An improved method for production of intravenous contrast during echocardiography.
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Biomedical subjects
Publications and source records attributed to C Russo.
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As previously reported, old mice produce lower avidity plaque-forming cells (PFC) after immunization with 2,4,6-trinitrophenyl-Ficoll (TNP-F) than do young mice. However, if spleen cells from TNP-F-immunized old mice are incubated with hapten to elute auto-anti-idiotype antibody then high avidity PFC, comparable to those in young mice, are detected. To further evaluate the effect of age on the B-cell repertoire anti-2,4,6-trinitrophenyl-bovine gamma globulin (TNP-BGG) hybridomas were prepared from young (6 to 8 weeks old) and old (18 to 24 months old) mice which had been primed and boosted with TNP-BGG. The monoclonal antibodies (MoAb's) were TNP-specific. Spleens from old and young mice were comparable with respect to the incidence of immunoglobulin-secreting hybridomas obtained, the incidence of TNP-BGG-specific hybridomas obtained, and the isotype distribution of the anti-TNP-BGG hybridomas. The avidities for TNP-BGG of the IgG1 anti-TNP-BGG MoAb's obtained from old and young donors were also comparable. The overall results thus suggest that old and young mice have similar B-cell repertoires and that differences in the antibodies produced are due to regulatory influences.
Analysis of surgical biopsies with monoclonal antibodies (mAbs) to framework determinants of major histocompatibility complex class I antigens has shown that malignant transformation is frequently associated with a marked loss of these cell surface molecules. The present study sought to determine whether more selective losses of major histocompatibility complex class I expression occur. Multiple specimens from 13 different types of primary and metastatic tumors were tested utilizing mAb BB7.2, which recognizes a polymorphic HLA-A2 epitope. In each case, expression of HLA-A,B,C molecules was determined by testing with mAb W6/32 directed to a framework HLA class I determinant. We have found that in HLA-A2-positive patients (identified by reactivity of their normal tissues with mAb BB7.2), HLA-A2 products are not detectable or are reduced in their expression in 70-80% of endometrial, colorectal, mammary, and renal tumors; in 40-60% of soft-tissue, skin, ovary, urinary bladder, prostate, and stomach tumors; and in 25-30% of melanomas and lung carcinomas tested. All tumors expressed the framework HLA-A,B,C determinant. The HLA-A2 epitope recognized by mAb BB7.2 is located in a portion of the HLA-A2 molecule postulated to react with the T-cell receptor. Immune surveillance to tumors is thought to depend on cytotoxic T cells, which require corecognition of polymorphic HLA class I epitopes, and on natural killer cells, which are, on the contrary, activated by the absence of HLA class I antigens. The selective loss of an HLA class I polymorphic epitope shown in this study may explain the mechanism by which tumor cells escape both T-cell recognition and natural killer cell surveillance.
These studies have shown that the alterations in the repertoire of antibody produced by old mice is not due to an intrinsic defect in the bone marrow or in the B-lymphocyte population arising from the bone marrow but rather to a selective downregulation by auto-anti-idiotypic antibody and idiotype-anti-idiotype interactions, shifting the idiotype distribution in the peripheral B-cell population. Thus, the clonal distributions of B cells generated by bone marrow of old and young mice are very comparable. The age-related differences in antibodies expressed by young and old mice are, to a great extent, determined by the activity of a peripheral regulatory immune network. This immune cellular network operates prior to exposure to antigen, presumably on the basis of an idiotype-anti-idiotype network between T and B lymphocytes. After exposure to antigen, a network of idiotype-anti-idiotype antibody interactions also contributes to differences in the immune responses of old and young mice to foreign antigens. If the expressed repertoire of antibody reflects down-regulation of auto-anti-idiotypic antibody, comparable repertoires of B-cell clones would be expected to be recovered from old and young mice if B cells from old mice were rescued from selective peripheral downregulatory influences active in old mice. Support for this hypothesis has been obtained by generating B-cell hybridomas from young and old mice immunized with TNP bovine gamme globulin (Marcenario