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Biomedical subjects

C C Kannapell

Publications and source records attributed to C C Kannapell.

15 recordsLinked to original sources
PubMed2001

NZM2328: a new mouse model of systemic lupus erythematosus with unique genetic susceptibility loci.

Among NZB/W-derived New Zealand mixed (NZM) strains, only NZM/Aeg2410 (NZM2410) has been well characterized. In contrast to NZM2410, NZM2328 mice develop autoantibodies and acute and severe chronic glomerulonephritis (GN) with female predominance similarly to NZB/WF1 and humans with systemic lupus erythematosus (SLE). Chronic GN with glomerular sclerosis and tubular atrophy but not acute GN was correlated with severe proteinuria. In a backcross analysis of (NZM2328 X C57L/J) F1 X NZM2328, four SLE susceptibility genomic intervals were identified. One of them (Cgnz1) is on the telomeric end of chromosome 1 and close to Sle1. It was significantly linked to chronic GN. A locus (Agnz1) distinct from Cgnz1 on this interval was suggestively linked to acute GN. Two genetic intervals on chromosome 17 were also suggestively linked to acute GN, one of which is the H-2-Tnf complex, while the other (Agnz2) is on the distal end of the chromosome. A single locus (Adaz1) identified in the midregion of chromosome 4 in NZM2328 mice was suggestively linked to plasma levels of IgG anti-dsDNA autoantibodies. These results differ significantly from those in the backcross analysis of (NZM2410 X C57BL/6)F1 X NZM2410 by other investigators. They support the concept that different sets of genes are involved in acute and chronic GN. The genomic differences between the NZM strains and between C57L/J and C57BL/6 account for the differences between our analysis and that on NZM 2410. These results provide evidence for the importance of background genes on the expression of SLE, with implications for genetic studies of human SLE.

Animals↗
PubMed2000

Ro60 peptides induce antibodies to similar epitopes shared among lupus-related autoantigens.

The coexistence of autoantibodies to ribonucleoproteins (RNP) in sera of patients with systemic lupus erythematosus has been attributed to intermolecular determinant spreading among physically associated proteins. Recently, we showed that murine Ab responses to rRo60 or Ro60 peptides were diversified unexpectedly to small nuclear RNP. In this investigation, the mechanisms for this autoantibody diversification were examined. Intramolecular determinant spreading was demonstrated in mice immunized with human or mouse Ro60316-335. Immune sera depleted of anti-peptide Ab immunoprecipitated Ro60-associated mY1 and mY3 RNA and remained reactive to a determinant on Ro60128-285. Absorption with the immunogen depleted the immune sera completely of anti-Golgi complex Ab (inducible only with human Ro60316-335) and anti-La Ab, and reduced substantially Ab to SmD and 70-kDa U1RNP. Mouse rRo60 completely inhibited the immune sera reactivity to La, SmD, and 70-kDa U1RNP. However, La, SmD, and 70-kDa U1RNP preferentially inhibited the antiserum reactivities to these Ags, respectively. Affinity-purified anti-La Ab were reactive with Ro60, La, SmD, and 70-kDa U1RNP. These results provide evidence that a population of the induced autoantibodies recognized determinants shared by these autoantigens. Lack of sequence homology between Ro60316-335 and La, SmD, or 70-kDa U1RNP suggests that these determinants are conformational. Interestingly, similar cross-reactive autoantibodies were found in NZB/NZW F1 sera. Thus, a single molecular mimic may generate Ab to multiple RNP Ags. Furthermore, cross-reactive determinants shared between antigenic systems that are not associated physically (Ro/La RNP and small nuclear RNP) may be important in the generation of autoantibody diversity in systemic lupus erythematosus.

Absorption↗
PubMed1999

Immune responses to Ro60 and its peptides in mice. I. The nature of the immunogen and endogenous autoantigen determine the specificities of the induced autoantibodies.

