Quantitative analysis of immunoglobulin G subclass responses to Pseudomonas aeruginosa antigens in cystic fibrosis.

The four subclasses of IgG have different structures, functions and implications in the antibody response. IgG subclass reactions to individual Pseudomonas aeruginosa structural antigens in 22 adolescents and young adults with cystic fibrosis (CF) were studied qualitatively and quantitatively by densitometric analysis of Western blot assays. These patients had been infected by P. aeruginosa for 7 years or longer and were divided into two groups according to their pulmonary status: Group 1 comprised 11 patients with relatively good pulmonary status; Group 2 consisted of 11 patients with poor pulmonary status. There was a relative decrease of IgG1 and a relative increase of IgG2 and, especially, of IgG3 and IgG4 antibodies against P. aeruginosa antigens in the CF patients. Comparison of the two CF patient groups showed a significant increase in the proportion of IgG3 in the Group 2 patients. This could be a potential cause or effect in the deterioration of their pulmonary function. Densitometric analysis of Western blots revealed more than 24 P. aeruginosa antigens and indicated those that were the targets of the isotype antibody response(s) that were apparently most harmful. Thus, there was a significant increase of IgG2 or IgG3 reactivity (or of both) against proteins F, H (H1 and H2), and I in the Group 2 patients. One other striking observation of this study was the high reactivity of IgG4 antibodies to protein H. IgG4 was the major antibody to this protein in seven of the 11 Group 1 patients compared to two of the 11 in Group 2. We hypothesise that IgG4 antibodies may antagonise IgG2 antibodies, helping to preserve stable pulmonary function.     

Development of a Maturing T-Cell-Mediated Immune Response in Patients with Idiopathic Parkinson’s Disease Receiving r-metHuGDNF Via Continuous Intraputaminal Infusion

The development of a maturing T-cell-mediated immune response was characterized in Parkinson's disease subjects receiving recombinant human glial-derived neurotrophic factor (r-metHuGDNF) via continuous bilateral intraputaminal infusion. Eighteen of 34 subjects tested positive for anti-r-metHuGDNF-binding antibodies. Four subjects developed neutralizing activity, three of which demonstrated classic immunoglobulin class switching from IgM to IgG. An increase of anti-r-metHuGDNF IgG-binding antibodies correlated with the development of neutralizing activity. All serum samples from two subjects with neutralizing activity were characterized for IgG subclasses. These data revealed an initial anti-r-metHuGDNF IgG population where IgG1 > IgG2 > IgG4, and IgG3 concentrations were negligible. However, continued antigenic stimulation resulted in concentration changes where IgG4 > IgG1> IgG2, indicating a mature immune response. In addition, using in silico techniques, two immunodominant MHC class II T-cell epitopes were predicted for the native GDNF sequence. These data demonstrate development of a mature T-cell-mediated immune response in these subjects.     

IgG subclasses in human immune response to wild and attenuated (vaccine) Junin virus infection

Different proportions of IgG subclasses have previously been reported to distinguish the immune response elicited by primary and recurrent viral infections, as well as viral vaccines. The goal of this study was to study the IgG subclasses composition in the immune response of patients with Argentine hemorrhagic fever, and vaccinees with Candid #1 strain of Junin virus. Twenty-four individuals inoculated with Candid #1 vaccine and 67 patients with Argentine hemorrhagic fever were studied. Blood samples were drawn at 30, 60, and/or 180 days post-inoculation with Candid #1 and 30, 60, and 90 days after clinical onset of the disease. Specific anti-Junin virus IgG subclasses were titrated with specific human monoclonal antibody fluorescence isothiocyanate conjugate (FITC) by immunofluorescent assay (IFA). IgG(1) anti-Junin virus was found in every subject studied and IgG(3) was also detected in some patients with a severe form of Argentine hemorrhagic fever. IgG(2) and IgG(4) were not detected in any serum sample studied. The mean titer of specific IgG(1) in vaccinees was significantly lower than in patients with Argentine hemorrhagic fever (P < 0.05), but no difference was found between mild and severe cases of the disease (P > 0.05). The results of this study demonstrated a central role of IgG(1) in human recovery from infection with every strain of Junin virus, an observation stressed by the immune response to Candid #1 vaccine, which resulted in no difference in IgG subclasses composition from that found in mild cases of Argentine hemorrhagic fever.     

