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J S Rosenberg

Publications and source records attributed to J S Rosenberg.

At least 19 recordsLinked to original sources
PubMed1997

Intersite helper function of T cells specific for a protein epitope that is not recognized by antibodies.

Humoral responses to a protein require T-B cell communication for B cell activation by T cells. Previous studies from this laboratory have mapped the T and B cell recognition sites (epitopes) on sperm-whale myoglobin (Mb) and several other proteins. It was found that, five of six regions on Mb recognized by T cells are also recognized by B cells (i.e. antibodies). There is, however, one region (E6) residing within Mb residues 61-77, that is recognized only by T cells and to which no antibody (Ab) responses are detectable. To investigate the function of this exclusive T cell epitope, we established, from E6-primed BALB/c mice, an E6-specific T cell line (T(e6)) which comprised Th2-type cells. These T cells provided help in vitro to B cells from Mb-primed BALB/c mice and activated them to produce anti-Mb Abs of the IgM (58.2%) and IgG (41.8%) isotypes. The helper activity of T(e6) cells was dependent on the concentration of the challenging Ag (intact Mb or peptide E6) in culture. Action of soluble factors released from E6-activated T(e6) cells on B(mb) cells led to low production of anti-Mb Abs, suggesting that activation of the B cells was more dependent on their contact with T cells. Mapping of the epitope recognition of the anti-Mb Abs produced in vitro by B(mb) cells on activation by T(e6) revealed that this activation was not general to all antigenic regions recognized by anti-Mb Abs in BALB/c mice. E6-specific T cells caused in vitro activation and differentiation of B(mb) cells into plasma cells that secreted anti-Mb Abs directed, in decreasing order, against the following Mb regions: E4 (107-120) > E3 (87 - 100) > E1 (10 - 22). Little or no Ab responses could be detected against peptides E2 (50 - 62), E5 (141 - 153) and E6 (61 - 77). With B cells of peptide-primed BALB/c mice, T(e6) cells activated strongly E4-, E3- or E1, and only very slightly E2- or E6-, primed B cells to secrete Abs against the correlate peptide, but failed completely to activate E5-primed B cells. The results show that a protein T cell epitope, to which no Abs are detectable, plays an active role in B cell responses against other epitopes within the same protein.

Amino Acid Sequence↗
PubMed1997

Localization of the regions on the C-terminal domain of the heavy chain of botulinum A recognized by T lymphocytes and by antibodies after immunization of mice with pentavalent toxoid.

We have mapped the regions recognized by T and/or B cells (Abs) on the C-terminal domain (Hc) of the heavy chain of botulinum neurotoxin serotype A (BoNT/A) after immunization of two inbred mouse strains with pentavalent toxoid (BoNTs A, B, C, D and E). Using a set of synthetic overlapping peptides, encompassing the entire Hc domain (residues 855-1296), we demonstrated that T cells of Balb/c (H-2d) mice, primed with one injection of toxoid, recognized two major regions within residues 897-915 and 939-957. After multiple inoculations with toxoid, T cells of Balb/c expanded their recognition ability and responded very well to challenge with peptide 1261-1279 and moderately to stimulation with peptide 1149-1167. Unlike Balb/c T cells, those of toxoid-primed SJL (H-2s) mice exhibited a more complex profile and responded to challenge with a large number of overlapping peptides. After one toxoid injection, however, three peptides, 897-915, 939-957/953-971 overlap and 1051-1069, were the most potent T cells stimulators. After three toxoid injections, peptides 897-915 and 1051-1069 remained immunodominant while the third region was shifted upstream to 925-943/939-957 overlap. The immunodominant epitope within peptide 897-915 was recognized exclusively by T cells, since no Abs were detected against this region. The Ab binding profiles of the two mouse strains were quite similar, showing only small quantitative differences. Both, Balb/c and SJL anti-toxoid Abs displayed strong binding mainly to peptide 1177-1195, followed by peptides 869-887/883-901 overlap and 1275-1296. In addition, a significant amount of Balb/c anti-toxoid Abs was bound to peptide 1135-1153. Unlike Balb/c Abs, that interacted weakly with peptides 995-1013 and 1051-1069, the anti-toxoid Abs of SJL mice exhibited strong binding toward both peptides. The results showed that, in a given strain, the regions recognized by anti-toxoid Abs and T cells may coincide or may be uniquely B or T cell determinants.

Amino Acid Sequence↗
PubMed1996

B-cell activation in vitro by helper T cells specific to region alpha 146-162 of Torpedo californica nicotinic acetylcholine receptor.

