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Articles 181 - 207 of 207

Full-Text Articles in Medical Immunology

Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada Oct 1997

Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Ligation of B cell receptor (BCR) on BKS-2, an immature B cell lymphoma by anti-IgM antibodies (Ab) caused apoptosis. Here we report that signaling through B cell receptor in wild type BKS-2 cells down-regulated the expression of Egr-1, a zinc finger-containing transcription factor. A reduction in the level ofEgr-1 mRNA could be demonstrated as early as 30 min after the ligation of BCR on BKS-2 cells. Immunocytochemical and Western blot analysis revealed that the expression of EGR-1 protein was also inhibited by anti-IgM treatment. Antisense oligonucleotides to Egr-1 caused growth inhibition and apoptosis in BKS-2 cells, suggesting that …

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Metabolically Inactive Insulin Analog Prevents Type I Diabetes In Prediabetic Nod Mice, Dennis G. Karounos, J. Scott Bryson, D. A. Cohen Sep 1997

Metabolically Inactive Insulin Analog Prevents Type I Diabetes In Prediabetic Nod Mice, Dennis G. Karounos, J. Scott Bryson, D. A. Cohen

Internal Medicine Faculty Publications

The purpose of this study was to determine the relative importance of the metabolic effects of insulin for diabetes prevention by administering insulin or an inactive insulin analog by daily subcutaneous injections to prediabetic mice. A recombinant monomeric human insulin analog, which does not bind to the insulin receptor as a consequence of an alteration of a single amino acid at position 25 of the B chain, was shown to be equally effective at diabetes prevention as was intact insulin. In contrast to native insulin, the insulin analog did not cause hypoglycemia after subcutaneous injection. The insulin analog, however, protected …

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Identification Of A Gal/Galnac Lectin In The Protozoan Hartmannella Vermiformis As A Potential Receptor For Attachment And Invasion By The Legionnaires' Disease Bacterium, Chandrasekar Venkataraman, Bradley J. Haack, Subbarao Bondada, Yousef Abu Kwaik Aug 1997

Identification Of A Gal/Galnac Lectin In The Protozoan Hartmannella Vermiformis As A Potential Receptor For Attachment And Invasion By The Legionnaires' Disease Bacterium, Chandrasekar Venkataraman, Bradley J. Haack, Subbarao Bondada, Yousef Abu Kwaik

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Legionnaire's disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen which invades and replicates within two evolutionarily distant hosts, free-living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaire's disease. Although attachment and invasion of human macrophages by L. pneumophila is mediated in part by the complement receptors CR1 and CR3, the protozoan receptor involved in bacterial attachment and invasion has not been identified. To define the molecular events involved in invasion of protozoa by L. pneumophila, we examined the role of protein tyrosine phosphorylation …

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Anti-Idiotype Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon Mar 1997

Anti-Idiotype Monoclonal Antibody 1a7 And Use For The Treatment Of Melanoma And Small Cell Carcinoma, Malaya Chatterjee, Kenneth A. Foon

Microbiology, Immunology and Molecular Genetics Faculty Patents

The present invention relates isolation of anti-idiotypic antibody 1A7 raised against anti-GD2 mAb 14G2a and its use for the treatment of melanoma and small cell carcinoma. The antibody may be used as a substitute for isolated purified GD2 antigen in any appropriate application.

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Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada Jan 1997

Role Of Egr-1 Gene Expression In B Cell Receptor-Induced Apoptosis In An Immature B Cell Lymphoma, Subramanian Muthukkumar, Seong-Su Han, Sumathi Muthukkumar, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Ligation of B cell receptor (BCR) on BKS-2, an immature B cell lymphoma by anti-IgM antibodies (Ab) caused apoptosis. Here we report that signaling through B cell receptor in wild type BKS-2 cells down-regulated the expression of Egr-1, a zinc finger-containing transcription factor. A reduction in the level of Egr-1 mRNA could be demonstrated as early as 30 min after the ligation of BCR on BKS-2 cells. Immunocytochemical and Western blot analysis revealed that the expression of EGR-1 protein was also inhibited by anti-IgM treatment. Antisense oligonucleotides to Egr-1 caused growth inhibition and apoptosis in BKS-2 cells, suggesting that expression …

