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Biomedical subjects

S O Sharrow

Publications and source records attributed to S O Sharrow.

At least 109 records · Page 6Linked to original sources
PubMed1982

Detection of a common antigen on murine B cells and Lyt-2+ T cells by a rat monoclonal antibody, 14D10.

This paper reports the production of a rat monoclonal antibody, 14D10, which recognizes a determinant shared between B cells and Lyt-2+ T cells. Three subpopulations of spleen cells were defined based on the density of bound 14D10. They have been designated 14D10-SP (strongly positive), 14D10-WP (weakly positive), and 14D10-N (negative). Dual parameter immunofluorescence studies showed that 90% of 14D10-SP cells are IgM+ cells and more than 92% IgM+ cells are 14D10-SP. Of 14D10-WP cells, approximately 60% are Lyt-1+2+ T cells and less than 10% are IgM+ cells. However, most (greater than 90%) of Lyt-2+ T cells are reactive with 14D10. Staining of purified populations of Lyt-2+ and Lyt-2- T cells with fluoresceinated 14D10 also showed greater than 90% of Lyt-2+ T cells to be 14D10+, and fewer than 10% of Lyt-2- T cells are 14D10+. Mouse thymus contained very few (congruent to 5%) 14D10+ cells. Analysis of bone marrow cells shows almost all small cells to be 14D10+. Six Abelson virus-transformed cell lines all express the antigen recognized by 14D10.

Abelson murine leukemia virus↗
PubMed1982

Idiotypes of anti-Ia antibodies. II. Effects of in vivo treatment with xenogeneic anti-idiotype.

The effects of in vivo treatment with xenogeneic anti-idiotypic antibodies were examined in an anti-Ia idiotypic system. Monoclonal antibody 14-4-4S, specific for Ia.7, has been shown to bear idiotopes that are expressed at readily detectable levels in conventional alloantibody responses. Sera from mice treated with purified anti-idiotypic antibodies (anti-Id) were found to contain inhibitory activity in an ELISA specific for the 14-4-4S Id, whereas sera from control mice treated with heterologous normal Ig did not. In addition, sera of anti-Id-treated C3H.SW mice contained specific anti-I-E activity, shown by binding to B10.A(2R) but not B10.A(4R) LPS blasts in flow microfluorometry. The anti-I-E induced by anti-Id included more IgG1 than IgG2. Even though a significant amount of anti-I-E activity was present in the serum, absorption analysis showed that most of the idiotope-positive antibody was not I-Ek-specific. Penetrance of induction of anti-I-E by anti-Id was 100% in the C3H.SW mice tested, and activity persisted in the serum for at least 8 to 9 mo in some cases. B10 mice produced only marginal anti-I-E activity after treatment, suggesting that induction is due to specific triggering rather than due entirely to a resemblance of anti-Id to the I-E antigen. The results thus indicate long-lasting alterations in an anti-Ia idiotypic system in the absence of exposure to conventional antigen, and represent specific manipulation of anti-Ia immunity.

Animals↗
PubMed1981

Anti-idiotypes to monoclonal anti-H-2 antibodies. II. Expression of anti-H-2Kk idiotypes on antibodies induced by anti-idiotype or H-2Kk antigen.

Anti-idiotypic antibodies were prepared against two monoclonal anti-H-2Kk antibodies, 11-4.1 and 3-83P. These reagents were used to examine idiotype (Id) expression on anti-H-2Kk antibodies induced by the in vivo administration of the anti-idiotypic antibodies and/or H-2Kk antigen. Treatment of BALB/c mice with anti-Id induced both antigen-binding and nonantigen-binding Id-positive molecules in the absence of antigen. The level of production of anti-Id-induced Id (Id') has been shown to be linked to VH genes using allotype congenic mice and backcross analyses. The idiotypes expressed on the Id' induced in anti-Id-treated mice were closely related or identical to those of the original monoclonal anti-H-2Kk antibody. However, the idiotopes were present on immunoglobulins of different subclasses and in some cases were not all expressed on the same molecules, as reflected by differences in their antigen specificities and isoelectric focusing patterns. In vivo administration of anti-Id had a marked influence on the subsequent humoral response to immunization with H-2 antigen.

