Chronic mucocutaneous candidiasis. II. Class and subclass of specific antibody responses in vivo and in vitro

Patients with chronic mucocutaneous candidiasis (CMC) succumb to persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been repeatedly reported while antibody responses were mostly found to be normal. The underlying defect remains poorly understood. It has recently been shown that CMC patients are also susceptible to infections with encapsulated bacteria, and may have associated IgG2 and IgG4 deficiency. Our previous studies demonstrated altered cytokine production in CMC patients. As cytokines can influence production and isotype of specific antibody, in 10 patients with CMC we measured the levels and isotype distributions of serum antibodies to Candida antigens (CAg), pneumococcal polysaccharide (PPS) and tetanus toxoid (TT) antigens. Peripheral blood lymphocytes were also stimulated in culture and the antibodies made in vitro were measured. Our data demonstrated that in vivo, CMC patients had very high levels of IgG and IgA CAg-specific antibodies. CAg-specific and PPS-specific IgG1 was markedly higher than in controls. Children but not adults with CMC had significantly lower levels of IgG2-specific antibody to CAg and PPS compared with age-matched controls. Patients had significantly higher levels of IgG3-specific antibody to all three antigens tested. These findings were in accordance with increased total IgG and IgG3 levels seen in CMC patients. In vitro, CMC patients, particularly children, did not respond as frequently to antigen stimulation as did their healthy controls. The level of specific antibody produced was also lower to all antigens tested, as was the amount of total immunoglobulins following antigenic and particularly mitogenic stimulation. Addition of interferon-alpha (IFN-α) or IFN-γ to cultures had variable, sometimes marked, effects. Our results demonstrate that CMC patients manifest subtle alterations in specific antibody responses to CAg, PPS and TT, which are most pronounced in children. This may relate to altered cytokine production also seen in these patients.     

The anti-apoptotic factor Bcl-2 can functionally substitute for the B cell survival but not for the marginal zone B cell differentiation activity of BAFF

The TNF family ligand B cell-activating factor (BAFF, BLyS, TALL-1) is an essential factor for B cell development. BAFF binds to three receptors, BAFF-R, transmembrane activator and CAML interactor (TACI), and B cell maturation antigen (BCMA), but only BAFF-R is required for successful survival and maturation of splenic B cells. To test whether the effect of BAFF is due to the up-regulation of anti-apoptotic factors, TACI-Ig-transgenic mice, in which BAFF function is inhibited, were crossed with transgenic mice expressing FLICE-inhibitory protein (FLIP) or Bcl-2 in the B cell compartment. FLIP expression did not rescue B cells, while enforced Bcl-2 expression restored peripheral B cells and the ability to mount T-dependent antibody responses. However, many B cells retained immaturity markers and failed to express normal amounts of CD21. Marginal zone B cells were not restored and the T-independent IgG3, but not IgM, response was impaired in the TACI-IgxBcl-2 mice. These results suggest that BAFF is required not only to inhibit apoptosis of maturating B cells, but also to promote differentiation events, in particular those leading to the generation of marginal zone B cells.     

Synergistic convergence of microbiota-specific systemic IgG and secretory IgA

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Ability of rosetting or non-rosetting individual control and inflammatory macrophages to kill Escherichia coli X43 intracellularly

An autoradiographic method combined with a rosette technique was used to assess the bactericidal activity of individual control and inflammatory peritoneal macrophages (PM phi) in the presence or absence of expression of Fc receptor for IgG (FcR). There was a lack of FcR reactivity in a certain percentage of both categories of PM phi exposed to E. coli X43, a bacterium which is readily phagocytosed in the presence of specific antibody. Both rosetting and non-rosetting PM phi were capable of phagocytosing E. coli X43, but inflammatory PM phi showed a marked reduction in their capacity to ingest these bacteria compared with control PM phi. Once ingested the E. coli X43 were killed equally well by non-rosetting and rosetting control and inflammatory PM phi.     

Competitive inhibition enzyme immunoassays for the measurement of human IgG, IgA and IgM

Competitive-inhibition enzyme immunoassays for the measurement of human IgG, IgA and IgM are described. These assays can be readily performed with commercial antisera and a recently developed method for purifying human IgA and IgM with high yield. The assays described are specific, with undetectable (<0.5%) cross-reactivity between the immunoglobulin classes in all systems, except with purified IgM, which cross-reacted to 1.9% with the IgG enzyme immunoassay.Minimal detectable concentrations of 2.5±0.8 ng/ml for IgG 4.2±0.9 ng/ml for IgA and 7.2±1.4 ng/ml for IgM were recorded, indicating that these assays are particularly sensitive. There is little within-assay variation (mean coefficient of variation = 3.9%), although the between-assay variation was substantially greater (mean coefficient of variation = 23.5%). These assay systems appear to be particularly suited to the measurement of immunoglobulin production by lymphocytes in culture. In such studies the assay must be specific, sensitive and be capable of discriminating between levels of immunoglobulin produced in response to various experimental treatments.     