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Cellular Basis Of Decreased Immune Responses To Pneumococcal Vaccines In Aged Mice, Manju Garg, Wei Luo, Alan M. Kaplan, Subbarao Bondada Nov 1996

Cellular Basis Of Decreased Immune Responses To Pneumococcal Vaccines In Aged Mice, Manju Garg, Wei Luo, Alan M. Kaplan, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previously, model systems were developed in our laboratory to study murine immune responses to the 23-valent pneumococcal polysaccharide vaccine Pnu-Imune, both in vivo and in vitro (M. Garg and B. Subbarao, Infect. Immun. 60:2329-2336, 1992; M. Garg, A. M. Kaplan, and S. Bondada, J. Immunol. 152: 1589-1596, 1994). Using these systems, we found that aged mice did not respond to the vaccine in vivo or in vitro. Cell separation studies showed that the unresponsiveness of the aged spleen cells to the vaccine was not due to an intrinsic B-cell defect or to T-cell-mediated immunosuppression but resulted from an accessory cell …

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Involvement Of P59FynT In Interleukin-5 Receptor Signaling, Mark W. Appleby, James D. Kerner, Sylvia Chien, Charles R. Maliszewski, Subbarao Bondada, Roger M. Perlmutter Sep 1995

Involvement Of P59FynT In Interleukin-5 Receptor Signaling, Mark W. Appleby, James D. Kerner, Sylvia Chien, Charles R. Maliszewski, Subbarao Bondada, Roger M. Perlmutter

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previous studies implicate the nonreceptor protein tyrosine kinase (PTK) p59fyn in the propagation of signals from the B cell antigen receptor. To elucidate the functions of this kinase, we examined B cell responsiveness in mice engineered to lack the hematopoietic isoform of p59fyn. Remarkably, antigen receptor signaling was only modestly defective in fynTnull B cells. In contrast, signaling from the interleukin (IL)-5 receptor which ordinarily provides a comitogenic stimulus with antiimmunoglobulin, was completely blocked. Our results document the importance of p59fynT in IL-5 responses in B cells, and they support a general model …

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Identification Of An Idiotypic Peptide Recognized By Autoantibodies In Human Immunodeficiency Virus-1-Infected Individuals, Q. L. Wang, H.-T. Wang, Edwin Blalock, Sybille Müller, Heinz Köhler Aug 1995

Identification Of An Idiotypic Peptide Recognized By Autoantibodies In Human Immunodeficiency Virus-1-Infected Individuals, Q. L. Wang, H.-T. Wang, Edwin Blalock, Sybille Müller, Heinz Köhler

Markey Cancer Center Faculty Publications

Antibodies against HIV-1 proteins in HIV-1-infected individuals share a cross-reactive idiotype defined by the monoclonal antiidiotypic antibody 1F7 (5). Using a computer algorithm based on the molecular recognition theory, regions of inverse hydropathy between the variable sequence of 1F7 and human monoclonal anti-HIV-1 antibodies were identified, which are assumed to be involved in idiotype-antiidiotype contacts. A peptide was designed from the proposed contact in the variable heavy chain framework 3-complementarity determining region 3 (FR3-CDR3) of human antibodies and was synthesized. This peptide is recognized by the antiidiotype 1F7 and inhibits the binding of 1F7 to human anti-HIV-1 antibodies which express …

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Immune Response To The Carcinoembryonic Antigen In Patients Treated With An Anti-Idiotype Antibody Vaccine, Kenneth A. Foon, Mala Chakraborty, William J. John, Amanda Sherratt, Heinz Köhler, Malaya Bhattacharya-Chatterjee Jul 1995

Immune Response To The Carcinoembryonic Antigen In Patients Treated With An Anti-Idiotype Antibody Vaccine, Kenneth A. Foon, Mala Chakraborty, William J. John, Amanda Sherratt, Heinz Köhler, Malaya Bhattacharya-Chatterjee

