaluating long-term efficacy, safety, and immune reconstitution. Methods: 102 Pts treated between the years of 2001 and 2015 were evaluated. Tx consisted of HDMP 1gm/m2 IV on days 1, 2, and 3 of each cycle. Rituximab (R) was administered as either 375 mg/m2 weekly; 750 mg/m2 daily on days 1, 2 and 3; or 750 mg/m2 weekly times during cycle one and daily times three for cycle two and three. Obinutuzumab (G) and ofatumumab (O) were administered per FDA standard dosing. Pts received 3-6 cycles of Tx. Some Pts who achieved a partial response (PR) to initial therapy underwent alemtuzumab (Alem) consolidation, 10mg, administered three times a week for a total of eight weeks. All Pts received anti-microbial prophylaxis consisting of fluconazole, bactrim and acyclovir. Response assessment was performed using iwCLL criteria. Results: The Pts had a median age of 66 (range; 40-85). Rai stage at time of Tx initiation: I 6%; II 43%; III 17%; Stage IV 34%. 63% of Pts were previously treated. The median number of previous Txs was 2 (range; 1-5). 55% of Pts had been treated with immunotherapy alone, 67% with chemoimmunotherapy, and 13% of Pts with a BCL2 inhibitor. Pts harbored the following cytogenetic abnormalities: del(13q) 46%; trisomy 12 30%; del(11q) 22%; normal 13%; del(11q) 22%; del(17p) 19%; and complex in 26%. 58% of Pts harbored an unmutated immunoglobulin heavy chain (IGHV). 84% of Pts were treated with R, 11% with G, and 5% with O. 96 Pts (94%) had a response to Tx (OR). 18 Pts (18%) achieved a complete response (CR); 78 Pts (76%) achieved a PR; and six Pts (6%) had stable disease (SD). Seventeen Pts underwent Alem consolidation. Twelve Pts (71%) achieved a CR; four Pts (24%) achieved a PR; and one patient (6%) had SD after Alem consolidation. With a median follow-up of 114 months, the median progression free survival (PFS) for the entire cohort was 27.1 months. The median time to next treatment (TTNT) for the entire cohort was 30.0 months. For Pts who received Alem consolidation, the median PFS was 90.1 months, and the median TTNT was 97.8 months. (Figure 1A) Employing cox proportional hazards model, factors associated with improved PFS were IGHV mutated (HR 0.38; 95% CI 0.18 to 0.79); CR (HR 0.17; 95% CI 0.05 to 0.47); and Alem consolidation (HR 0.21; 95% CI 0.09 to 0.46). Factors associated with improved TTNT was presence of del13q (HR 0.41; 95% CI 0.18 to 0.93); IGHV mutated (HR 0.36; 95% CI 0.13 to 0.92); CR (HR 0.12; 95% CI 0.03 to 0.37); and Alem consolidation (HR 0.24; 95% CI 0.10 to 0.53). 9% Pts developed infection requiring hospitalization, and 5% Pts developed an opportunistic infection. Immediately after Tx, serum IgA, IgG and IgM levels decreased (mean IgA pre-Tx 69.4mg/dL vs post-Tx 43.0mg/dL; p <0.0001; mean IgG pre-Tx 738.0mg/dL vs post-Tx 494.3mg/dL; p <0.001; mean IgM pre-Tx 94.8mg/dL vs post-Tx 44.5mg/dL; p = 0.07). At approximately 36- and 48-months serum IgA and IgG levels returned to normal levels, respectively. (Figure 1B) 57% of Pts received supplemental intravenous immunoglobulin, thus we investigated factors associated with recovery of serum IgA levels at 36 months. We found that only disease status at 36 months impacted serum IgA levels. (Mean IgA without progression at 36 months 74.7mg/dL vs 44.9 mg/dL with progression at 36 months; p = 0.035). Conclusions: In our analysis of Pts with CLL treated with an anti-CD20 mAB + HDMP we found a high OR of 94% and median PFS of 27.1 months. This compares favorably to traditional low intensity chemoimmunotherapy approaches for CLL. Pts who received Alem consolidation had durable remissions, with a median PFS of 90.1 months. The overall incidence of infectious complications was manageable, with normalization of serum IgA and IgG three and four years after completion of therapy. Patients without progression at 36 months were found to have higher serum IgA levels. While the Tx landscape for CLL has dramatically changed, the addition of HDMP to an anti-CD20 mAB can be a Tx option for patients desiring short course of Tx, requiring bridging to more definite therapy, or debulking strategy prior to venetoclax based Tx. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Vaccination of mice with recombinant novel aminopeptidase P and cathepsin X alone or in combination induces protective immunity against Trichinella spiralis infection

