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M F Kagnoff

Publications and source records attributed to M F Kagnoff.

At least 91 records · Page 5Linked to original sources
PubMed1991

Molecular analysis of HLA DP and DQ genes associated with dermatitis herpetiformis.

HLA class II DQ and DP genes from dermatitis herpetiformis patients were amplified and analyzed using molecular probes and compared to those from celiac disease patients and to an HLA and ethnically matched control group. In dermatitis herpetiformis, as in celiac disease, the strongest association of disease was with the DQ subregion alleles DQB1*0201 and DQA1*0501 that are linked to the DRB1*0301 allele. DQB1*0201 determines the DQw2 serologic marker whereas DRB1*0301 determines the DRw17 serologic marker (formerly termed DR3). A DP subregion allele DPB1*0301 was increased and a constellation of DPB1 alleles that included DPB1*0202, *0901, and *1301 was decreased in dermatitis herpetiformis. DPB1*0101, an allele reported to be increased in celiac disease, was not increased in dermatitis herpetiformis. DP beta chains that lack a negatively charged amino acid residue at position 69 of the DP beta chain are significantly over-represented both in dermatitis herpetiformis and celiac disease patients with the DRw17, DQw2 haplotype, compared to healthy controls with that haplotype. These data favor a multigenic model for the contribution of HLA class II D region genes to dermatitis herpetiformis susceptibility. Further, they indicate that a specific DQ molecule, when present in combination with the product of one of several different DPB1 alleles, may contribute to susceptibility to the intestinal lesion, which is common to dermatitis herpetiformis and celiac disease.

Alleles↗
PubMed1990

Transforming growth factor beta 1 increases IgA isotype switching at the clonal level.

Transforming growth factor beta 1 (TGF beta 1) has important effects on expression of the IgA isotype. TGF beta 1 alone, or in combination with IL-5 or IL-2 increases IgA secretion by populations of LPS-activated surface IgA negative (sIgA-) spleen B cells, while concurrently decreasing IgM and IgG secretion. The present study demonstrates the activity of TGF beta 1 as an IgA isotype switch factor at the clonal level. Stimulation of LPS-activated sIgA- spleen B cell populations with TGF beta 1, or a combination of TGF beta 1 and IL-2, resulted in a significant increase in total numbers of IgA secreting cells, and this increase ultimately was paralleled by an increase in total IgA secretion. Using limiting dilution analysis, TGF beta 1 was shown to increase the frequency of IgA secreting B cell clones, by approximately 20-fold. This was not accompanied by increased numbers of IgA secreting cells/clone. In contrast, IL-2 does not have activity as an IgA switch factor, but does increase IgA production by B cells already committed to secrete that isotype. Cell cycle inhibitors such as thymidine and hydroxyurea also selectively increased numbers of IgA secreting cells and total IgA secretion among populations of LPS-activated sIgA- spleen B cells. This suggests the IgA enhancing activity of TGF beta 1 may, in part, be related to its ability to inhibit cell growth.

Animals↗
PubMed1990

Transforming growth factor-beta 1 is a costimulator for IgA production.

Transforming growth factor-beta 1 (TGF-beta 1) belongs to a family of polypeptides involved in the regulation of cell growth and differentiation. We have examined the ability of TGF-beta 1 to regulate isotype specific Ig secretion by murine spleen B cells. TGF-beta 1, in the presence of rIL-2, induced a synergistic 10-fold or greater increase in IgA secretion by LPS-stimulated spleen B cells. TGF-beta 1 alone had little to no effect on IgA secretion. In contrast, TGF-beta 1, with or without rIL-2, markedly inhibited IgG1 and IgM secretion under the same conditions. The costimulatory activity of TGF-beta 1 and rIL-2 on IgA secretion was seen in cultures of surface IgA negative B cells and was inhibited by anti-TGF-beta 1 antibody in a dose dependent manner. Vicia villosa agglutinin non-adherent Peyer's patch T cells, which secrete IL-2, also synergized with TGF-beta 1 and could substitute for the activity of LPS and rIL-2 on the IgA response. Finally, IL-5 added after 2 days of culture, but not at the beginning of culture, synergized with TGF-beta 1 on the IgA response. These studies indicate that TGF-beta 1 can interact with other lymphokines and selectively modulate the IgA response.