We have previously mapped the T and B cell epitopes on the alpha-subunit of acetylcholine receptor (AChR) in human myasthenia gravis (MG) and in experimental autoimmune MG-susceptible (C57BL/6 (B6)) and nonsusceptible mouse strains. In addition to regions recognized by both T and B cells, the AChR alpha-subunit has regions that are recognized solely by T cells. An exclusive T cell epitope within residues alpha 146-162 of Torpedo californica (t), tAChR, plays an important role in experimental autoimmune MG pathogenesis in B6 mice. To study its function, we established, from tAChR-primed B6 mice, two t alpha 146-162-specific T cell lines (P14Th) which comprised Th2-type cells because they secreted IL-4 but not IL-2. P14Th did not recognize the corresponding region on mouse (m) AChR (m alpha 146-162). They caused in vitro differentiation of tAChR-primed B cells into plasma cells that secreted anti-AChR Abs directed, in decreasing order, against the following tAChR alpha regions: t alpha 122-138 > t alpha 134-150 > t alpha 45-60 > t alpha 170-186 > t alpha 56-71. Little or no Ab response could be detected against peptides t alpha 182-198 or t alpha 146-162 itself. The major enhancement was in the Abs against region t alpha 122-150 (spanning the t alpha 122-138/t alpha 134-150 overlap) that is involved in ACh binding. These Abs cross-reacted completely with m alpha 122-150, the corresponding region on mAChR. Therefore, t alpha 146-162-specific T cells, although unable to recognize m alpha 146-162, are nevertheless pathogenic because they help B cells responding to a tAChR region that is conserved in mAChR and involved in ACh binding. These Abs cross-react with the corresponding effector-binding region of mAChR, thereby disrupting the normal physiologic function of the mouse receptor.

Amino Acid Sequence↗
PubMed1992

Immunization of cats against feline infectious peritonitis with anti-idiotypic antibodies.

Anti-idiotypic antibodies (Ab2s) generated against neutralizing antibodies (Ab1s) specific for feline infectious peritonitis virus (FIPV) were shown to be specific for paratope-associated idiotopes of the Ab1s and not against isotypic determinants. In a study to determine the efficacy of an anti-idiotypic vaccine against feline infectious peritonitis (FIP), cats that were immunized with a pool of monoclonal Ab2s developed Ab3s that recognized the variable regions of the Ab2s as well as the natural antigen. In cats challenged with a lethal dose of virus the control group followed a predictable course of infection ultimately succumbing to FIP. Two immunized cats survived virus challenge and a third cat lived twice as long as the controls. The fourth immunized cat showed no evidence of protection. The ability to induce levels of protection against FIP lends support to the concept of using anti-idiotypic antibodies as a prophylactic vaccine.

Animals↗
PubMed1985

Fc receptors for IgG on human neutrophils: analysis of structure and function by using monoclonal antibody probes.

Structural and functional characteristics of Fc receptors for IgG (Fc gamma) on human neutrophils were examined with two monoclonal antibody probes specific for the Fc gamma receptors, Leu 11b and 3G8. To determine the distribution, density, and membrane mobility of the Fc gamma receptor, we used immunogold staining techniques, flow cytometry analysis, and fluorescence microscopy. Both 3G8 and Leu 11b inhibited several cell functions, thereby depicting the regulatory role of the Fc gamma receptor in mediating neutrophil activities. Among the functions studied were release of lysosomal enzymes, release of superoxide anion (O2-), and Fc-dependent rosette formation and phagocytosis. The densities of Fc gamma determinants recognized by Leu 11b and 3G8 on cells from a patient with chronic myelogenous leukemia were less than the density of epitopes on neutrophils from a normal individual. Taken together, the detailed analysis of physical and functional aspects of the Fc gamma receptor on neutrophils described in this study serve as a model for further assessment of the use of Fc gamma phenotyping of cells as a diagnostic tool.

Antibodies, Monoclonal↗
PubMed1984

Improved T cell subset monitoring by immunogold staining following renal transplantation.

Enumeration of peripheral blood T cells, functional T cell subsets, and B cells by immunogold staining (IGS) was compared with analysis by flow cytometry in 52 renal allograft recipients. Results by the IGS method compared favorably with those obtained by flow analysis. IGS is a simple, inexpensive technique that is readily adaptable to the setting of posttransplant immune monitoring.

Antigens, Surface↗
PubMed1984

Counter inhibitor: a low molecular weight cytokine derived from human leukocyte dialysates reverses antigen dependent PMN and macrophage migration inhibition.

A low molecular weight component, termed counter inhibitor (CI), has been partially purified from human dialyzable leukocyte extracts. Addition of CI to either a direct leukocyte or macrophage migration inhibition system results in reversal of antigen-induced migration inhibition. CI activity requires the presence of antigen for expression, but does not require that the donor of the CI be immune to the antigen used in the migration inhibition assay. Reversal of migration inhibition by CI appears to be a consequence of its ability to prevent PMNs or macrophages from responding to lymphokines which induce migration inhibition.