Trichinella spiralis is a major foodborne zoonotic parasitic nematode which has a serious threat to meat food safety. Development of anti-Trichinella vaccine is requisite for control and elimination of Trichinella infection in food animals to ensure meat safety. Aminopeptidase P (TsAPP) and cathepsin X (TsCX) are two novel proteins identified in T. spiralis intestinal infectious L1 larvae (IIL1). The objective of this study was to investigate the protective immunity elicited by immunization with TsAPP and TsCX alone and TsAPP-TsCX in combination in a mouse model. The results demonstrate that subcutaneous vaccination of mice with rTsAPP, rTsCX or rTsAPP + rTsCX elicited a systemic humoral response (high levels of serum IgG, IgG1/IgG2a and IgA) and significant local gut mucosal sIgA responses. The vaccination with rTsAPP, rTsCX or rTsAPP + rTsCX also induced a systemic and local mixed Th1/Th2 response, as demonstrated by clear elevation levels of IFN-γ and IL-4 in vaccinated mice. Vaccination of mice with rTsAPP+rTsCX exhibited a 63.99 % reduction of intestinal adult worms and 68.50% reduction of muscle larva burdens, alleviated inflammation of intestinal mucosal and muscle tissues, and provided a higher immune protection than that of vaccination with rTsAPP or rTsCX alone. The results demonstrated that TsAPP and TsCX might be considered novel candidate target molecules for anti-Trichinella vaccines.

High serum IgA and activated Th17 and Treg predict the efficacy of abatacept in patients with early, seropositive rheumatoid arthritis

To identify the predictive biomarkers for achieving remission with abatacept in patients with seropositive rheumatoid arthritis (RA). We enrolled patients with RA who were treated with abatacept. We compared the baseline laboratory results and longitudinal immune-phenotyping data between patients who achieved remission and those who did not achieve remission at 6months according to the clinical disease activity index. One hundred and twenty RA patients were enrolled. In the seropositive patients with early RA (n = 24), high serum IgA levels, anti-citrullinated peptide (CCP) titers, and neutrophil counts before treatment were predictors of remission (area under the curve [AUC], 0.659, 0.741, and 0.704, respectively). Additionally, activated Th17 (aTh17) cells and activated Treg (aTreg) cells before treatment were found to be significantly higher in patients with remission compared to those without remission (2.9% vs 1.1%, P = 0.02; 34.3% vs 17%, P = 0.03, respectively). The measurement of longitudinal cell subpopulation revealed a decrease in the effector CD4 T cell population after abatacept treatment, which correlated with anti-CCP titers and neutrophil counts, and was associated with remission achievement. In seropositive patients with established RA (n = 79), high RF titers and low IFN-γ levels were associated with the good response to abatacept. Our study has shown that serum IgA levels, anti-CCP titer, and neutrophil counts are predictive biomarkers for predicting the response to abatacept in patients with seropositive and early RA and may reflect the inhibition of effector CD4 T cell subpopulations by abatacept. Key Points • Serum IgA levels and neutrophil counts are novel biomarkers for predicting the efficacy of abatacept. • Those may reflect the inhibition of effector CD4 T cell subpopulations by abatacept.

Tissue-Specific Autoantibodies Improve Diagnosis of Primary Sjögren's Syndrome in the Early Stage and Indicate Localized Salivary Injury.

