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T J Kipps

Publications and source records attributed to T J Kipps.

At least 91 records · Page 5Linked to original sources
PubMed1993

Function of B cells expressing a human immunoglobulin M rheumatoid factor autoantibody in transgenic mice.

We have generated transgenic mice that express the immunoglobulin (Ig)M heavy chain and kappa light chain genes coding for a human IgM rheumatoid factor (RF), Les. Transgenic B cells expressing human IgM RF show striking similarities to their counterparts in normal humans. They comprise a significant proportion of the adult B cell population, but secrete only low levels of RF into the serum. The RF transgene-expressing B cells localize to primary B cell follicles and the mantle zone regions of secondary follicles in the spleen. Using these mice we have been able to show that one of the central functions of normal RF-expressing B cells may be to act as highly efficient antigen-presenting cells for low concentrations of immune-complexed antigen. High levels of secretion of IgM RF can not be induced under normal circumstances, although RF-expressing B cells proliferate well in vitro to both aggregated human IgG and anti-human IgM antibodies. However, these mice are not intrinsically secretion deficient. By crossing the RF transgenic mice with the autoimmune MRL/lpr background, we find a dramatic increase, > 200-fold, in levels of serum RF. The results strongly suggest that a major function of normal resting RF B cells is unrelated to antibody secretion. Rather, the RF B cells in the follicles may play a role in antigen presentation and regulation of immune responses to antibody-bound nonself-, and possibly self-antigens. This physiologic role of RF B cells may be disrupted in RF-associated autoimmune disease.

Animals↗
PubMed1993

Gene therapy for cancer.

Recent advances in our understanding of the molecular basis of neoplasia and of the mechanics underlying activation of the immune system provide us with exciting new possibilities for the treatment of cancer. This article reviews several of the recent developments that may enter widespread clinical use by the start of the next century. Indeed, the twenty-first century may well become for medicine, the era of gene therapy and molecular pharmacology.

Biotransformation↗
PubMed1993

Immunoglobulin genes in chronic lymphocytic leukemia.

Common B cell chronic lymphocytic leukemia (CLL) cells frequently produce polyreactive autoantibodies. Molecular studies have revealed that the leukemia cells in this disease use a restricted repertoire of conserved immunoglobulin variable region genes (Ig V genes) that generally have not undergone somatic mutation. Studies indicate that this polyreactive autoantibody activity expressed in CLL is dependent upon the third complementarity determining region (CDR) of the heavy chain variable region and on proper pairing of the Ig light and heavy chains. In this light, the high frequency at which CLL patients have leukemia cells that make IgM autoantibodies does not appear secondary to the genetic constraints on the potential diversity of the antibodies that may be expressed in this disease. Rather, even though they express nonmutated Ig V genes, CLL B cells appear to have been selected for their ability to bind self-antigens. Conceivably, normal B cells that express such autoantibodies may be perpetually stimulated, thereby increasing their risk for malignant transformation into CLL. Alternatively, anti-self-reactivity may enhance the survival of a B cell clone subsequent to its malignant transformation. In either case, the autoantibody activity of the immunoglobulins expressed by leukemia B cells may be an important factor in the etiopathogenesis of this disease.

Autoantibodies↗
PubMed1992

Epstein-Barr virus-induced human B-cell lymphomas in SCID mice reconstituted with human peripheral blood leukocytes.

Epstein-Barr virus (EBV) infection is associated with immunoblastic B-cell lymphomas in immunosuppressed or human immunodeficiency virus-infected individuals and in SCID mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID) from EBV-seropositive donors. The risk of tumors appearing in the hu-PBL-SCID mice differs among EBV-seropositive donors. Four different outcomes have been noted: (a) no tumors appear (no incidence donors); (b) tumors appear in a fraction of hu-PBL-SCID mice with a 10-20 week latent period (low- and intermediate-incidence donors); or (c) tumors appear in all hu-PBL-SCID mice within 6-10 weeks (high-incidence donors). The latter category of rapidly appearing tumor invariably involved activation of EBV replication, whereas more slowly growing tumors rarely activated EBV. The results indicate that prospective screening of high-risk individuals in the hu-PBL-SCID model may predict the risk of EBV-associated lymphoma development.

