Linda Spatz - Academia.edu (original) (raw)
Papers by Linda Spatz
Immunity, inflammation and disease, 2016
The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Eryt... more The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE). EBV nuclear antigen-I (EBNA-1) is the major nuclear protein of EBV. We previously generated an IgG monoclonal antibody (MAb) to EBNA-1, 3D4, and demonstrated that it cross-reacts with double stranded DNA (dsDNA) and binds the 148 amino acid viral binding site (VBS) in the carboxyl region of EBNA-1. The aim of the present study was to characterize another antibody to EBNA-1 that cross-reacts with dsDNA, compare its immunoglobulin genes to 3D4, and finely map the epitope in EBNA-1 that is recognized by these cross-reactive antibodies. We generated an IgM MAb to EBNA-1, 16D2, from EBNA-1 injected mice and demonstrated by ELISA that it cross-reacts with dsDNA and binds the 148 amino acid VBS. We sequenced the variable heavy and light chain genes of 3D4 and 16D2 and compared V gene usage. To more finely map the epitope in EBNA-1 recognized by these MAbs, we examined their bin...
Biological Psychiatry, 2010
Frontiers in Immunology, 2021
Molecular Immunology, 2006
Mice transgenic for the R4A-C heavy chain of an anti-dsDNA antibody, maintain tolerance by anergy... more Mice transgenic for the R4A-C heavy chain of an anti-dsDNA antibody, maintain tolerance by anergy and deletion. In C57BL/6 mice overexpressing CD19, a molecule, which lowers the threshold for B cell activation, elevated levels of serum autoantibodies have been observed. In the present study, we wished to determine whether CD19 overexpression could alter the induction of tolerance in R4A-C mice and lead to the secretion of transgenic anti-dsDNA antibodies. We, therefore, bred R4A-C transgenic mice-to-mice transgenic for human CD19 (hCD19) and generated R4A-C mice heterozygous and homozygous for hCD19. We, now report the spontaneous secretion of transgenic IgM anti-dsDNA antibody in the sera of R4A-C mice overexpressing CD19, indicative of a loss of B cell tolerance. We observe that transgenic B cells secreting anti-dsDNA antibody in these mice are T independent and display a marginal zone like phenotype althought they do not reside in the MZ. In addition, they appear to be derived from the conventional B2 subset rather than the B1 subset. Interestingly, a subset of the anti-dsDNA B cells in these mice still display the phenotype and functional characteristics of anergic B cells. These B cells cannot be activated to secrete antibody following BCR crosslinking, however, they are hyper-responsive to activation by innate signaling mechanisms. This suggests that CD19 overexpression may promote anergic B cells to escape tolerance by converging with BCR independent pathways, thereby rendering these B cells hyper-responsive to innate signaling.
European Journal of Immunology, 1999
One of the challenges in the study of autoimmunity is to understand which autoreactive cells are ... more One of the challenges in the study of autoimmunity is to understand which autoreactive cells are subject to regulation and what mechanisms of regulation are operative. In mice transgenic for the R4A-+ 2b heavy chain of an anti-double stranded (ds) DNA antibody, the + 2b heavy chain can pair with the full spectrum of endogenous light chains to produce a multitude of antibodies, including anti-dsDNA antibodies of different affinities and fine specificities. We have previously demonstrated the existence of two populations of anti-DNA B cells in non-autoimmune hosts: a high-affinity population which is rendered anergic in vivo, and a second high-affinity population which is deleted. We have now identified a third population of dsDNA-binding B cells. These cells produce germ-line-encoded antibodies with an apparent affinity for dsDNA that is 1 to 4 logs lower than the apparent affinities of antibodies made by anergic or deleted B cells, and represent a non-tolerized population which escapes regulation. Based on its characterization, we can define a molecular threshold for tolerance induction, and can speculate on the fate of these B cells when they are recruited to an immune response and undergo somatic mutation to become high-affinity anti-DNA B cells.
Annals of Neurology, 1987
Human hybridomas that secrete monoclonal IgM anti-myelin-associated glycoprotein antibodies were ... more Human hybridomas that secrete monoclonal IgM anti-myelin-associated glycoprotein antibodies were generated by fusion with cells from a patient with peripheral neuropathy and IgM monoclonal gammopathy. Karyotypic analysis of the hybridoma cells revealed no chromosomal abnormalities. The cells were positive for cell-surface idiotype HLA-DR and the plasma cell antigen PCA-1, and negative for the B-cell determinant B4 and for Leu-1, which has been postulated to distinguish a subpopulation of B cells that secrete IgM with autoantibody activity.