Markey Cancer Center Faculty Publications

We have generated an IgG1 murine monoclonal anti-idiotype antibody (Ab2) designated 3H1, which mimics a specific epitope on the carcinoembryonic antigen (CEA). Patients with CEA positive tumors are immunologically "tolerant" to CEA. We used 3H1 as a surrogate for CEA for vaccine therapy of 12 patients with advanced colorectal cancer. Each of the patients received a minimum of four intracutaneous injections of aluminum hydroxide precipitated 3H1 at either 1, 2, or 4 mg dosage per injection. 9 of 12 patients demonstrated anti-anti-idiotypic (Ab3) response to 3H1. All nine patients generated specific anti-CEA antibody demonstrated by reactivity with radiolabeled purified CEA; …

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Enhanced Immunogenicity Of Protein-Dextran Conjugates: I. Rapid Stimulation Of Enhanced Antibody Responses To Poorly Immunogenic Molecules, Andrew Lees, Fred Finkelman, John K. Inman, Kim Witherspoon, Penny Johnson, Jasiri Kennedy, James J. Mond Jan 1994

Enhanced Immunogenicity Of Protein-Dextran Conjugates: I. Rapid Stimulation Of Enhanced Antibody Responses To Poorly Immunogenic Molecules, Andrew Lees, Fred Finkelman, John K. Inman, Kim Witherspoon, Penny Johnson, Jasiri Kennedy, James J. Mond

Microbiology, Immunology, and Molecular Genetics Faculty Publications

In view of our observation that anti-immunoglobulin antibody conjugated to high-molecular-weight dextran stimulates high levels of B-cell activation (Brunswick et al. J. Immunol . 1989, 143, 1239), we coupled T cell-dependent antigens to dextran. When mice were immunized, in the absence of adjuvant, with a BSA-dextran conjugate (BSA-dex), a persistent, high-titre anti-BSA IgG1 response was induced. Titres were dose-dependent and seen with as little as 10 I~g of conjugated protein. Anti-BSA titres were detected as early as day 7, usually peaked at about day 14 and persisted for at least 4 weeks. Anti-hapten antibodies were also elicited in mice that …

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Reversal Of Age-Associated Decline In Immune Response To Pnu-Imune Vaccine By Supplementation With The Steroid Hormone Dehydroepiandrosterone, Manju Garg, Subbarao Bondada May 1993

Reversal Of Age-Associated Decline In Immune Response To Pnu-Imune Vaccine By Supplementation With The Steroid Hormone Dehydroepiandrosterone, Manju Garg, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Recently, we reported that murine antibody responses to the 23-valent pneumococcal polysaccharide (Pnu-Imune) vaccine declined with age. Here we present data to support the concept that age-associated immune defects are not only due to intrinsic defects in immune cells but are also due to extrinsic factors emanating from the neuroendocrine system. We found that supplementation with dehydroepiandrosterone, a steroid hormone known to be reduced in the aged, corrects the immune deficiency of aged mice and significantly enhanced their splenic immune responses to the Pnu-Imune vaccine.

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Immune Responses Of Systemic And Mucosal Lymphoid Organs To Pnu-Imune Vaccine As A Function Of Age And The Efficacy Of Monophosphoryl Lipid A As An Adjuvant, Manju Garg, Subbarao Bondada Jun 1992

Immune Responses Of Systemic And Mucosal Lymphoid Organs To Pnu-Imune Vaccine As A Function Of Age And The Efficacy Of Monophosphoryl Lipid A As An Adjuvant, Manju Garg, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A murine model system was established to study immune responses to the Pnu-Imune vaccine, which is made up of 23 different pneumococcal capsular polysaccharides. In this animal model, antibody-forming cell responses to 21 of 23 individual polysaccharides in the vaccine were detected. The Pnu-Imune vaccine elicited good antibody responses from the spleens and mesenteric lymph nodes (MLN) of young mice, whereas a variety of other peripheral lymph nodes were unresponsive. The immunoglobulin M plaque-forming cell (PFC) response in the spleen to the Pnu-Imune vaccine (given intraperitoneally or subcutaneously) decreased dramatically with increasing age. However, the spleen and MLN differed in …