Lipopolysaccharide- and cholera toxin-specific subclass distribution of B-cell responses in cholera.

The immunoglobulin subclass responses to homologous lipopolysaccharide (LPS) and to cholera toxin (CT) in adult patients infected with Vibrio cholerae O1 and V. cholerae O139 were studied. LPS-specific antibody-secreting cells (ASC) of both the immunoglobulin A1 (IgA1) and IgA2 subclasses were seen, with the IgA1 ASC response predominating in both V. cholerae O1- and O139-infected patients. For antibodies in plasma, by day 11 after onset of disease, all V. cholerae O1- infected patients responded to homologous LPS with the IgA1 subclass (P = 0.001), whereas fewer (68%) responded with the IgA2 subclass (P = 0.007). About 89% of V. cholerae O139-infected patients responded with the IgA1 subclass (P = 0.003), and only 21% responded with the IgA2 subclass (not significant [NS]). Both groups of cholera patients showed significant increases in LPS-specific IgG1, IgG2, and IgG3 antibodies in plasma. In feces, the response to homologous LPS occurred in both groups of patients with the IgA1 and IgA2 subclasses, with 55 to 67% of patients showing a positive response. V. cholerae O1- and O139-infected patients showed CT-specific ASC responses of the different IgG and IgA subclasses in the circulation, and the pattern followed the order IgG1 > IgA1 > IgG2 > IgA2, with low levels of IgG3 and IgG4 ASC. Plasma anti-CT antibody responses in all subclasses were seen by day 11 after onset of disease. Although there were no increases in CT-specific ASC of the IgG3 (NS) and IgG4 (NS) subtypes, there were significant increases of these two subclasses in plasma (P 相似文献   

Sialidase activity and antibodies to sialidase-treated autologous erythrocytes in bronchoalveolar lavages from patients with idiopathic pulmonary fibrosis or sarcoidosis.

Earlier studies have shown that IgG1 and IgG4 are the dominant IgG subclasses in the specific response during a chronic helminthic infection. It has also been suggested that IgG4 production results from chronic or repetitive antigenic stimulation and a correlation between IgG4 and IgE levels exists. An outbreak of Trichinella spiralis infection in Poland provided the opportunity to follow the sequential appearance of the IgG subclass and IgE responses in 15 patients during the early stage of Trichinella infection and to compare these observations in sera obtained one year later from the same patients. The results show that the sequential appearance of the IgG subclasses were IgG1 before IgG3 and IgG3 before IgG4. IgG1 antibodies dominated the immune response in all patients. A statistically significant increase in the number of IgG4 positive sera was observed in patients during the chronic stage compared to the findings during the early stage of infection (13% vs 73%; p less than 0.001), supporting the view that IgG4 results from a chronic antigenic stimulation. A correlation between the appearance of IgG4 and IgE was not found. The highest levels of IgE were seen in the first serum samples obtained, with a decrease during the course of infection.     

Evaluation of B-cell immunity in patients with pretransplant sensitization

The influence of presensitization (blood transfusions) on B-cell immunity as reflected in the serum of two groups of candidates for cadaveric donor renal allografts was examined. The first group initially had a high level of panel-reactive antibody (PRA) greater than 72% but experienced a large decrease in PRA (>70%) 6–34 months prior to transplantation. In contrast, the second group maintained a high PRA (100%) for up to 28 months after sensitization and before transplantation. Three blood samples from each patient, representing a maximum time span of 34 months, were analyzed. Levels of IgG, IgM isohemagglutinins, and antitetanus antibody were used as indicators of B-cell function. There were no significant differences between the individual values of a single patient with regard to each parameter. However, Group II patients had elevated values of total IgG relative to Group I patients. Total serum IgG-subclass levels (IgG1, IgG2, IgG3, IgG4) were measured and the relationship between a specific IgG subclass and the PRA activity was determined. IgG1 values in Group II were higher than those found for Group I. The other IgG subclasses were all within normal levels and were not significantly different between Group I and Group II. When IgG-subclass typing of PRA was performed, IgG1 accounted for most of the activity in both groups and a fall in PRA-specific IgG1 was associated with the reduced PRA observed in Group I. The data indicate that humoral immunity, as reflected by total and specific immunoglobulin levels, is intact in general in the two groups of presensitized renal allograft candidates examined and that any loss of PRA activity reflects a reduction in a specific immune response.     

