IgG1 Synthesis Research Articles

HLA dependency and possible clinical relevance of intrathecally synthesized anti-IgLON5 IgG4 in anti-IgLON5 disease.

Anti-IgLON5 disease is a rare chronic autoimmune disorder characterized by IgLON5 autoantibodies predominantly of the IgG4 subclass. Distinct pathogenic effects were described for anti-IgLON5 IgG1 and IgG4, however, with uncertain clinical relevance. IgLON5-specific IgG1-4 levels were measured in 46 sera and 20 cerebrospinal fluid (CSF) samples from 13 HLA-subtyped anti-IgLON5 disease patients (six females, seven males) using flow cytometry. Intervals between two consecutive serum or CSF samplings (31 and 10 intervals, respectively) were categorized with regard to the immunomodulatory treatment active at the end of the interval, changes of anti-IgLON5 IgG1 and IgG4 levels, and disease severity.Intrathecal anti-IgLON5 IgG4 synthesis (IS) was assessed using a quantitative method. The median age at onset was 66 years (range: 54-75), disease duration 10 years (range: 15-156 months), and follow-up 25 months (range: 0-83). IgLON5-specific IgG4 predominance was observed in 38 of 46 (83%) serum and 11 of 20 (55%) CSF samples. Anti-IgLON5 IgG4 levels prior clinical improvement in CSF but not serum were significantly lower than in those prior stable/progressive disease. Compared to IgLON5 IgG4 levels in serum, CSF levels in HLA-DRB1*10:01 carriers were significantly higher than in non-carriers. Indeed, IgLON5-specific IgG4 IS was demonstrated not only in four of five HLA-DRB1*10:01 carriers but also in one non-carrier. Immunotherapy was associated with decreased anti-IgGLON5 IgG serum levels. In CSF, lower anti-IgLON5 IgG was associated with immunosuppressive treatments used in combination, that is, corticosteroids and/or azathioprine plus intravenous immunoglobulins or rituximab. Our findings might indicate that CSF IgLON5-specific IgG4 isfrequently produced intrathecally, especially in HLA-DRB1*10:01 carriers.Intrathecally produced IgG4 may be clinically relevant. While manyimmunotherapies reduce serum IgLON5 IgG levels, more intense immunotherapies induce clinical improvement and may be able to target intrathecally produced anti-IgLON5 IgG. Further studies need to confirm whether anti-IgLON5 IgG4 IS is a suitable prognostic and predictive biomarker in anti-IgLON5 disease.

Does SARS-CoV-2 Induce IgG4 Synthesis to Evade the Immune System?

SARS-CoV-2, the virus that causes the COVID-19 disease, has been shown to cause immune suppression in certain individuals. This can manifest as a reduced ability of the host's immune system to effectively control the infection. Studies have reported that patients with COVID-19 can exhibit a decline in white blood cell counts, including natural killer cells and T cells, which are integral components of the immune system's response to viral pathogens. These cells play critical roles in the immune response to viral infections, and their depletion can make it harder for the body to mount an effective defense against the virus. Additionally, the virus can also directly infect immune cells, further compromising their ability to function. Some individuals with severe COVID-19 pneumonia may develop a "cytokine storm", an overactive immune response that may result in tissue damage and organ malfunction. The underlying mechanisms of immune suppression in SARS-CoV-2 are not entirely understood at this time, and research is being conducted to gain a more comprehensive understanding. Research has shown that severe SARS-CoV-2 infection promotes the synthesis of IgG4 antibodies. In this study, we propose the hypothesis that IgG4 antibodies produced by B cells in response to infection by SARS-CoV-2 generate immunological tolerance, which prevents its elimination and leads to persistent and chronic infection. In summary, we believe that this constitutes another immune evasion mechanism that bears striking similarities to that developed by cancer cells to evade immune surveillance.

IgG4 Antibodies Induced by Repeated Vaccination May Generate Immune Tolerance to the SARS-CoV-2 Spike Protein.

