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PubMed2001

Allergic and immunologic parameters in patients with Fanconi's anemia.

BACKGROUND: Fanconi's anemia (FA) is a rare recessive chromosomal instability disorder, characterized by progressive bone marrow failure and congenital defects. Patients with FA present with recurrent infections, particularly those of the respiratory tract. OBJECTIVE: The aim of the present study was to evaluate whether patients with FA have altered antibody-mediated immune responses. METHODS: A group of 12 patients with FA, 5-32 years old (6 males) was studied. Serum levels of IgG, IgM, IgA and IgG subclasses, isohemagglutinin titers and specific IgG antibodies to poliovirus and measles were determined using standard methods. Immediate skin tests to common inhalant allergens were performed, and total and specific serum IgE was quantitated using a fluoroenzymatic assay (Uni-CAP, Pharmacia). Antipneumococcal antibodies were measured by ELISA before and 4-8 weeks after immunization with pneumococcal vaccine (Pneumo 23, Pasteur Mérieux Connaught). Responses to serotypes 1, 3, 5, 6B, 9V and 14, which are the most prevalent in our country, were studied. RESULTS: Ten patients had elevated IgE levels in sera, and 7 of them had detectable specific IgE and positive immediate skin tests. An inadequate response to pneumococcal vaccination was found in 2 of the 12 patients. Isohemagglutinin titers and levels of IgG, IgM, IgA and IgG subclasses and antipoliovirus and antimeasles antibodies were within the normal limits for age in all patients. Two patients had undetectable IgG4 levels (below 5 mg/dl). CONCLUSIONS: The results indicate that a proportion of patients with FA (2/12) in our study had inadequate responses to pneumococcal vaccination. No other significant abnormalities of the immune system were found in these patients.

Adolescent↗
PubMed1985

Cyclosporin partitions into phospholipid vesicles and disrupts membrane architecture.

Cyclosporin is a fungal metabolite demonstrating potent immunosuppressive activity both in vitro and in vivo, but the mechanism of action is poorly understood. Using [3H]dihydrocyclosporin C ([3H]CsC) we observed significant binding by mononuclear cells, erythrocytes and phosphatidyl choline (PC) vesicles which was reversible by the addition of excess CsA. Trypsin, pronase or heat treatments demonstrated that B cells and adherent cells express a protease-sensitive membrane binding site not observed on T cells. The nature of the interaction between CsA and the PC vesicles was studied using the membrane surface probe 1-anilino-8-naphthyl sulfonic acid (ANS-). ANS- -induced fluorescence was reduced by 24% in the presence of 4.75 X 10(-7). M CsA indicating that CsA displaces ANS- from the PC vesicles. CsA also effected a shift in the phase transition temperature of PC vesicles from 23 degrees C to 19 degrees C. Finally, the rate of concanavalin A (Con A)-induced cap formation by T lymphocytes was approximately doubled in the presence of 2.6 X 10(-5) M CsA. These data demonstrate that CsA partitions into phospholipid vesicle membranes and the plasmalemma of mononuclear cells resulting in an increased membrane fluidity.

Concanavalin A↗
PubMed2003

Ephrin B2 induces T cell costimulation.

Eph kinases form the largest family of receptor tyrosine kinases, and their ligands are ephrins (EFNs), which are cell surface proteins. Some Eph kinases and EFNs are expressed on T cells, B cells, and dendritic cells, but their functions in the immune system are largely unknown. In this study, we investigated the effect of EFNB2 on murine T cells. EFNB2 mRNA was expressed in the cortex of the thymus and white pulp of the spleen. At the protein level, it was expressed on T cells and monocytes/macrophages, but not on B cells. EFNB2Rs were expressed mainly on T cells. Solid-phase EFNB2 along with suboptimal anti-CD3 strongly stimulated T cell proliferation, with concomitant augmentation of IFN-gamma but not IL-2 or IL-4 secretion. The activity of cytotoxic T cells was also significantly enhanced in the presence of solid-phase EFNB2. These results indicate that EFNB2R cross-linking results in costimulation of T cells. EFNB2Rs were normally scattered on the T cell surface; after TCR cross-linking, they rapidly congregated to capped TCR complexes and then to patched rafts. This provides a morphological base for EFNB2Rs to participate in T cell costimulation. We also demonstrated that EFNB2R signaling led to augmented p38 and p44/42 mitogen-activated protein kinase activation. Our study shows that EFNB2 plays important roles in immune regulation.

