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Articles 661 - 690 of 692

Full-Text Articles in Medical Microbiology

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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Toxoplasma Gondii-Induced Immune Suppression By Human Peripheral Blood Monocytes: Role Of Gamma Interferon., Jacqueline Y. Channon, Lloyd H. Kasper Apr 1996

Toxoplasma Gondii-Induced Immune Suppression By Human Peripheral Blood Monocytes: Role Of Gamma Interferon., Jacqueline Y. Channon, Lloyd H. Kasper

Dartmouth Scholarship

The ability of Toxoplasma gondii to evade the host immune response during primary infection in humans is poorly understood. In murine toxoplasmosis, infected spleen macrophages release soluble factors that mediate a transient immunosuppression, which may allow the parasite to become established. When an enriched population of human monocytes from seronegative individuals was incubated with toxoplasmas in vitro, soluble factors that mediated market suppression of mitogen-induced lymphocyte DNA synthesis were released. Irradiated tachyzoites that do not undergo replication were sufficient stimuli for near-maximal soluble factor release. Up to 50% of the soluble factor-mediated suppression is attributable to a gamma interferon (IFN-gamma)-dependent …

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Antibody To The Ligand For Cd40 (Gp39) Inhibits Murine Aids-Associated Splenomegaly, Hypergammaglobulinemia, And Immunodeficiency In Disease-Susceptible C57bl/6 Mice., Kathy A. Green, Karen M. Crassi, Jon D. Laman, Arjan Schoneveld, Rendall R. Strawbridge, Teresa M. Foy, Randolph J. Noelle, William R. Green Apr 1996

Antibody To The Ligand For Cd40 (Gp39) Inhibits Murine Aids-Associated Splenomegaly, Hypergammaglobulinemia, And Immunodeficiency In Disease-Susceptible C57bl/6 Mice., Kathy A. Green, Karen M. Crassi, Jon D. Laman, Arjan Schoneveld, Rendall R. Strawbridge, Teresa M. Foy, Randolph J. Noelle, William R. Green

Dartmouth Scholarship

Infection of genetically susceptible C57BL/6 mice with the LP-BM5 isolate of murine retroviruses cause profound splenomegaly, hypergammaglobulinemia, lymphadenopathy, and an immunodeficiency syndrome which includes the development of terminal B-cell lymphomas. Because many of these and the other manifestations of LP-BM5 virus-induced disease are similar to those seen in AIDS, this syndrome has been named murine AIDS, or MAIDS. Previous reports have shown that the onset of MAIDS depends on the presence of both CD41 T cells and B cells and have suggested that CD41 T-cell-B-cell interactions are important to disease pathogenesis. Here, we assessed the possibility that interactions between CD40 …

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Survival Of Immunoglobulin G-Opsonized Toxoplasma Gondii In Nonadherent Human Monocytes., Camilo E. Fadul, Jacqueline Y. Channon, Lloyd H. Kasper Nov 1995

Survival Of Immunoglobulin G-Opsonized Toxoplasma Gondii In Nonadherent Human Monocytes., Camilo E. Fadul, Jacqueline Y. Channon, Lloyd H. Kasper

Dartmouth Scholarship

Toxoplasma gondii is a protozoan parasite that is able to penetrate human monocytes by either passive uptake during phagocytosis or active penetration. It is expected that immunoglobulin G (IgG) opsonization will target the parasite to macrophage Fc gamma receptors for phagocytic processing and subsequent degradation. Antibody-opsonized T. gondii tachyzoites were used to infect nonadherent and adherent human monocytes obtained from the peripheral blood of seronegative individuals. The infected monocytes were evaluated for the presence of intracellular parasites and the degree of parasiticidal activity. A marked difference in both the numbers of infected macrophages and numbers of parasites per 100 macrophages …

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A Toxoplasma Gondii-Derived Factor(S) Stimulates Immune Downregulation: An In Vitro Model., Sakhina Haque, Azizul Haque, Lloyd H. Kasper Sep 1995

A Toxoplasma Gondii-Derived Factor(S) Stimulates Immune Downregulation: An In Vitro Model., Sakhina Haque, Azizul Haque, Lloyd H. Kasper