Animals↗
PubMed1989

Vicia villosa agglutinin separates freshly isolated Peyer's Patch T cells into interleukin 5- or interleukin 2-producing subsets.

Murine L3T4 T cells freshly isolated from Peyer's Patch were fractionated based on differential adherence to Vicia villosa agglutinin (VVA). VVA adherent cells secreted IL-5, but not IL-2, after stimulation with Con A and IL-1. In striking contrast, VVA nonadherent PP L3T4 T cells secreted IL-2, but not IL-5, under the same conditions. In addition, supernatants from VVA adherent, but not from VVA nonadherent cells cultures, enhanced IgA secretion by LPS-stimulated splenic B cells to the same extent as purified IL-5. Thus, IL-5-producing T cells are present in PP in situ and may play an important role in the development of mucosal immunity. Further, differential adherence to VVA can be used to separate T cell populations that preferentially secrete IL-5 or IL-2.

Animals↗
PubMed1989

Interleukin 5 is a differentiation factor for IgA B cells.

Interleukin 5 (IL5) stimulates murine B cells to IgA production in vitro. The present study examined the B cell target of IL5 activity, and asked whether IL5 acts as an isotype switch factor, a growth factor, or a differentiation factor on B cells that produce the IgA isotype. Lipopolysaccharide-activated surface IgM-positive, surface IgA-positive or surface IgA-negative B cell populations from spleen or Peyer's patches were stimulated with IL5, after which the expression of cell surface IgA, IgA secretion, and numbers of IgA-secreting cells were determined. IL5 increased the IgA response by acting on B cells that are already committed to IgA expression. Thus, with regard to the IgA response, IL5 acts as a differentiation factor, rather than a growth or IgA isotype switch factor.

Animals↗
PubMed1989

Structural analysis of the HLA-DR, -DQ, and -DP alleles on the celiac disease-associated HLA-DR3 (DRw17) haplotype.

Celiac disease is strongly associated with the HLA class II D-region serologic markers DR3 (DRw17) and DQw2. Moreover, by restriction fragment length polymorphism analysis, greater than 90% of DR3 (DRw17), DQw2 celiac disease patients have a polymorphic 4.0-kilobase Rsa I DP B gene DNA fragment. The present study sought to determine if there is a unique HLA class II D-region A or B gene structural variant on the DR3 (DRw17) haplotype found in celiac disease. The polymorphic second exons of the coding DRB, DQA and DQB, and DPA and DPB genes in celiac disease patients with the DR3 (DRw17) haplotype were sequenced after amplification by the polymerase chain reaction. To define the DP B genes associated with celiac disease, the second exons of the coding DP B genes from 27 celiac disease patients were amplified similarly and probed by using a panel of sequence specific oligonucleotides. The HLA-DR, -DQ, and -DP A and B gene second exon sequences of celiac disease patients were noted to be identical to sequences that can be found also, although at a significantly lower frequency, in unaffected individuals. This is compatible with a disease model wherein the HLA class II genes on the DR3 (DRw17) haplotype are necessary, but not sufficient, for the phenotypic expression of celiac disease. Analysis of the DP B genes revealed a significant increase in the frequency of the alleles DPB1 and DPB3 in celiac disease. Furthermore, the increased frequency of the 4.0-kilobase Rsa I DP B gene restriction fragment length polymorphism in celiac disease can be accounted for by the overrepresentation in disease of the alleles DPB1 and DPB3. The HLA-associated susceptibility to celiac disease appears to be multigenic, with specific, but structurally normal, allelic variants in the DP and DQ/DR subregions contributing to disease susceptibility.

Alleles↗
PubMed1989

Development and characterisation of T lymphocyte lines from human small intestinal biopsies.