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Due to the absence of specific clinical manifestations and biomarkers in the early stage, pSS is generally underrecognized. To elucidate the role of the tissue-specific autoantibodies (TSAs), i.e., anti-CA6, anti-SP1, and anti-PSP antibodies, we enrolled 137 pSS patients, 32 secondary Sjögren's syndrome (sSS) patients, and 127 healthy controls (HCs), whose serum and saliva samples were collected. TSA levels were detected by ELISA, and the clinical and laboratory data was reviewed from the medical records. The analysis results showed the following: (1) Compared to HCs, the serum IgA levels of anti-CA6, anti-SP1 and anti-PSP were significantly higher in pSS as well as in sSS patients, and anti-CA6 IgG was also notably higher in pSS patients. (2) The positivity of anti-CA6, anti-PSP and all the three antibodies together were significantly increased in anti-SSA-negative pSS patients. (3) The average IgM levels of anti-CA6 and anti-SP1 decreased as the disease duration extended. (4) The anti-CA6-positive patients have significantly higher levels of serum IgA, while the anti-PSP-positive group has a notably higher serum IgM level. (5) Another autoantibody specific to the salivary glands, anti-α-fodrin antibody, was elevated in TSA-positive patients, especially in the anti-CA6-positive group. (6) Preliminary detection of saliva TSAs showed that all the IgG levels of these three antibodies increased significantly in pSS patients. In conclusion, TSAs improve diagnosis of pSS in the early stage, especially in anti-SSA-negative patients, and their tissue-specific nature indicates localized salivary injury, which deserves further studies to clarify the mechanism.

Tripterygium Wilfordii inhibits tonsillar IgA production by downregulating IgA class switching in IgA nephropathy.

IgA nephropathy (IgAN) is characterized by high serum IgA levels and IgA deposition in the renal mesangium. Recent research has indicated that pathogenic IgA may originate from affected tonsils, where present enhancement of IgA production by IgA class switching and immuno-activation. Tripterygium Wilfordii (TW) was found to be especially effective in IgAN by its’ immunosuppression effect. Given this background, we investigated the mechanisms underlying the role of TW in the generation of IgA and IgA class switching in tonsillar GCs of IgAN patients. Immunohistochemistry and RT-PCR revealed that the expression of thymic stromal lymphopoietin (TSLP) and IgA inducing cytokines were decreased in the tonsils of IgAN patients with TW treatment compared with those without treatment, followed by significantly decreased of IgA-bearing cells. The location of TSLP and IgA inducing cytokines in tonsillar tissue was confirmed by double immunofluorescence. Importantly, TW inhibit TSLP and IgA production in isolated FDC-associated clusters. Serum TSLP levels were decreased and correlated with IgA downregulation in the tonsils and serum of IgAN patients. These data indicated that TW may be involved in IgA production in the tonsils of IgAN patients, inhibiting IgA class switching in IgAN patients through the cooperative roles of AID, TGF-β1, BAFF, and APRIL, highlighting a promising strategy for therapeutic intervention in IgAN.

The monitoring of laboratory indices of immune status of healthy children residing in conditions of intensive immunotropic zone of industrial town.

The complex evaluation was implemented concerning to quantitative and functional indices of immune-competent cells of peripheral blood, cytokine and immunoglobulin profile of blood serum with detection of confidence ranges of immunologic parameters of healthy children aged 3-11 years (n=98) residing in intensive immunotropic zone with the highest ecological risk. The multi-parametric flow cytofluorimeter COULTER EPICS XL (Beckman Coulter Inc.) with selection of of panels of monoclonal antibodies with multi-color combination of fluorichromуes was applied to analyze leukocytes, sub-population composition of lymphocites and processes of activation of cells of peripheral blood. The levels of cytokines were detected using immunoenzyme technique applying reagents by «R&D Diagnostics Inc.» (USA). The reagents' kit of «Vektor-Best» (Novosibirsk) was applied to detect spontaneous and mitogen-induced production of cytokines by cells of total blood The immuneturbidimetry technique was applied to detect content of immunoglobulins in blood serum. The total and specific IgE was detected using solid-phase immune enzyme analysis with reagents' kits by «Alkor Bio Company» (St. Petersburg). The statistical data processing was implemented using software Statistica 10 with data verification 95%-99%. In junior school children as compared with children aged 3-6 years, statistically reliable greater number of leukocytes were detected with preservation of high ratio of neutrophils, prevalence of helper sub-population of T-lymphocytes, expressed activation of B-lymphocytes, higher levels of serum IgA, IgG, common and specific IgE (latent sensibilization by domestic allergens), prevalence of intensity of production of interleukins IL-13 over IL-4 and significantly higher provision with natural killers.

