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At least 55 records · Page 3Linked to original sources
PubMed1999

Comparative sensitivity of urinary CYFRA 21-1, urinary bladder cancer antigen, tissue polypeptide antigen, tissue polypeptide antigen and NMP22 to detect bladder cancer.

PURPOSE: We compare the individual and combined sensitivity of urinary CYFRA 21-1, urinary bladder cancer antigen, tissue polypeptide antigen and NMP22 to detect bladder cancer, evaluate the false-positive rates for different pathological conditions, and assess differential sensitivity regarding histological and clinical characteristics of disease. MATERIALS AND METHODS: A total of 267 subjects entered the study. Sensitivities of the tests were evaluated in 111 patients with active bladder cancer and 76 with no evidence of disease. False-positive rates were evaluated in 80 symptomatic and asymptomatic controls, including patients with benign urological conditions and nonbladder malignancies, and healthy subjects. CYFRA 21-1 was determined by electrochemoluminescent immunoassay in the Elecsys 2010, urinary bladder cancer antigen was quantified by enzyme linked immunosorbent assay (IDL Biotech), tissue polypeptide antigen was measured by the Prolifigen TPA-IRMA and NMP22 was assayed by enzyme linked immunosorbent assay (Matritech). Cutoffs were obtained by the 95% percentile in patients with no evidence of disease, which gave a 95% specificity for all biomarkers. Differences in sensitivity of urinary biomarkers regarding stage, grade, tumor size, pattern of growth, focality and recurrence were evaluated. RESULTS: At a specificity of 95% cutoffs were 5.4 ng./ml. for CYFRA 21-1, 15.5 microg./l. for urinary bladder cancer antigen, 760.8 U./l. for tissue polypeptide antigen and 14.6 U./ml. for NMP22. Using these cutoffs sensitivities were 75.7% for NMP22, 83.8% for CYFRA 21-1, 73.9% for urinary bladder cancer antigen quantitative and 80.2% for tissue polypeptide antigen. The additional determination of cytokeratins increased the sensitivity of NMP22. Cytokeratins did not appear to be specific for bladder cancer, and false-positives rates were between 20% for urinary bladder cancer antigen and 36% for tissue polypeptide antigen for benign urological conditions, and between 40% and 52%, respectively, for nonbladder malignancies. NMP22 showed lower false-positives rates, mainly for benign diseases. Urinary tumor markers appeared to be associated with some of the most relevant histological and clinical parameters of bladder cancer. CONCLUSIONS: Our preliminary evaluation showed the tests to be potential noninvasive adjuncts to help determine the need for cystoscopy. The combination of 2 tumor markers, NMP22 and 1 cytokeratin (CYFRA 21-1 or urinary bladder cancer antigen), seemed to be the most effective. Further comparative studies are needed to assess the promising diagnostic role of these markers.

Aged↗
PubMed1985

Immunohistochemical studies of human renal cell carcinomas for ABO(H) blood group antigens, T antigen-like substance and carcinoembryonic antigen.

Immunohistochemical methods were used to examine human renal cell carcinoma tissues for the presence of ABO(H) blood group antigens, T antigen-like substance and carcinoembryonic antigen. None of the 30 tumors examined showed positive staining for the blood group antigens. In the normal adjacent kidney tissues blood group antigens were noted in the glomeruli, distal tubules and collecting ducts, while proximal convoluted tubules were uniformly negative. The presence of T antigen-like substance was noted in 10 of the 30 tumors (33 per cent). Likewise, T antigen-like substance appeared at the distal tubules and collecting ducts in the normal adjacent kidney tissues, while proximal convoluted tubules were negative. With a monoclonal antibody to carcinoembryonic antigen, 19 of the 30 tumors (63 per cent) showed positive staining. Carcinoembryonic antigen also was observed in the glomeruli and tubular epithelia in the normal kidney tissues. Immunohistochemical findings of T antigen-like substance and carcinoembryonic antigen were not found to be correlated with the tumor grade, cell type and stage, as well as survival of patients with renal cell carcinoma.

ABO Blood-Group System↗
PubMed1985

Maintenance of antigen specificity by human interleukin-2-dependent T cell lines. Use of antigen-presenting cells and OKT3 antibody in the absence of antigen.