Less than a year after the global emergence of the coronavirus SARS-CoV-2, a novel vaccine platform based on mRNA technology was introduced to the market. Globally, around 13.38 billion COVID-19 vaccine doses of diverse platforms have been administered. To date, 72.3% of the total population has been injected at least once with a COVID-19 vaccine. As the immunity provided by these vaccines rapidly wanes, their ability to prevent hospitalization and severe disease in individuals with comorbidities has recently been questioned, and increasing evidence has shown that, as with many other vaccines, they do not produce sterilizing immunity, allowing people to suffer frequent re-infections. Additionally, recent investigations have found abnormally high levels of IgG4 in people who were administered two or more injections of the mRNA vaccines. HIV, Malaria, and Pertussis vaccines have also been reported to induce higher-than-normal IgG4 synthesis. Overall, there are three critical factors determining the class switch to IgG4 antibodies: excessive antigen concentration, repeated vaccination, and the type of vaccine used. It has been suggested that an increase in IgG4 levels could have a protecting role by preventing immune over-activation, similar to that occurring during successful allergen-specific immunotherapy by inhibiting IgE-induced effects. However, emerging evidence suggests that the reported increase in IgG4 levels detected after repeated vaccination with the mRNA vaccines may not be a protective mechanism; rather, it constitutes an immune tolerance mechanism to the spike protein that could promote unopposed SARS-CoV2 infection and replication by suppressing natural antiviral responses. Increased IgG4 synthesis due to repeated mRNA vaccination with high antigen concentrations may also cause autoimmune diseases, and promote cancer growth and autoimmune myocarditis in susceptible individuals.

B-cell response to seasonal influenza vaccine in mice is amenable to pharmacological modulation through β-adrenoceptor

AimsGiven that deprivation of noradrenaline acting on lymphocytes through β-adrenoceptor influences antibody response, the effects of propranolol treatment beginning two days before immunization with quadrivalent inactivated influenza vaccine (QIV) on IgG response and underlying cellular molecular mechanism in mice were investigated. Main methodsTwenty-one days post-immunization the total QIV antigen-specific IgG titer and IgG subclass titers in sera were determined using ELISA. Additionally, the total counts of germinal centre (GC) B cells, T follicular helper (Tfh) and T follicular regulatory (Tfr) cells in draining lymph nodes (dLNs) and spleens, in vitro proliferation of interacting B cells and Th cells and IL-21 synthesis in Th cells in response to QIV antigens and/or mitogen were attested using flow cytometry analysis. In QIV antigen-stimulated dLN cell and splenocyte cultures were also measured concentrations of INF-γ and IL-4, cytokines upregulating IgG2a and IgG1 synthesis, respectively. Key findingsPropranolol decreased the total QIV antigen-specific IgG titer. This correlated with lower GC B cell count and the shift in Tfr/Tfh cell and Tfr/GC B cell ratio towards Tfr in propranolol-treated mice compared with controls. Consistently, QIV antigen-stimulated proliferation of B cells and Th cells from propranolol-treated mice in vitro was impaired. This correlated with the lower frequency of QIV antigen-specific IL-21-producing cells among Th cells. Additionally, in propranolol-treated mice, in accordance with the changes in INF-γ/IL-4 ratio in dLN cell/splenocyte cultures, serum IgG2a/IgG1 ratio was shifted towards IgG1 reflecting decreased IgG2a response. SignificanceThe study indicates that chronic propranolol treatment may impair response to QIV.

Specific IgE and IgG4 Profiles of House Dust Mite Components in Allergen-Specific Immunotherapy.

BackgroundAllergen immunotherapy (AIT) can induce immune tolerance to allergens by activating multiple mechanisms, including promoting IgG4 synthesis and blunting IgE production. However, the longitudinal data of sIgE and sIgG4 to allergen components during AIT are limited.ObjectiveWe sought to investigate the persistence and evolution of sIgE and sIgG4 against house dust mite (HDM) components during AIT and explore their correlation with clinical responses.MethodsSixty allergic rhinitis (AR) with/without asthma patients receiving AIT for HDM were enrolled in AIT group. Thirty AR patients without receiving AIT served as control group. Blood samples were collected for sIgE, sIgG4 to HDM components (Derp 1, Derf 1, Derp 2, Derf 2, Derp 7, Derp 10, Derp 21 and Derp 23) assay at baseline, Month 6 and Month 18 of AIT. Combined symptom and medication scores (CSMS) were obtained accordingly.ResultsIn the AIT group, sIgG4 to the HDM components of Derp 1, Derf 1, Derp 2 and Derf 2, Derp 21 significantly increased at Month 18 compared to the baseline (36.2 UA/mL vs 158.8 UA/mL, 46.4 UA/mL vs 94.6 UA/mL, 80.5 UA/mL vs 152.3 UA/mL, 78.3 UA/mL vs 205.1 UA/mL, 42.3 UA/mL vs 59.3 UA/mL, all p<0.05), sIgE to HDM components didn’t see differences at baseline and at Month 18 (all p>0.05).The numbers of positive HDM component sIgE and sIgG4 increased from 4.5 to 5 and 0 to 1.5 respectively (both p<0.05). However, the changes of sIgE, sIgG4, sIgE/sIgG4 ratio and the numbers of positive HDM components had no correlations with the improvement of CSMS after AIT (all ρ<0.3). For the control group, the sIgE and sIgG4 did not change significantly during the observational period (all p>0.05).ConclusionAIT can induce the production of sIgG4 to HDM components. However, the increased sIgG4 levels of HDM component do not correlate with the corresponding sIgE levels at baseline or with AIT response. sIgG4 to HDM components do not qualify as a biomarker to evaluate the efficacy of AIT.

