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J D Capra

Publications and source records attributed to J D Capra.

299 records · Page 17Linked to original sources
PubMed1968

Antigenic specificities related to the cold agglutinin activity of gamma M globulins.

Certain antiserums prepared against isolated cold agglutinins demonstrate specificity for gamma M globulins with this activity and not for similar gamma M globulins lacking such activity. The cold agglutinin specific antigens fall into several major and minor groups. Their exact relation to the presumed antibody-combining sites remains to be determined.

Antibodies↗
PubMedDate not supplied

Calreticulin is transcriptionally upregulated by heat shock, calcium and heavy metals.

Calreticulin is a new human rheumatic disease-associated autoantigen that plays a multifaceted role in cell biology. In earlier studies, this protein was shown to share an intimate relationship with the Ro/SS-A autoantigen complex, although the nature of this association continues to be debated. Since modulation of the Ro/SS-A autoantigen in epidermal keratinocytes has been implicated in the pathogenesis of subacute cutaneous lupus erythematosus and neonatal lupus erythematosus, we have begun to examine the transcriptional regulation of calreticulin. A 504 bp calreticulin promoter fragment was subcloned into a reporter gene plasmid containing firefly luciferase. Calcium ionophore, heat shock, and heavy metals such as zinc and cadmium were consistently found to increase calreticulin transcriptional activities in A431 cells (a human epidermoid squamous carcinoma cell line) under transient transfection conditions. These studies suggest that (a) calreticulin is regulated at the transcriptional level, and (b) calreticulin, like some other LE-related autoantigens, appears to function as a heat shock/stress-response gene.

Autoantigens↗
PubMedDate not supplied

A serologic marker for the Ars-C family of anti-arsonate antibodies.

Attempts are being made to define, at the serologic, structural and genetic levels, the anti-arsonate repertoire. We previously identified three families of anti-arsonate antibodies based on the amino acid sequence of the heavy chain V regions. The present report establishes the serologic correlates of one of these families, the Ars-C family. The determinants defining this family are expressed by anti-Ar molecules displaying the A/J minor idiotype or the BALB/c major idiotype; these determinants are also expressed on molecules of different specificity, notably by the DNP-binding myelomas, MOPC-460 and MOPC-315. All strains tested employed the Ars-C family in the response to arsonate.

Animals↗
PubMedDate not supplied

Interaction of cell-type-specific nuclear proteins with immunoglobulin VH promoter region sequences.

All human and murine immunoglobulin heavy chain variable region (VH) genes contain the sequence ATGCAAAT approximately 70 nucleotides 5' from the site of transcription initiation. This octanucleotide, in reverse orientation, is also found in all light chain variable region (VL) genes, and in the immunoglobulin heavy chain transcriptional enhancer. Transfection studies have established that this octamer is involved in the lymphoid-specific transcription of immunoglobulin genes. Octamer-containing fragments have been reported to bind a factor present in nuclear extracts of human cell lines; however, identical binding activity was detected in both B lymphoid and non-lymphoid cells. Here we establish that nuclear extracts from distinct cell types differ in their ability to interact with octamer-containing fragments. We have also detected a DNA-protein interaction that may be involved in the cell-type specificity of immunoglobulin expression, and we have determined that a sequence upstream of the octamer participates in an interaction with a nuclear protein(s).

Animals↗
PubMedDate not supplied

Immunoglobulin heavy-chain receptor editing is observed in the NOD/SCID model of human B-cell development.

Receptor editing and receptor revision are the two mechanisms of antibody diversity that result in either complete V-gene replacement or the formation of hybrid V genes. We do not yet understand how this process unfolds, because they are rare and difficult to study in vivo. In this study, we describe a family of VH4-34:VH4-61 hybrids isolated from a human B-cell chimeric non-obese diabetic/severe combined immunodeficient mouse. The observation of hybrid immunoglobulin sequences in human B cells that developed in this model system makes it useful for the study of this mechanism of diversification and tolerance.

Amino Acid Sequence↗
PubMedDate not supplied

The amino acid sequence of the variable regions of the light chains from two idiotypically cross reactive IgM anti-gamma globulins.

Amino acid sequence analysis of the light chains of two IgM rheumatoid factors is presented. The parent molecules of these chains are human IgM proteins with specificity for human IgG and sharing idiotypic cross reactivity. The heavy chains had previously been shown to have extremely similar hypervariable regions. This communication presents data indicating that the light chains, even though representing two different kappa subgroups, also share identities in their hypervariable regions. These data can be most easily interpreted in terms of a gene interaction model for immunoglobulin V region assembly.

Amino Acid Sequence↗