Animals↗
PubMed1981

Lyt 1+23- cells appear in the thymus before Lyt 123+ cells.

Most thymocytes are either immature or functionally deficient and express a series of lymphocyte cell-surface antigen markers designated Lyt 1, Lyt 2 and Lyt 3 (refs 1, 2) which have been useful in distinguishing functional subsets of T cells. In contrast, a small population of cortisone-resistant thymocytes (CRT), confined to the thymic medulla after acute corticosteroid treatment are functionally more mature. These cells, like peripheral T cells, have restricted expression of Lyt antigens and mostly are either Lyt 1 or Lyt 123 cells. It has thus been assumed that all thymocytes initially are Lyt 1+, 2+, 3+ and by differentiation lose either Lyt 1 or Lyt 2, 3 to result in Lyt 1+(23-) and Lyt (1-)23+ cells. Using immunofluorescence (IF) and flow microfluorometry (FMF) analyses to detect Lyt antigen expression quantitatively without the requirement for cell lysis, we have now re-examined the expression of Lyt 1, 2 and 3 antigens on murine fetal thymocytes from 14 to 19 days of gestation and on normal thymocytes from birth to 2-3-month-old adults. These studies demonstrate that cells with the Lyt 1+23- phenotype first appear in the thymus several days before Lyt 123+ thymocytes are detected, and suggest either a micro-environmental or site-specific influence for phenotypic differentiation and/or two independent, pre-committed lineages.

Animals↗
PubMed1981

Preparative separation of human T cells reactive with the OKT4 monoclonal antibody.

A cell separation technique is described which can provide large numbers (i.e. greater than 5 x 10(7)) of human lymphoid cells which are positively and negatively selected for their ability to react with the OKT4 monoclonal antibody. Peripheral blood lymphocytes are depleted of plastic-adherent cells and then exposed to OKT4 antibody. Unbound OKT4 antibody is removed by washing and then this OKT4-exposed cell population is placed on plastic Petri dishes that are coated with affinity-purified goat anti-mouse immunoglobulin. Cells which do not bind the OKT4 antibody (OKT4- cells) can be obtained by gently washing the nonadherent cells from the plates, while the adherent (OKT4+) cells can be recovered by vigorous pipetting. This procedure yields functional OKT4+ and OKT4- cell populations with a purity which approaches that obtained by separation using the fluorescence-activated cell sorter. The principal advantages of this plate separation technique are that: (1) large numbers of functional cell populations can be obtained; (2) very small quantities of monoclonal antibody (e.g. 1:10(4) dilution of ascites) are required; and (3) sterility of the cell preparations can be maintained quite easily.

Animals↗
PubMed1981

Fc (IgG) receptor distributions in homogeneous and heterogeneous cell populations by flow microfluorometry.

A flow microfluorometric method has been developed for quantitating the numbers of Fc receptors on individual cells. The cells were equilibrated at 0 degrees C with radiolabeled, affinity-crosslinked rabbit IgG dimers, washed, and treated with fluorescent antibodies against rabbit IgG. The stained cells were analyzed for fluorescence emission by using a fluorescence-activated cell sorter and for bound dimer molecules by using a gamma counter. Standard curves relating fluorescence emission to numbers of dimer molecules bound to cells were used to determine Fc receptor distributions on P388D1 cells, human peripheral blood lymphocytes, and normal mouse spleen cells. Essentially all of the P388D1 cells bore Fc receptors, distributed in a skewed Gaussian profile having a peak at 2 X 10(5) receptors per cell. Human peripheral blood lymphocytes and mouse spleen cells contained positive and negative subpopulations. The percentage of positive cells in human lymphocytes from different donors ranged from 50 to 25; the receptor distributions of these cells were symmetrical and similar in all donors in shape and average receptor density (4.2 X 10(4) receptors per cell). Mouse spleen cells contained 55% positive cells with nonsymmetrical heterogeneous distributions of receptor densities. These cells peaked at 1 to 2 X 10(4) receptors per cell, but significant numbers of cells had receptor densities 10- to 20-fold greater.