Antigens↗
PubMed1984

Immunogold staining: adaptation of a cell-labeling system for analysis of human leukocyte subsets.

We have assessed the Immunogold Cell-Labeling System (IGS) for potential use in the clinical laboratory. In this technique, cell suspensions incubated with monoclonal mouse antibodies are reacted with anti-mouse antibodies labeled with colloidal gold. Surface marker cells, bearing dark blue-black granules, are easily distinguished by light microscopy. The percentages of T cells, T cell subsets, B cells, monocytes, or granulocytes identified by IGS corresponds with numbers obtained by flow cytometry analysis or immunofluorescence studies. Results by IGS and flow cytometry were similar for samples from patients with aberrant lymphocyte populations (e.g., leukemias) or from transplant recipients. IGS may thus be a useful diagnostic technique for studying neoplasias or other immunologically mediated disorders. This technique can also be used to characterize the surface phenotype of leukemic cell lines. The sensitivity and accuracy of IGS can be evaluated by measurements of different cell lines mixed in predetermined ratios.

Antibodies, Monoclonal↗
PubMed1984

Modulation of human T cell production of migration inhibitory lymphokines by cytokines derived from human leukocyte dialysates.

Human leukocyte dialysates contain components capable of amplifying cutaneous delayed-type hypersensitivity (DTH) reactions. In the present study, two such amplifiers, both less than 3500 m.w., were partially purified from human leukocyte dialysates by gel filtration on Sephadex G-10 followed by high pressure reverse-phase liquid chromatography. These amplifiers of DTH were examined for their effects on production of the migration inhibitory lymphokines leukocyte migration inhibition factor (LIF) and macrophage migration inhibition factor (MIF). The amplifiers were found to increase LIF and MIF production by antigen- or alloantigen-stimulated human peripheral blood lymphocytes in a dose-dependent fashion. Further analysis demonstrated that although antigen-stimulated T4 and T8 cell subpopulations could produce LIF activity under the assay conditions employed, amplification of lymphokine production by modulator was only observed with the T4 subset.

Animals↗
PubMed1983

Effects of aging on cell cooperation and lymphocyte responsiveness to cytokines.

Functional activities and cell cooperation of macrophages (Mphi), T cells, and B cells of young and old Lewis rats were compared. Splenic M phi from young and old rats provided accessory help for T cell mitogenesis and B cell mitogenesis, provided accessory help for generation of PFC, and produced IL 1 equally well as measured in costimulator assays. Splenic T cells of aged Lewis rats, however, were poorly responsive in mitogen assays and did not respond to supplemental IL 2 and antigen with blast transformation and with increased help for B cells to produce PFC. "Old" B cells did not respond in vitro to mitogens with help from M phi and T cells, nor did they respond to B cell helper factor with increased PFC. The data indicate that hyporesponsiveness of the immune system, especially of B cells, in aged rats is due in part to defective reactivity to interleukins and cytokine(s) and to defective cell-cell cooperation.

Aging↗
PubMed1983

Inhibition of interleukin synthesis and T cell proliferation by a monoclonal anti-Ia antibody.

The proliferative response in vitro of Lewis rat spleen cells to Con A was inhibited by a monoclonal antibody, OX4, with specificity for a public rat la antigen. Inhibition was dose-dependent and was observed only if the antibody was present during the first 48 hr of culture. OX4 anti-la antibody inhibited production of IL 1 by peritoneal exudate cells activated by lipopolysaccharide and inhibited the production of IL 2 by spleen cells activated by Con A. Addition of exogenous IL 1 to spleen cell cultures inhibited by OX4 anti-la antibody augmented production of IL 2 and returned the proliferative response of T cells to levels observed in Con A-stimulated cultures. We suggest that OX4 anti-la antibody reacts with la+ accessory cells to inhibit production of IL 1, which in turn limits production of IL 2 and finally T cell proliferation.

Animals↗
PubMed1982

Activation of rat B lymphocytes. II. Functional and structural changes in "aged" rat B lymphocytes.

Anti-mu, anti-gamma, and anti-delta antibodies induce proliferation of splenic B lymphocytes from young Lewis rats, measured by 3H-TdR uptake. In contrast, splenic B cells of aged Lewis rats respond poorly or not at all to these reagents. T lymphocytes or interleukin 2 (IL-2) of young or aged rats augment the uptake of 3H-TdR in cultures of "young" B cells responding to anti-Ig reagents or LPS and DxS, but have no significant effect on the responses of "old" B cells. Analysis of spleen cells of young and aged rats in a fluorescence-activated cell sorter indicates the density of mu, gamma, and delta isotypes is reduced in "old" B cells, and that B cells of aged rats are significantly larger than those of young rats. These results delineate anatomic and structural changes in B lymphocytes of aged rats.