et al. 1989). The same number of anti-TNP hybridomas and a comparable number of IgG and high-affinity antibody-producing clones were recovered from the spleens of young and old mice. Thus, the actual B-cell clonal repertoires of young and old mice appear to be similar although the expressed repertoires of antibody-producing lymphocytes from old and young mice are very different. This conclusion has considerable impact on strategies that could be employed to reverse the senescence of humoral immunity. Strategies to counter downregulatory influences which constrain the expression of the B-cell population should be more effective than attempts to reconstitute the repertoire of B lymphocytes in aged individuals. Finally, the mechanisms underlying these age-associated shifts in the expressed humoral antibody response can be attributed to life-long interactions with self and foreign antigens. The overall shift may be described as a decreased reactivity to foreign antigens and a complementary increase in reactivity with self antigens.(ABSTRACT TRUNCATED AT 400 WORDS)
The role of Class I major histocompatibility complex (MHC) molecules in the autologous (AMLR) and allogeneic mixed lymphocyte reactions was investigated by using monoclonal antibodies (MoAb) directed to polymorphic MHC determinants. The AMLR from subjects with the HLA-A2 phenotype was consistently inhibited by the anti-HLA-A2 MoAb, CR11-351, and the inhibition was dose-dependent and complete even at low antibody concentrations. The allogeneic MLR was inhibited by CR11-351 less than 30% when HLA-A2-bearing cells were used either as stimulator or responder cells. Addition of interleukins 1 and/or 2 to the AMLR in the presence of the inhibiting MoAbs did not restore the proliferative response. These studies suggest that Class I MHC polymorphic determinants, or closely related structures, participate in the induction of the AMLR.
Binding of angiotensin II has been detected in soluble extracts of rabbit liver, adrenal gland, aorta, brain, kidney and uterus. In each case, binding required p-chloromercuriphenylsulfonic acid and bound angiotensin II was released by treatment with dithiothreitol. These properties resemble those of the 75 kDa binding protein purified from liver. Immobilized guinea pig antiserum developed against the isolated hepatic protein removed binding activities from the different extracts in an immune-specific, quantitatively comparable manner. In addition, the activities were removed by a mouse monoclonal antibody which specifically recognized a protein of 75 kDa in the various preparations. An immunologically homologous angiotensin II-binding protein with similar characteristics was also identified in the soluble fraction of rat liver.
Long-term growth of antigen-specific human T cells requires, in addition to IL-2, periodic exposure to antigen and accessory cells. In certain cases, accessory cells are not available or their presence in culture is undesired. We have developed a method of growing and sustaining human T cell lines and clones in long-term tissue culture in the absence of specific antigen or accessory cells. The requirement for antigen and/or accessory cells could be replaced by a monoclonal antibody to the CD3 determinant of human T cells (OKT3) bound to the surface of plastic tissue culture wells. Autoreactive, alloreactive, and antigen-reactive T cell lines and clones were maintained in culture for 8-12 weeks without antigen or accessory cells. The antigen specificity of these T cells was maintained.
Splenic T cells proliferate in response to the anti-I-Ab reactive T cell hybridoma T1.203 in an H-2-restricted but MHC antigen-independent manner. We propose that this anti-idiotypic response is mediated by "Type 2 autoreactive" T cells that are induced in peripheral lymphoid tissues following interaction with the particular idiotype expressed by the anti-self-I-A T cells. Thus, we define this phenomenon as an idiotype-restricted MHC-related cell interaction. To study the ontogeny of this response, we examined the distribution of Type 2 autoreactive cells. Spleen and lymph node but not thymic C57BL/6 T cells vigorously proliferate to T1.203. Mature (PNA-) as well as immature (PNA+) thymic T cells respond poorly. The frequency of cells responding to T1.203 is far greater in the spleen than in the thymus. The responding T cells were of both Lyt 1+ and Lyt 2+ T phenotype. The results suggest that Type 2 autoreactive cells are induced in peripheral lymphoid tissues following interaction with anti-I-A autoreactive T cells which escape from the thymus or develop in the periphery.