Animals↗
PubMed1992

Immunoglobulin V gene expression in CD5 B-cell malignancies.

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphomas (SLL) generally are malignancies of CD5 B cells. Immunophenotypic and clinicopathologic data, however, are required to distinguish subtypes that apparently have a different cytogenesis than that of conventional CLL or SLL. In addition to expressing CD5, neoplastic cells of the latter are also distinctive in that they frequently coexpress surface immunoglobulin (Ig), bearing one or more cross-reactive idiotypes (CRIs) (e.g. 17.109, G6,) that commonly are found on monoclonal IgM autoantibodies. The frequent occurrence of such CRIs reflects both the biased rearrangement and subsequent selected expression of Ig V genes with little or no somatic mutation. IgM/L CLL, for example, frequently (8/33) harbor abortive Ig rearrangements involving Humkv325, the VK gene encoding the 17.109-CRI. Also, the VH1 gene(s) encoding the G6 CRI accounts for over 10% of all VH genes and over 60% of all the VH1 genes used in randomly selected common CLL/SLL. Furthermore, comparison with the Ig expressed by nonmalignant G6 CRI+ B cells reveals an apparent restriction in the CDR3 of IgH expressed by G6 CRI+ CLL. Coupled with the observed potential bias in antibody light chain and heavy chain pairing in B-CLL, these data suggest that the autoantibodies expressed in this disease are selected based on antigen-binding activity. Collectively, our studies indicate that nonstochastic Ig V gene rearrangement and subsequent selection may influence the Ig repertoire expressed in this common B-cell malignancy.

Animals↗
PubMed1992

Heterogeneity among Epstein-Barr virus-seropositive donors in the generation of immunoblastic B-cell lymphomas in SCID mice receiving human peripheral blood leukocyte grafts.

Epstein-Barr virus (EBV) is associated with B-cell malignancy in immunosuppressed humans and SCID mice receiving human peripheral blood leukocyte grafts (hu-PBL-SCID). We have further characterized the process of lymphoma development in hu-PBL-SCID mice. We report that EBV-seropositive donors differ markedly in the capacity of their PBL to give rise to immunoblastic lymphomas in SCID mice; some donors (high incidence) generated tumors rapidly in all hu-PBL-SCID mice, other donors (intermediate-low incidence) gave rise to sporadic tumors after a longer latent period (greater than 10 weeks), and some donors failed to produce tumors. B-cell lymphomas arising from high incidence donors were multiclonal in origin, and EBV replication was detected in all tumors. Tumors derived from intermediate-low incidence donors were monoclonal or oligoclonal and often had no evidence of viral replication. All tumors, regardless of the donor, resembled EBV-transformed lymphoblastoid cell lines in surface phenotype but differed from lymphoblastoid cell lines by having less Epstein-Barr nuclear antigen 2 and CD23 expression. The variable patterns of lymphomagenesis seen among different EBV-sero-positive donors may be explained by lower levels of specific immunity to EBV in high incidence donors, permitting activation of EBV replication and potential transformation of secondary B-cell targets. In addition, there may be differences in the transforming potential of EBV infecting different donors. The use of the hu-PBL-SCID model may help predict patients at high risk for posttransplant or acquired immunodeficiency syndrome-associated lymphomas.

Age Factors↗
PubMed1992

Oral antilymphocyte activity and induction of apoptosis by 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine.