PD-L1 Blockade During Allergen Sensitization Inhibits the Synthesis of Specific Antibodies and Decreases Mast Cell Activation in a Murine Model of Active Cutaneous Anaphylaxis

Programmed cell death ligand 1(PDL-1) is known for its inhibitory effect on the cellular immune response. Even though it is expressed on the surface of mast cells, its role in allergic diseases is unknown. We analyzed the effects of PD-L1 blockade in a murine model of active cutaneous anaphylaxis (ACA). C57BL/6 mice were sensitized and challenged with ovalbumin (OVA). Blood samples were collected to measure specific immunoglobulins. The mice were divided into six groups that underwent the active cutaneous anaphylaxis procedure. Group 1 (negative control) received 50 μl of phosphate-buffered saline (PBS) subcutaneously, and the other five groups were sensitized with 50 μg of OVA subcutaneously. Group 2 was the positive control, and the others received the anti-PD-L1 antibody or its isotype during sensitization (groups 3 and 4) or during the challenge (groups 5 and 6). All animals that underwent ACA on the ears with OVA and PBS were sacrificed, and the reaction was evaluated by extravasation of Evans blue (measured by spectrophotometry) and histological analysis of the collected fragments. Anti-PD-L1 blockade during the sensitization phase led to a reduction in specific IgE and IgG1 levels, allergic reaction intensity at the ACA site, and mast cell degranulation in the tissue. There was no significant biological effect of anti-PD-L1 administration on the challenge phase. PD-L1 blockade during allergen sensitization inhibited the synthesis of specific IgE and IgG1 and decreased mast cell activation in this murine model of anaphylaxis.

Humoral immune response in mice immunized orally with conventional and transgenic soy extracts (Glycine max)

ABSTRACTThe soybean is widely used in food industry due to its nutritional and functional qualities, but some studies have pointed it as a potent food allergen, especially in children. The concentration of IgG, IgG1 and IgE immunoglobulins in mice supplemented orally with common and transgenic soy was analysed. Mice were divided into two groups (6 animals each): lyophilized conventional soy (LCS) and lyophilized transgenic soy (LTS). Both received 100 μg of extracts for 10 consecutive days. Animals before immunization (pre-immune) formed the control group. The serum samples of the animals were undergone enzyme-linked immunosorbent assay (ELISA). The results of the ELISA tests showed that LCS and LTS induced the synthesis of specific IgG1 and IgG classes immunoglobulins and induced the formation of IgE immunoglobulin when evaluated by western blotting test. These results evidence the allergenicity of soybean and individuals with some food hypersensibility should avoid the consumption of this food.

Selective intrathecal enrichment of G1m1-positive B cells in multiple sclerosis.

Immunoglobulin gamma (IgG) heavy chain genes are associated with susceptibility to multiple sclerosis (MS) and IgG levels in the cerebrospinal fluid (CSF). However, how these variants are implicated in disease mechanisms remains unknown. Here, we show that proliferating plasmablasts expressing the G1m1 allotype of IgG1 are selectively enriched in CSF of G1m1/G1m3 heterozygous MS patients, whereas plasmablasts expressing either G1m1 or G1m3 are evenly distributed in blood. Moreover, there was a preferential intrathecal synthesis of oligoclonal IgG1 of the G1m1 allotype in heterozygous patients, whereas controls with Lyme neuroborreliosis displayed oligoclonal IgG1 of both allotypes. This points to a disease‐specific mechanism involved in B‐cell establishment within the central nervous system in MS.