Dartmouth Scholarship

Suppression of the T-cell lymphoproliferative response and downregulation of interleukin 2 (IL-2) production by Toxoplasma gondii has been observed following in vivo infection. In this study, an experimental in vitro murine system was developed to evaluate the kinetics of these responses. Normal splenocytes from uninfected mice were stimulated with either concanavalin A or an anti-CD3 monoclonal antibody and cocultured with Toxoplasma tachyzoites either directly or separated by a transwell. A progressive decline in the lymphoproliferative response was observed as the concentration of parasites in culture increased. Neither heat-killed nor formaldehyde-fixed parasites stimulated this downregulatory response by the splenocytes. A decline …

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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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A Novel Translational Regulation Function For The Simian Virus 40 Large-T Antigen Gene., Prithi Rajan, Sathyamagalam Swaminathan, Jiyue Zhu, Charles N. Cole Feb 1995

A Novel Translational Regulation Function For The Simian Virus 40 Large-T Antigen Gene., Prithi Rajan, Sathyamagalam Swaminathan, Jiyue Zhu, Charles N. Cole

Dartmouth Scholarship

Cells use the interferon-induced, double-stranded-RNA-dependent protein kinase PKR as a defense against virus infections. Upon activation, PKR phosphorylates and thereby inactivates the protein synthesis initiation factor eIF-2, resulting in the cessation of protein synthesis. Viruses have evolved various strategies to counteract this cellular defense. In this paper, we show that simian virus 40 (SV40) large-T antigen can antagonize the translational inhibitory effect resulting from the activation of PKR in virus-infected cells. Unlike the situation with other virus-host cell interactions, SV40 large-T antigen does not block the activation of PKR, suggesting that SV40 counteracts the cellular antiviral response mediated by PKR …

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Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi Jul 1994

Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi

Dartmouth Scholarship

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.

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Comparison Of Cytotoxic Properties Of Neonatal And Adult Neutrophils And Monocytes And Enhancement By Cytokines., E . R. Stiehm, R. L. Roberts, B. J. Ank, S. Plaeger-Marshall, N. Salman, L. Shen, M. W. Fanger May 1994

Comparison Of Cytotoxic Properties Of Neonatal And Adult Neutrophils And Monocytes And Enhancement By Cytokines., E . R. Stiehm, R. L. Roberts, B. J. Ank, S. Plaeger-Marshall, N. Salman, L. Shen, M. W. Fanger

Dartmouth Scholarship

We studied cytotoxic capabilities of newborn polymorphonuclear leukocytes (PMNs) and monocytes and their enhancement by cytokines and antibodies. Umbilical cord PMNs were assessed for their ability to kill various target cells spontaneously, after activation with phorbol myristate acetate, in the presence of antiserum (antibody-dependent cellular cytotoxicity), and in the presence of dually specific antibody (heteroantibody-mediated cytotoxicity). Target cells included the K562 cell line (natural killer cell target), chicken erythrocytes (CRBCs), and herpes simplex virus-infected CEM cell lines. Newborn PMNs were equivalent to adult PMNs in their cytotoxic capacity in several cytotoxicity assays. Neither adult nor newborn PMNs lyse tumor cell …

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Interleukin-12 Enhances Murine Survival Against Acute Toxoplasmosis., Imtiaz A. Khan, Tadashi Matsuura, Lloyd H. Kasper May 1994

Interleukin-12 Enhances Murine Survival Against Acute Toxoplasmosis., Imtiaz A. Khan, Tadashi Matsuura, Lloyd H. Kasper

Dartmouth Scholarship

Protective immunity against Toxoplasma gondii is mediated by the host cellular immune response. Interleukin-12 (IL-12), a recently described cytokine that stimulates NK cells to produce gamma interferon (IFN-gamma), is able to enhance host protection against this parasite in SCID mice. Administration of IL-12 to A/J mice significantly increased survival over that of control mice when IL-12 was delivered early in the course of acute infection. If it was administered at day 3 or thereafter, there was no observed difference in mortality between treated and control mice. Antibody depletion of IL-12 increased susceptibility to infection, as measured by mortality, only when …

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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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Antiparasitic And Antiproliferative Effects Of Indoleamine 2,3-Dioxygenase Enzyme Expression In Human Fibroblasts., Sohan L. Gupta, Joseph M. Carlin, Padma Pyati, Wei Dai, Elmer R. Pfefferkorn, Martin J. Murphy Jr Jan 1994

Antiparasitic And Antiproliferative Effects Of Indoleamine 2,3-Dioxygenase Enzyme Expression In Human Fibroblasts., Sohan L. Gupta, Joseph M. Carlin, Padma Pyati, Wei Dai, Elmer R. Pfefferkorn, Martin J. Murphy Jr