Distinct serum immunoglobulins pattern in Egyptian patients with chronic HCV infection analyzed by nephelometry

Hepatitis C has emerged as a major worldwide public health problem. The host immune response to HCV infection is composed of both a non-specific immune response, including interferon (IFN) production and natural killer (NK) cell activity, and a virus-specific immune response, including humoral and cellular components. Susceptibility to infection has been related to immunological disturbances. Several studies have provided experimental evidence of disorders of both cellular and humoral immunity. The present study was carried out to evaluate the serum immunoglobulins level (IgG, IgM, IgA) and IgG-subclasses (IgG1-4) in chronic hepatitis C patients in comparison with healthy control patients. This study included 50 patients with biochemical, serologic, virologic, and histologic evidence of chronic hepatitis C. Total IgG, IgA, and IgM were assayed by nephelometry. IgG subclasses were assayed using human IgG subclasses enzyme immunoassay. The results showed a significant increase of total serum IgG and IgM levels found in patients with chronic HCV compared with the healthy control patients (P < 0.001 for each). There was a statistically significant difference in the IgG subclasses (IgG1 to IgG4) between the patients and controls (P < 0.001 for each). On the other hand, no significant difference was found between patients and healthy controls in IgA level (P = 0.4). The normal total serum immunoglobulins pattern is apparently shifted in chronic hepatitis C infection in the Egyptian patients. This pattern may include an ethnic or biologic background and could be used in the differentiation of the patients with minimal liver disease.     

Changes of tetanus specific IgG, IgM and IgG subclasses after DPT vaccination

We evaluated tetanus specific IgG, IgM, IgG subclasses after DPT vaccination in infants and children. Tetanus toxoid specific IgG, IgM IgG subclasses were measured to characterize the isotope profile of antibody against tetanus toxoid. The values of the tetanus specific IgG in the positive group were significantly increased compared to those of the control group, and were significantly increased after two inoculation. Tetanus specific IgG was very low in adults and neonates. In our tetanus specific IgG subclasses study, forty-five of 56 cases (80%) showed predominantly IgG1 antibody responses to tetanus toxoid, while twenty-five of 56 cases (45%) showed IgG4 responses. Both IgG1 and IgG4 responses were demonstrated in 17 cases (30%). So we suggest that IgG was mainly involved in humoral immune response after DPT vaccination, and IgG1 may play an important role among IgG subclasses. IgG4, alone or together with IgG1, can also play a role in immune response to tetanus toxoid.     

The IgG subclasses of antibodies to grass pollen allergens produced in hay fever patients during hyposensitization

Total IgG, IgG subclass and IgE antibodies specific for grass pollen allergens were measured by the red cell linked antigen-antiglobulin reaction (RCLAAR) in serum samples from nineteen patients who had undergone a course of hyposensitization. Increases in both specific IgG and IgE antibodies were seen after treatment in most patients. In the IgG subclasses the predominant response was for IgG1 and IgG4 antibodies. Attempts were made to correlate the antibody responses with the clinical response and the results are discussed with reference to the possible mechanisms of hyposensitization.     

Neutrophil Fcγ and complement receptors involved in binding soluble IgG immune complexes and in specific granule release induced by soluble IgG immune complexes