2-Chlorodeoxyadenosine (CdA) is active in chronic lymphocytic leukemia, hairy-cell leukemia, and low-grade lymphomas. In part, this spectrum of activity may be attributable to the selective toxicity of CdA to nondividing lymphocytes and monocytes. However, CdA is unstable at acidic pH and is degraded by bacterial nucleoside phosphorylases. The present experiments demonstrate that the 2'-arabino-fluoro derivative of CdA, designated CAFdA, is also directly toxic to quiescent lymphocytes and macrophages. Unlike CdA, CAFdA was stable at pH 2 and resisted degradation by Escherichia coli nucleoside phosphorylase. Cell killing was preceded by the formation of DNA strand breaks and could be prevented by supplementation of the medium with deoxycytidine. The initial DNA damage initiated the pattern of oligonucleosomal DNA fragmentation characteristic of apoptosis. Mutant lymphoblasts, deficient in deoxycytidine kinase, with elevated cytoplasmic 5'-nucleotidase, or with expanded deoxynucleotide pools secondary to increased ribonucleotide reductase activity, were cross-resistant to both CAFdA and CdA toxicity. One-week oral treatment with CAFdA (1 mg/ml in drinking water) achieved an average plasma concentration of 0.56 microM and eliminated 90% of chronic lymphocytic leukemia cells transplanted into severe combined immunodeficiency (scid) mice. Under the same conditions, CdA was much less active. Collectively, these results suggest that CAFdA could be effective as an oral agent in indolent lymphoproliferative diseases and in autoimmune diseases where lymphocyte and monocyte depletion is desirable.

2-Chloroadenosine↗
PubMed1992

Evidence for somatic selection of natural autoantibodies.

Natural autoantibodies are primarily immunoglobulin M (IgM) antibodies that bind to a variety of self-antigens, including self-IgG. Accounting for a large proportion of the early B cell repertoire, such polyspecific autoantibodies are speculated to contribute to the homeostasis and/or competence of the primary humoral immune system. Recent studies indicate that the leukemia cells from most patients with chronic lymphocytic leukemia (CLL) also express such IgM autoantibodies. Similarly, the leukemia cells from many CLL patients react with murine monoclonal antibodies (mAbs) specific for crossreactive idiotypes (CRIs) associated with human IgM autoantibodies. In particular, leukemic cells frequently react with G6, a mAb specific for an Ig heavy chain (H chain)-associated CRI, and/or with 17.109, a mAb that defines a kappa light chain (L chain)-associated CRI. Generated against IgM rheumatoid factor (RF) paraproteins, G6 and 17.109 each recognize a major CRI that is present in many IgM RF paraproteins. Furthermore, over 90% of the IgM paraproteins found to bear both H and L chain-associated CRIs also are found to have RF activity. Molecular characterization of these CRIs demonstrates that each is a serologic marker for expression of a highly conserved Ig V gene. As such, the frequent production of IgM polyspecific autoantibodies in CLL simply may reflect the frequent use of such highly conserved autoantibody-encoding Ig V genes with little or no somatic mutation. To test this hypothesis, we generated murine transfectomas to pair the 17.109-reactive kappa L chain of SMI, a 17.109/G6-reactive CLL population, with the Ig H chain of SMI or other G6-reactive leukemia cells or tonsillar lymphocytes. Cotransfection of vectors encoding the Ig H and L chains of SMI generated transfectomas that produce IgM kappa RF autoantibodies reactive with human IgG1 and IgG4. In contrast to G6/17.109-reactive IgM kappa RF Waldenstrom's paraproteins, the SMI IgM kappa also reacts with several other self-antigens, including myoglobin, actin, and ssDNA. However, cotransfection of the SMI L chain with a vector encoding any one of 10 different G6-reactive Ig H chains generated transfectomas that produce IgM kappa antibodies without detectable polyspecific autoantibody activity. These results indicate that polyspecific antiself-reactivity of G6/17.019-reactive Ig is dependent on the somatically generated Ig third complementarity determining region. Collectively, these studies imply that selection may be responsible for the frequent expression of polyspecific autoantibodies in CLL and early B cell ontogeny.

Amino Acid Sequence↗
PubMed1992

An anti-B cell autoantibody from Wiskott-Aldrich syndrome which recognizes i blood group specificity on normal human B cells.