Humoral immune response in mice immunized by oral route with phaseolamine extracted from common bean (Phaseolus vulgaris)

ABSTRACTThe prevalence of obesity is increasing in Brazil, generating high costs for the health system. In the search for alternative therapies to control the obesity, several researches seek active compounds in natural products in order to find better pharmacological effects. Inhibitors of α-amylase such as phaseolamine extracted from common beans (Phaseolus vulgaris) have shown satisfactory results in weight loss. The present study aimed to verify the possibility of phaseolamine-causing allergic reactions through the humoral response in mice sensitized with phaseolamine. Swiss female mice (n = 10) were sensitized orally with 100 µg of lyophilized phaseolamine diluted in water for 10 consecutive days and reinforced on the 21th and 35th days after the beginning of this experiment. The production of immunoglobulins IgG, IgG1 and IgE was measured by ELISA and western blotting. The immunological response was investigated and it was found that phaseolamine induced the synthesis of IgG and did not induce the synthesis of IgG1 and IgE. The present study indicates that the product did not cause allergic reactions.

Enhancement of anti-OVA IgG2c production in vivo by enalapril.

Angiotensin-converting enzyme (ACE) inhibitors have non-hemodynamic, pleiotropic effects on the immune response. The effects of ACE inhibitors on the production of cytokines and T-cell functions are well established. However, little is known on the effects of these medicines on humoral response to foreign antigens. In this study, we investigated the effect of enalapril treatment on ovalbumin (OVA)-specific IgG1 and IgG2c production in mice determined by ELISA. Two groups of 8-week-old C57BL/6 females mice (3–4/group) were subcutaneously immunized with OVA (10 μg/animal) in presence of Alhydrogel (1 mg/mouse) and boosted at day 21. The mice were treated with enalapril (5 mg/kg daily, po) or were left without treatment for one month. The animals were bled from the orbital plexus on days 0, 7, 14, 21, and 28 after the first immunization and the sera were stored at –20°C until usage. OVA-specific serum IgG1 and IgG2c were determined by ELISA using serum from each individual animal. The results showed that enalapril significantly increased anti-OVA serum IgG2c in the secondary response without affecting IgG1 synthesis. These data expand our understanding on the properties of enalapril on the immune response, including antibody production.

Sex hormones modulate the immune response to Plasmodium berghei ANKA in CBA/Ca mice.

Susceptibility to malaria differs between females and males, and this sexual dimorphism may have important implications for the effects of vaccines and drugs. However, little is known about the mechanisms mediating these sexual differences. Because the main differences between sexes are dictated by sex hormones, we studied the effect of gonadal steroids on immune responses to malaria in CBA/Ca mice. We decreased sex hormones levels by gonadectomy and evaluated the splenic index and the cells involved in the immune response, including T cells (CD3(+), CD4(+), CD8(+) and NK(+)), B cells and macrophages (Mac-3(+)) in the spleens of female and male mice infected with Plasmodium berghei ANKA. In addition, we measured antibody and cytokine levels in blood. Gonadectomy increased T(+) and B(+) splenic cells in both sexes but increased Mac-3(+) cells only in male mice. By contrast, gonadectomy decreased the NK(+) cell population only in male mice. In general, female mice developed higher antibody levels than males. Contrary to our expectations, gonadectomy increased the synthesis of IgG1, IgG2b, IgG3, and total IgG in female mice, indicating negative regulation of antibody production by female sex hormones. Gonadectomy increased the synthesis of tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) only in female mice, suggesting that female sex hormones have anti-inflammatory properties. This work demonstrates that the levels of sex hormones affect the immune response and should be considered when designing malaria vaccines.

Anti-Toll-like receptor 2 and 4 antibodies suppress inflammatory response in mice.