Aging↗
PubMed1982

T lymphocytes of young and aged rats. II. Functional defects and the role of interleukin-2.

Splenic T lymphocytes of aged Lewis rats respond to Con A and PHA with diminished 3H-TdR uptake compared with splenic T lymphocytes of young Lewis rats. After immunization with allogeneic tumor cells, uptake of 3H-TdR in mixed lymphocyte-tumor cultures and T cell cytotoxicity against tumor target cells are significantly lower with spleen cells of aged rats compared with those of young rats. The culture of spleen cells of aged rats with Con A results in a diminished conversion of Ia-positive T cells from Ia-negative precursors compared with similar cultures of spleen cells of young rats. Spleen cells of both young and aged rats produce high amounts of IL-2 in response to Con A stimulation. "Old" T cells, however, bind relatively little IL-2, do not utilize it in culture, and do not respond to exogenous IL-2 with enhanced 3H-TdR uptake as do "young" T cells. In allogeneic MLTC, "old" T lymphocytes produce little IL-2 compared with "young" cells, and both "young" and "old" cells respond to exogenous IL-2 with enhanced 3H-TdR uptake and increased cytotoxic activity. The data suggest defects in the synthesis and/or recognition of IL-2 as well as defects in the regulation of Ia antigen expression may be responsible, in part, for the reduced T cell function in aged animals.

Aging↗
PubMed1982

Activation of rat B lymphocytes. I. Characterization of anti-immunoglobulin responses and isotype density of rat B cells.

Spleen cells of two rat strains, Lewis and Brown Norway (BN), have been activated by lectins and by antibodies specific for immunoglobulin isotypes embedded in their cell membranes. Optimal concentrations of antibodies specific for mu, gamma, or delta-chains of rat augments in vitro incorporation of 3H-TdR 5 to 18-fold in Lewis B lymphocytes and 1.5 to 4-fold in BN B lymphocytes. In addition, F(ab')2 fragments of anti-Ig reagents induced Lewis splenic B cells but not BN B cells to incorporate 3H-TdR. Responses to LPS and dextran sulfate, B lymphocyte mitogens, measured by radioactive uptake, were five to 10 times greater in Lewis B cell populations than in BN B cell populations. Density of surface Ig isotypes and capping kinetics were similar in the two rat strains, although the percentage of T cells, T cell subsets, B cells, and Ia+ B cells differed in the spleens of these strains of rats. Both T lymphocytes and macrophages were needed in culture to effect an optimal response. IL-2 restored the response in B cell cultures depleted of T cells and macrophages, and enhanced 3H-TdR uptake in whole spleen cells of Lewis but not BN rats. The strain-dependent responsiveness of B cells to specific anti-Ig reagents or B cell mitogens appears to be associated with inherent (genetic) defects in T cells and B cells or defects in T cell to B cell cooperation in BN rats.

Animals↗
PubMed1982

Regulation of rat B cell responses by T cell subsets and interleukin 2.

T cell and interleukin 2 (IL 2) regulation of two phases of B cell activation, 3H-TdR uptake and differentiation to antibody-forming cells, were examined. Monoclonal antibody specific for rat kappa light chains (Mab alpha K) stimulated 3H-TdR uptake in vitro in B cell fractions of Lewis spleen cell populations in the presence of T cells and macrophages (M phi); IL 2 reconstituted the response in enriched B cell cultures depleted of T cells and M phi. When IL 2 was added to primary in vitro cultures, spleen cells yielded 100 to 400 anti-SRBC PFC/culture; no PFC were recorded in the absence of IL 2. These results suggested that IL 2 served as a " second signal" for activation in responsive B cell populations. When monoclonal antibody specific for the W3/25+ T cell subset (Mab W3/25) was incorporated into the assay system, both 3H-TdR uptake and PFC responses were inhibited. IL 2 enhancement of B cell responses or responses of reconstituted B cell and T cell fractions was eliminated in the presence of Mab W3/25, indicating that IL 2 mediation of B cell responses was due in part to participation of W3/25+ T cell helper function. In contrast, monoclonal antibody directed to the OX8-bearing T cells (Mab OX8) had no effect on B cell responses. W3/25+ T cells provided helper activity in the generation of a PFC response, whereas OX8+ cells suppressed the antibody response. W3/25+ T cells responded to antigenic stimuli in the presence of IL 2 by undergoing increased blast transformation. OX8+ cells did not exhibit any response. These data define a regulatory network by which T cells, IL 2, and B cells interact to produce in vitro DNA synthesis and antibody formation in activated rat B cells.

Animals↗