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Priming Of Peripheral Lymph Node B Cells With Tnp-Ficoll: Role Of Lymphokines In B Cell Differentiation, S. Niranjan Goud, Alan M. Kaplan, Subbarao Bondada Jan 1992

Priming Of Peripheral Lymph Node B Cells With Tnp-Ficoll: Role Of Lymphokines In B Cell Differentiation, S. Niranjan Goud, Alan M. Kaplan, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We have previously shown that peripheral lymph node (PLN) B lymphocytes of adult DBA/ 25 mice failed to make an antibody responseto type 2 antigen TNP-Ficoll, but exhibited a good antibody response to type 1 antigen TNP-BruceNa abortus. In the present study we wanted to find out whether the unresponsivenessof PLN B cells to TNP-Ficoll is due to defectsin the early activation and proliferation stage or in the final differentiation stageof B cells. Therefore, we have used a two-step protocol of in vivo immunization of mice with TNP-Ficoll and the subsequent in vitro challenge with TNP-Brucella abortus and studied the …

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Physiology Of Murine B Lymphocytes Ii. Life-Spans Of Mitogen And Thymus-Independent Antigen (Type 2) Reactive B Lymphocytes From Aged Mice, Venkatachalam Udhayakumar, S. Niranjan Goud, Richard J. Cross, Subbarao Bondada Jan 1991

Physiology Of Murine B Lymphocytes Ii. Life-Spans Of Mitogen And Thymus-Independent Antigen (Type 2) Reactive B Lymphocytes From Aged Mice, Venkatachalam Udhayakumar, S. Niranjan Goud, Richard J. Cross, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We showed earlier that life spans of murine B lymphocytes could be estimated by measuring the functional reactivities of normal B cells upon transfer into x-linked immunodeficient (xid) mice, which do not respond to anti-mouse IgM (anti-μ) antibodies and thymic-independent type -2 (TI-2) antigens. Here the same approach was adopted, to evaluate the life spans of B-lymphocytes from aged mice. Spleen cells from normal young and aged mice were transferred into young or aged xid recipients and the decay kinetics were followed by measuring the proliferative response to anti-μ and PFC response to TNP-Ficoll, a prototype TI-2 antigen. The results …

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Inability Of Mitogen-Activated Lymphocytes Obtained From Patients With Malignant Primary Intracranial Tumors To Express High Affinity Interleukin 2 Receptors, Lucinda H. Elliott, W. H. Brooks, T. L. Roszman Jul 1990

Inability Of Mitogen-Activated Lymphocytes Obtained From Patients With Malignant Primary Intracranial Tumors To Express High Affinity Interleukin 2 Receptors, Lucinda H. Elliott, W. H. Brooks, T. L. Roszman

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Patients with primary malignant brain tumors manifest a variety of abnormalities in cell-mediated and humoral immunity. Diminished T cell reactivity has been shown in these patients to be linked to deficiencies in interleukin 2 (IL-2) production that cannot be overcome by exogenous IL-2. In this study, specific binding of radiolabeled IL-2 to PHA-stimulated lymphocytes from brain tumor patients demonstrates that the number of high affinity interleukin 2 receptors (IL-2R) is greatly reduced. FACS analysis indicates that the relative density of the p55 protein (Tac protein) is lower on the mitogen-activated lymphocytes obtained from patients than on comparably treated lymphocytes from …

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Macrophages But Not B Cells From Aged Mice Are Defective In Stimulating Autoreactive T Cells In Vitro, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti, Subbarao Bondada, Venkatachalam Udhayakumar Jan 1990

Macrophages But Not B Cells From Aged Mice Are Defective In Stimulating Autoreactive T Cells In Vitro, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti, Subbarao Bondada, Venkatachalam Udhayakumar