T lymphocyte lines were developed from human small intestinal biopsies obtained at the time of gastroduodenoscopy. Lines were established as outgrowths from biopsy specimens in microculture using a combination of T cell mitogens, indomethacin, interleukin (IL-2) and autologous irradiated feeder cells. The predominant phenotype of T cells after six to 12 weeks in culture was CD2, CD3, and CD4 positive. Functionally, these T cell lines secreted IL-2 in response to stimulation with phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) in combination, but not to PHA or PMA alone. Two to 7% of cells in each line expressed natural killer (NK) cell-associated markers--that is, Leu 7, CD16, and Leu 19. Moreover, such cells were cytotoxic for NK sensitive targets, but not for NK resistant targets or allogeneic or autologous Epstein Barr Virus (EBV) transformed B cells. Sufficient numbers of small intestinal lymphoid cells for study were previously available only from patients undergoing surgical resections of the small bowel. The ability to isolate and culture human small intestinal T lymphocytes from gastroscopic intestinal biopsies provides an important new tool for studies of human small intestinal lymphocytes.

Cell Line↗
PubMed1989

Analysis of RNA transcripts for HLA class II genes in human small intestinal biopsies.

Studies of the expression of selected genes within the intestinal mucosa will provide important new information about physiologic pathological processes that effect mucosal growth, differentiation, and function. To study gene expression in the gut, we developed a method to obtain sufficient undegraded RNA from human endoscopic intestinal biopsy specimens for Northern and slot blot analysis. To verify the method, we examined the differential expression of HLA class II genes in small intestinal mucosa. Levels of RNA transcripts for HLA-DR, -DP, and -DQ alpha and beta chains were assessed in freshly isolated endoscopic intestinal mucosal biopsy specimens and compared with levels in Epstein-Barr virus transformed B cells from the same individuals. Sufficient undegraded cellular RNA with distinct 28S and 18S ribosomal bands could be obtained from as few as two 2-3 mm endoscopic biopsies. Using chain and locus specific cDNA probes, HLA-DR, -DP, and -DQ subregion genes were shown to be expressed in intestinal mucosa, with the relative magnitude of RNA transcripts being DR greater than DP greater than DQ. The same hierarchy of expression was seen for EBV-transformed B cell lines. This method, in conjunction with the polymerase chain reaction for amplifying specific RNA transcripts and in situ hybridisation methods for the cellular localisation of RNA transcripts, will enable studies on the regulation of gene expression in the intestinal mucosa.

Biopsy↗
PubMed1988

An 80 to 85 kilodalton human phosphoglycoprotein associated with cell activation.

This report describes the identification and biochemical characterization of a new proliferation- and activation-associated membrane Ag. The M21C5 Ag (Mr 80 to 85 kDa) initially was immunoprecipitated from 125I-cell surface-labeled HT29 human tissue culture colon cancer cells by using a monoclonal antibody (M21C5) prepared from HT-29 immunized BALB/c mice. The M21C5 Ag is a glycoprotein as shown by metabolic labeling with 3H-leucine and 2-[3H]-mannose. It has a broad distribution on most proliferating tissue culture cell lines tested, but is absent from several normal human tissues that were examined. Although not detected on unstimulated PBL, the expression of the M21C5 Ag could be induced by stimulation of PBL with the T cell mitogens PHA or Con A. Two-color fluorescence analysis showed that M21C5 is expressed on both CD4 and CD8 activated T cells. After mitogen stimulation, the expression of the M21C5 Ag was delayed relative to the expression of IL-2 and transferrin receptors. M21C5 glycoprotein was shown to be an integral membrane protein that is phosphorylated primarily on serine residues. Based on its biochemical and tissue distribution properties, M21C5 phosphoglycoprotein appears distinct from other known proliferation and activation-associated molecules.

Animals↗
PubMed1988

An extended HLA-D region haplotype associated with celiac disease.