Mouse and Human Liver Contain Immunoglobulin A–Secreting Cells Originating From Peyer's Patches and Directed Against Intestinal Antigens

The liver receives blood from the gastrointestinal tract through the portal vein, and thereby is exposed continuously to dietary antigens and commensal bacteria. Alcoholic liver disease (ALD) is associated with intestinal dysbiosis, increased intestinal permeability, release of microbes into the portal circulation, and increased serum levels and liver deposits of IgA. We characterized B-cell production of IgA in livers of mice at homeostasis, after oral immunization, in a mouse model of ALD and in human liver samples. We performed studies with Balb/c and C57BL/6-Ly5.1 mice, as well as transgenic mice (quasimonoclonal, activation-induced [cytidine] deaminase-Cre-tamoxifen-dependent estrogen receptor 2 [ERT2], Blimp-1-green fluorescent protein [GFP]). C57BL/6-Ly5.1 mice were fed chronic plus binge ethanol to create a model of ALD. Some mice also were given repeated injections of FTY720, which prevents egress of IgA-secreting cells from Peyer's patches. We obtained nontumor liver tissues from patients with colorectal carcinoma undergoing surgery for liver metastases or hepatocellular carcinoma. B cells were isolated from mouse and human liver tissues and analyzed by flow cytometry and enzyme-linked ImmunoSpot (ELISpot). In wild-type and transgenic mice, we traced newly generated IgA-secreting cells at steady state and after oral immunization with 4-hydroxy-3-nitrophenylacetyl (NP)-Ficoll or cholera toxin. IgA responses were also evaluated in our model of ALD. Livers of control mice contained proliferative plasmablasts that originated from Peyer's patches and produced IgAs reactive to commensal bacteria. After oral immunization with cholera toxin or a thymus-independent antigen, a substantial number of antigen-specific IgA-secreting cells was found in the liver. Mice fed ethanol had features of hepatitis and increased numbers of IgA-secreting cells in liver, compared with mice given control diets, as well as higher levels of serum IgA and IgA deposits in liver sinusoids. Injection of FTY720 during ethanol feeding reduced liver and serum levels of IgA and IgA deposits in liver and prevented liver injury. Human liver tissues contained a significant proportion of IgA-producing plasma cells that shared phenotypic and functional attributes with those from mouse liver, including reactivity to commensal bacteria. Based on studies of mice and human liver tissues, we found the liver to be a site of IgA production by B cells, derived from gut-associated lymphoid tissues. These IgAs react with commensal bacteria and oral antigens. Livers from mice with ethanol-induced injury contain increased numbers of IgA-secreting cells and have IgA deposits in sinusoids. IgAs in the liver could mediate clearance of gut-derived antigens that arrive through portal circulation at homeostasis and protect these organs from pathogens.

Temporary Immunity of Blackbelly Lambs Reinfected with Trichostrongylus colubriformis

Background: Trichostrongylus colubriformis is one of the most prevalent gastrointestinal nematodes of sheep in warm climates. In this nematode species, anthelmintic resistance (AR) has been reported, which has motivated the search for alternative methods to control it. One practice is to increase the immune response level through the selection of animals with natural resistance, such as Blackbelly sheep. The aim of this study was to investigate the response of IgA and IgG in serum and saliva and the level of cells involved in the acquired resistance in Blackbelly lambs after single artificial reinfection with a resistant strain of Trichostrongylus colubriformis.Materials, Methods &amp; Results: Sixteen weaned lambs grazed for one month in nematode-contaminated grasslands. All the lambs were treated with Albendazole and Levamisole; later, they were stabled for two months. After that, eight lambs were re-infected with 6000 larvae of T. colubriformis and other eight lambs remained naturally infected. In addition, eight nematode-free lambs raised in cages, served as negative control. Blood samples were taken fortnightly to determine packed cell volume (PCV, %), plasmatic protein (g dL-1), as well as absolute and differential leukocytes. The eggs per gram of feces (EPG) were recorded. An indirect ELISA against T. colubriformis Ag was performed to determine the IgG and IgA levels. All data were analyzed by repeated measures. The EPG in the re-infected group increased after 34 days (625 ± 287), while in the naturally infected group it remained close to 200 ± 158 throughout the study. The control lambs did not show any infection. The PCV (29.4 ± 3.4 %), basophils (44 ± 74), lymphocytes (8443 ± 2845) and monocytes (77 ± 91) counts were not affected by infection. The IgA OD against T. colubriformis increased significantly after 15 days post-infection (dpi) in the re-infected lambs (1.69 ± 0.5, 80% with regards to standard). With IgG was not possible to distinguish the effect of infection.Discussion: Highly persistent infection of T. colubriformis was observed for at least four months in the naturally infected group despite having been treated with anthelmintics. It is a significant problem because this species has a high prevalence in the region of study and shows anthelmintic resistance. For such reason, is important to evaluate the ability of the animal to develop an immune response. In other study, a natural reduction in the fecal egg count (FEC) was indicated at 100 dpi in the same species, but in the present work, the FEC could not be reduced until around 120 days when the naturally infected lambs were evaluated. The larger number of neutrophils and leukocytes in both the naturally infected and re-infected groups implies a sustained response for a long time. While the higher counts of eosinophils only in the re-infected group were produced as an immediate response to infection with T. colubriformis. Similarly, with a single infection of T. colubriformis, in Santa Ines sheep the infected lambs showed significantly higher levels of serum IgA than the control group. In this case, differences in IgA activity were observed between the re-infected lambs and the other groups at fifteen dpi, but the basal levels of IgA in the naturally pre-infected lambs were maintained at least five weeks after infection. In conclusion, an increase in the peripheral immune response in lambs re-infected with T. colubriformis resulted from the increase in IgA levels in serum and saliva, and increase in the number of peripheral eosinophils, total leukocytes and neutrophils. Re-infected lambs had a higher level of IgA than naturally infected lambs and control lambs, making possible to promote the immune response with a single re-infection with Trichostrongylus colubriformis.