Toll-like receptors (TLRs) 2 and 4 recognize different endogenous and exogenous agonists and play a distinct role in infection and inflammation. However, their ultimate effect in a given infectious and inflammatory disease is less understood. We produced polyclonal anti-murine TLR2 and TLR4 antibodies and investigated their effect on cutaneous leishmaniasis and inflammatory arthritis. Administration of these antibodies to susceptible BALB/c mice, infected in the footpad with Leishmania major, reduced footpad swelling but not the parasite load compared with mice treated with control IgG. The antibodies synergistically reduced leishmanial-specific T-cell proliferation, T helper type 1 and type 2 cytokine production, specific IgG1 and IgG2a antibody synthesis, and T-cell receptor and co-stimulatory molecule expression on dendritic cells in infected mice. We then tested the effect of these antibodies on collagen-induced arthritis (CIA) in DBA/1 mice, a classic model of chronic inflammation. Both antibodies markedly suppressed the development of clinical parameters with concomitant reduction of pro-inflammatory cytokine production. These data therefore suggest that anti-TLR2 and 4 antibodies may have a synergistic therapeutic effect on inflammatory disease in vivo.

Intravenous IgA complexed with antigen reduces primary antibody response to the antigen and anaphylaxis upon antigen re-exposure by inhibiting Th1 and Th2 activation in mice

Context: Serum IgG, IgE and IgM have been shown to enhance the primary antibody responses upon exposure to the soluble antigens recognized by those antibodies. However, how IgA affects these responses remains unknown.Objective: We investigated the effects of intravenously administered monoclonal IgA on the immune responses in mice.Materials and methods: DBA/1J mice were immunized with ovalbumin in the presence or absence of anti-ovalbumin monoclonal IgA. The Th1 and Th2 immune responses to ovalbumin and the anaphylaxis induced by re-exposure to ovalbumin were measured.Results: IgA complexed with antigen attenuated the primary antibody responses to the antigen in mice, in contrast to IgG2b and IgE. The primary antibody responses, i.e. the de novo synthesis of anti-ovalbumin IgG2a, IgG1 and IgE in the serum, and the subsequent anaphylaxis induced with re-exposure to ovalbumin were reduced by the co-injection of anti-ovalbumin monoclonal IgA at ovalbumin immunization. The Th1, Th2 and Tr1 cytokines interferon-γ, interleukin-4 and interleukin-10, respectively, released from ovalbumin-restimulated cultured splenocytes collected from allergic mice were also reduced by the treatment. The induction of interferon-γ and interleukin-4 secretion by splenocytes from ovalbumin-immunized mice stimulated in vitro with ovalbumin was also significantly reduced by the antigen complexed with anti-ovalbumin IgA.Conclusion: These data suggest that the direct inhibition of Th1 and Th2 activation by anti-ovalbumin monoclonal IgA participates in the inhibition of the primary antibody responses. IgA plays important immunosuppressive roles under physiological and pathological conditions and is a promising candidate drug for the treatment of immune disorders.

Grass tablet sublingual immunotherapy downregulates the TH2 cytokine response followed by regulatory T-cell generation

Sublingual administration of Phleum pratense allergen immunotherapy (SLIT) tablets is a clinically efficient treatment for grass pollen-induced rhinoconjunctivitis. This immunotherapy downregulates TH2 immune responses, induces tolerogenic pathways, and increases regulatory T cells. However, associated immune response markers of allergen desensitization remain undefined. We sought to characterize the kinetics of individual changes in the immunologic response to grass tablet SLIT. We evaluated the systemic effects of SLIT in a longitudinal analysis of humoral and cellular immune parameters in peripheral blood samples. Grass tablet SLIT administration induced a 2-phase systemic humoral and cellular response. The TH2 response was initially exacerbated and detected as increased allergen-specific IgE (sIgE) and IgG4 (sIgG4) levels and an increase in IL-4-producing cells, followed by downregulation of the TH2 response with a shift toward a TH1 cytokine profile. T cells with a regulatory phenotype were also elicited. Statistical correlations between immunologic measurements for each patient throughout therapy indicated that TH2 response downregulation and reduction of the immediate SLIT-induced IgE response were associated with increased allergen-specific IgG4 synthesis early in therapy. TH2 response downregulation by month 4 correlated with increased frequency of CD4(+) T cells with a regulatory phenotype by 12 months. Changes in sIgE levels after therapy were linked to a specific IgG4 response, and production of blocking antibodies correlated with TH2 response downregulation. Reduced IL-4(+) cell frequency was linked to an increase in the frequency of CD4(+) T cells with a regulatory phenotype. Changes in sIgE levels and reduced IL-4 and blocking antibody levels could thus be used as indicators of a patient's immune response to therapy.