We previously identified IgM autoantibodies in the sera of patients with Wiskott-Aldrich syndrome (WAS) that react with a subset of normal human B lymphocytes and induce B cell differentiation in vitro. From splenocytes of a patient with WAS we generated heterohybridomas (HY18 and HY21) and a lymphoblastoid cell line (LWA10) that produce human IgM lambda or IgM kappa anti-B lymphocyte autoantibodies, respectively. Immunohistochemical and multiparameter flow cytometric analyses demonstrate that these autoantibodies are specific for lymphocytes of the B lineage and preferentially stain B cells that reside in the mantle zone of secondary follicles and that constitutively co-express the CD5 surface antigen and most major autoantibody-associated cross-reactive idiotypes; in addition, these antibodies stain most pre-B cells in adult bone marrow. Molecular studies show that these anti-B lymphocyte autoantibodies are encoded by a highly conserved VH4 gene, designated VH4.21. The gene encodes a number of autoantibodies, especially anti-i and anti-I IgM cold agglutinins. Hemagglutination and surface labeling studies reveal that HY18 and LWA10 recognize the "i" carbohydrate antigenic determinant(s) which is classically found on human cord red blood cells and, as shown now by this study, on a subpopulation of human B cells which expresses it early in B cell development. These studies raise the possibility that the gene product encoded by this highly conserved germ-line VH4 gene may play a physiological role in B cell development and/or differentiation.

Amino Acid Sequence↗
PubMed1992

Transfer of human chronic lymphocytic leukemia to mice with severe combined immune deficiency.

B chronic lymphocytic leukemia (CLL) cells were transferred into mice with severe combined immunodeficiency (SCID). Leukemia cells injected into the peritoneal cavity of these animals may survive for at least 10 weeks in vivo. In contrast, leukemia cells do not survive for long periods when injected intravenously. Despite the longevity of CLL cells injected i.p., these cells apparently do not migrate to other lymphoid tissues. Eight to sixteen weeks after receiving CLL cells, SCID mice develop human IgG autoantibodies to human red blood cells and/or high serum levels of human Ig. Soon thereafter, these animals develop lethal human B-cell tumors. In contrast to the original CLL cells, these human B-cell tumors are CD5-negative, have genomic DNA of Epstein-Barr virus (EBV), express antigens associated with latent EBV infection and have distinctive Ig gene rearrangements by Southern. We conclude that bystander B cells may generate tumors in CLL-reconstituted SCID mice that emulate the EBV-associated lymphoproliferations noted in SCID mice reconstituted with normal human PBL.

Animals↗
PubMed1992

EBV-induced human B cell lymphomas in hu-PBL-SCID mice.

Epstein-Barr virus (EBV) infection is associated with Burkitt's lymphoma (BL) in normal individuals and immunoblastic B cell lymphomas in immunosuppressed or HIV-infected individuals. SCID mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID) from EBV-seropositive donors also may develop spontaneous B cell lymphomas which histologically and phenotypically resemble post-transplant tumors, and are distinct from BL. These tumors always contain EBV DNA. We have noted three different reproducible outcomes depending upon the EBV-seropositive donor used for generation of hu-PBL-SCID mice: (i) no tumors appear; (ii) tumors appear in a fraction of hu-PBL-SCID mice with a 10-20 wk. latent period; or (iii) tumors appear in all hu-PBL-SCID mice within 6-10 wk. Southern blot analysis of late versus early tumors using a probe specific for the EBV terminal repeat sequences (BamNJ), which allows distinction between circular latent and linear replicating genomes, shows that late tumors do not involve active EBV replication but that early tumors do show replicating genomes. In addition, EBV genomes were monoclonal in late tumors but polyclonal in early tumors. These data suggest two mechanisms for EBV lymphomagenesis, slow outgrowth of rare latently-infected B cells, and more rapid transformation of uninfected bystander B cells by replicating virus. The latter process may be highly amenable to therapy in patients at risk for EBV-related lymphomas. In addition, prospective screening of EBV-seropositive transplant recipients in the hu-PBL-SCID model may predict the risk of post-transplant lymphoma development.

Animals↗
PubMed1992

New developments in flow cytometric analyses of lymphocyte markers.

This article addresses several fundamental features of clinical flow cytometry. A practical overview of the technical and methodologic aspects of this fast-growing and increasingly important new clinical and investigative field is provided. The use of flow cytometry for the diagnosis and monitoring of various chronic lymphoproliferative diseases also is discussed. This article may serve as a useful guide to those seeking to set up or maintain a clinical flow cytometry laboratory.