Induction of Local Secretory IgA and Multifunctional CD4⁺ T-helper Cells Following Intranasal Immunization with a H5N1 Whole Inactivated Influenza Virus Vaccine in BALB/c Mice.

Avian influenza subunit vaccines have been shown to be poorly immunogenic, leading to the re-evaluation of the immunogenic and dose-sparing potential of whole virus vaccines. In this study, we investigated the immune responses after one or two doses of intramuscular or intranasal whole inactivated influenza H5N1 virus vaccine in BALB/c mice. Serum samples and nasal washings were collected weekly post-vaccination and analysed using enzyme-linked immunosorbent assay (ELISA). Sera were also analysed by the haemagglutination inhibition (HI) assay. Antibody-secreting cells were measured in lymphocytes from spleen and bone marrow via enzyme-linked immunospot (ELISPOT). Splenocytes were stimulated in vitro, and T-helper profiles were measured through multiplex bead assay in the supernatants, or intracellularly by multiparametric flow cytometry. Both vaccine routes induced high HI titres following the second immunization (intramuscular = 370, intranasal = 230). Moreover, the intramuscular group showed significantly higher levels of serum IgG (P < 0.01), IgG1 (P < 0.01) and IgG2a (P < 0.01) following the second vaccine dose, while the intranasal group exhibited significantly higher levels of serum IgA (P < 0.05) and local IgA (P < 0.01) in the nasal washings. Also, IgA antibody-secreting cells were found in significantly higher numbers in the intranasal group in both the spleen (P < 0.01) and the bone marrow (P < 0.01). Moreover, Th1 (TNF-α, IL-2, IFN-γ) and Th2 (IL-4, IL-5, IL-10) cytokines were expressed by both groups, yet only the intranasal group expressed the Th17 marker IL-17. As the intranasal vaccines induce local IgA and are easily administered, we suggest the intranasally administered whole virus vaccine as a promising candidate for a pandemic H5N1 vaccine.

Development of serum antibodies during early infancy in rhesus macaques: Implications for humoral immune responses to vaccination at birth

BackgroundA better understanding of immune responses in human infants could lead to more effective immunization and vaccination strategies in early life. MethodsSince antibodies are key components of protective vaccine responses, we examined developmental changes in serum levels of immunoglobulins (IgG, IgA, IgM) in infant rhesus macaques from birth through 6 months of age. ResultsAs in human infants, macaques are born with high levels of IgG in sera, with rapid increases in serum IgM, yet very slow increases in levels of IgA from birth. We also examined levels of anti-tetanus antibodies in infants born to vaccinated dams to distinguish and track maternal and infant antibodies. These data suggest essentially all serum IgG in newborn infants is derived from the dams, which gradually wanes over a few weeks. In contrast, levels of IgM and IgA appear to all be infant-derived, as evidenced by their low to undetectable levels at birth. In addition, abnormally high levels of serum IgM and IgA were detected in a few infants, which correlated with specific, yet clinically silent disease processes. ConclusionsOur data indicate that newborn macaques have competent immune systems, and are able to produce their own antibodies in response to exposure to environmental antigens immediately upon birth.