Dartmouth Scholarship

Studies were carried out to evaluate the proposed role of indoleamine 2,3-dioxygenase (INDO) induction in the antimicrobial and antiproliferative effects of gamma interferon (IFN-gamma) in human fibroblasts. The INDO cDNA coding region was cloned in the pMEP4 expression vector, containing the metallothionein (MTII) promoter in the sense (+ve) or the antisense (-ve) orientation. Human fibroblasts (GM637) stably transfected with the sense construct expressed INDO activity after treatment with CdCl2 or ZnSO4, but cells transfected with the antisense construct did not. The growth of Chlamydia psittaci was strongly inhibited in INDO +ve cells but not in INDO -ve cells after treatment …

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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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Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green May 1992

Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green

Dartmouth Scholarship

LP-BM5 retrovirus complex-infected C57BL/6 mice develop immunodeficiency, somewhat analogous to AIDS, termed murine AIDS (MAIDS). After secondary stimulation with syngeneic B-cell lymphomas from LP-BM5-infected mice, C57BL/6 mice produced vigorous CD8+ cytotoxic T lymphocytes specific for MAIDS-associated tumors. An anti-LP-BM5 specificity was suggested because spleen and lymph node cells from LP-BM5-infected mice served as target cells in competition assays, and cells from LP-BM5, but not ecotropic, virus-infected mice functioned as secondary in vitro stimulators to generate cytotoxic T lymphocytes to MAIDS tumors.

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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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Murine Gamma Interferon Fails To Inhibit Toxoplasma Gondii Growth In Murine Fibroblasts., Joseph D. Schwartzman, Steven L. Gonias, E R. Pfefferkorn Mar 1990

Murine Gamma Interferon Fails To Inhibit Toxoplasma Gondii Growth In Murine Fibroblasts., Joseph D. Schwartzman, Steven L. Gonias, E R. Pfefferkorn

Dartmouth Scholarship

Although treatment of human macrophages or fibroblasts with human gamma interferon results in the inhibition of intracellular Toxoplasma gondii, murine gamma interferon stimulated only murine macrophages, not murine fibroblasts, to inhibit T. gondii. This species difference may be important in understanding the control of acute and chronic toxoplasmosis.

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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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Identification Of Stage-Specific Antigens Of Toxoplasma Gondii., Lloyd H. Kasper Mar 1989

Identification Of Stage-Specific Antigens Of Toxoplasma Gondii., Lloyd H. Kasper

Dartmouth Scholarship

An immunologic evaluation of the surface antigens of the three major life-cycle stages of Toxoplasma gondii was performed. Mouse antisera were raised against these stages, which included the oocyst-sporozoite (feline-excreted stage), bradyzoite (chronic tissue cyst stage), and tachyzoite (invasive stage). The antisera were used in an enzyme-linked immunosorbent assay and Western blot (immunoblot) analysis to demonstrate the presence of stage-specific antigens. These antigens were of various molecular weights and were specific to each stage investigated. Cross-reaction studies showed that the mouse antisera recognized commonly shared antigens to at least two of the three stages. A panel of monoclonal antibodies identified …

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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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Proteins Antigenically Related To The Human Erythrocyte Glucose Transporter In Normal And Rous Sarcoma Virus-Transformed Chicken Embryo Fibroblasts., Donald W. Salter, Stephen A. Baldwin, Gustav E. Lienhard, Michael J. Weber Mar 1982

Proteins Antigenically Related To The Human Erythrocyte Glucose Transporter In Normal And Rous Sarcoma Virus-Transformed Chicken Embryo Fibroblasts., Donald W. Salter, Stephen A. Baldwin, Gustav E. Lienhard, Michael J. Weber

Dartmouth Scholarship

Antibody raised against the purified human erythrocyte glucose transporter specifically precipitated four proteins from normal and Rous sarcoma virus-transformed chicken embryo cells: a major protein of Mr 41,000 and minor proteins of Mr 68,000, 73,000, and 82,000. The Mr 41,000 and 82,000 proteins were found only in a membrane fraction, not in the soluble fraction, and displayed a heterogeneous mobility on NaDodSO4/polyacrylamide gel electrophoresis, suggesting glycosylation. The Mr 41,000 and 82,000 proteins were increased in amount after malignant transformation in direct proportion to the increase in hexose transport rate, and the increase was dependent on the expression of the src …

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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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