Animals↗
PubMed1981

Fc (IgG) receptors on rat basophilic leukemia cells.

Receptors for IgG and IgE on rat basophilic leukemia cells (the 2H3 subline of RBL-IV) were detected by their ability bind IgE and IgG in fluorescence or radioactive assays. The 2H3 cells have approximately two-thirds as many receptors for IgG as for IgE. The IgE receptors bind monomeric IgE with high affinity and IgE binding is uninhibited by high concentrations of monomeric or oligomeric IgG. In contrast, the IgG receptors bind both (rabbit and rat) IgG and (rat) IgE. The affinity of IgG receptors for monomeric IgG and IgE is much lower than that of the IgE receptor for its ligand; binding of radiolabeled IgG or IgE to IgG receptors can be detected only with cross-linked oligomers. Although both receptors are sensitive to tryptic digestion than IgE receptors. Dual laser flow microfluorometric studies revealed that the numbers of IgG and IgE receptors per cell varied considerably among 2H3 cells and that the distributions of the 2 types of receptors were independent of each other. 2H3 cells released histamine through an IgE-mediated system, but cross-linked IgG, even in saturating amounts, did not elicit histamine release, nor have any effect upon IgE-induced release. Moreover, 2H3 cells would not mediate ADCC of IgG-coated chicken red blood cells.

Animals↗
PubMed1981

Cell surface appearance of unexpected host MHC determinants on thymocytes from radiation bone marrow chimeras.

The phenotypic appearance of cell surface antigens on murine thymocytes from long-term radiation bone marrow chimeras was analyzed using indirect immunofluorescence and flow microfluorometry. Cells maturing in the thymi of these mice were typed for MHC (Kk, I-Ak, H-2b, Kb, and Ib) and non-MHC (Lyt 1, Ly 9, and TL) determinants. All cells were of donor origin as determined by non-MHC (Ly) phenotype in P1 leads to P2, P1 X P2 leads to P1, and P1 leads to P2 radiation chimeras. In contrast, the MHC phenotypes of these thymocytes were markedly affected by the host environment. Specifically, H-2 and I-A determinants of both parental phenotypes were detected on thymocytes from P1 leads to P1 X P2 chimeras; I-A determinants of host phenotype were present, whereas I-A determinants of donor phenotype were reduced on thymocytes from P1 X P2 leads to P1 chimeras; and thymocytes from P1 leads to P2 chimeras possessed H-2 and I-A determinants of host phenotype but showed reduction of donor I-A phenotype determinants. The appearance of host cell surface H-2 and I-A determinants on thymocytes from chimeras closely parallels the functional recognition of MHC determinants by T cells from chimeric mice and thus may be significantly related to the development of the self-recognition repertoire by maturing T cells.

Animals↗
PubMed1981

A mouse IgM allotypic determinant (Igh-6.5) recognized by a monoclonal rat antibody.