Cerebrospinal Fluid Analysis in Immunoglobulin G4-related Hypertrophic Pachymeningitis

To the Editor: Immunoglobulin G4-related disease (IgG4-RD) is characterized by fibrous swelling of affected organs, elevations in serum IgG4 concentrations, and responsiveness to glucocorticoid treatment1. Affected tissues display similar histological features: diffuse lymphoplasmacytic infiltration by numerous IgG4-positive plasma cells, occasional eosinophils, storiform fibrosis, and obliterative phlebitis2. IgG4-related hypertrophic pachymeningitis (IgG4-HP) has been identified as a characteristic central nervous system (CNS) manifestation of IgG4-RD, but comprehensive cerebrospinal fluid (CSF) analyses are substantially lacking3,4. Recently, we demonstrated an intrathecal IgG and IgG4 synthesis in the CSF of a patient with IgG4-HP and suggested IgG4 Indices as safe potential diagnostic tools for IgG4-HP5. Here, we describe 2 new cases of IgG4-HP with CSF evaluation at diagnosis and in response to treatment. In case 1, March 2007, a 56-year-old man was admitted with a 1-year history of right frontal headache. Magnetic resonance imaging (MRI) showed right frontal pachymeningitis. Granulomatous meningeal inflammation was suspected and oral prednisone (1 mg/kg body weight/day) was started with clinical and radiological improvement. Prednisone was discontinued after 8 months, but in July 2008 the headache recurred. Blood and CSF analyses are shown in Table 1. MRI evidenced a right frontotemporal progression of the pachymeningitis (Figure 1A). A meningeal biopsy … Address correspondence to Dr. E. Della-Torre, Department of Medicine and Clinical Immunology, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy. E-mail: dellatorre.emanuel{at}hsr.it

Enhancement of the Frequency and Function of IL-10-Secreting Type I T Regulatory Cells after 1 Year of Cluster Allergen-Specific Immunotherapy

Background: Allergen-specific immunotherapy (SIT) is a highly effective treatment for allergic diseases, but the underlying mechanisms are unclear. In this study, we investigated the effects of cluster SIT with Dermatophagoides pteronyssinus (Der p) on IL-10-secreting type I T regulatory (Tr1) cells in Der p-sensitized patients with allergic rhinitis. Methods: This was a prospective randomized study involving 68 participants (aged 18–60 years) of whom 38 were patients with allergic rhinitis and received Der p-SIT for 1 year and 30 were nonallergic controls. IL-10+IL-4–CD4+ T cells were measured by flow cytometry for the patient group at baseline and at the end of 1 year of SIT, and for nonallergic controls. Similarly, IL-10 in supernatants from allergen-stimulated peripheral blood mononuclear cell (PBMC) cultures were measured by ELISA, and the suppressive effect of Tr1 cells on cell proliferation and cytokine release (IFN-γ and IL-4) in PBMCs was estimated in cultures from both groups. Allergen-specific serum IgE and IgG4 were also assessed by RAST and ELISA for the SIT group. Results: The levels of IL-10-secreting Tr1 cells, IgG4 and allergen-induced IL-10 synthesis from PBMC cultures were significantly increased and the function of Tr1 cells was enhanced after 1 year of SIT compared to baseline levels. In contrast, the level of IgE was not significantly changed. Conclusion: These data suggest that the cluster Der p-SIT may enhance the frequency and function of IL-10-secreting Tr1 cells.

Responses of CD4+CD25+Foxp3+ and IL‐10‐secreting type I T regulatory cells to cluster‐specific immunotherapy for allergic rhinitis in children