곡물 및 사료오염 데옥시니발레놀 및 대사체에 의한 인축질환 연계 생체지표 및 바이오모니터링

Deoxynivalenol (DON) and related trichothecene mycotoxins are extensively distributed in the cereal-based food and feed stuffs worldwide. Recent climate changes and global grain trade increased chance of exposure to more DON and related toxic metabolites in poorly managed production systems. Monitoring the biological and environmental exposures to the toxins are crucial in protecting human and animals from toxicities of the hazardous contaminants in food or feeds. Exposure biomarkers including urine DON itself are prone to shift to less harmful metabolites by intestinal microbiota and liver metabolic enzymes. De-epoxyfication of DON by gut microbes such as Eubacterium strain BBSH 797 and Eubacterium sp. DSM 11798 leads to more fecal secretion of DOM-1. By contrast, most of plant-derived DON-glucoside is also easily catabolized to free DON by gut microbes, which produces more burden to body. Phase 2 hepatic metabolism also contributes to the glucuronidation of DON, which can be useful urine biomarkers. However, chemical modification could be very typical depending on the anthropologic or genetic background, luminal bacteria, and hepatic metabolic enzyme susceptibility to the toxins in the diet. After toxin exposure, effect biomarkers are also important in estimating the linkage and mechanisms of foodborne diseases in human and animal population. Most prominent adverse effects are demonstrated in the DON-induced immunological and behavioral disorders. For instance, acutely elevated interleukin-8 from insulted gut exposed to dietaty DON is a dominant clinical biomarker in human and animals. Moreover, subchronic exposure to the toxins is associated with high levels of serum IgA, a biological mediator of IgA nephritis. In particular, anorexia monitoring using mouse models are recently developed to monitor the biological activities of DON-induced feed refusal. It is also mechanistically linked to alteration of serotoin and peptide YY, which are promising biomarkers of neurological disorders by the toxins. As animal-alternative biomonitoring, huamn enterocyte-based assay has been developed and more realistic gut mimetic models would be useful in monitoring the effect biomarkers in resposne to toxic contaminants in the future investigations.

Disruption of Smad4 Expression in T Cells Leads to IgA Nephropathy-Like Manifestations

The link between glomerular IgA nephropathy (IgAN) and T helper 2 (Th2) response has been implicated, however, the mechanisms are poorly defined because of the lack of an appropriate model. Here we report a novel murine model characterized by lineage-restricted deletion of the gene encoding MAD homologue 4 (Smad4) in T cells (Smad4co/co;Lck-cre). Loss of Smad4 expression in T cells results in overproduction of Th2 cytokines and high serum IgA levels. We found that Smad4co/co;Lck-cre mice exhibited massive glomerular IgA deposition, increased albumin creatinine ratio, aberrant glycosylated IgA, IgA complexed with IgG1 and IgG2a, and polymeric IgA, all known features of IgAN in humans. Furthermore, we examined the β1, 4-galactosyltransferases (β4GalT) enzyme which is involved in the synthesis of glycosylated murine IgA, and we found reduced β4GalT2 and β4GalT4 mRNA levels in B cells. These findings indicate that Smad4co/co;Lck-cre mice could be a useful model for studying the mechanisms between IgAN and Th2 response, and further, disruption of Smad4-dependent signaling in T cells may play an important role in the pathogenesis of human IgAN and contributing to a Th2 T cell phenotype.

Development of a Model of Early-Onset IgA Nephropathy

ddY mice spontaneously develop IgA nephropathy (IgAN) with a variable age of disease onset. Establishing a model with early-onset IgAN could aid the investigation of mechanisms that underlie the pathogenesis of this disease. On the basis of histologic grading in serial biopsies, we previously classified ddY mice into early-onset, late-onset, and quiescent groups. Here, we selectively mated mice with the early-onset phenotype for >20 generations and established "grouped ddY" mice that develop IgAN within 8 weeks of age. Similar to human IgAN, the prognosis was worse for male mice than females. These mice homogeneously retained genotypes of four marker loci previously associated with the early-onset phenotype, confirming a close association of these loci with early-onset IgAN in ddY mice. Grouped ddY mice comprised two sublines, however, which had distinct genotypes at a susceptibility locus for high serum IgA levels, which maps within the Ig heavy-chain gene complex. The subline bearing the Igh-2(a) IgA allotype had a more rapid course of fatal disease and lower oligosaccharide content, suggesting that aberrant IgA glycosylation may promote the progression of murine IgAN. Taken together, these data indicate that grouped ddY mice may be a useful model for the identification of susceptibility genes and the underlying molecular mechanisms involved in the pathogenesis of human IgAN.