Two monoclonal rat anti-mouse IgM antibodies, Bet 1 and Bet 2, are described in this paper. Bet 1 defines a new allotypic determinant, Igh-6.5, expressed on IgM molecules in serum and on B lymphocytes, whereas Bet 2 recognizes a determinant on IgM molecules of all mouse strains tested. Both reagents bind to the IgM myeloma protein MOPC104E, but not to IgG myeloma proteins, including FLOPC21, MOPC21, and UPC10. Using serum from various mouse strains to inhibit the binding of Bet 1 to MOPC104E, 3 distinct inhibition patterns were found. BALB/c, DBA/2, and CBA sera inhibited strongly, C56BL/6 (B6), SJL, AKR, and NZB sera inhibited weakly, and A and AL sera showed no inhibition of binding of BET 1 to MOPC104E. All sera tested were equivalent in their inhibition of the binding of Bet 2 to MOPC104E. When spleen cells from different mouse strains were reacted with fluorescein-conjugated Bet 1 (F-Bet 1) and subjected to flow microfluorometry analysis, 3 types of staining patterns, corresponding to those obtained with the serum inhibition assay, were also found. The determinant recognized by Bet 1 is controlled by a gene linked to the Igh-C gene complex. C.AL20 behaved like AL, and C.B20 and BAB/14 behaved like B6, both in the serum inhibition assay and in flow microfluorometry analysis of spleen cells stained with F-Bet 1. In addition, the capacity of serum from individual (BALB/c X B6) X B6 backcross progeny to inhibit the binding of Bet 1 to MOPC104E was linked to the expression of the Ig-1a marker.

Animals↗
PubMed1981

The human autologous mixed lymphocyte reaction. I. Suppression by macrophages and T cells.

The autologous mixed lymphocyte reaction (AMLR) is a proliferative response of T cells to signals from autologous non-T cells. The AMLR has been an enigma to immunologists because spontaneous proliferation of cells removed from the body is usually substantially less than that observed with a strong AMLR. However, the AMLR is thought to represent an important in vitro function, since it has the attributes of other immune responses, and it is abnormal in a variety of disease states thought to have an immune basis. We reasoned that if the AMLR represented a fundamental immune phenomenon, it should be subject to regulation. In the present study, we present evidence for suppression of the AMLR by macrophages and by T cells. Macrophages inhibited the T cell proliferation to (B + null) cells in a dose-dependent fashion and throughout the time course of the AMLR. Elimination of suppressor T cells by a specific antiserum led to an increase in the AMLR, which was again suppressed in a dose-dependent way by addition of the suppressive T cells. It may be concluded that the AMLR itself is subject to immune regulation and that the suppressive influences observed probably strongly inhibit the AMLR in vivo. Removal of the suppressive principles allows the maximal expression of the AMLR in vitro. We believe that our demonstration of regulation of the AMLR should remove the enigma associated with it and lead to a better understanding of normal cell-cell interactions as well as the basis for abnormalities in a variety of immune-mediated diseases.

Animals↗
PubMed1981

T cell subpopulations required for the human cytotoxic T lymphocyte response to influenza virus: evidence for T cell help.

The requirement for specific T cell subsets in the in vitro generation of human influenza virus-immune cytotoxic T lymphocyte (CTL) responses was investigated. Peripheral blood T cell populations were identified by and selected for their reactivity with the monoclonal antibodies OKT3, OKT4, and OKT8. Influenza virus-immune CTL effectors are OKT3+, OKT4-, and OKT8+. Analysis of CTL precursors demonstrates that: 1) influenza-immune CTL precursors are OKT3+, OKT4-, and OKT8+; 2) CTL precursors require radioresistant OKT3+ helper T cells in order to generate strong cytotoxic responses; and 3) helper T cells can be obtained from either the OKT4+ or OKT4- populations, but more potent help was generated by the OKT4+ subset. The demonstration of a helper T cell requirement for the generation of influenza virus-immune CTL suggests that helper T cells may be involved in the previously documented HLA-linked Ir gene control of influenza-immune CTL responsiveness.

Animals↗
PubMed1981

Separation and characterization of two component tumor lines within the AKR lymphoma, AKTB-1, by fluorescence-activated cell sorting and flow microfluorometry analysis. I. the coexistence of sIg+ and sIg- sublines.