We examined the effect of soluble IgG immune complex (IC) characteristics on the binding of IC to human neutrophils and IC-induced specific granule release of neutrophils via Fcγ receptors (CD16 and CD32) and complement receptors (CR1 and CR3). A set of soluble IgG IC varying in size, IgG subclass, antigen epitope density and complement (C) incorporation were formed between 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) coupled to bovine serum albumin (BSA) and chimeric mouse-human anti-NIP monoclonal antibodies (mAb) of all four IgG subclasses. High and low epitope density IC of all four IgG subclasses induced specific granule release with C, but in the absence of C only IgG1 and IgG3 IC were functionally active. The Fcγ and C receptors responsible for IgG IC-induced specific granule release and IC binding were determined using mAb specific for the ligand binding sites of CD16, CD32 and CR3, and recombinant soluble CR1. Each defined IC displayed a unique pattern of receptor preference, dependent upon subclass and antigenic epitope density. IC binding and IC-induced specific granule release was not mediated by the same receptor, or combination of receptors. High and low epitope density IgG3 IC binding and induction of specific granule release was mediated predominantly via CD16. Other IC subclasses bound differently, i.e. IgG1 IC used CD16 and CR3; IgG2 and IgG4 predominantly used complement receptors; but all three induced specific granule release via CD32. In vivo these results may translate into differential activation of neutrophils by soluble IC dependent upon their characteristics, leading to subtle nuances in the etiology, pathology and control of the immune response in IC-related diseases.     

Immunoglobulin G subclass antibodies to measles virus in patients with subacute sclerosing panencephalitis or multiple sclerosis

Mouse monoclonal antibodies specific for human immunoglobulin G (IgG) subclasses and a sensitive immunoassay were used to evaluate the IgG subclass antibody response to measles virus antigens in cerebrospinal fluid and serum samples from 20 patients with subacute sclerosing panencephalitis (SSPE), 12 patients with multiple sclerosis (MS), and 11 controls with high measles virus antibody titers in serum. In patients with SSPE, measles virus-specific antibodies were found mainly in the IgG1 subclass and the IgG subclass distribution remained unchanged, irrespective of the clinical stage or duration of the disease. In patients with MS and in controls, measles virus activity was also associated mainly with IgG1. However, the activity was significantly lower than that found in patients with SSPE. The results suggest that there is no primary abnormality in humoral immune response to measles virus in patients with MS. The disproportionately high levels of the measles virus-specific IgG1 subclass found in patients with SSPE may be due to persistent antigenic stimulation or reflect a defect in immunoregulatory mechanisms in response to viral infection.     

Bovine serum albumin (BSA) nephritis in rats II. Histological findings and complement activation by immune complex in SHR rats

We introduced a mesangiopathic form of glomerulonephritis in spontaneously hypertensive (SHR) rats. Bovine serum albumin (BSA) was given i.v. to primed rats for 3 weeks and they were unilaterally nephrectomized (Nx). Then, they received rabbit anti-BSA- (Group A) or normal serum (Group B) for seven days, and half the rats were killed to obtain another kidney (Ex-1). The remainder were killed two weeks later and their kidneys were examined (Ex-2). In Nx kidneys, the glomerular lesions were characterized by leucocyte accumulation in the capillary lumina and by deposition of rat IgG, rat C3 and BSA both in the mesangial area and along the capillary walls. Glomeruli of Ex-1 kidneys manifested varying degrees of hypercellularity in the mesangium; a few leucocyte accumulations in the capillary lumina were noted and the immune deposits had decreased in the mesangium but not on the capillary walls. In Ex-2 kidneys, mesangial hypercellularity was conspicuous. There were no remarkable histological differences between Group A and B rats; in Ex-1 and Ex-2 kidneys of Group A, rabbit IgG was closely associated with rat IgG or C3. Serological evaluation revealed that the amount of circulating rat anti-BSA antibody was relatively small and that C3 was consumed by newly formed circulating immune complexes during BSA administration. Polymorphonuclear leucocyte (PMN) binding assay revealed that complement fixation to the immune deposits occurred in vitro and that this activity was highest in tissue from Nx kidneys.     

Bovine serum albumin (BSA) nephritis in rats II. Histological findings and complement activation by immune complex in SHR rats.