Anti-Ro60 autoantibodies are found in a variety of autoimmune disorders including systemic lupus erythematosus (SLE), Sjögren's syndrome, primary biliary cirrhosis, and active hepatitis. They are the most prevalent autoantibodies in normal individuals and in asymptomatic mothers of infants afflicted with neonatal lupus. In the present study, immune responses to recombinant human Ro60 (rhRo60) and recombinant mouse Ro60 (rmRo60) and selected Ro60 peptides in non-SLE-prone mice were investigated. Multiple T and B cell epitopes were identified in Ro60. Immunizations with either xenogeneic or autologous Ro60 induced autoantibodies to a diverse group of autoantigens. In addition to La and Ro52, proteins in the small nuclear ribonucleoprotein (snRNP) particles such as SmA, SmB, SmD, and 70-kD U1-RNP were unexpectedly identified as targeted antigens. In the studies involving synthetic Ro60 peptides, both human and mouse Ro60316-335 peptides, which differ in three amino acids, were found to contain dominant cross-reactive T cell determinants. Immunizations with these peptides induced autoantibodies to Ro60, La, SmD, and 70-kD U1-RNP without autoantibodies to Ro52, SmA, or SmB. With human Ro60316-335 as the immunogen, additional autoantibodies reactive with the Golgi complex were found. In contrast to the immunodominance of both human and mouse Ro60316-335 peptides, the T cell determinant in human Ro60441-465 was dominant, whereas that in the mouse peptide was cryptic. Immunization with human Ro60441-465 induced primarily anti-peptide Abs. Mouse Ro60441-465 failed to induce an antibody response. These results show that both the nature of the immunogen and the immunogenicity of the related endogenous antigen are important in determining the specificities of the autoantibodies generated. They have significant implications for proposed mechanisms on the generation of complex patterns of autoantibodies to a diverse group of autoantigens in SLE patients.

Animals↗
PubMed1995

VH and VL gene usage by anti-beta-amyloid autoantibodies in Alzheimer's disease: detection of highly mutated V regions in both heavy and light chains.

In a previous study, four human IgM kappa monoclonal antibodies (mAbs) secreted by Epstein-Barr-virus-transformed B cell lines independently derived from the peripheral blood of a patient with Alzheimer's disease (AD) were found to react with a conformational epitope of beta-amyloid protein and to stain amyloid plaques in AD brain. Three of these mAbs were studied further. They did not react with an additional panel of antigens and autoantigens. By a competitive inhibition ELISA, the Kd was determined to be 5.7 x 10(-8) M. The VH and V kappa of these mAbs were sequenced at the cDNA level and found to be identical. The corresponding VH and V kappa germline counterpart genes hsigghvm148 and hsiggkvm148 were identified to be analogous to the previous reported VH3 germline gene humighvf1/dp53 and the V kappa IV germline gene hsigk18. DA1/4 and JH4b were used by the heavy chain and J kappa 4 was used by the light chain. Multiple nucleotide substitutions were seen in both VH and V kappa when their sequences were compared to the germline sequences. High replacement/silent ratios in the CDR regions of both VH and V kappa indicate positive-selective pressure. Of a total of 22 amino acid replacements in VH and V kappa, 12 were nonconservative replacements. Furthermore, 7 of these 12 resulted in charge changes. The monoreactivity, the moderately high affinity constant, the clonal expansion evident by identical VH and VL used by these B cells secreting antibodies of interest, and the excessive replacement mutations in both VH and VL segments lead to the conclusion that these antibodies have been generated due to an antigen-driven process.

Alzheimer Disease↗
PubMed1994

Human rheumatoid factors with restrictive specificity for rabbit immunoglobulin G: auto- and multi-reactivity, diverse VH gene segment usage and preferential usage of V lambda IIIb.

To determine the molecular and functional properties of human rheumatoid factors (RF), we established stable hybridomas and Epstein-Barr virus-transformed B cell lines from the synovial fluid or peripheral blood of three patients with rheumatoid arthritis and one patient with systemic lupus erythematosus. 17 cell lines were obtained that produced high-titer immunoglobulin M (IgM) RF that reacted exclusively with rabbit but not human IgG or IgG of other mammalian species. Certain anti-rabbit IgG RF also had specificity for other mammalian antigens (Ag), including cytoskeletal proteins and intracellular proteins found in HeLa cells, as well as for Ag present in an extract prepared from the cell wall of group A streptococci. 13 of the 17 RF contained lambda-type light (L) chains, of which 12 were classified serologically as members of the lambda-L chain variable region (V lambda) subgroup, designated V lambda III. The heavy chain V region (VH) and V lambda sequences of nine of these IgM lambda RF were determined at the cDNA level. Five VH genes in three VH families were used by these antibodies (Ab), including VH1 (dp21/1-4b and dp10 [51p1]/hv1051), VH3 (dp38/3-15 and dp77/13-21), and VH4 (dp70/4-4b). The deduced V gene-encoded amino acid sequences of the lambda chains of these IgM lambda RF confirmed their serological classification as lambda III, and they were further classified as members of the relatively uncommon V lambda III subgroup, designated V lambda IIIb. Based on cDNA analyses, nine were the product of three different V lambda III b germline genes. Two such genes, designated hsiggll150 and hsiggll295, were cloned and sequenced from genomic DNA. Unique combinations of these VH and V lambda III b genes could be related to distinctive patterns of reactivity among the IgM lambda RF. Although the VH and V lambda regions of these Abs were expressed primarily as germline-encoded sequences, four of nine multireactive Abs had extensive V region mutation, indicative of an Ag-driven process. The finding that lambda IIIb L chains are preferentially found among anti-rabbit IgG RF, and that some of these Ab have specificity for other protein, cellular, and bacterial Ag, provides new insight into the pathogenesis of RA and related diseases.