The in vitro growth of T cells obtained from localized anatomic sites of pathology may offer a new approach to the investigation of certain human autoimmune diseases. However, if interleukin-2-dependent T cell cloning is to be useful in helping to elucidate putative pathogenetic antigens in these diseases, the expansion of the small number of T cells obtainable from localized anatomic sites of pathology will often have to be accomplished in the absence of these, as yet undetermined, antigens. At present, it is a generally held belief that antigen-responsive, interleukin-2-dependent T cell lines and clones will lose antigen responsiveness if propagated in the absence of specific antigen. Thus, the use of T cell cloning might be viewed as being of limited usefulness in the investigation of certain human autoimmune diseases. In this report we demonstrate that, when propagated in the absence of antigen, human tetanus toxoid-specific, interleukin-2-dependent T cell lines will indeed lose antigen reactivity. However, if propagated in the absence of antigen but in the presence of antigen-presenting cells, the tetanus toxoid reactivity of a subset of such lines can be maintained. Moreover, the propagation with OKT3 antibody, in addition to antigen-presenting cells, may be even more effective in maintaining antigen reactivity. These results may suggest a new approach to the use of T cell cloning technology in the investigation of certain autoimmune diseases.

Antibodies, Monoclonal↗
PubMed1993

Comparative study of bullous pemphigoid antigens among Japanese, British, and U.S. patients indicates similar antigen profiles with the 170-kD antigen present both in the basement membrane and on the keratinocyte cell membrane.

There are a number of controversies relating to studies of bullous pemphigoid (BP) antigens from different institutions, mainly regarding the detection of the 230-kD and 170-kD BP antigens. In this study, in an attempt to resolve the discrepancies, we have examined and compared the reactivity by immunofluorescence, immunoblotting, and immunoprecipitation among the sera from Japanese, British and U.S. BP patients. Both the 230-kD and 170-kD BP antigens were detected by various sera from all populations with immunoblotting, whereas immunoprecipitation detected only the 230-kD BP antigen but not the 170-kD BP antigen. Immunoprecipitation was more sensitive than immunoblotting to detect the 230-kD antigen. These results indicate that both the 230-kD and 170-kD proteins are BP antigens found in all three populations. By immunofluorescence cell surface staining in the lower epidermis in addition to basement membrane zone staining was shown by a considerable number of patients' sera in all populations. Comparison between the results of immunofluorescence and immunoblotting revealed a clear correlation of this cell surface staining with the presence of antibodies against the 170-kD BP antigen. That the affinity-purified antibodies specific to the 170-kD BP antigen showed this cell surface staining further confirmed this correlation. These results may indicate a different nature of the 170-kD BP antigen from that of the 230-kD BP antigen.

Antigens, Surface↗
PubMed1996

Enolase antigen, mannan antigen, Cand-Tec antigen, and beta-glucan in patients with candidemia.

We compared the specificities and sensitivities of four tests used for the serodiagnosis of candidemia in 39 patients with candidemia, including 10 patients with superficial Candida colonization, 10 patients with deep mycosis, and 20 healthy subjects. The results obtained by the dot immunoblotting assay for detecting the enolase antigen (48 kDa) were compared with those of assays for detecting mannan antigen, heat-labile antigen (a threshold titer of four times), and beta-glucan (> or = 60 pg/ml). Enolase antigen was detected in 28 (71.8%) patients with candidemia, while 30 (76.9%), 10 (25.6%), and 27 (84.4%) patients were positive for the heat-labile antigen by the Cand-Tec assay, the mannan antigen by the Pastorex Candida assay, and beta-glucan by the limulus test, respectively. Ten patients with superficial Candida colonization, 5 patients with invasive pulmonary aspergillosis, 5 patients with cryptococcosis, and 20 healthy subjects were negative for both enolase antigen and mannan antigen. Two patients with superficial Candida colonization, one patient with invasive pulmonary aspergillosis, and two patients with cryptococcosis were positive by the Cand-Tec assay. The beta-glucan concentration was more than 60 pg/ml in all patients with invasive pulmonary aspergillosis; however, it was less than 10 pg/ml in all patients with cryptococcosis. The specificity of enolase antigen in the serodiagnosis of candidemia was 100%, but the sensitivity was 71.8%. The specificity and sensitivity of Cand-Tec, the assay for mannan antigen, and the assay for beta-glucan were 76.9 and 87.5%, 25.6 and 100%, and 84.4 and 87.5%, respectively. Our results demonstrated that antigen detection tests are useful for the diagnosis of candidemia; however, none is satisfactory for the serodiagnosis of candidemia. We suggest that a combination of two assays may increase the accuracy of diagnosis of candidiasis.