Antibodies, Monoclonal↗
PubMed1991

Molecular characterization of a supratypic cross-reactive idiotype associated with IgM autoantibodies.

Neoplastic B cells from patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphomas (SLL) frequently express surface Ig reactive with the mouse mAb, Lc1. Raised against a human monoclonal IgM with rheumatoid factor activity, Lc1 detects a major cross-reactive Id (CRI) present on the H chain of many monoclonal IgM autoantibodies. In contrast to other major autoantibody-CRI investigated to date, we note that the Lc1-CRI is expressed by subpopulation of cells in the germinal centers, as well as in the mantle zones, of secondary human B cell follicles. To examine the molecular basis for Lc1 expression, we used the polymerase chain reaction to isolate the functionally rearranged Ig VH genes of monoclonal Lc1-reactive B cell populations from six unrelated patients with CLL or SLL. Although the neoplastic B cells from most patients with CLL or SLL express the CD5 surface differentiation Ag, the lymphoma cells from one patient with SLL were CD5-negative. We find that the Lc1-reactive cells from each cell population have Ig rearrangements involving a VH gene of the VH4 subgroup. However, the VH4 genes rearranged in different Lc1-reactive tumor populations may originate from at least two disparate germ-line VH4 genes. Also, in contrast to the CD5-positive tumor populations, we find evidence for intraclonal diversity in the functionally rearranged VH4 genes of the CD5-negative SLL. Collectively, this study discerns a degeneracy in the VH4 genes that can encode the Lc1 CRI, indicating the term "supratypic cross-reactive idiotype" may best describe the specificity of the Lc1 mAb. Also, this study suggests that expression of CD5 may delineate categories of B cell SLL that differ in their relative rates of constitutive Ig V gene somatic mutation.

Amino Acid Sequence↗
PubMed1991

Autoantibody-encoding kappa L chain genes frequently rearranged in lambda L chain-expressing chronic lymphocytic leukemia.

Patients with kappa L chain expressing chronic lymphocytic leukemia (CLL) frequently have leukemia cells reactive with a murine mAb, designated 17.109. Raised against a monoclonal IgM rheumatoid factor autoantibody, this mAb recognizes a major kappa-L chain-associated cross reactive Id, designated 17.109-CRI. Molecular studies reveal that the 17.109-CRI in CLL is a serologic marker for expression of a conserved kappa L chain V region gene (V Kappa gene) of the V Kappa 3 subgroup, designated Humkv325. We isolated an upstream gene fragment of Humkv325 to examine for Ig gene rearrangements of this and other closely related V Kappa 3 genes by Southern analyses. Consistent with Humkv325 encoding the 17.109-CRI, we find that the genomic DNA from all 17.109-reactive leukemia cell populations have gene rearrangements that are detected using this probe. In addition, we observe V Kappa 3 gene rearrangements frequently in the genomic DNA of lambda L chain-expressing leukemia cells. Of the genomic DNA from 33 lambda-L chain-expressing CLL samples, 8 (24%) had additional nongerm-line bands detected with the Humkv325 probe. Consistent with these bands representing Ig gene rearrangements, the additional band in each but one sample also hybridized with probes specific for the J Kappa region and/or the kappa-deleting element. Using the polymerase chain reaction (PCR), we examined the genomic DNA from all lambda L chain-expressing CLL for V Kappa 3 gene rearrangements to J Kappa and/or Kde. PCR on each DNA sample with V Kappa 3 gene rearrangements detected by Southern analysis generated gene fragments that hybridized specifically with oligonucleotides corresponding to framework or CDR of the Humkv325 gene. Nucleic acid sequence analyses of representative samples confirmed that these DNA contained abortive Humkv325 gene rearrangements. PCR for rearranged V Kappa 3 genes in the DNA of other lambda-L chain-expressing CLL either did not generate any PCR product or produced fragments that failed to hybridize with all Humkv325 oligonucleotide probes. Nucleic acid sequence analyses of the latter demonstrated that these represent abortive V Kappa gene rearrangements involving another conserved V Kappa 3 gene, designated Vg. These studies indicate that Humkv325 and Vg frequently may undergo Ig gene rearrangement independent of their expression. As such, the frequent use of Humkv325 in CLL may be secondary, in part, to an enhanced propensity of this V Kappa 3 gene to undergo genetic rearrangement during B cell ontogeny.