Opsonizing antibodies (IgG1) up-regulate monocyte proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and IL-6 but not anti-inflammatory cytokine IL-10 in mycobacterial antigen-stimulated monocytes-implications for pathogenesis

Cachexia is one of the prominent features of advanced tuberculosis (TB) seen in association with increased expression of the monokine TNF-alpha. Several mycobacterial proteins, including PPD, stimulate TNF-alpha secretion from monocytes. Host factors that may play a role in cytokine expression from monocytes remain largely unknown. One such factor is the opsonizing antibodies. Monocytes have high-affinity receptors (FcgammaI and FcgammaIII) for IgG1 and IgG3 antibodies that mediate antigen uptake. We have reported selective up-regulation of IgG1 (which bind to Fcgamma receptors) in advanced TB and have recently shown the ability of PPD-specific IgG1 antibodies to augment TNF-alpha expression in PPD-stimulated monocytes. These observations have now been extended to other cytokines with semipurified fractions from secreted antigens of Mycobacterium tuberculosis (containing 30 kD and 58 kD) that were devoid of lipids, glycolipids and carbohydrates. In the presence of heat-inactivated TB plasma containing known amounts of antigen-specific IgG1 antibodies, these fractions induced significantly increased TNF-alpha, IL-6 and IL-10 secretion. Absorption of IgG1 with Protein 'A' removed the augmenting activity for TNF-alpha and IL-6 secretion from the TB plasma samples. In the case of IL-10, removal of IgG1 resulted in increased rather than decreased IL-10 secretion. These results suggest a possible pathogenic role for antibodies in TB by enhancing proinflammatory and blocking down-regulatory cytokines such as IL-10 cytokines during the chronic phase of TB.     

Minor salivary glands: Clinical,histological and immunohistochemical features of common and less common pathologies

Hundreds of minor salivary glands (MiSGs) are scattered in the oral cavity located at the submucosa layer. Beside their role in the oral cavity lubrication and immunity defence system, MiSGs are beneficial tissue source for diagnosing oral and non-oral related diseases. The advantage of MiSGs as a diagnostic tool reside on their fairly simple excisional procedure on one hand and negligible impact of the normal secretion capability of the salivary gland system on the other hand. The review focuses on pathologies related to developmental, reactive, metabolic, inflammatory and immunologic conditions, Iatrogenic causes and other undefined causes.     

Effect of age on serum immunoglobulin G subclass antibody responses to inactivated influenza virus vaccine

We previously reported an age-associated impairment of serum immunoglobulin G (IgG) antibody responses to inactivated influenza virus vaccine. The present study extends these observations by examining the IgG subclass distribution of vaccine responses measured by enzyme linked immunosorbent assay in healthy adults aged <40 (young), 40–64 (middle-aged), and ?65 (elderly) years. Serological responses in all age groups showed antibodies that were predominantly IgG1 and secondarily IgGS. Influenza antigen-specific IgG4 titers did not change following vaccination, and antibodies of the IgG2 subclass were not detected in any serum specimens. Aging was associated with a significant impairment of IgG1, but not of IgGS, antibody production. Relative differences in the magnitude and frequency of response between IgG1 and IgGS subclasses, which were present in young and middle-aged adults (viz., IgG1 > IgGS), were less apparent in the elderly. This observation was confirmed in a second analysis of IgG subclass-specific responses in a separate cohort of elderly vaccinees. These results suggest that the age-related impairment of humoral responses to inactivated influenza virus vaccine is primarily accounted for by differences in IgG1 antibody production, and that IgGS antibodies make up a larger proportion of the overall serologic response in the elderly than they do in younger persons. © 1994 Wiley-Liss, Inc.     

Use of the enzyme-linked immunosorbent assay for measurement of allergen-specific antibodies

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for allergen-specific IgG antibodies is described. Various solid-phase supports (microtiter plates), coating procedures, binding kinetics, and presentation of allergen in the assay were investigated. Using optimal conditions the indirect ELISA, in which the allergen is coated onto the well, was capable of detecting 2.4 ng/ml specific IgG antibodies to bee venom phospholipase A2(PLA2). The sandwich ELISA, in which the allergen was immobilized via specific antibody precoated onto the well, detected 0.24 ng/ml IgG antibodies to PLA2.