Adult↗
PubMed1985

The interaction of nominal antigen with T cell antigen receptors. I. Specific binding of multivalent nominal antigen to cytolytic T cell clones.

In this report, we describe an experimental strategy for analyzing the interaction of nominal antigen with antigen-specific T cell clones. Our approach was based on the notion that low affinity interactions between nominal antigen and T cell antigen receptors might be detected by using a highly multivalent form of the antigen in which a large number of identical, appropriately spaced epitopes are attached to a polymer backbone. Antigens of this kind should be capable of multivalent binding to receptors on the T cell, resulting in a marked enhancement of the overall avidity of the interaction. To examine this possibility, we established a series of murine cytolytic T cell (Tc) clones specific for the readily detectable hapten fluorescein isothiocyanate (FL). These clones lysed FL-conjugated target cells in an antigen-specific fashion and also showed specificity for target cell MHC gene products. The interaction of these clones with the nominal antigen FL was assessed by flow cytometry, using a series of water-soluble FL-conjugated polymers varying in polymer backbone and FL isomer. High m.w. (600 to 2000 Kd) polymers of acrylamide, dextran, or Ficoll conjugated with 300 to 800 FL groups/molecule bound specifically to anti-FL Tc clones. There was little binding to syngeneic spleen cells, thymocytes, noncytolytic T cell clones, or T cell clones specific for other haptens such as NIP. Polymer concentrations in the 1 to 10 micrograms/ml range produced readily detectable binding within minutes at 20 degrees C, and the binding approached plateau levels at polymer concentrations of between 100 and 300 micrograms/ml. Studies with closely related FL isomers showed that the same antigen fine specificity was operative in both lysis of FL-conjugated target cells and in binding of FL-conjugated polymers. The functional significance of the observed binding was assessed by measuring the effect of FL-conjugated polymers on lymphokine secretion by the clones. High m.w. FL-conjugated polymers caused a dose-dependent increase in the production of macrophage activation factor (MAF) by anti-FL Tc clones, but did not increase MAF production by an NIP-specific clone. In contrast, concanavalin A induced MAF production by both FL-specific and NIP-specific clones. Thus, the observed binding is both specific and functionally significant. These results suggest that soluble nominal antigen, in an appropriately multivalent form, can bind specifically to antigen receptors on Tc clones.

Animals↗
PubMed1984

Antigen-reactive cloned helper T cells. II. Exposure of murine cloned helper T cells to IL 2-containing supernatant induces unresponsiveness to antigenic restimulation and inhibits lymphokine production after antigenic stimulation.

Cloned murine helper T lymphocytes (HTL) reactive to alloantigen or to ovalbumin (OVA) become unresponsive to antigenic restimulation after exposure to antigen or to culture supernatant fluids (SF) containing multiple lymphokine activities. Unresponsiveness is manifest by a failure of antigen-stimulated cells to incorporate thymidine or to produce lymphokines after antigenic challenge. Antigen-unresponsive HTL, however, will incorporate thymidine when exposed to an exogenous source of interleukin 2 (IL 2). The duration of unresponsiveness to antigen is correlated with the concentration of IL 2 in SF to which the cloned HTL had been exposed. Chromatographic fractionation of IL 2-containing supernatant from EL-4 thymoma cells (EL-4 SF) yielded a pool of SF that was enriched for IL 2 activity. Exposure of HTL to lymphokines contained in this pool induced unresponsiveness to antigen that was comparable to that observed when HTL were exposed to unfractionated EL-4 SF. Unresponsiveness to antigen also developed after cloned HTL were stimulated with concanavalin A (Con A) or with OVA and syngeneic splenic filler cells. We have used monoclonal antibody (mAb) GK1.5 (anti-L3T4) to investigate the role of lymphokine production in the induction of unresponsiveness. This antibody did not inhibit IL 2-induced thymidine incorporation by cloned HTL, and did not inhibit the induction of unresponsiveness after exposure of cloned HTL to EL-4 SF. In the presence of mAb GK1.5, however, HTL that were stimulated with Con A or OVA did not become unresponsive to antigenic restimulation, an effect that was overcome by the addition of EL-4 SF. These results suggest that HTL become unresponsive to antigen after exposure to IL 2-containing SF, and that stimulation by antigen or Con A can induce the unresponsive state by virtue of stimulating lymphokine production.