Microbiology, Immunology, and Molecular Genetics Faculty Publications

In the present study the effect of aging on the capacity of Ia+ cells to stimulate autoreactive T cells in the syngeneic mixed lymphocyte reaction (SMLR) was investigated. Using young CD4+ T cells as responders, it was observed that unseparated whole spleen cells from aged mice had normal stimulatory activity comparable to that of young spleen cells. Interestingly, however, when purified splenic adherant cells (SAC) enriched for macrophages or splenic B cells were used as stimulators, aged SAC but not aged B cells were found to be defective in stimulating autoreactive T cells. This defect in aged SAC …

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Phenotypic And Functional Properties Of B Lymphocytes From Aged Mice, Subbarao Bondada, Joan Morris, Richard J. Kryscio Jan 1990

Phenotypic And Functional Properties Of B Lymphocytes From Aged Mice, Subbarao Bondada, Joan Morris, Richard J. Kryscio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Phenotypic and functional properties of B lymphocytes from individual young and old mice of different inbred strains were studied. B lymphocyte subpopulation defined by the ratios of the densities of cell surface IgM and IgD were found to be altered with age. However, such alterations in B cell subsets were found only in 30-40% of the old mice. B cell mitogenic responses to anti-μ and anti-Lyb2 antibodies were decreased in a majority of DBA/2 mice. Proliferative responses to LPS and antiμ were reduced only in a minority of CBA/Ca mice but there was a very good correlation in the responsiveness …

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Isolation And Immunological Characterization Of A Group Of New B Lymphomas From Cba Mice, Venkatachalam Udhayakumar, Peter H. Brodeur, M. S. Rajagopalan, Stephen Zimmer, Karen E. Pollok, Subbarao Bondada Jan 1989

Isolation And Immunological Characterization Of A Group Of New B Lymphomas From Cba Mice, Venkatachalam Udhayakumar, Peter H. Brodeur, M. S. Rajagopalan, Stephen Zimmer, Karen E. Pollok, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We have isolated and characterized a new series of B lymphomas which occurred spontaneously in a group of CBA N mice that were transferred with spleen or lymph node cells from 24-month-old CBA Ca mice. Tumor cell lines from six CBA N mice that received spleen cells were rescued and designated as BKS-2, BKS-3, BKS-4, BKS-5, BKS-6, and BKS-7. Also, tumor cells from a recipient of lymph node cells were rescued and the resulting cell line was designated BKL. These tumor cells expressed membrane immunoglobulin (μ,κ), major histocompatibility complex Class I and Class II molecules, B220, Lyb8, Fc receptors, J11d, …

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A Specific Defect In The Proliferative Capacity Of B Cells From Old Mice Stimulated With Autoreactive T Cells, Prakash S. Nagarkatti, Aruna Seth, Mitzi Nagarkatti, Natarajan Muthusamy, Barbara Rychlik, Subbarao Bondada Jan 1989

A Specific Defect In The Proliferative Capacity Of B Cells From Old Mice Stimulated With Autoreactive T Cells, Prakash S. Nagarkatti, Aruna Seth, Mitzi Nagarkatti, Natarajan Muthusamy, Barbara Rychlik, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B lymphocytes from aged mice were found to be defective in their ability to proliferate in response to stimulation with an autoreactive T cell clone D1.4. The differentiative response leading to antibody secretion was also impaired in the auto D1.4 T cell-stimulated B cells from old mice in comparison to similarly stimulated B cells from young mice. The B cells from old mice were competent in activating the autoreactive T cells such that the T cells were induced to proliferate. The B cell defect appears to be restricted to a certain phase of B cell activation, since old mouse B …

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Properties Of Anti-Lyb-2-Mediated B-Cell Activation And The Relationship Between Lyb-2 Molecules And Receptors For B-Cell Stimulatory Factor-1 On Murine B Lymphocytes, Subbarao Bondada, Joan Morris, A. R. Baluyut Jan 1988