Celiac disease has one of the strongest associations with HLA (human leukocyte antigen) class II markers of the known HLA-linked diseases. This association is primarily with the class II serologic specificities HLA-DR3 and -DQw2. We previously described a restriction fragment length polymorphism (RFLP) characterized by the presence of a 4.0-kilobase Rsa I fragment derived from an HLA class II beta-chain gene, which distinguishes the class II HLA haplotype of celiac disease patients from those of many serologically matched controls. We now report the isolation of this beta-chain gene from a bacteriophage genomic library constructed from the DNA of a celiac disease patient. Based on restriction mapping and differential hybridization with class II cDNA and oligonucleotide probes, this gene was identified as one encoding an HLA-DP beta chain. This celiac disease-associated HLA-DP beta-chain gene was flanked by HLA-DP alpha-chain genes and, therefore, was probably in its normal chromosomal location. The HLA-DP alpha-chain genes of celiac disease patients also were studied by RFLP analysis; 84% of HLA-DR3, -DQw2 patients had a 16-kb Xba I fragment that was present in only 36% of HLA-DR3, -DQw2 controls. Moreover, 79% of these patients had both alpha- and beta-chain polymorphisms in contrast to 27% of controls. Thus, celiac disease is associated with a subset of HLA-DR3, -DQw2 haplotypes characterized by HLA-DP alpha- and beta-chain gene RFLPs. Within the celiac-disease patient population, the joint segregation of these HLA-DP genes with those encoding the serologic specificities HLA-DR3 and -DQw2 indicates: (i) that the class II HLA haplotype associated with celiac disease is extended throughout the entire HLA-D region, and (ii) that celiac-disease susceptibility genes may reside as far centromeric on this haplotype as the HLA-DP subregion.

B-Lymphocytes↗
PubMed1988

Immune-related intestinal Cl- secretion. I. Effect of histamine on the T84 cell line.

The mast cell mediator, histamine, induces a rapid and transient increase in chloride secretion across monolayers of the human colonic epithelial cell line, T84. Threshold stimulation occurred at 3 X 10(-6) M histamine and a maximal effect at 10(-4) M. The effect was reproduced by the H1 agonists 2-methylhistamine and 2-pyridylethylamine, but not by the H2 agonists 4-methylhistamine and dimaprit, suggesting the involvement of an H1 receptor. Additionally, histamine's action was inhibited by an H1 antagonist, diphenhydramine, but not by an H2 antagonist, cimetidine. Histamine treatment increased free cytosolic calcium levels, but not those of adenosine 3',5'-cyclic monophosphate (cAMP) or guanosine 3',5'-cyclic monophosphate (cGMP). The mechanism of chloride secretion induced by histamine resembled that of carbachol, in that both 1) were associated with an increase in free cytosolic calcium, 2) had a site of activation at a basolaterally localized K+ channel, and 3) were potentiated by both cAMP- and cGMP-mediated secretagogues. These results suggest that histamine may act as an intestinal secretagogue via direct interactions with epithelial cells.

Biological Transport↗
PubMed1988

Abnormalities of the intestinal immune system in AIDS.

Significant abnormalities in the distribution of lymphocyte subsets have been noted in the intestinal mucosa of ARC and AIDS patients. Abnormalities are most striking among the CD4 helper-inducer T-cell subset and likely reflects the direct effects of HIV infection of those cells. A deficiency in CD4-positive T cells in the intestinal mucosa potentially could result in significant abnormalities in mucosal immune function, including defects both in cell-mediated immunity and in the secretory IgA system. Such alterations in mucosal immunity and mucosal defense may render AIDS and ARC subjects susceptible to enteric infections and systemic infections in which the intestinal tract is the portal of entry.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Phorbol myristate acetate induces IL-2 secretion by HUT 78 cells by a mechanism independent of protein kinase C translocation.

The protein kinase C (PKC) inhibitor H-7 was used to study the role of PKC in IL-2 secretion. In Jurkat E6.1, a phenotypically non-activated human T-cell line, IL-2 secretion in response to a combination of PMA and the calcium ionophore, ionomycin, or to the mitogen phytohaemagglutinin (PHA) was completely inhibited by H-7. In contrast, HUT-78, a phenotypically activated T-cell line, secreted IL-2 in response to PMA alone, and IL-2 secretion was not inhibited by doses of H-7 that completely blocked PKC activity. We conclude that PMA can stimulate IL-2 secretion independent of the translocation of PKC activity, and suggest that there is an alternative mechanism of action for phorbol esters in activated T cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1988

Oral tolerance.

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Administration, Oral↗