Induction and suppression of allergic diarrhea and systemic anaphylaxis in a murine model of food allergy

The clinical manifestations of food allergy include diarrhea and systemic anaphylaxis (shock), which can occur together or by themselves in different subjects. Although ingested food antigens need to be absorbed to induce shock, it is not known whether they need to be absorbed to induce diarrhea. We sought to identify mechanisms that determine whether food allergy induces diarrhea versus shock and determine whether diarrhea requires absorption of ingested antigens. These issues were studied in mice in active, passive, and hybrid immunization models. The active model was used to determine the allergic diarrhea susceptibility of J chain- and polymeric immunoglobulin receptor-deficient mice, which are unable to secrete IgA. The hybrid model was used to determine whether intravenously administered antigen-specific IgG antibody, which is not secreted into the gut, can protect against allergic diarrhea, as well as shock. Shock, but not diarrhea, was induced in naive mice by using intravenous IgE anti-trinitrophenyl (TNP) antibody, followed by oral TNP-BSA, whereas both were induced in mice presensitized with intraperitoneal ovalbumin/alum plus oral ovalbumin. More TNP-BSA was required to induce shock than diarrhea in presensitized mice, and intravenous IgG anti-TNP antibody, which is not secreted into the gut, protected these mice against both diarrhea and shock. Consistent with this, chicken ovalbumin-immunized J chain- and polymeric immunoglobulin receptor-deficient mice, which have high serum IgA levels but little intestinal IgA, resisted diarrhea induction. Intestinal immunity and oral antigen dose determine whether diarrhea, systemic anaphylaxis, or both are induced, and ingested antigen must be absorbed to induce either response.

Toll-like receptors are critical for clearance of Brucella and play different roles in development of adaptive immunity following aerosol challenge in mice

Brucella spp. cause undulant fever in humans and brucellosis in variety of other animals. Both innate and adaptive immunity have been shown to be important in controlling Brucella infection. Toll-like receptors (TLRs) represent a group of pattern recognition receptors (PRRs) that play critical roles in the host innate immune response, as well as development of adaptive immunity. In the current report, we investigated the role of TLR signaling in the clearance of Brucella and development of adaptive immunity in TLR2−/−, TLR4−/−, or MyD88−/− mice following aerosol exposure to B. melitensis 16 M. Consistent with previous reports, MyD88 is required for efficient clearance of Brucella from all three organs (lung, spleen, and liver). The results reveal Th2-skewed immune responses in TLR2−/− mice late in infection and support a TLR2 requirement for efficient clearance of Brucella from the lungs, but not from the spleen or liver. Similarly, TLR4 is required for efficient clearance of Brucella from the lung, but exhibits a minor contribution to clearance from the spleen and no demonstrable contribution to clearance from the liver. Lymphocyte proliferation assays suggest that the TLRs are not involved in the development of cell-mediated memory response to Brucella antigen. Antibody detection reveals that TLR2 and 4 are required to generate early antigen-specific IgG, but not during the late stages of infection. TLR2 and 4 are only transiently required for IgM production and not at all for IgA production. In contrast, MyD88 is essential for antigen specific IgG production late in infection, but is not required for IgM generation over the course of infection. Surprisingly, despite the prominent role for MyD88 in clearance from all tissues, MyD88-knockout mice express significantly higher levels of serum IgA. These results confirm the important role of MyD88 in controlling infection in the spleen while providing evidence of a prominent contribution to protection in other tissues. In addition, although TLR4 and TLR2 contribute little to control of spleen infection, a significant contribution to clearance of lung infection is described.