Properties Of Anti-Lyb-2-Mediated B-Cell Activation And The Relationship Between Lyb-2 Molecules And Receptors For B-Cell Stimulatory Factor-1 On Murine B Lymphocytes, Subbarao Bondada, Joan Morris, A. R. Baluyut

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The murine B-cell differentiation antigen Lyb-2 has been shown to be involved in B-lymphocyte activation and has been postulated by some to be related to a receptor for B-cell stimulatory factor I (BSF-1) (H. Yakura et al., J. Immunol. 137, 1475, 1986). Here we have demonstrated that monoclonal antibody (mAB) to Lyb-2 resembles BSF-1 in its ability to activate small resting B cells and enhancement of surface Ia. Anti-Lyb-2 antibodies bound B cells with very high avidity and were able to induce mobilization of cytosolic-free calcium. Anti-Lyb-2 mAB differs from BSF-1 in that BSF-1 but not anti-Lyb-2 is able to …

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Impaired Autoreactive T Cell-Induced T Cell-T Cell Interaction In Aged Mice, Venkatachalam Udhayakumar, Subbarao Bondada, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti Jan 1988

Impaired Autoreactive T Cell-Induced T Cell-T Cell Interaction In Aged Mice, Venkatachalam Udhayakumar, Subbarao Bondada, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Self-Ia-reactive (autoreactive) L3T4+ T cell clones have been shown earlier to stimulate the proliferation of syngeneic naive L3T4+ T cells and initiate a T cell-T cell (T-T) interaction leading to the generation of immunoregulatory circuits. Since aging has been shown to be associated with a decline of the immune responsiveness, age-related alterations in the T-T interaction was investigated in the present study. Using several I-Ed-specific autoreactive T cell clones isolated from 2- to 3-month-old (young) DBA/2 mice as stimulators, it was observed that L3T4+ T cells from 22- to 24-month-old (aged) DBA/2 mice, failed to …

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Early Events In B-Cell Activation: Anti-Lyb2, But Not Bsf-1, Induces A Phosphatidylinositol Response In Murine B Cells, Stephan A. Grupp, Judith A. K. Harmony, Arthur R. Baluyut, Subbarao Bondada Jan 1987

Early Events In B-Cell Activation: Anti-Lyb2, But Not Bsf-1, Induces A Phosphatidylinositol Response In Murine B Cells, Stephan A. Grupp, Judith A. K. Harmony, Arthur R. Baluyut, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previous studies have indicated that the murine surface antigen Lyb2 is involved in an activation pathway that apparently does not involve the surface immunoglobulin receptor. As sIg has been shown to transduce its activation signal through the breakdown of phosphatidylinositol (PI), and since activation via Lyb2 does not involve sIg, it was of interest to determine if binding to Lyb2 generates a PI response. We have demonstrated that an allele-specific monoclonal antibody to Lyb2 (anti-Lyb2 mab), which has previously been shown to drive B cells into S, also activated PI metabolism in these cells. This activation occurred in a dose-dependent …

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Activation Of B Lymphocytes By Monovalent Anti-Lyb-2 Antibodies, Subbarao Bondada, D. E. Mosier Jan 1984

Activation Of B Lymphocytes By Monovalent Anti-Lyb-2 Antibodies, Subbarao Bondada, D. E. Mosier

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Small resting B lymphocytes are activated when their cell surface immuno-globulin (Ig) receptors interact with specific antigen or anti-Ig antibodies. Such a receptor-ligand interaction leads to enlargement and proliferation of B lymphocytes. These activated B cells can subsequently mature into Ig-secreting cells in the presence of appropriate accessory cell signals (1-3). However, monovalent anti-Ig antibodies cannot induce B cell activation even though they can bind to the surface Ig (4-7). It has thus been concluded that membrane Ig has to be cross-linked to induce early steps in B cell activation (membrane depolarization; 8) as well as later steps (proliferation). T …

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Role Of A Nonimmunoglobulin Cell Surface Determinant In The Activation Of B Lymphocytes By Thymus-Independent Antigens*, Subbarao Bondada, Donald E. Mosier, Aftab Ahmed, James J. Mond, Irwin Scher, William E. Paul Jan 1979