The AKTB-1 tumor line, previously described as having both T and B cell characteristics, was separated by electronic cell sorting (ECS) on a fluorescence-activated cell sorter (FACS) on the basis of surface immunoglobulin (sIg). This resulted in 2 distinct sIg+ and sIg- subpopulations, which were transferred in graded doses (10(1) to 10(3)) into groups of normal AKR animals. The resulting splenic tumor cells were analyzed at several time points by flow microfluorometry for surface characteristics (sIg, Thy 1, Lyt 2, and Ly9) and by erythrocyte-antibody rosetting for FcR. Two distinct sublines were identifiable--one of which was sIg+, FcR-, Thy 1.1+, Lyt 2.1+, PNA+, Ly9+ and the other of which was sIg+, FcR+, Thy 1.1-, Lyt 2.1-, PNA-, Ly 9+. When these 2 sublines, generated by ECS fractionation and high dilution transfer, were serially transferred at high doses (10(5)), they maintained their unique characteristics as distinct sublines, now designated AKTB-1t and AKTB-1b.

Animals↗
PubMed1981

The H-2 phenotype of the thymus dictates the self-specificity expressed by thymic but not splenic cytotoxic T lymphocyte precursors in thymus-engrafted nude mice.

The present study was performed to examine the specificity of the self-recognition repertoire expressed by TNP-specific CTL precursors present in the thymus and the spleen of congenitally athymic nude mice engrafted with either semiallogeneic or fully allogeneic neonatal thymuses. It was shown that the engrafted thymus lobes were fully repopulated with cells of nude host origin and that the engrafted thymus tissue was capable of reconstituting peripheral CTL function in the nude host. Assessing the specificity of the lymphocytes differentiating within the thymus graft, the present study revealed that CTL precursors of nude host origin in the thymus grafts were nonalloreactive to both nude-host-type and thymus-type MHC determinants but were invariably restricted to the self-recognition of thymus-type, not nude-host-type, MHC determinants. Furthermore, the restricted self-recognition of thymic MHC determinants was not mediated by detectable suppression. In contrast to the restricted self-recognition repertoire of CTL precursors in the thymus of these mice, CTL precursors from the spleens of the same mice were not restricted to the self-recognition of thymus-type MHC determinants but instead recognized TNP in association with both host and thymus-type MHC determinants. These data demonstrate that at least in thymus-engrafted nude mice the self-recognition repertoire of thymocyte CTL, but not spleen CTL, is entirely dictated by the MHC phenotype of the thymus tissue in which they differentiate. It is proposed that the spleen CTL repertoire in these mice reflects the coexistence of at least 2 CTL subpopulations, 1 that differentiated within the engrafted thymus and 1 that differentiated outside the engrafted thymus.

Animals↗
PubMed1981

Natural killer activity in the rat. II. Analysis of surface antigens on LGL by flow cytometry.

With the use of monoclonal antibodies and continuous flow microfluorometry, we have examined the cell surface antigenic characteristic of rat large granular lymphocytes (LGL) and compared them with monocytes, T cells, and polymorphonuclear leukocytes (PMN). The antigenic profile of rat LGL was of particular interest because these cells have been shown to be highly associated with natural killer (NK) activity. This analysis of enriched populations demonstrated that rat LGL are in antigenically distinct population of cells that share some characteristics with monocytes, T cells, and PMN. Essentially all of the cells in the enriched LGL population expressed with W3/13, OX-8, leukocyte-common (L-C), and asialo GM1 antigens. A portion of these cells were also positive with a monoclonal Ab against the ART-1a antigen. In contrast, few LGL expressed the Ia, W3/25, surface immunoglobulin (sIg), or Thy 1.1 antigens. Monocytes demonstrated a pattern of reactivity similar to LGL but were found to by OX-8 negative. As previously reported, a portion of the T cells were found to express ART-1a, W3/25, and/or OX-8. These results demonstrate that rat LGL are not typical T cells, B cells, monocytes, or PMN. However, the sharing of antigenic markers by LGL with some T cells and monocytes raises the possibility that LGL may be in the development lineage of 1 of these populations.

Animals↗