Adjuvants, Immunologic↗
PubMed1976

[Comparison between anti-lymphocyte antibodies in systemic lupus erythematosus and in Hodgkin's disease].

Anti-lymphocyte antibodies of cold-reactive IgM-type in Systemic Lupus Erythematosus (SLE) and IgG-type in Hodgkin's disease (HD) by means of immunofluorescent technique have been demonstrated. The contemporaneous attachment of SLE and HD sera on selected peripheral lymphocytes demonstrate that the target cell is T-lymphocyte and that the two kinds of antibodies coat the same cell. Co-capping experiments have shown that the phenomenon has the same behaviour as regard to SLE and HD antibody, indicating that the antigen is the same. Hypothesis about the meaning of these antibodyies have been made.

Antibody Formation↗
PubMed1980

[Effect of thymosin on human lymphocyte subpopulations in vitro].

The incubation of healthy donors peripheral blood lymphocytes with thymosin was shown to increase the content of high avide "active" lymphocytes bearing receptors for SRBC, lymphocytes bearing receptors for C(2) component of complement and for Fc-portion of immunoglobulins. The proportion of cap-forming Ig-positive lymphocytes was shown to increase too. The role of T and B lymphocyte subpopulations and their precursors as thymosin action target cells is discussed.

B-Lymphocytes↗
PubMed2006

IgE sensitization, respiratory allergy symptoms, and heritability independently increase the risk of otitis media with effusion.

BACKGROUND AND AIMS: Epidemiological evidence examining the role of atopy and/or allergy in the pathogenesis of otitis media with effusion (OME) is inconclusive. The aim of this study was to assess any increased risk for OME attributable to allergy-related factors, in a well-characterized population using a case-control design and multivariate analysis. SUBJECTS AND METHODS: Eighty-eight 1-7-year-old children with OME, diagnosed by clinical and tympanometric evaluation and 80 matched controls were enrolled. A standardized questionnaire was completed, in order to assess factors related to OME and allergy-related symptoms and diagnoses using strict clinical definitions. Specific IgE was measured by skin-prick tests and/or CAP-FEIA. RESULTS: The patient and control groups were well matched. Factors conferring increased risk for OME in the univariate analysis included IgE sensitization, dyspnea, wheezing, asthma, paroxysmal sneezing, rhinitis, eczema, 'any allergic disease,' family history of otitis media, and family history of allergy. After multivariate analysis IgE sensitization, wheezing, nasal obstruction, family history of otitis, and child-care attendance remained as independent risk factors for development of OME. CONCLUSION: IgE sensitization and respiratory allergy symptoms are independent risk factors for the development of OME, suggesting that both immunological and mechanical pathways may contribute to the development of the disease. Otitis heritability provides additional risk, as well as frequent exposure to viral upper respiratory tract infections in children attending daycare. Treatment and/or prevention of OME using anti-allergic medications should be further examined.

Age Distribution↗
PubMed2000

Recombinant Hev b 1: large-scale production and immunological characterization.