We investigated the effects of cluster specific immunotherapy (SIT) with Dermatophagoides pteronyssinus (Der p) on CD4(+) CD25(+) Foxp3(+) Treg cells and IL-10-secreting type I T regulatory (Tr1) cells in Der p-sensitized children with allergic rhinitis (AR). We performed a prospective randomized study involving 46 children (aged 8-13 yr), of whom 25 children received Der p-SIT + pharmacotherapy and 21 received only pharmacotherapy, over a period of 1 yr. Prior to and at end of treatment, CD4(+) CD25(+) Foxp3(+) Treg cells and allergen-specific IL-10(+) IL-4(-) , IFN-γ(+) IL-4(-) , and IL-4(+) IFN-γ-CD4(+) T cells were measured by flow cytometry. Similarly, IL-4, IFN-γ, and IL-10 in supernatants from allergen-stimulated peripheral blood mononuclear cell (PBMC) cultures were measured by ELISA, and the suppressive effect of CD4(+) CD25(high) T cells on cell proliferation and cytokine release was estimated from both groups. Allergen-specific serum IgE and IgG4 were also assessed at the beginning and end of treatment by RAST and ELISA, respectively. The levels of allergen-specific Tr1 cells, IgG4, and allergen-induced IL-10 synthesis from PBMC cultures were significantly increased after SIT for 1 yr compared with baseline levels (p < 0.001 for all), with significant correlation between increased levels of Tr1 cells and improvements in nasal symptoms (r = 0.48, p < 0.05). In contrast, the levels of CD4(+) CD25(+) Foxp3(+) T cells, allergen-specific Th1 and Th2 cells, the production of IL-4 and IFN-γ, and the function of CD4(+) CD25(high) T cells were not altered in either group at the end of treatment. These data suggest that the up-regulation of Tr1 cells may play an important role in SIT and be a useful marker of successful SIT in AR patients.

Infectivity of Strongyloides venezuelensis is influenced by variations in temperature and time of culture

The present research investigated the influence of temperature and time of larvae culture on the infectivity of Strongyloides venezuelensis. Mice were infected s.c. with 1500 larvae of S. venezuelensis maintained at 28 °C for three days of culture (dc), 28 °C for seven dc or 18 °C for seven dc. On days 1, 3, 5, 7, 14 and 21 post-infection the animals were sacrificed and cell numbers in the blood, peritoneal cavity fluid (PCF), broncoalveolar fluid (BALF), cytokines, immunoglobulins, number of parasites and eggs/g of feces were quantified. Results demonstrated an increase in eosinophils and mononuclear cells in the blood, PCF and BALF of infected mice. Larvae at 28 °C/3dc induced earlier eosinophils in the PCF and BALF as opposed to larvae at 28 °C/7dc and 18 °C/7dc. Larvae at 28 °C/7dc induced higher synthesis of IL-4, IL-5 and IL-10 on days 5 and 7 post-infection. Larvae at 28 °C/3dc in culture induced higher synthesis of IL-12 than larvae of seven dc, but time in culture induced better synthesis of IFN-γ after larval migration had ceased and only adult worms were present. Larvae at 28 °C/3dc in culture induced higher synthesis of IgG and IgG1 and expelled less female parasites than larvae cultivated for seven days. In conclusion, it was observed that the infectivity of S. venezuelensis is influenced by variations in temperature and time of culture.

Features of intrathecal immunoglobulins in patients with multiple sclerosis

We have analyzed immunoglobulin (Ig) isotypes and IgG subclasses in cerebrospinal fluid (CSF) and serum of patients with multiple sclerosis (MS) and other neurological diseases to determine whether different Ig isotype patterns correlate with clinical or paraclinical findings and CSF B cell populations. Intrathecal IgG1 synthesis was elevated in MS patients. An increased intrathecal IgM production was found in patients with a higher cerebral MRI lesion burden, whereas other clinical and paraclinical parameters were not associated with a specific Ig isotype or subclass profile. Finally, intrathecal IgG production (IgG1 and IgG3) correlated with the presence of mature B cells and plasma blasts.

The effect of large-dose prednisone therapy on IgG subclasses in multiple sclerosis.

The effect of large-dose prednisone therapy (3960 mg over 56 days) on IgG subclasses in the cerebrospinal fluid and sera, as well as on their intrathecal synthesis, was studied in 15 patients with clinically definite multiple sclerosis. The concentration of IgG subclasses was measured using ELISA with monoclonal antibodies against human IgG subclasses, secondary biotinylated antibody and avidin-biotin-peroxidase complex. There was a decrease of IgG1, IgG3 and IgG4 in the CSF of MS patients after the treatment, but the differences did not reach statistical significance. The IgG index was decreased about 34% (p < 0.01) after the therapy. This was mainly due to diminished synthesis of IgG1 and IgG3. The significance of IgG subclasses in the pathogenesis of MS is discussed.