Animals↗
PubMed1989

Ki-1 (CD30) antigen is released by Ki-1-positive tumor cells in vitro and in vivo. I. Partial characterization of soluble Ki-1 antigen and detection of the antigen in cell culture supernatants and in serum by an enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) has been developed that allows the quantitative determination of the Ki-1 (CD30) antigen in soluble form. Similar levels of sensitivity of this new Ki-1 ELISA and the ELISA previously described for measuring the soluble 55-kDa chain of the interleukin 2 receptor were seen. As assessed with this ELISA, the investigated Ki-1+ permanent cell lines released the Ki-1 antigen into the culture supernatant. In culture supernatants of concanavalin A-activated human peripheral blood lymphocytes, however, this antigen could not be detected. The released Ki-1 antigen has an apparent molecular weight (Mr) of 85,000, whereas the cell-associated Ki-1 antigen has an Mr of 105,000. We investigated sera from 30 normal donors, 15 patients with systemic infections, and 63 patients suffering from lymphomas for soluble Ki-1 antigen. In all sera from normal donors and patients with systemic infectious diseases, soluble Ki-1 antigen was below the detection limit (i.e., less than 70 pg). In contrast, high amounts of the soluble Ki-1 antigen were found in sera from 18 malignant lymphomas containing Ki-1+ tumor cells. This finding demonstrates that the release of the Ki-1 antigen takes place not only in vitro, but in vivo as well. Moreover, these results imply that the Ki-1 antigen may be used as a serum tumor marker.

Adult↗
PubMed1982

Ia antigen-bearing B cell tumor lines can present protein antigen and alloantigen in a major histocompatibility complex-restricted fashion to antigen-reactive T cells.

Several Ia-positive BALB/c B cell tumor lines were screened for their ability to present alloantigen and protein antigens to alloreactive and antigen-reactive T cells. Of six Ia-positive tumor lines studied, three were found to be effective as antigen presenting cells (APC). Indeed, on a per cell basis, one of the stimulatory lines, A20.3, was substantially more effective than whole spleen cells. The other three lines, although Ia-positive, were nonstimulatory. A20.3 was chosen for further study. This tumor appeared to behave like the conventional APC because (a) the tumor cells presented alloantigen, (b) they presented protein antigen in an MHC-restricted fashion to both primed donor T cells and to long-term continuous T cell lines, (c) alloantigen presentation was blocked by the inclusion of an anti-Ia antibody in the culture system, and (d) A20.3 cells could be effectively pulsed with antigen, although the continuous presence of antigen in the culture system resulted in a superior response. The addition of an exogenous source of interleukin 1 proved necessary to obtain an alloreactive but not an antigen-specific T cell response, although its inclusion did enhance the magnitude of antigen-stimulated proliferation. These tumor cells should prove useful in studying the biochemical events that occur during antigen processing and the requirements for T cell triggering by processed antigen in association with Ia molecules.

Animals↗
PubMed1983

Antigenic reactivities of purified preparations of carcinoembryonic antigen (CEA) and related normal antigens using four different radioimmunoassay systems for CEA.

Antigenic reactivities of 4 purified carcinoembryonic antigen (CEA) preparations including the WHO standard CEA and 4 CEA-related antigens--nonspecific cross-reacting antigen (NCA) from normal lungs, nonspecific cross-reacting antigen-2 (NCA-2) from meconium, normal fecal antigen-1 (NFA-1) and normal fecal antigen-2 (NFA-2) from normal adult feces--were investigated using 4 different radioimmunoassay (RIA) systems (Hoffman-La Roche, CEA-IRE-SORIN, Dainabot and our system). In general, all CEA preparations including the respective standard CEAs gave similar reactions with these assay systems. Differences in reaction intensity were, however, observed among the CEA preparations, and the order of reaction intensity among the preparations varied due to assay systems, e.g., a given CEA preparation which reacted most strongly with an assay system reacted very weakly with another assay system, and vice versa. Both NCA-2 and NFA-2, which possessed physiochemical properties very similar to those of CEA, revealed reactivities indistinguishable from those of the CEA preparations in all systems. NCA, which showed a partial cross-reactivity with CEA in the double immunodiffusion test, revealed a remarkably weak reactivity in all systems. NFA-1, however, which was also partially cross-reactive with CEA but antigenically unrelated to NCA, showed a fairly strong reactivity in all systems, but its dose-dependent slope was apparently different from that of the other antigen preparations.