The role of distinct regions of HLA class I molecules in regulating T-cell activation via the CD3-antigen receptor complex was investigated. Monoclonal antibodies (MoAbs) which recognize monomorphic and polymorphic epitopes on HLA Class I molecules were shown to inhibit T-cell proliferation to OKT3. These MoAbs have differential effects on the synthesis of interleukin-2 (IL-2) and IL-2 receptor expression. Cell cycle analysis demonstrated that these MoAbs function both in inhibiting cell cycle entry (G0-G1 shift) and in blocking cell cycle progression (G1-S shift) of activated T cells. Furthermore, these MoAbs have regulatory effects on the alternate pathway of T-cell activation via the CD2 molecule, T-cell activation induced by PHA, and activation induced by the phorbol ester PMA in conjunction with the calcium ionophore Ionomycin. Thus these MoAbs have different effects depending upon the pathway of T-cell activation. The results indicate that HLA class I molecules are selectively involved in the sequence of intracellular events leading to T-cell activation and proliferation.
The effect of a cloned allospecific human Th cell, termed 86, on the in vitro generation of altered self-reactive cytolytic T lymphocytes (CTL) was investigated. Utilizing the induction of hapten altered self-reactive CTL as a model for virus or tumor-specific cell-mediated immunity, we determined that the presence of small numbers of clone 86 cells markedly amplified the generation of hapten altered self-reactive CTL. The killer cells induced belong to the CD4-, CD8+ subset, are specific for the hapten-modified autologous stimulator cells present in culture, and are MHC class I restricted. The CTL induced under these culture conditions are readily expanded in the presence of IL-2 with maintenance of efficient and specific altered self-killing. Of interest, clone 86 cells preferentially enhance the growth of CD8+ T cells and selectively amplify altered self-cytolysis but not NK cell activity. Although in vitro clone 86 cells mediate help for CTL generation via the production of lymphokines (IL-4 but little IL-2), one can envision immunotherapeutic strategies for human disease that involve the adoptive transfer of Th cells functionally analogous to clone 86.
The anti-HLA-DR + DP monoclonal antibody (MoAb) CR11-462 was unexpectedly found to cross-inhibit the binding to B lymphoid cells of the anti-HLA Class I MoAb CR10-215 and CR11-115. The latter two antibodies recognized the same or spatially close antigenic determinant. The cross-blocking of anti-HLA Class I MoAb CR10-215 and CR11-115 by MoAb CR11-462 reflects neither its contamination by anti-HLA Class I antibodies nor its cross-reactivity with HLA Class I antigens. On the other hand, the cross-blocking appears to reflect redistribution of HLA Class II antigens by the MoAb CR11-462, since the MoAb CR10-215 and CR11-115 are not susceptible to blocking when lymphoid cells are treated with 0.025% glutaraldehyde or are coated with Fab' fragments of the MoAb CR11-462. Furthermore, immunoprecipitates from B lymphoid cells preincubated with the MoAb CR11-462 before solubilization contain HLA Class I antigens. Therefore, these results have shown for the first time an antibody-induced association between discrete regions of HLA Class I and Class II antigens on the membrane of B lymphoid cells.
We have applied a double determinant immunoassay (DDIA) to HLA-A2,A28, and B13 typing, using serum as an antigen source. The results obtained show a correlation of 96% (B13) and 89.1% (A2,A28) with the results obtained by conventional HLA typing. Furthermore, the results obtained were highly reproducible, since testing of 18 sera on two occasions gave concordant results with all samples tested. The variation in the content of HLA-A2 antigens in sera taken at different times from a given donor was less than 5%. A sevenfold variation was found in the serum level of HLA-A2,A28 antigens: the highest level was found in the sera from HLA-A2,A28 donors and in decreasing order in HLA-A2 homozygous, HLA-A28 homozygous, HLA-A2 heterozygous, and HLA-A28 heterozygous donors. The results of this study indicate that the DDIA is a sensitive, simple, and reproducible procedure for HLA class I typing. The DDIA offers the following advantages in comparison with the conventional lymphocytotoxic assay: it provides information not only about the expression of a given alloantigen, but also about its level; it does not require viable cells, thus facilitating retrospective studies and typing of leucopenic patients; it eliminates variability of results caused by abnormal susceptibility of target cells to complement-dependent lysis.