Animals↗
PubMed1993

Differential regulation of human B-lymphocyte tumor necrosis factor-alpha (TNF-alpha) and lymphotoxin (TNF-beta) production by protein phosphatase 1 and 2A inhibitor.

Tumor necrosis factor (TNF) and lymphotoxin (LT; TNF-beta) are major cytokines produced by B lymphocytes. Stimulation by okadaic acid, a phosphatase 1 and 2A inhibitor, markedly increased TNF mRNA accumulation and cytokine production. On the other hand, the accumulation of LT mRNA was not affected by okadaic acid despite structural and functional similarities between TNF and LT. The increase in TNF mRNA accumulation was due to the stimulation of gene transcription and a marked stabilization of this mRNA. The binding activities of the transcription factors AP-1 and AP-2 and NF kappa B, which regulates TNF gene transcription, were also stimulated by okadaic acid. In addition, okadaic acid was shown to increase TNF production at the protein level. These results show the importance of protein phosphatases in the regulation of cytokine production in B cells, and further identifies differences in the regulation of TNF-alpha and LT production.

B-Lymphocytes↗
PubMed1990

Two ultraviolet tumor-specific suppressor cell clones. One expresses Ig RNA and the other expresses T cell receptor-alpha and -beta RNA.

Two splenic cell clones were derived from mice bearing UV-induced skin tumors; both clones are I-J+, Thy-1+, and J11D+. Cellular extracts, but not culture supernatants, from the two clones, designated T4 and T5, specifically suppress primary cytotoxic and proliferative responses to UV-induced tumor targets. Therefore, clones T4 and T5 would appear to function as putative I-J+ suppressor cells with specificity for an antigenic epitope common to several UV-induced tumors. To derive more information concerning the status of Ag-receptor genes in the suppressive clones, we analyzed the rearrangement and expression of Ig and TCR genes. The first clone, T4, expressed Thy-1, a T cell-surface marker, yet it had not rearranged its TCR-beta, -gamma, and -delta gene families, nor were TCR-alpha, -beta, -gamma, or -delta transcripts detectable. Instead, clone T4 contained rearranged Ig H chain genes and expressed mu RNA. Because neither lambda nor kappa L chain transcripts were detected, this clone could not utilize a complete Ig molecule as its Ag receptor. On the other hand, clone T5 contained exclusively TCR gene rearrangements; it expressed alpha and beta transcripts of the correct sizes. However, the level of RNA that could encode the delta-chain of the CD3 accessory molecule was below detection, so it is unlikely that this TCR was expressed on the cell surface. The rearrangement of Ig genes in one clone and TCR genes in the other clone does not necessarily indicate that these genes encode the Ag receptors used by these clones. However, it suggests either that suppressor-like cells can derive from different lymphocyte precursor lineages or that rearrangements of the known TCR genes or the Ig genes are irrelevant to the function of this cell lineage.

Animals↗
PubMed1986

A new polymorphic determinant on HLA-DQ molecules.

In man, the immune response genes are located within the HLA-D/DR region, and the gene products, the Ia antigens, are expressed on B lymphocytes, monocytes, and a percentage of null cells and activated T lymphocytes. We recently identified a human Ia antigen, K19, which appeared to be limited in its expression to B lymphocytes, and to be preferentially expressed on the more mature cells within this population. This work was facilitated by a monoclonal antibody. HK-19, which recognized a monomorphic determinant of this Ia molecule. We now report the characterization of a second monoclonal antibody, HK-13, which recognized the same molecule as HK-19, but only on cells from some individuals. The greater affinity of HK-13 allowed more complete characterization of the K19/K13 molecule. This characterization included cytofluorography, two-dimensional gel electrophoresis, tryptic peptide mapping, and partial N-terminal amino acid sequencing, and indicated that K19 and K13 were epitopes on HLA-DQ (DC) molecules. The pattern of reactivity of HK-13 on a panel of typing cells did not correlate with any of the known HLA-DQ polymorphic determinants. Thus, HK-13 is a new polymorphic determinant of the HLA-DQ series.