Proceedings of the …, 1992
Nonautoimmune mice transgenic for the heavy chain of an IgG2b anti-double-stranded-DNA antibody e... more Nonautoimmune mice transgenic for the heavy chain of an IgG2b anti-double-stranded-DNA antibody express the transgene in lymphoid organs and display partial allelic exclusion of this y2b transgene. The spleens ofthese mice are characterized by marked B-cell depletion. Although there are B cells in these mice that express the transgene and recognize double-stranded DNA, they are anergic in vivo. Recovery from the state of anergy occurs in vitro after lipopolysaccharide stimulation. Thus this transgenic model demonstrates the induction ofselftolerance to an IgG autoantibody.
International …, 2002
One mechanism by which anti-double stranded (ds) DNA B cells are regulated is anergy. Multiple ph... more One mechanism by which anti-double stranded (ds) DNA B cells are regulated is anergy. Multiple phenotypes have been attributed to anergic B cells in various transgenic models. Differences in the nature of the antigen and in the avidity of antigen-antibody interactions may account for these variations in phenotype. In the present study we describe a population of dsDNA binding B cells that display many of the features of anergic B cells, but have characteristics which suggest they are partially functional as well. These B cells do not spontaneously secrete antibody nor can they be induced to secrete antibody following receptor cross-linking in vitro. Furthermore, they display an immature phenotype and have a shortened lifespan, characteristic of anergic B cells. However, they can be induced to secrete anti-dsDNA antibody following activation with T cell-derived factors as well as with lipopolysaccharide (LPS) and they can be recovered by somatic cell hybridization even in the absence of LPS stimulation prior to fusion. These results suggest that antigen receptor signaling can be uncoupled from signaling induced by T cell-derived factors or LPS and that this may be a mechanism for maintaining tolerance. This may have protective advantages because it may enable B cells to be down-regulated in response to autoantigen yet be available for recruitment in an inflammatory response.
Cellular …, 2010
Overexpression of BAFF is believed to play an important role in Systemic Lupus Erythematosus and ... more Overexpression of BAFF is believed to play an important role in Systemic Lupus Erythematosus and elevated levels of serum BAFF have been found in lupus patients. Excess BAFF also leads to overproduction of anti-dsDNA antibodies and a lupus-like syndrome in mice. In the present study, we use mice transgenic for the R4A-Cμ (IgM) heavy chain of an anti-dsDNA antibody, to study the effects of BAFF overexpression on anti-dsDNA B-cell regulation. We observe that overexpression of BAFF promotes anti-dsDNA B cell maturation and secretion of antibody and enriches for transgenic anti-dsDNA B cells in the marginal zone and follicular splenic compartments. In addition, our data suggests that BAFF rescues a subset of anti-dsDNA B cells from a regulatory checkpoint in the transitional stage of development.
The Journal of …, 1997
Two major mechanisms for the regulation of autoreactive B cells that arise in the bone marrow are... more Two major mechanisms for the regulation of autoreactive B cells that arise in the bone marrow are functional silencing (anergy) and deletion. Studies to date suggest that low avidity interactions between B cells and autoantigen lead to B cell silencing, whereas high avidity interactions lead to deletion. Anti-double stranded (ds) DNA antibodies represent a pathogenic autospecificity in Systemic Lupus Erythematosus (SLE). An understanding of their regulation is critical to an understanding of SLE. We now demonstrate in a transgenic model in which mice express the heavy chain of a potentially pathogenic anti-DNA antibody that antibody affinity for ds-DNA does not alone determine the fate of anti-dsDNA B cells. B cells making antibodies with similar affinities for dsDNA are regulated differently, depending on light chain usage. A major implication of this observation is that dsDNA may not be the self antigen responsible for cell fate determinations of anti-dsDNA B cells. Light chain usage may determine antigenic crossreactivity, and cross-reactive antigens may regulate B cells that also bind dsDNA.
Methods, 1997
Studies of anti-double-stranded (anti-ds)DNA antibodies have provided insights into how and why t... more Studies of anti-double-stranded (anti-ds)DNA antibodies have provided insights into how and why these antibodies arise in systemic lupus erythematosus. In this review we discuss the experimental approaches that have been used by our laboratory to study these autoantibodies. ...
