Rabbit antibodies to ovine-submaxillary mucin. Detection, specificity and cross-reactivity

Expression of immune sensitization to epithelial cell-associated components in the cotton-top tamarin: a model of chronic ulcerative colitis

Chronic colitis is present in up to 50% of adult cotton-top tamarins, but the etiology is unknown. To explore one putative immunopathogenic pathway for the chronic colitis, we determined whether immune sensitization to macromolecules associated with mucosal epithelium of intestine (designated ECAC) had occurred in this primate species. Specifically, we sought to define (a) whether antigenic determinants associated with ECAC are present on tamarin gut epithelium in vivo; (b) if immunoglobulin, capable of binding ECAC, is detectable in tamarin serum; (c) whether the presence of ECAC-specific immunoglobulin is positively correlated with age of the animal or the severity of the colitis, or both; and (d) the number of glycoprotein fractions composing ECAC (denoted as P1 through P4) that are reactive with tamarin immunoglobulin. Expression of ECAC was found by immunofluorescence using characterized oligo-specific or monoclonal antibody: tamarin intestinal epithelium--but not lamina propria, muscularis mucosae, subserosa, or glycocalyx--demonstrated determinants of the ECAC antigen system. Furthermore, coded sera from 10 tamarins with biopsy-proven inflammation involving colonic intestinal mucosa and in which disease activity was moderate to severe showed ECAC-specific cytotoxicity of 3.6% +/- 1.6%. Test values for 9 of 10 of those animals were above the upper limit of normal for the assay (2.1%), and exceeded the level of lysis found with serum from histologically normal tamarins less than 2 yr old (less than 0.3%). When the data were reanalyzed by age of the animal, the incidence of ECAC-specific cytotoxicity correlated with age greater than 2 yr (r = 0.86, p less than 0.001). Epithelial cell-associated component-specific serum binding was confirmed by a second methodology (enzyme-linked immunosorbent assay), where the A405 for tamarins with lesions of moderate-severe grade (0.35 +/- 0.26) clearly exceeded that for young tamarins who were histologically normal (0.02 +/- 0.039) (p less than 0.05). Most of the reactivity was directed toward the P1 fraction of ECAC. Thus, immune sensitization to a fraction of macromolecules associated with colonic epithelium has been found in the cotton-top tamarin, analogous to findings in humans with chronic inflammatory bowel disease.

Shared and unique determinants on human and murine intestinal epithelium as established by monoclonal antibodies

To characterize macromolecules from intestinal epithelium known to be reactive with human disease sera, monoclonal antibodies (MAbs) were elicited to determine cell localization, organ-specificity and cross-reactivity of the immunodominant determinants. Eight MAbs, reactive with murine epithelial cell-associated components by enzyme-linked immunosorbent assay, immunoblotting and immunofluorescence, demonstrated binding by the same techniques to constituents in determinant-bearing epithelial macromolecules were glycoproteins of approximately 180,000 (human and 199,000 (murine) mol. wt. Pre-incubation of sera from patients with chronic inflammatory bowel disease (but not normal human sera or control protein) inhibited binding of the 199 K macromolecule by three MAbs elicited and characterized in this study.

Sensitization to epithelial antigens in chronic mucosal inflammatory disease. III. Serum factor modulates circulating and mucosal mononuclear-cell reactivity to epithelial cell-associated components of colon (ECAC-C)

A prior report indicated that sera together with peripheral blood mononuclear cells from patients with Crohn's disease were reactive with epithelial cell-associated components derived from small bowel (ECAC-SB). In the present study, we sought to determine whether similar components (designated ECAC-C) from everted, inflated loops of murine colon could be purified to homogeneity in aqueous soluble form and physiochemically characterized; if sera and/or peripheral mononuclear cells from patients with a chronic idiopathic inflammatory disorder of intestinal mucosa were specifically reactive with ECAC-C; whether immunoglobulin was the factor conferring specificity to the anti-ECAC-C response; and if this immunoglobulin was actively synthesized by human lamina propria B lymphocytes isolated from disease-involved intestinal mucosa. Preparative polyacrylamide gel electrophoresis followed by elution of specific bands resulted in the isolation of three major proteins in homogeneous form. Each was a distinctive macromolecule by molecular weight (39,000, 63,000, 148,000), carbohydrate/protein content, and serologically detectable determinants as assessed by quantitative hemagglutination inhibition. By a 51Cr release microcytotoxicity assay, ECAC-C-labeled indicator cells were specifically lysed by sera and peripheral blood mononuclear cells from patients with ulcerative colitis (8.0 +/- 6.8%) and Crohn's disease (13.2 +/- 4.7%), compared with age-/sex-matched controls (0.6 +/- 0.9 and 0.2 +/- 0.4%, respectively). That the factor conferring ECAC-C specificity was immunoglobulin was demonstrated by the retention of ECAC-C-specific reactivity of patient sera in the presence of normal peripheral blood mononuclear cells, the ability of patient sera (without cells) to effect complement-mediated lysis against erythrocytes labeled with ECAC-C (8.0 +/- 6.7%) but not with control kidney antigen (0.7 +/- 0.7%), and the fact that purified immunoglobulin from patient sera could substitute for the latter in an ECAC-C-specific antibody-dependent cellular cytotoxicity assay. Unique aspects of this ECAC-C reactivity included its absence from sera in other disorders with a known or presumed autoimmune basis (systemic lupus erythematosus, chronic active hepatitis) and the lack of simultaneous reactivity directed toward control antigens, isolated from kidney in a manner analogous to that used for ECAC-C. The importance of ECAC-C-specific immune responses at the mucosal level was also examined using mononuclear cells isolated from disease and control intestinal lamina propria (LPMC).(ABSTRACT TRUNCATED AT 400 WORDS)