Data are presented that male homosexuals with chronic lymphadenopathy and reduced numbers of T4-antigen-bearing cells have an increased incidence of activated T8-antigen-bearing cells. Evidence suggesting an increase in activated T cells in these subjects includes an increase in incidence of T10-antigen-bearing cells, an increase in Ia-bearing T cells and an increase in the intensity of staining of a fraction of the T8-antigen-bearing cells with fluorescein-labeled OKT8 monoclonal antibody. It was shown by double staining that most of the Ia-bearing T cells also bore the T8 marker. The heterogeneity of the Ia, assayed by reactivity with several monoclonal anti-Ia antibodies which detect different epitopes on the Ia molecule, was comparable in lymphadenopathy subjects and controls.
The results of dermal or autologous full-thickness skin graft implantation in a series of 20 patients are reported. Seventeen patients were affected by incisional hernia, 2 by a large umbilical hernia and 1 by fibromatosis of the abdominal wall. The surgical procedure is described together with the histological findings of the skin grafts, 4 years after implantation.
Allo-I-A-reactive T cell hybridomas were generated from MLR-activated lymphoblasts. Cloned hybridomas T1.203, T1.321, and T1.426 were stimulated by I-Ab determinants, as shown by their ability to secrete IL-2 in response to a panel of MHC-recombinant mice. T2.146, T2.205, and T3.116 were found to be specific for I-Ak determinants using a similar panel of MHC-recombinant mice. Inhibition of IL-2 secretion by anti-I-A mAb confirmed these data. Some I-Ab-specific hybrids stimulated the proliferation of T cells from C57BL/6 (H-2b) mice. Similarly, some I-Ak-specific hybrids stimulated the proliferation of T cells from C3H/HeJ (H-2k) mice. These hybrids expressed no detectable surface I-A, and stimulation of T cells was not inhibited by anti-I-A mAb. These results are consistent with the hypothesis that normal mice possess a population of T cells responsive to idiotypic determinants on anti-MHC class II T cell receptors.
The relationship between immunoregulatory T-cell function and the expression of T-cell subset-specific differentiation antigens was examined using a phenotypically anomalous human T-cell line (TCL), termed H-1. H-1 cells were found to express T11, extremely high levels of T3, but no T4 nor T8 antigen. Despite their lack of T4 antigen expression, H-1 cells could be activated by coculture with pokeweed mitogen (PWM), anti-T3 antibody, or autologous B cells to provide potent help for B-cell differentiation into plaque-forming cells (PFC). In contrast, H-1 cells did not suppress the PFC response triggered by PWM-activated T4+ cells. These results demonstrate that the expression of the T-cell subclass-specific differentiation antigen, T4, is not required for a T cell to become activated and to implement the program for helper function. In addition, enhanced expression of T3 on the T4-, T8-, H-1 cell surface may reflect a compensatory upregulation of the T3/Ti receptor complex on T cells which are deficient in these nonpolymorphic associative recognition structures.
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The requirements for activation of human peripheral blood T cells by the mitogenic monoclonal antibody OKT3 were examined. OKT3 binds to a T cell molecule, T3, associated with the T cell antigen receptor and involved in T cell activation. Activation of T cells by OKT3 requires signals provided by accessory cells and is IL 2 dependent. In the presence of accessory cells, OKT3 induces loss of T3 molecules from the cell surface, production of IL 2, expression of IL 2 receptors, and proliferation. Modulation of T3 molecules by OKT3 can be induced in the absence of accessory cells with anti-mouse IgG. These T cells, however, are not induced to express IL 2 receptors or secrete IL 2. The addition of IL 1 induces expression of IL 2 receptors, but does not induce IL 2 secretion or proliferation. Thus, peripheral blood T cells appear to have different requirements for activation compared with antigen-specific T cell clones that can be induced to produce IL 2 when stimulated with OKT3 and IL 1. Expression of IL 2 receptors does not require modulation of T3 molecules, because the binding of OKT3 to T cells in the presence of IL 1 alone is sufficient to induce IL 2 receptor expression. The results suggest that IL 2 secretion depends on cross-linking and modulation of T3 molecules, and additional, as yet undefined, accessory cell signals. The expression of IL 2 receptors and proliferation of T cells can be induced in the absence of these signals when exogenous IL 2 is provided.