Amino Acid Sequence↗
PubMed1984

The MT4 allodeterminant is borne on an HLA-DS molecule on DR5 cells.

Human HLA-DR molecules have been shown to be structurally homologous to the murine I-E subregion molecules by amino acid sequence analysis. Recent studies have demonstrated the isolation of an I-A subregion-homologous molecule (HLA-DS) from human B-cell lines with the rabbit antiserum RbO3, made against a marmoset I-A-like Ia molecule. Previous work from our laboratory has demonstrated that the DR5 homozygous lymphoblastoid cell line Swei expresses at least two different Ia alpha chains and four different Ia beta chains, which associate to form four distinct human Ia molecules, alpha 1 beta 2, alpha 1 beta 3, alpha 2 beta 1, and alpha 2 beta 4, and that the alpha 2 beta 1 molecule bears the allodeterminants MB3 and MT4. To determine whether the MT4-bearing alpha 2 beta 1 molecule was an HLA-DS molecule, the alpha 2 beta 1 molecule reactive with an anti-MT4 alloserum was compared with the Ia molecule reactive with the rabbit xenoantiserum RbO3 by two-dimensional gel electrophoresis and sequential immunoprecipitation. The alpha 2 chain and the RbO3-reactive alpha chain yielded essentially similar spot patterns. The beta 1-chain spot pattern was a subset of the RbO3-reactive beta-chain spot pattern. Sequential immunoprecipitation indicated that RbO3 removed all molecules reactive with MGH88B. These results indicate that on DR5 cells the allosera-reactive alpha 2 beta 1 molecule, which bears MT4, is an HLA-DS molecule.

Electrophoresis, Agar Gel↗
PubMed1983

An HLA-DR5 homozygous cell line expresses two DS (I-A-like) molecules.

Previous studies have indicated that LLA-DR homozygous cell lines express two DR molecules but only a single DS (I-A-like) molecule. This report demonstrates that an HLA-DR5 homozygous cell line expresses at least two distinct DS molecules. These two DS molecules are formed by the association of a single DS alpha chain with either of two DS beta chains. Four distinct Ia molecules have now been identified from this DR5 homozygous cell line.

Antigen-Antibody Reactions↗
PubMed1983

A unique DR-related B cell differentiation antigen.

The Ia or class II molecules in both mouse and man are the basis for the genetic control of the immune response. In addition to DR, other class II antigens have been described in man. We describe a new human Ia antigen K19, recognized by three monoclonal antibodies (HK-9, HK-19, and HK-20). This antigen has the general biochemical characteristics of an Ia antigen but is different from a DR antigen. Further, this antigen is found only on mature B lymphocytes and not on monocytes and activated T cells. Thus, this antigen may represent a new Ia-like molecule that is preferentially expressed on mature B cells.

Animals↗
PubMed1982

Demonstration of a third structurally distinct human Ia beta chain by two-dimensional gel electrophoresis.

Previous studies have indicated that HLA-DR homozygous cell lines express two Ia alpha and Ia beta chains that combine to form at least two Ia molecules. This report demonstrates by two-dimensional gel electrophoresis the existence of a third structurally distinct human Ia beta chain on DR2 and DR5 cell lines. This suggests that at least five separate genes control the expression of Ia molecules on HLA-DR homozygous cell lines.

B-Lymphocytes↗
PubMed1982

Molecular relationships of the human B cell alloantigens, MT2, MB3, MT4, and DR5.

The human class II, HLA-linked, B cell alloantigens include the HLA-DR, MB, MT, and Te determinants. Interest in the molecular relationships of these antigens has recently intensified because of their homology to the murine Ia antigens and their possible importance in disease predisposition and transplantation. We have used alloantisera with carefully defined immunochemical as well as serologic specificity, and two immunochemical techniques, sequential immunoprecipitation with analysis by SDS-PAGE and two-dimensional gel electrophoresis, to explore the molecular relationships of the MT2, MB3, MT4, and HLA-DR5 antigenic determinants. The data presented here indicate that 1) all class II molecules that bear the DR5 antigenic determinant also bear the MT2 antigenic determinant; (2) the homozygous DR5 cell line, Swei, expresses at least two structurally distinct class II molecules, both of which bear MT2: one bears the MT2, MB3, and MT4 antigenic determinants, and the second bears the MT2, but not the MB3 or MT4 antigenic determinant; and (3) the DR5 determinant is located on at least one and possibly both of these distinct class II molecules.

Absorption↗