Sensitization to epithelial antigens in chronic mucosal inflammatory disease. Characterization of human intestinal mucosa-derived mononuclear cells reactive with purified epithelial cell-associated components in vitro

To explore the auto-reactive potential of cells infiltrating the gut mucosa in idiopathic chronic inflammatory bowel disease, intestinal lamina propria mononuclear cells (LPMC) were isolated, characterized morphologically and phenotypically, and evaluated for antigen-specific reactivity. The last was assessed by quantitating LPMC cytotoxic capabilities against purified, aqueous-soluble, organ-specific epithelial cell-associated components (ECAC) characterized previously. Enzyme-isolated inflammatory bowel disease LPMC were constituted primarily by T lymphocytes (57 +/- 12% OKT 3-positive), B lymphocytes (18 +/- 9% surface immunoglobulin-positive), and macrophages (11 +/- 6% esterase-positive), and were responsive to phytohemagglutinin (mean uptake 86,933 cpm/5 X 10(5) cells). LPMC present in abnormal segments from 71% of patients with chronic inflammatory bowel disease were cytotoxic for ECAC isolated from colon (12.5 +/- 8.9% specific lysis) and small bowel (7.1 +/- 6.5%), but not for kidney control antigen (0.8 +/- 1.1%) isolated in a manner analogous to that used for ECAC (P less than 0.02). In contrast, despite comparable responses to phytohemagglutinin (mean uptake 59,200 cpm/5 X 10(5) cells), LPMC from histologically normal mucosa of patients with benign (adult megacolon, Hirshsprung's disease, diverticulosis) or malignant disease failed to lyse indicator cells labeled with colon-derived ECAC (0.3 +/- 0.08%), small bowel-derived ECAC (0.4 +/- 1.11%), or kidney antigen (0.29 +/- 0.79%). LPMC reactivity for individual gel-purified macromolecules of small bowel-derived ECAC (designated as the "P" series of components) was greatest against component P1 (by 2-3-fold), but was detectable against three other purified components as well. The addition of patient's serum did not enhance cytotoxicity to ECAC. Characterization of the cytotoxic cell showed that it was nonadherent to plastic surfaces, bore T lymphocyte-specific markers detectable by OKT 11 and OKT 3 monoclonal antibodies, and could be depleted by removal of cells with receptors for sheep erythrocytes. ECAC-specific reactivity was markedly reduced (greater than 93%) in most experiments when LPMC were preincubated for 1 h with ECAC. These data support the concept that autosensitization to several epithelial cell-associated components has occurred in patients with chronic inflammatory bowel disease, and provide initial evidence that antigen-specific, cell-mediated mechanisms may play a role in the pathogenesis of these disorders.

Diurnal variation of sialomucin concentration in female mouse submandibular glands measured by radioimmunoassay

The validity of a radioimmunoassay (RIA) for the predominant sialomucin from female mouse submandibular glands was confirmed by immunological and non-immunological approaches. The maximum sensitivity was in the low nanogramme range. The RIA did not cross-react with parotid, sublingual, trachea, stomach or colon tissues, but showed incomplete cross-reactivity with duodenal tissue. An analysis of protein, sialic acid and mucin contents of submandibular glands obtained during diurnal samplings, indicated that mean sialic acid and mucin concentrations, relative to protein in sample groups, decreased overnight approx. 30 per cent and showed a net increase during the day. Sialic acid per gland showed a 3-fold variation among individuals in the population; mucin showed greater than 20-fold variation. An analysis of variation indicated that influence by time of day was the greatest factor affecting sialic-acid concentrations and was statistically significant but, variation in mucin concentration was not. Variation between individuals accounted for more than 90 per cent of the total population variation in mucin concentrations and in sialic acid to mucin ratios. Regression analyses of the sialic acid to mucin ratios at different times of day suggested that the rates of replenishment of sialic acid and mucin may be co-ordinated.

Cytomegalovirus: detection in human colonic and circulating mononuclear cells in association with gastrointestinal disease

The specificity and strength of the reported association between cytomegalovirus (CMV) and colonic adenocarcinoma were tested by analysis of a consecutive series of surgically resected colons for: CMV-DNA by a DNA-DNA reassociation kinetics (hybridization) procedure; latent virus by co-cultivation of fresh tissue with indicator fibroblasts; and CMV viral antigens by immunofluorescence. Ten of 13 cancer patients whose colonic tissue was able to be examined by all techniques showed evidence of active or prior CMV infection. Four cancer specimens were CMV-DNA (hybridization)- positive; an additional specimen from a cancerous colon was culture-positive. In six instances, CMV DNA was detected in mucosal cells adjacent to colon adenocarcinoma. In tissue from one of three patients with ulcera tive colitis and two of seven patients with other non-neoplastic colonic disease, CMV DNA was also detected. No fresh colonic tissues were demonstrated to have CMV surface or nuclear antigens when examined by immunofluorescence. Culture of peripheral lymphocytes was positive for CMV in three of 14 cancer patients. A CMV specific defect in humoral immunity could not be documented in that most cancer patients, as well as cancer-free patients, exhibited circulating specific antibody to CMV and had a normal capacity for CMV-specific antibody-dependent cellular cytotoxicity. We conclude that CMV, probably in a latent form, is readily detectable in colonic cells of man, including those derived from malignant, pre-malignant and non-malignant tissues. Neither preferential replication in damaged tissue nor carriage of CMV by peripheral lymphocytes homing to gut appear to explain the presence of CMV in colon cells.