Sublingual vaccination with fusion protein consisting of the functional domain of hemagglutinin A of Porphyromonas gingivalis and Escherichia coli maltose-binding protein elicits protective immunity in the oral cavity

This study demonstrated that sublingual immunization with a fusion protein, 25k-hagA-MBP, which consists of a 25-kDa antigenic region of hemagglutinin A purified from Porphyromonas gingivalis fused to maltose-binding protein (MBP) originating from Escherichia coli as an adjuvant, elicited protective immune responses. Immunization with 25k-hagA-MBP induced high levels of antigen-specific serum IgG and IgA, as well as salivary IgA. High level titers of serum IgG and IgA were also induced for almost 1 year. In an IgG subclass analysis, sublingual immunization with 25k-hagA-MBP induced both IgG1 and IgG2b antibody responses. Additionally, numerous antigen-specific IgA antibody-forming cells were detected from the salivary gland 7 days after the final immunization. Mononuclear cells isolated from submandibular lymph nodes (SMLs) showed significant levels of proliferation upon restimulation with 25k-hagA-MBP. An analysis of cytokine responses showed that antigen-specific mononuclear cells isolated from SMLs produced significantly high levels of IL-4, IFN-γ, and TGF-β. These results indicate that sublingual immunization with 25k-hagA-MBP induces efficient protective immunity against P. gingivalis infection in the oral cavity via Th1-type and Th2-type cytokine production.

Serum IgA Responses against Pertussis Proteins in Infected and Dutch wP or aP Vaccinated Children: An Additional Role in Pertussis Diagnostics

BackgroundWhooping cough is a respiratory disease caused by Bordetella pertussis, which induces mucosal IgA antibodies that appear to be relevant in protection. Serum IgA responses are measured after pertussis infection and might provide an additional role in pertussis diagnostics. However, the possible interfering role for pertussis vaccinations in the induction of serum IgA antibodies is largely unknown.Methods/Principal FindingsWe compared serum IgA responses in healthy vaccinated children between 1 and 10 years of age with those in children who despite vaccinations recently were infected with Bordetella pertussis. All children have been vaccinated at 2, 3, 4 and 11 months of age with either the Dutch whole-cell pertussis (wP) vaccine or an acellular pertussis (aP) vaccine and additionally received an aP booster vaccination at 4 years of age. Serum IgA responses to pertussis toxin (PT), filamentous heamagglutinin (FHA) and pertactin (Prn) were measured with a fluorescent multiplex bead-based immuno-assay. An ELISPOT-assay was used for the detection of IgA-memory B-cells specific to these antigens. Serum IgA levels to all pertussis vaccine antigens were significantly higher in infected children compared with healthy children. High correlations between anti-PT, anti-FHA or anti-Prn IgA and IgG levels were found in infected children and to some degree in wP primed children, but not at all in aP primed children. Highest numbers of IgA-pertussis-specific memory B-cells were observed after infection and generally comparable numbers were found after wP and aP vaccination.ConclusionsThis study provides new insight in the diagnostic role for serum IgA responses against PT in vaccinated children. Since aP vaccines induce high serum IgG levels that interfere with pertussis diagnostics, serum IgA-PT levels will provide an additional diagnostic role. High levels of serum IgA for PT proved specific for recent pertussis infection with reasonable sensitivity, whereas the role for IgA levels against FHA and Prn in diagnosing pertussis remains controversial.

Vaccination of goats with a glutathione peroxidase DNA vaccine induced partial protection against Haemonchus contortus infection

Due to their critical functions in worm physiology, glutathione peroxidases in Haemonchus contortus are potential candidates for vaccine to control haemonchosis. However, information on the protection potential of these molecules is lacking. In this study, recombinant HC29 antigen was tested for protection against experimental H. contortus infections in goats. Fifteen animals were allocated into three trial groups. The animals of HC29 group was vaccinated with a recombinant HC29 DNA vaccine twice at day 0 and day 14, and then challenged with 5000 infective H. contortus L3 (third larval stage) on the 28th day. An unvaccinated positive control group was challenged with L3 at the same time. An unvaccinated negative control group was not challenged with L3. The results indicated HC29 DNA vaccine was transcribed at local injection sites and expressed in vivo post immunizations, respectively. Following L3 challenge, the mean eggs per gram feces and worm burdens of HC29 group were reduced by 36.1% and 35.6% respectively compared to the positive control group. After immunization with the DNA vaccine, significantly high levels of serum IgG, serum IgA, mucosal IgA and CD4+ T lymphocytes were detected. These results suggest that recombinant H. contortus HC29 glutathione peroxidase DNA vaccine induced a partial immune response and has protective potentials against caprine haemonchosis.