A cDNA clone that encodes the heavy chain variable region (VH) of an IgM M-protein with anti-myel... more A cDNA clone that encodes the heavy chain variable region (VH) of an IgM M-protein with anti-myelin-associated glycoprotein (MAG) activity secreted by chronic lymphocytic leukemia cells (B-C11) from a patient with peripheral neuropathy was cloned and sequenced. The JH region was identical to the germline JH4 sequence except for deletion of a thymidine residue at the site of D-JH recombination, and the D region showed greatest homology to DM2. Sequence analysis of the VH region revealed greatest homology to VH26, a member of the VH3 gene family, but homology was only 83.7% over 326 bases, suggesting that it was derived from as yet an unidentified member of the VH3 gene family.
Human antibodies and hybridomas, 1992
The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient w... more The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient with neuropathy were inserted into expression vectors containing the gamma and kappa constant regions respectively and co-transfected into monkey kidney CV1P cells. The expressed antibody had the same antigenic specificity but significantly lower avidity than the native IgM, anti-MAG, antibody as detected by ELISA. When the variable heavy chain gene of the anti-MAG antibody was co-transfected with the variable light chain gene from another monoclonal, IgM, anti-MAG antibody, a fully assembled antibody was expressed as determined by a trapping ELISA, but it did not bind to (MAG) or to sulfated glucuronic acid paragloboside, indicating that both heavy and light chains contribute to the binding activity.
Human antibodies and hybridomas, 1992
The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient w... more The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient with neuropathy were inserted into expression vectors containing the gamma and kappa constant regions respectively and co-transfected into monkey kidney CV1P cells. The expressed antibody had the same antigenic specificity but significantly lower avidity than the native IgM, anti-MAG, antibody as detected by ELISA. When the variable heavy chain gene of the anti-MAG antibody was co-transfected with the variable light chain gene from another monoclonal, IgM, anti-MAG antibody, a fully assembled antibody was expressed as determined by a trapping ELISA, but it did not bind to (MAG) or to sulfated glucuronic acid paragloboside, indicating that both heavy and light chains contribute to the binding activity.
Immunity, inflammation and disease, 2016
The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Eryt... more The Epstein Barr Virus (EBV) has been associated with the autoimmune disease, Systemic Lupus Erythematosus (SLE). EBV nuclear antigen-I (EBNA-1) is the major nuclear protein of EBV. We previously generated an IgG monoclonal antibody (MAb) to EBNA-1, 3D4, and demonstrated that it cross-reacts with double stranded DNA (dsDNA) and binds the 148 amino acid viral binding site (VBS) in the carboxyl region of EBNA-1. The aim of the present study was to characterize another antibody to EBNA-1 that cross-reacts with dsDNA, compare its immunoglobulin genes to 3D4, and finely map the epitope in EBNA-1 that is recognized by these cross-reactive antibodies. We generated an IgM MAb to EBNA-1, 16D2, from EBNA-1 injected mice and demonstrated by ELISA that it cross-reacts with dsDNA and binds the 148 amino acid VBS. We sequenced the variable heavy and light chain genes of 3D4 and 16D2 and compared V gene usage. To more finely map the epitope in EBNA-1 recognized by these MAbs, we examined their bin...
Biological Psychiatry, 2010
Frontiers in Immunology, 2021
Molecular Immunology, 2006
Mice transgenic for the R4A-C heavy chain of an anti-dsDNA antibody, maintain tolerance by anergy... more Mice transgenic for the R4A-C heavy chain of an anti-dsDNA antibody, maintain tolerance by anergy and deletion. In C57BL/6 mice overexpressing CD19, a molecule, which lowers the threshold for B cell activation, elevated levels of serum autoantibodies have been observed. In the present study, we wished to determine whether CD19 overexpression could alter the induction of tolerance in R4A-C mice and lead to the secretion of transgenic anti-dsDNA antibodies. We, therefore, bred R4A-C transgenic mice-to-mice transgenic for human CD19 (hCD19) and generated R4A-C mice heterozygous and homozygous for hCD19. We, now report the spontaneous secretion of transgenic IgM anti-dsDNA antibody in the sera of R4A-C mice overexpressing CD19, indicative of a loss of B cell tolerance. We observe that transgenic B cells secreting anti-dsDNA antibody in these mice are T independent and display a marginal zone like phenotype althought they do not reside in the MZ. In addition, they appear to be derived from the conventional B2 subset rather than the B1 subset. Interestingly, a subset of the anti-dsDNA B cells in these mice still display the phenotype and functional characteristics of anergic B cells. These B cells cannot be activated to secrete antibody following BCR crosslinking, however, they are hyper-responsive to activation by innate signaling mechanisms. This suggests that CD19 overexpression may promote anergic B cells to escape tolerance by converging with BCR independent pathways, thereby rendering these B cells hyper-responsive to innate signaling.