BACKGROUND: Hev b 1 represents one of the most important allergens in Hevea brasiliensis latex. It is difficult to get an appropriate amount of native Hev b 1 (nHev b 1) for research purposes. OBJECTIVE: The aim of this study was to produce sufficient amounts of Hev b 1 by recombinant methods to prove its suitability for latex allergy diagnostics. METHODS: We isolated total RNA of Hevea brasiliensis leaves and synthesized cDNA by RT PCR. Recombinant Hev b 1 (rHev b 1) as well as three fragments (amino acid residues 29-137, 48-137, 78-137) were subcloned and expressed as fusion proteins with Maltose-binding protein (MBP) in Escherichia coli. The MBP-rHev b 1 fusion protein was examined by RAST with the CAP method, histamine release test and immunoblots with human sera from spina bifida patients as well as from health care workers with latex allergy and monoclonal antibodies. RESULTS: Histamine release test and immunoblots revealed the high allergenicity of the MBP-rHev b 1 construct. By the CAP method, 54 out of 58 serum samples (93%) from latex-sensitized spina bifida patients previously showing immunoglobulin (Ig) E to nHev b 1 exhibited IgE-binding to rHev b 1. Among 71 latex-allergic health care workers tested, 16 (22.5%) had IgE antibodies to rHev b 1. The analysis of the fusion proteins carrying rHev b 1 fragments revealed that the loss of the N-terminal 28 amino acid residues did not affect IgE-binding. In contrast, the lack of the first 47 amino acid residues led to decreased IgE-binding reactivity in two out of four sera tested, whereas the absence of the N-terminal 77 residues abolished IgE-binding in these two sera. CONCLUSION: The MBP-rHev b 1 fusion protein exhibits a corresponding IgE-binding reactivity to nHev b 1 and may therefore substitute natural Hev b 1 for both in vitro diagnostics and research purposes.

ATP-Binding Cassette Transporters↗
PubMed1978

Allogeneic corneal grafting in inbred strains of rats. Histology of graft reaction.

Histological studies of interlamellar keratoplasty in different inbred strains of rats (CAP, LEW) without additional sensitization--i.e. first-set reactions--are described. The corneas of 65 eyes, after allogeneic or syngeneic grafting, were examined from the 3rd to the 90th day--every 2nd day at the beginning of the reaction and later every 5th day. After syngeneic grafting (LEW leads to LEW) a non-specific healing-reaction (only slight vascularization of the graft bed, edema, granulocytic infiltration) reached its climax on the 6th day and subsided by the 10th day. After allogeneic grafting (CAP leads to LEW; RtH-1-incompatible) the non-specific-healing reaction progressed into a second phase, namely the specific reaction: increasing infiltration of the host cornea and the graft with small lymphocytes, blast cells and macrophages, directly followed by severe vascularization, reaching its climax about the 14th day. A third, phagocytic phase succeeded the infiltration leading to elimination of the donor cells, but leaving the donor stroma undamaged. All these alterations had almost completely disappeared after 35 days. Thus, the corneal allograft reaction is discussed as a typical immunological reaction leading to the destruction of transplantation-antigen-bearing cells and permitting observation of the different reaction phases more clearly than in most other tissues.

Animals↗
PubMed2000

In vitro diagnosis of cypress pollen allergy by using cytofluorimetric analysis of basophils (Basotest).

BACKGROUND: Cupressaceae pollen allergy is a worldwide pollinosis, but its in vitro diagnosis is notoriously difficult. The Basotest is a newly available in vitro test for the detection of allergen-specific IgE based on the level of cellular activation of basophils by using flow cytometry. OBJECTIVES: The Basotest was compared with the measurement of cypress pollen-specific IgE in highly selected patients. METHODS: We analyzed 34 patients allergic to cypress pollen selected on the basis of a suggestive clinical history and positive skin test and nasal challenge responses to cypress pollen extract. We also analyzed 8 patients with positive skin test responses to cypress pollen extract who did not present symptoms during the pollen season (intermediate group) and 33 control subjects. Sensitivity, specificity, and efficiency of the Basotest and serum-specific IgE levels measured by using the CAP System were determined in patients allergic to cypress pollen. Histamine release was studied in a selected group of patients. RESULTS: The Basotest was more sensitive (91.2%) than the CAP System (76%) for the in vitro diagnosis of cypress pollen allergy. A dose-response curve was observed in basophils obtained from patients allergic to cypress pollen. There were no false-positive results with either test (specificity 100%). The results of the Basotest or those of the CAP System did not correlate with the patients' in vivo threshold sensitivity assessed by skin tests and nasal challenge. CONCLUSIONS: The Basotest was found to be an effective diagnostic test in patients allergic to cypress pollen.