Antigen-Antibody Reactions↗
PubMed1990

Interleukin-2 receptor antigen, leukocyte common antigen, and Ki-1 antigen-expressing gastric plasmacytoma. A case report with an immunohistochemical study.

A case of primary gastric plasmacytoma expressing various surface and cytoplasmic antigens is reported. With the use of formalin-fixed and deparaffinized sections, 13 different antibodies were applied. Neoplastic plasma cells revealed monoclonal IgG and kappa light chain in the cytoplasm, and expressed epithelial membrane antigen, Ki 67 antigen, cytokeratin, CD 22 antigen, interleukin-2 receptor antigen, leukocyte common antigen and Ki-1 (CD 30) antigen. However, tumor cells were devoid of HLA-DR antigen. These data suggest that the neoplastic plasma cells are at the plasmoblastic stage of maturation and express various surface and cytoplasmic phenotypes.

Aged↗
PubMed1986

Immunodominance in the T cell response to multiple non-H-2 histocompatibility antigens. III. Single histocompatibility antigens dominate the male antigen.

Immunization of mice with multiple non-H-2 histocompatibility antigens results in the generation of cytolytic T lymphocytes that are specific for a limited number of immunodominant antigens. The experiments presented in this communication were designed to reveal immunodominance in pairwise combinations of autosomal and sex-linked non-H-2 histocompatibility (H) antigens. Priming and boosting responders with the male antigen, H-Y, paired with the H-4.2, H-7.1, or H-3.1 antigens, resulted in the generation of cytolytic T cells specific for the autosomal H antigens but not the H-Y antigen. Furthermore, co-immunization and boosting of C57BL/6 female responder spleen cells with BALB.B male cells resulted in the generation of cytolytic T cells specific for the BALB.B immunodominant antigens but not H-Y. No dominance was observed in H-4-plus H-7-incompatible combinations. Co-immunization of three different H-3 congenic strains with H-3.1 plus H-Y demonstrated that an efficient anti-H-3.1 T cell response is required for observing H-3.1 immunodominance over H-Y. Co-expression of H-3.1 and H-Y on the same priming and boosting cells was required for immunodominance. In fact, immunization with H-3.1 and H-Y presented on different cells resulted in normal generation of H-Y-specific cytolytic T cells, but no generation of H-3.1-specific cytolytic T cells resulted unless H-Y-specific cells were stimulated in the mixed lymphocyte cultures. These observations suggest that in vitro T cell responses to paired, non-H-2 H antigens may be independent, competitive, or synergistic, depending on the identity of the antigens and the priming and boosting conditions.

Animals↗
PubMed1982

Molecular composition of an antigen-specific, Ly-1 T suppressor inducer factor. One molecule binds antigen and is I-J-; another is I-J+, does not bind antigen, and imparts an Igh-variable region-linked restriction.

Immunized Ly-1+2-T cells (Ly-1 cells) make an antigen-specific soluble suppressor product (Lyl-1 TsiF) that will induce Ly-2+ cells to express suppressive activity but only if the Ly-2+ and the Ly-1 producer cell share genetic polymorphisms that are linked to the Igh locus and in particular that part where the Igh-V (or VH) is encoded. Ly-1 TsiF can be separated into entities, one binds antigen and does not express I-J determinants, and the other is I-J+ and does not bind antigen. Neither of these "subfactors" has biological activity, but a 50:50 mixture of them reconstitutes biological activity that expresses the antigen specificity of the antigen-binding molecule. Any of the three heterologous erythrocytes (antigens) studied can be used for immunization to produce the I-J+ nonantigen-binding factor, i.e., the I-J+ moiety makes no contribution to the factor's specificity. It does, however, determine the intact factor's Igh-V linked restriction. Thus, the antigen combining site of the factor is irrelevant to the factor's Igh-V restriction but crucial for its specificity. The I-J+ molecule does not bind antigen nor influence the factor's antigen specificity but expresses the Igh-V polymorphism (or anti-Igh-V polymorphism) that is required for the transmission of an inductive signal to the factor's Ly-2+ acceptor cell.