Role Of A Nonimmunoglobulin Cell Surface Determinant In The Activation Of B Lymphocytes By Thymus-Independent Antigens*, Subbarao Bondada, Donald E. Mosier, Aftab Ahmed, James J. Mond, Irwin Scher, William E. Paul

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Lyb 5 is a B-cell alloantigen which is expressed on 50-60% of B cells. It was defined originally on the basis of cytotoxicity. We have described a new reactivity within the anti-Lyb 5 serum on the basis of selective inhibition of antibody responses in vitro by this antiserum in the absence of complement. This inhibitory activity of anti-Lyb 5.1 serum appears to be due to recognition of antigenic determinants different from the prototype antigens detected in the cytotoxicity assay. Anti-Lyb 5 serum incorporated into spleen cell cultures selectively inhibits antibody responses to a class of thymus-independent antigens (TI-2) previously characterized …

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Tritium (3h) Radiolabeling Of Protein A And Antibody To High Specific Activity: Application To Cell Surface Antigen Radioimmunoassays, Ronald L. Wilder, Catherine C. Yuen, Subbarao Bondada, Virgil L. Woods, Cornelius B. Alexander, Rose G. Mage Jan 1979

Tritium (3h) Radiolabeling Of Protein A And Antibody To High Specific Activity: Application To Cell Surface Antigen Radioimmunoassays, Ronald L. Wilder, Catherine C. Yuen, Subbarao Bondada, Virgil L. Woods, Cornelius B. Alexander, Rose G. Mage

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Staphylococcal protein A and several different immunoglobulins have been radio-labeled to high specific activities (> 106 cpm/pg) by reductive methylation with tritiated (3H) sodium borohydride. The proteins retain excellent functional and antigenic properties. The utility of these reagents in a variety of assays for cell surface antigens is illustrated. The results indicate that this radiolabeling procedure may become the method of choice for many cell surface and solution immunoassays.

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Inactivation Of Brain Hexokinase By An Adenosine 5'-Triphosphate Analog, Subbarao Bondada, Umakant W. Kenkare Jan 1977

Inactivation Of Brain Hexokinase By An Adenosine 5'-Triphosphate Analog, Subbarao Bondada, Umakant W. Kenkare

Microbiology, Immunology, and Molecular Genetics Faculty Publications

An analog of ATP, 6-mercapto-9+nribofuranosylpurine 5’-triphosphate (SH-TP), functions as a phosphoryl donor for the reaction catalyzed by hexokinase. Incubation of the enzyme with millimolar concentrations of this reagent led to its rapid inactivation. However, the corresponding monophosphate derivative of this reagent was much less effective. A plot of the initial rate of inactivation versus the concentration of SH-TP exhibited saturation, suggesting the formation of a reversible complex between the enzyme and SH-TP prior to the inactivation reaction. The dissociation constant of this enzyme-inhibitor complex was the same as the K, of this reagent with respect to hexokinase in the phosphoryl …

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Reaction Of Brain Hexokinase With Tetranitromethane: Oxidation Of Essential Thiol Groups, Subbarao Bondada, Umakant W. Kenkare Jan 1977

Reaction Of Brain Hexokinase With Tetranitromethane: Oxidation Of Essential Thiol Groups, Subbarao Bondada, Umakant W. Kenkare

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Treatment of bovine brain mitochondrial hexokinase with a fivefold molar excess of tetranitromethane (TNM) at pH 8.0 results in a complete loss of activity of the enzyme. Spectral measurements and amino acid analysis showed that only cysteinyl residues were modified by TNM under these conditions. The products of the reaction of TNM with the enzyme were cysteic acid and disulfides as found by amino acid analysis of the carboxymethylated hexokinase. Failure of 2-mercaptoethanol to reverse the effect of TNM suggested that the thiol group that is oxidized to cysteic acid is the one essential for enzyme activity. Substrates glucose and …

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