Adult↗
PubMed2000

Identification and characterization of cross-reactive natural rubber latex and Ficus benjamina allergens.

BACKGROUND: An association between allergy to Ficus benjamina and natural rubber latex (NRL) has been suspected based on clinical and immunological observations. The responsible cross-reactive allergens have not been identified yet. This study was undertaken to investigate the cross-reactivity between hevein (Hev b 6.02, 4.7 kD), a major allergen of NRL, and F. benjamina and identify its counterpart in F. benjamina. METHODS: 89 serum samples from subjects allergic to NRL were used in the study. Skin prick tests were performed with highly purified hevein and sap extract of F. benjamina. Specific IgE antibodies to NRL, F. benjamina and Hev b 6.02 were determined by the Pharmacia CAP method. Cross-reactivity among these allergens was investigated by means of CAP and immunoblot inhibition experiments. Two-dimensional gel electrophoresis separation and protein microsequencing were performed to identify the cross-reactive allergens in F. benjamina. RESULTS: 67 out of 89 (75%) sera showed elevated IgE to hevein. Specific IgE to Ficus were found in 22 (24.7%) sera, and with 1 exception, all these sera also had IgE to Hev b 6.02. Results of CAP inhibition assays using 11 sera showing IgE to both Hev b 6.02 and Ficus demonstrated that the IgE to Ficus could be completely inhibited by Hev b 6.02 in 6 of 11 sera. Immunoblots and immunoblot inhibition assays revealed that a protein of about 45 kD in F. benjamina is strongly recognized by serum IgE. In addition, the IgE-binding reactivity to this 45-kD protein could be completely inhibited by preincubation of the sera with Hev b 6.02. N-terminal protein sequencing of 14 amino acids indicated that this 45-kD protein has a hevein-like domain at the N-terminal region and may belong to the endochitinase family. CONCLUSION: Latex-allergic patients are at higher risk of becoming sensitized to Ficus. Hev b 6.02 in latex is a major cross-reactive allergen and its counterpart in F. benjamina is an acidic protein with a molecular weight of about 45 kD and a hevein-like N-terminal domain.

Adult↗
PubMed1974

Cell-to-cell interaction in the immune response. X. T-cell-dependent suppression in tolerant mice.

Specific immunological tolerance was induced in CBA mice by a single injection of deaggregated fowl immunoglobulin G (FgammaG). The unresponsive state was stable on adoptive transfer and irreversible by pretreatment of tolerant cells with trypsin. Tolerant spleen cells could suppress the response of normal syngeneic recipients. They also suppressed the adoptive primary response of spleen cells to FgammaG in irradiated hosts. The inhibitory effect was on the indirect (7S) plaque-forming cell (PFC) response. Incubation of the tolerant cell population with anti-theta serum and complement reversed the suppressor effect. Furthermore, the addition of purified T cells from normal donors restored the capacity of the anti-theta serum-treated tolerant cells to transfer an adoptive response to FgammaG. The existence of FgammaG-reactive B cells was supported by the demonstration of normal numbers of antigen-binding cells in the spleen and thoracic duct lymph from tolerant animals. Moreover, the formation of caps by these cells implied that they could bind antigen normally. These experiments provided direct evidence for the existence of suppressor T cells in the tolerant population. Further evidence was derived from examination of the effect of antigen "suicide". Tolerant spleen cells were treated with radioactive FgammaG under conditions known to abrogate T-cell helper function. When these cells were transferred together with normal spleen cells into irradiated hosts, suppression of the primary adoptive response to FgammaG was no longer observed. Inhibition of an adoptive secondary response to FgammaG was obtained by transferring tolerant spleen cells with primed B cells provided high doses of tolerant cells were used. By contrast low doses exerted a helper rather than a suppressor effect in this system.

Animals↗
PubMed2003

Antigen dose, type of antigen-presenting cell and time of differentiation contribute to the T helper 1/T helper 2 polarization of naive T cells.