Absorption↗
PubMed1986

Antigen presentation by human antigen-presenting cells to antigen-specific xenogeneic murine T cells.

Successful antigen presentation by xenogeneic human antigen-presenting cells (APC) to stimulate the proliferation of antigen-specific, keyhole limpet hemocyanin (KLH)-specific, ovalbumin (OVA)-specific, and purified protein derivative of Mycobacterium tuberculosis (PPD)-specific murine T cells was observed. Evidence indicating a direct cell interaction between antigen-specific murine T cells and xenogeneic human APC was given by experiments using antigen-specific murine T cell clones. The OVA-specific B10.S(9R) T cell line (9-0-A1) and PPD-specific B10.A(4R) T cell line (4-P-1) were stimulated by both xenogeneic human APC and murine APC from syngeneic or I-A compatible strains, while the PPD-specific human T cell line (Y-P-5) was stimulated by autologous human APC but not by murine APC. Anti-HLA-DR monoclonal antibodies (MoAb) blocked the xenogeneic human APC-antigen-specific murine T cell clone interaction. Thus, human xenogeneic APC can stimulate antigen-specific murine T cells through HLA-DR molecules in the same manner as syngeneic murine APC do through Ia molecules coded for by the I region of the H-2 complex, while murine APC failed to present antigen to stimulate human antigen-specific T cells.

Animals↗
PubMed1990

Molecular mapping of the active site of an aging antigen: senescent cell antigen requires lysine(s) for antigenicity and is located on an anion-binding segment of band 3 membrane transport protein.

An aging antigen, senescent cell antigen, resides on the 911 amino acid membrane protein band 3. It marks cells for removal by initiating specific IgG binding. The active antigenic sites of the aging antigen have been localized to residues 538-554 and 778-827. Two peptides within these regions interact synergistically to generate a synthetic aging antigen that is an effective inhibitor of senescent cell IgG binding to old cells. We synthesized peptides corresponding to these residues (pep-ANION 1: SKLIKIFQDHPLQKTYN, and pep-COOH: LFKPPKYHPDVPYVKR). These are extracellular regions of band 3 containing lysines which are implicated in anion transport. The contribution of lysine to the antigenicity of the aging antigen and to anion transport was examined by chemically modifying the lysines on both synthetic peptides and whole cells, and by synthesizing peptides in which glycines or arginines were substituted for lysines. Anion transport sites were localized using 16- to 18-mer peptides followed by 6- to 8-mer peptides. Functional studies with the peptide pep-COOH indicate that it contains sulfate-binding sites and inhibits sulfate transport in addition to carrying aging antigenic determinants. Substitution of arginines or glycines for lysines in pep-COOH reduces the sulfate-binding properties of the peptide although significant inhibition still occurs. Residues 812-827 (pep-COOH) and 813-818 (N6, the six amino acids on the amino side of pep-COOH) and 822-839 are inhibitors of anion transport when used in equimolar amounts with sulfate suggesting that these regions may be transport regions in situ. Results of this study indicate that: (a) lysines are required for the integrity of the aging antigenic site; (b) pep-COOH (residues 812-827) is part of senescent cell antigen and an anion-binding site; (c) pep-ANION 1 (538-554), which has been reported to be a transport segment of band 3, does not bind sulfate; (d) residues 588-602 are part of an anion binding/transport segment; (e) band 3 residues 822-839 are part of an anion binding/transport site, and (f) lysines contribute to anion binding but are not the only amino acid(s) required for anion binding and, thus, anion transport.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1992

[Comparative study on antigenicity and immunogenicity of the 24-26 kDa antigen and the recombinant Sj26 antigen of Schistosoma japonicum].