European Journal of Immunology, 1999
One of the challenges in the study of autoimmunity is to understand which autoreactive cells are ... more One of the challenges in the study of autoimmunity is to understand which autoreactive cells are subject to regulation and what mechanisms of regulation are operative. In mice transgenic for the R4A-+ 2b heavy chain of an anti-double stranded (ds) DNA antibody, the + 2b heavy chain can pair with the full spectrum of endogenous light chains to produce a multitude of antibodies, including anti-dsDNA antibodies of different affinities and fine specificities. We have previously demonstrated the existence of two populations of anti-DNA B cells in non-autoimmune hosts: a high-affinity population which is rendered anergic in vivo, and a second high-affinity population which is deleted. We have now identified a third population of dsDNA-binding B cells. These cells produce germ-line-encoded antibodies with an apparent affinity for dsDNA that is 1 to 4 logs lower than the apparent affinities of antibodies made by anergic or deleted B cells, and represent a non-tolerized population which escapes regulation. Based on its characterization, we can define a molecular threshold for tolerance induction, and can speculate on the fate of these B cells when they are recruited to an immune response and undergo somatic mutation to become high-affinity anti-DNA B cells.
Annals of Neurology, 1987
Human hybridomas that secrete monoclonal IgM anti-myelin-associated glycoprotein antibodies were ... more Human hybridomas that secrete monoclonal IgM anti-myelin-associated glycoprotein antibodies were generated by fusion with cells from a patient with peripheral neuropathy and IgM monoclonal gammopathy. Karyotypic analysis of the hybridoma cells revealed no chromosomal abnormalities. The cells were positive for cell-surface idiotype HLA-DR and the plasma cell antigen PCA-1, and negative for the B-cell determinant B4 and for Leu-1, which has been postulated to distinguish a subpopulation of B cells that secrete IgM with autoantibody activity.
Proceedings of the …, 1992
Nonautoimmune mice transgenic for the heavy chain of an IgG2b anti-double-stranded-DNA antibody e... more Nonautoimmune mice transgenic for the heavy chain of an IgG2b anti-double-stranded-DNA antibody express the transgene in lymphoid organs and display partial allelic exclusion of this y2b transgene. The spleens ofthese mice are characterized by marked B-cell depletion. Although there are B cells in these mice that express the transgene and recognize double-stranded DNA, they are anergic in vivo. Recovery from the state of anergy occurs in vitro after lipopolysaccharide stimulation. Thus this transgenic model demonstrates the induction ofselftolerance to an IgG autoantibody.
International …, 2002
One mechanism by which anti-double stranded (ds) DNA B cells are regulated is anergy. Multiple ph... more One mechanism by which anti-double stranded (ds) DNA B cells are regulated is anergy. Multiple phenotypes have been attributed to anergic B cells in various transgenic models. Differences in the nature of the antigen and in the avidity of antigen-antibody interactions may account for these variations in phenotype. In the present study we describe a population of dsDNA binding B cells that display many of the features of anergic B cells, but have characteristics which suggest they are partially functional as well. These B cells do not spontaneously secrete antibody nor can they be induced to secrete antibody following receptor cross-linking in vitro. Furthermore, they display an immature phenotype and have a shortened lifespan, characteristic of anergic B cells. However, they can be induced to secrete anti-dsDNA antibody following activation with T cell-derived factors as well as with lipopolysaccharide (LPS) and they can be recovered by somatic cell hybridization even in the absence of LPS stimulation prior to fusion. These results suggest that antigen receptor signaling can be uncoupled from signaling induced by T cell-derived factors or LPS and that this may be a mechanism for maintaining tolerance. This may have protective advantages because it may enable B cells to be down-regulated in response to autoantigen yet be available for recruitment in an inflammatory response.