We introduced a mesangiopathic form of glomerulonephritis in spontaneously hypertensive (SHR) rats. Bovine serum albumin (BSA) was given i.v. to primed rats for 3 weeks and they were unilaterally nephrectomized (Nx). Then, they received rabbit anti-BSA- (Group A) or normal serum (Group B) for seven days, and half the rats were killed to obtain another kidney (Ex-1). The remainder were killed two weeks later and their kidneys were examined (Ex-2). In Nx kidneys, the glomerular lesions were characterized by leucocyte accumulation in the capillary lumina and by deposition of rat IgG, rat C3 and BSA both in the mesangial area and along the capillary walls. Glomeruli of Ex-1 kidneys manifested varying degrees of hypercellularity in the mesangium; a few leucocyte accumulations in the capillary lumina were noted and the immune deposits had decreased in the mesangium but not on the capillary walls. In Ex-2 kidneys, mesangial hypercellularity was conspicuous. There were no remarkable histological differences between Group A and B rats; in Ex-1 and Ex-2 kidneys of Group A, rabbit IgG was closely associated with rat IgG or C3. Serological evaluation revealed that the amount of circulating rat anti-BSA antibody was relatively small and that C3 was consumed by newly formed circulating immune complexes during BSA administration. Polymorphonuclear leucocyte (PMN) binding assay revealed that complement fixation to the immune deposits occurred in vitro and that this activity was highest in tissue from Nx kidneys.     

Vaccination with Rabies to Study the Humoral and Cellular Immune Response to a T-Cell Dependent Neoantigen in Man

We investigated the humoral (antigen-specific immunoglobulin isotypes, IgG subclasses, and avidity maturation) and cellular (antigen-specific in vitro proliferation) immune response in 18 healthy adult volunteers, following a primary and a single booster vaccination with the T-cell dependent neoantigen rabies administered at a 3-months interval. The IgG antibody titer showed a mean 31-fold increase (range 3-154) 4 weeks after the first vaccination and a memory response was observed after booster vaccination, i.e. high IgG titers, switch from IgM to IgG and IgA and increased antibody avidity. All healthy adults showed a rabies-induced proliferative response with a mean stimulation index of 45 (range 3.5-200) after in vitro stimulation of PBMC obtained at 4 weeks after booster vaccination. The results obtained in this study provide a frame of reference for the interpretation of specific immune responses to the T-cell dependent neoantigen rabies in patients suspected of a primary or secondary immunodeficiency. Humoral and cellular immune responses to the rabies neoantigen provide complementary information on the condition of the immune system of an individual. Five patients diagnosed with a combined immunodeficiency were vaccinated using the same protocol and showed a number of abnormalities, either in the humoral or the cellular immune response to the rabies neoantigen.     

Imbalanced serum IgG subclass pattern in toxic shock syndrome patients: deficiency of specific IgG1 and IgG4 subclass antibodies to toxic shock syndrome toxin 1

An imbalanced serum IgG subclass pattern was identified in 10 patients with toxic shock syndrome (TSS) showing remarkably low subclass levels of various combinations. IgG2 levels were significantly reduced as compared to normal controls. The IgG subclass-specificity of antibodies to toxic shock syndrome toxin (TSST-1) was investigated by a solid-phase radioimmunoassay. TSS-patients lacked pre-immunity to TSST-1 in all four IgG subclasses. Normally acquired immunity to the toxin as well as the serological response developing in two patients with TSS was generally restricted to IgG1 and IgG4. A strong booster response of all four IgG subclasses was seen in three patients with S. aureus septicaemia due to TSST-1 producing strains. The lack of specific IgG1 and IgG4 antibodies to TSST-1 and the low serum IgG subclass levels found in the TSS-patients could be of pathogenetic significance and help to explain the susceptibility to TSS in certain individuals.     

Detection of IgG subclasses with anti-IgE activity in patients with atopic diseases.

Significantly increased levels of IgG anti-IgE were seen in atopic patients as compared with controls. A correlation was observed between the levels of anti-IgE autoantibodies and serum IgE in the groups of atopic patients studied. No significant correlation was found between IgG anti-IgE levels and severity of the disease or between IgG subclasses with anti-IgE activity and clinical status. Analysis of IgG subclasses with anti-IgE activity showed that IgG1 and IgG4 were clearly factors in differentiating the atopics from the controls. IgG2 and IgG3 anti-IgE levels were not statistically significantly elevated. The lack of these autoantibodies may be explained by the presence of immune complexes or the lack of specificity of the monoclonal antibodies used in this study. These observations have not yet determined whether these autoantibodies and the isotypic selection and restriction observed play a role in the dysregulation of the immune response and in the evolution towards atopy.     