Antigenic encounter by T cells induces immunological synapse formation and T-cell activation. Using different concentrations of toxic shock syndrome toxin-1 (TSST-1) as stimulus, we examined the capacities of dendritic cells (DC) and macrophages (Mphi) to prime syngeneic naive T cells. DCs were, under all experimental settings, more efficient than Mphi at clustering T cells. Translocation of the T-cell receptor (TCR) to the contact area was found to be induced by DCs, as well as by Mphi, in an antigen-dependent manner, although Mphi were less efficient at inducing TCR translocation. Capping of protein kinase C theta (PKCtheta) was also antigen dependent but induced exclusively by DCs. Likewise, DCs were found to be more potent inducers of interleukin-2 (IL-2) production and proliferation of naive T cells than Mphi. After 3 days of culture, DCs presenting 100 ng/ml TSST-1 induced interferon-gamma (IFN-gamma)-secreting cells, whereas Mphi did not. After 7 days of culture, DCs presenting 0.1 ng/ml TSST-1, and Mphi presenting high (as well as low) doses of TSST-1, induced IL-4-producing cells. We therefore provide evidence to show that antigen dose, type of antigen-presenting cell and time of differentiation can contribute to T-cell differentiation.

Antigen-Presenting Cells↗
PubMed1985

Inhibition of receptor-mediated but not fluid-phase endocytosis in polymorphonuclear leukocytes.

We have found that hypertonic medium inhibited the receptor-mediated uptake of the chemotactic peptide N-formylnorleucylleucylphenylalanine without affecting fluid-phase endocytosis by polymorphonuclear leukocytes (PMNs). Morphological and biochemical evidence demonstrated that cells in hypertonic medium did not accumulate peptide in a receptor-mediated manner. However, the cells continued to form endosomes containing fluid-phase markers. Furthermore, the content of these endosomes was processed normally, i.e., both digested and intact material were released into the medium. The inhibition of receptor-mediated uptake was a function of the tonicity. Partial inhibition occurred in 0.45 and 0.6 osmolar medium and maximal inhibition occurred in 0.75 osmolar medium. The inhibition was independent of the solute used to increase the tonicity: sodium chloride, sucrose, and lactose all inhibited uptake to similar extents. Hypertonic medium had little effect on saturable peptide binding. However, it did prevent the clustering of surface molecules as indicated by the inhibition of capping of fluorescent concanavalin A. In addition, hypertonic medium prevented the peptide-stimulated increase in cytosolic calcium levels as measured by quin 2 fluorescence. The tonicity dependence of the inhibition of quin 2 fluorescence paralleled the inhibition of receptor-mediated uptake.

Animals↗
PubMed1979

Surface marker studies in chronic lymphocytic leukaemia and non-Hodgkin's lymphoma.

Immunological surface marker techniques were applied in a study of 29 cases of chronic lymphocytic leumaemia and 22 of non-Hodgkin's lymphoma. Surface marker characteristics distinguished 2 subtypes of B lymphocytes. Chronic lymphocytic leukaemia was a monoclonal proliferation of B lymphocytes which produced spontaneous rosettes with mouse erythrocytes and had faintly immunofluorescent surface immunoglobulin. The majority of non-Hodgkin's lymphomas also had their origin from B lymphocytes but in contrast, this subtype did not show receptors for mouse erythrocytes and their surface immunoglobulin was brightly staining and demonstrated "capping". The clonal origin of nodular lymphomas could also be demonstrated on frozen sections stained for surface immunoglobulin. Two cases of true histiocytic lymphoma were identified. The current information available on surface marker characteristics of the leukaemias and lymphomas is reviewed.

Adult↗
PubMed1989

Immunological relationships between specific sperm proteins and secretory polypeptides from seminal vesicles.