Cellular …, 2010
Overexpression of BAFF is believed to play an important role in Systemic Lupus Erythematosus and ... more Overexpression of BAFF is believed to play an important role in Systemic Lupus Erythematosus and elevated levels of serum BAFF have been found in lupus patients. Excess BAFF also leads to overproduction of anti-dsDNA antibodies and a lupus-like syndrome in mice. In the present study, we use mice transgenic for the R4A-Cμ (IgM) heavy chain of an anti-dsDNA antibody, to study the effects of BAFF overexpression on anti-dsDNA B-cell regulation. We observe that overexpression of BAFF promotes anti-dsDNA B cell maturation and secretion of antibody and enriches for transgenic anti-dsDNA B cells in the marginal zone and follicular splenic compartments. In addition, our data suggests that BAFF rescues a subset of anti-dsDNA B cells from a regulatory checkpoint in the transitional stage of development.
The Journal of …, 1997
Two major mechanisms for the regulation of autoreactive B cells that arise in the bone marrow are... more Two major mechanisms for the regulation of autoreactive B cells that arise in the bone marrow are functional silencing (anergy) and deletion. Studies to date suggest that low avidity interactions between B cells and autoantigen lead to B cell silencing, whereas high avidity interactions lead to deletion. Anti-double stranded (ds) DNA antibodies represent a pathogenic autospecificity in Systemic Lupus Erythematosus (SLE). An understanding of their regulation is critical to an understanding of SLE. We now demonstrate in a transgenic model in which mice express the heavy chain of a potentially pathogenic anti-DNA antibody that antibody affinity for ds-DNA does not alone determine the fate of anti-dsDNA B cells. B cells making antibodies with similar affinities for dsDNA are regulated differently, depending on light chain usage. A major implication of this observation is that dsDNA may not be the self antigen responsible for cell fate determinations of anti-dsDNA B cells. Light chain usage may determine antigenic crossreactivity, and cross-reactive antigens may regulate B cells that also bind dsDNA.
Methods, 1997
Studies of anti-double-stranded (anti-ds)DNA antibodies have provided insights into how and why t... more Studies of anti-double-stranded (anti-ds)DNA antibodies have provided insights into how and why these antibodies arise in systemic lupus erythematosus. In this review we discuss the experimental approaches that have been used by our laboratory to study these autoantibodies. ...
A cDNA clone that encodes the heavy chain variable region (VH) of an IgM M-protein with anti-myel... more A cDNA clone that encodes the heavy chain variable region (VH) of an IgM M-protein with anti-myelin-associated glycoprotein (MAG) activity secreted by chronic lymphocytic leukemia cells (B-C11) from a patient with peripheral neuropathy was cloned and sequenced. The JH region was identical to the germline JH4 sequence except for deletion of a thymidine residue at the site of D-JH recombination, and the D region showed greatest homology to DM2. Sequence analysis of the VH region revealed greatest homology to VH26, a member of the VH3 gene family, but homology was only 83.7% over 326 bases, suggesting that it was derived from as yet an unidentified member of the VH3 gene family.
Human antibodies and hybridomas, 1992
The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient w... more The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient with neuropathy were inserted into expression vectors containing the gamma and kappa constant regions respectively and co-transfected into monkey kidney CV1P cells. The expressed antibody had the same antigenic specificity but significantly lower avidity than the native IgM, anti-MAG, antibody as detected by ELISA. When the variable heavy chain gene of the anti-MAG antibody was co-transfected with the variable light chain gene from another monoclonal, IgM, anti-MAG antibody, a fully assembled antibody was expressed as determined by a trapping ELISA, but it did not bind to (MAG) or to sulfated glucuronic acid paragloboside, indicating that both heavy and light chains contribute to the binding activity.
Human antibodies and hybridomas, 1992
The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient w... more The variable heavy and light chain genes of a monoclonal, IgM, anti-MAG antibody from a patient with neuropathy were inserted into expression vectors containing the gamma and kappa constant regions respectively and co-transfected into monkey kidney CV1P cells. The expressed antibody had the same antigenic specificity but significantly lower avidity than the native IgM, anti-MAG, antibody as detected by ELISA. When the variable heavy chain gene of the anti-MAG antibody was co-transfected with the variable light chain gene from another monoclonal, IgM, anti-MAG antibody, a fully assembled antibody was expressed as determined by a trapping ELISA, but it did not bind to (MAG) or to sulfated glucuronic acid paragloboside, indicating that both heavy and light chains contribute to the binding activity.