Subclasses of human IgG anti-Fab antibodies: parameters for optimum detection

In this study we have defined the parameters needed for the optimum detection of anti-Fab antibodies in the serum of patients with rheumatoid arthritis. We have found that the majority of the anti-Fab antibodies are of the IgG3 and IgG4 subclasses which were not optimally detected using polyclonal heterologous anti-human IgG antisera; subclass-specific antibodies instead were needed. Additionally we determined that dissociation of circulating immune complexes by dialysis against urea for 3-7 days was also needed for the detection of these antibodies. Lastly we have shown that the dissociated complexes can recombine with their target Fab molecules, and therefore separation of the anti-Fab antibodies from the other immunoglobulins by chromatofocusing may enhance the detection of these antibodies. When the above conditions were fulfilled it was determined that IgG anti-Fab antibodies could be detected in rheumatoid arthritis and normal sera and that acidic IgG3 and IgG4 subclasses predominated. However, IgG3 levels were 10.5-fold higher in rheumatoid arthritis sera (p less than 0.05) and IgG4 levels 5-fold higher (p less than 0.01) than in normal sera.     

Plasma Cells and their Precursors III. Late Phases of anti-Bovine Serum Albumin IgG Antibody Responses Depend upon Newly Produced IgG B-Memory Cells

The sequential appearance of the IgG antibody clones constituting the primary, secondary or tertiary response to BSA was studied in individual rabbits by relating antibody titers, antibody affinities, and clonal spectra obtained by IEF. The results showed that after a single i.v. injection of BSA, the primary response IgG antibodies peaked at day 11 and had a constant and low average affinity during the first 20 days. A slow rise of affinity was observed during the following 20 days. In this period, new IgG antibody clones appeared, though antibody titers decreased. A number of these newly appearing, so-called late-phase clones were isolated by preparative IEF. Their affinities to BSA were high. Secondary responses showed the rapid rise of both titers and antibody affinities typical for the activity of B-memory AFC. One animal immunized for a tertiary response showed a still further increase of antibody affinity in its late phase.These results, together with those described in two earlier papers (1, 2), demonstrate that primary immunization, apart from triggering preexisting IgG AFCP into production of antibodies having low affinity, elicits the origination of IgG (B-memory)-AFCP capable of producing high affinity IgG upon antigenic triggering, and show that some of these may already be triggered during the ongoing response, thereby giving rise to the so-called late phase in the primary IgG antibody response.     

IgG Subclass Deficiency in Patients with Down''s Syndrome and Aberrant Hepatitis B Vaccine Response

Seventeen adult patients with Down's syndrome (DS) and 19 adult healthy references were vaccinated with a hepatitis B vaccine in order to study the IgG subclass response. An enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies specific for IgG subclasses was employed. In spite of normal levels of total IgG1 and normal or even high levels of IgG3 in the DS patients, a significantly lower IgG1 response to the vaccine was observed in trisomic patients than in the references.     

Development of serum antibodies of the immunoglobulin G class and subclasses against the capsular polysaccharide of Haemophilus influenzae type b in children and adults with invasive infections

The development of total immunoglobulin G (IgG) antibodies and antibodies of the four IgG subclasses in serum against Haemophilus influenzae type b capsular polysaccharide (CPS) was studied in 24 children and 11 adults with invasive Haemophilus influenzae type b infections, by using an enzyme-linked immunosorbent assay. None of the 8 children aged 10 months or younger had increases in the IgG class or in any of the IgG subclasses. In contrast, 14 of 16 children between 10 months and 6 years of age and 10 of 11 adults had significant increases in total IgG, IgG1, or IgG2 antibodies in various combinations, but none of them had increases in IgG3 or IgG4 antibodies. The increases in IgG1 and IgG2 antibodies in the children were of similar magnitudes. Of 11 adult patients, 9 had significant increases in IgG2 antibodies, while only 4 had increases in IgG1 antibodies. In conclusion, this study shows that children younger than approximately 1 year have no IgG response to H. influenzae type b CPS, while individuals above this age have a mixed IgG1 and IgG2 response.