Amino Acid Sequence↗
PubMed1991

Idiotypic cross-reactivity of immunoglobulins expressed in Waldenström's macroglobulinemia, chronic lymphocytic leukemia, and mantle zone lymphocytes of secondary B-cell follicles.

Monoclonal antibodies (MoAbs) specific for autoantibody-associated cross-reactive idiotypes (CRIs) of Waldenström's IgM react frequently with the surface Ig (slg) expressed by leukemia cells of patients with chronic lymphocytic leukemia (CLL). Evaluation of the molecular basis for this cross-reactivity indicates that such CRIs are encoded by conserved antibody variable region genes (V genes) that have undergone little or no somatic hypermutation. We find that such anti-CRI MoAbs stain a subpopulation of cells within the mantle zones surrounding the germinal centers of normal human tonsil. In contrast, MoAbs specific for variable region subgroup determinants react with cells in both the mantle zones and germinal centers of secondary B-cell follicles. To test whether mantle zone B cells not reactive with existing anti-CRI MoAbs may express slg bearing as-yet-unrecognized CRIs present on Igs produced by neoplastic cells of some patients with Waldenström's macroglobulinemia or CLL, we immunized mice with purified Waldenström's IgM that have been characterized for their variable region subgroups using subgroup-specific antisera raised against synthetic peptides. The supernatants of hybridomas generated from the splenocytes of immunized mice were screened for their ability to stain a subpopulation of mantle zone lymphocytes in human tonsil. With this approach, two new anti-CRI MoAbs were identified, designated OAK1 and VOH3. OAK1 binds to a CRI present on a subset of kappa light chains of the VK1 subgroup. VOH3 recognizes a CRI determinant(s) present on a subset of antibody heavy chains of the VH3 subgroup. Flow cytometric analyses demonstrated that OAK1 specifically binds leukemia cells from 5 to 20 patients (25%) with kappa light chain expressing CLL. In addition, VOH3 reacted with the leukemia cells from 1 of 17 (6%) patients tested. The success of these methods demonstrates that the variable regions of the Igs produced by mantle zone B cells share idiotypic determinants with Igs expressed in B-cell CLL (B-CLL) and Waldenström's macroglobulinemia.

Antibodies, Monoclonal↗
PubMed1991

Relationship of the CD5 B cell to human tonsillar lymphocytes that express autoantibody-associated cross-reactive idiotypes.

We examined human tonsillar B cells for expression of autoantibody heavy-chain or kappa light-chain cross-reactive idiotypes (CRIs), respectively defined by murine MAbs G6 or 17.109. We find 17.109 or G6 each specifically binds a subpopulation of B cells, respectively reacting with 3.8 +/- 3% (mean +/- SD) or 2.0 +/- 1.2% of all tonsillar lymphocytes. Cells reactive with both 17.109 and G6 comprise only 0.4 +/- 0.3% of tonsillar lymphocytes. Although each tested specimen had 17.109-positive cells, 2 of 19 tonsils (11%) did not have any G6-reactive cells. We find that CRI-positive cells and CD5 B cells both co-express slgD but fail to bind peanut agglutinin or MAbs specific for CD10, indicating that both cell types reside in the mantle zones of secondary B cell follicles. However, less than half of the B cells bearing one or both of these CRIs express detectable levels of CD5. Nevertheless, we find that G6-reactive lymphocytes constitute a multiclonal population of cells that express homologous heavy chain variable region genes, each rearranged to one of several distinct and apparently nonmutated D and JH gene segments. Collectively, these studies indicate that expression of nondiversified autoantibody-encoding variable region genes may not be an exclusive property of B cells that bear detectable levels of the CD5 surface antigen.

Amino Acid Sequence↗