This paper reports on the comparison of the recombinant Sj26 (rSj26) antigen originated from the Philippine strain and 24-26 kDa antigen isolated and purified from Chinese mainland strain of S. japonicum for their antigenicity and immunogenicity. The results showed that there were obvious cross reactions between rSj26 and 24-26 kDa antigen when rSj26 antigen was tested against specific antibodies in sera from mice infected with the mainland strain of S. japonicum or 24-26 kDa antigen was tested against specific anti-rSj26 antibodies by ELISA, IFA and Western blotting etc. Both of 24-26 kDa and rSj26 antigen had weak cross reaction with SEA antigen. The worm reduction rate after challenging with mainland strain cercariae in mice immunized with rSj26 was 26-32%, similar to that in mice immunized with 24-26 kDa antigen. It is suggested that rSj26 antigen can induce certain level of specific protective immunity to protect the host against infection by Chinese strain of S. japonicum cercaciae.

Animals↗
PubMed1996

Function of C3 in a humoral response: iC3b/C3dg bound to an immune complex generated with natural antibody and a primary antigen promotes antigen uptake and the expression of co-stimulatory molecules by all B cells, but only stimulates immunoglobulin synthesis by antigen-specific B cells.

Previous studies have shown that an optimal humoral response to a primary protein antigen requires C3 and CR2 (CD21). Sera from non-immunized donors contain natural IgM and IgG antibodies to the primary antigen keyhole limpet haemocyanin (KLH), and these have been previously shown to form immune complexes (IC) that activate the classical pathway of C, fixing iC3b/C3dg onto the KLH antigen. Such KLH IC bind to CR2 on KLH-non-specific B lymphocytes, resulting in antigen processing and MHC class II-dependent presentation to KLH-specific helper T cells. KLH IC also induce B lymphocytes to express the CD80 costimulatory molecule via simultaneous CR2 ligation with C3 and Fc gammaRII (CD32) stimulation by IgG natural antibody. The current study demonstrated that KLH IC ligation to either CR2 or Fc gammaRII resulted in activation of a second co-stimulatory molecule, LFA-1 (CD11a, CD18). The possibility of polyclonal B cell stimulation by the presentation of KLH-iC3b/C3dg by antigen-non-specific B cells was excluded by demonstration that in vitro cultivation of peripheral blood mononuclear cells (PBMC) with KLH-iC3b/C3dg elicited only anti-KLH, and did not stimulate synthesis of antibodies to hepatitis C virus (HCV) or tetanus toxoid (TT). Of greatest significance, a specific anti-KLH response was only detectable in cultures stimulated with KLH-iC3b/C3dg and not in cultures stimulated with KLH alone or KLH-IgG. Thus, iC3b/C3dg that was bound to a primary protein antigen enhanced recognition and specific immunoglobulin synthesis by antigen-specific B cells, even though the antigen was taken up and processed via CR2 by both antigen-specific and non-specific B cells.

Antibodies, Monoclonal↗
PubMed1992

Coexpression of ganglioside antigen Fuc-GM1, neural-cell adhesion molecule, carcinoembryonic antigen, and carbohydrate tumor-associated antigen CA 50 in lung cancer.

With the aid of specific monoclonal antibodies, tumor tissues from 68 patients with lung cancer were examined for their expression of two small cell lung carcinoma (SCLC) antigens, Fuc-GM1 (fucosyl GM1; IV2FucII3NeuAc GgOse4) and neural-cell adhesion molecule (NCAM), and two broader tumor antigens, carcinoembryonic antigen (CEA) and carbohydrate cancer-associated antigen CA 50. Expression of Fuc-GM1 was seen in 75% and NCAM in 78% of the SCLC specimens, but also in 12 and 20% of non-SCLC. Either or both of these antigens were expressed in more than 90% of SCLC and in 25% of non-SCLC. CEA was found in more than 80% of SCLC and non-SCLC. Expression of CA 50 was seen in 65-68% of non-SCLC and SCLC, showing preference for SCLC and lung adenocarcinoma. In SCLC, cellular expression of Fuc-GM1 was generally seen together with NCAM and CA 50, but rarely with CEA. There was considerable inter- and intratumor heterogeneity in the expression of all four antigens. The results suggest that CEA is the antigen of choice for the detection of lung cancer regardless of histotype. In combined analysis of CEA, CA 50, Fuc-GM1 and NCAM, two patterns of antigen expression were recognized that appear to discriminate between SCLC and non-SCLC tumors, respectively. A considerable fraction of SCLC and non-SCLC tumors, however, exhibited similar patterns of antigen expression. The biological and clinical significance of these observations remains to be investigated.

Antibodies, Monoclonal↗