Rat and bovine testicular and posttesticular spermatozoa, in situ or removed from the seminal pathways were studied for the presence and the binding of seminal vesicle secretory proteins. A protein cross-reactive with an antibody against rat seminal secretory sulfhydryloxidase was found in mitochondria of pachytene primary spermatocytes which are sequestered during spermiogenesis and collected in the residual bodies of late spermatids. This indicates the replacement of one generation of mitochondria by another during spermiogenesis. Using an antibody against the SVS II polypeptide from rat seminal vesicles, an intrinsic immunoreactive protein was detected in the principal piece of the sperm tail as well as an extrinsic protein (presumably secreted by the epididymis) on the sperm head. The actin-capping capacity of SVS II indicates the functional relation of this immunoreactive membrane protein with actin or an actinrelated protein. Ampullary bovine spermatozoa, contrary to their epididymal precursors contain immunoreactive major protein, secreted from bull seminal vesicles, firmly incorporated into the (sub) plasmalemmal protein in the middle piece. In this case, a secretory protein from seminal vesicles is incorporated into the sperm proteins. This is presumably an important process, related with the initiation of hypermotility of spermatozoa.

Animals↗
PubMed1978

Light- and electron microscopic localization of vasopressin or a vasopressin-like substance in the neurons of the rat suprachiasmatic nucleus.

In the suprachiasmatic nucleus of the rat light microscopic immunostaining for vasopressin reveals a distribution pattern of the immunoreactive material different from that known for the supraoptic nucleus. Among non-stained neurons positive-reacting perikarya display a cap- or tip-like labeling. The area of the suprachiasmatic nucleus is marked by delicate vasopressin-positive fibers. At the ultrastructural level the reaction product, after incubation with anti-vasopressin, is localized in small elementary granules unevenly distributed over the cytoplasm. Groups of axons containing specifically labeled granules contact non-reacting fibers.

Animals↗
PubMed2003

Detecting potential IgE-reactive sites on food proteins using a sequence and structure database, SDAP-food.

The high incidence of food allergies, including oral allergy syndrome, represent major considerations when introducing new crops and foods. A new structural database of allergenic proteins, SDAP-Food, http://fermi.utmb.edu/SDAP/, has been developed to aid in predicting the IgE-binding potential of novel food proteins and cross-reactivities among known allergens. The site is designed to facilitate the first steps of a decision tree approach to determine the allergenicity of a given protein, based on the sequence and structural similarity to known allergens and their IgE binding sites. Immunological tests can then be used to confirm the predictions. A hierarchical procedure for identifying potential allergens, using a physical property-based sequence similarity index, has been designed to identify regions that resemble known IgE binding sites. As an example, SDAP tools were used to find food allergen sequences similar to an IgE binding site of the Jun a 3 allergen from mountain cedar pollen. The SDAP sequence similarity search matched the Jun a 3 epitope to regions in several food allergens, including cherry (Pru av 2), apple (Mal d 2) and pepper (Cap a 1), which are, like Jun a 3, members of the plant pathogenesis-related (PR-5) protein family. Homology modeling, using our EXDIS/DIAMOD/FANTOM program suite, indicated a similar surface location and structure for the potential epitope region on all of these allergens. The quantitative approach presented here can be used as part of a screening process for potential allergenicity of recombinant food products.

Allergens↗
PubMed1998

Selective induction of apoptosis in mature T lymphocytes by variant T cell receptor ligands.

Activation, anergy, and apoptosis are all possible outcomes of T cell receptor (TCR) engagement. The first leads to proliferation and effector function, whereas the others can lead to partial or complete immunological tolerance. Structural variants of immunizing peptide-major histocompatibility complex molecule ligands that induce selective lymphokine secretion or anergy in mature T cells in association with altered intracellular signaling events have been described. Here we describe altered ligands for mature mouse CD4(+) T helper 1 cells that lead to T cell apoptosis by the selective expression of Fas ligand (FasL) and tumor necrosis factor (TNF) without concomitant IL-2, IL-3, or interferon gamma production. All ligands that stimulated cell death were found to induce FasL and TNF mRNA expression and TCR aggregation ("capping") at the cell surface, but did not elicit a common pattern of tyrosine phosphorylation of the TCR-associated signal transduction chains. Thus, TCR ligands that uniquely trigger T cell apoptosis without inducing cytokines that are normally associated with activation can be identified.

Amino Acid Sequence↗