Administration of group A streptococcal cell walls to rats induces an interleukin 2 deficiency

Intraperitoneal administration of group A streptococcal cell walls to Lewis rats induces a chronic arthritis, whereas the Fischer strain is resistant to the development of the lesion. Spleen cells from cell wall-treated rats (Lewis and Fischer) are deficient in the synthesis of IL-2. Using an mAb directed against the rat IL-2-R, the present studies indicate that the expression of IL-2-R on spleens of cell wall-treated rats is normal. However, the addition of exogenous IL-2 to spleen cells cultured with Con A does not stimulate the mitogenic response.

Inhibition of the glycogenolytic effects of alpha-adrenergic stimulation and glucagon by cobalt ions in perfused rat liver

Cobalt ions (2 mM) inhibited the glycogenolysis induced by phenylephrine and glucagon in perfused rat liver. Cobalt ions also inhibited 45Ca++ efflux from prelabelled livers induced by phenylephrine and glucagon. In addition, they inhibited the rise in tissue levels of cyclic AMP caused by glucagon, but did not inhibit the stimulation of 45Ca++ efflux or glycogenolysis by cyclic AMP or dibutyryl cyclic AMP. The specific binding of glucagon and alpha-agonist to hepatocytes was not inhibited by cobalt ions. These data suggest that cobalt ions, presumably through their high affinity for calcium binding sites on membranes inhibit the stimulation of glycogenolysis by phenylephrine and glucagon in distinct ways; one by inhibiting calcium mobilization and the other by inhibiting cyclic AMP production. Therefore, it is conceivable that membrane-bound calcium plays an important role in stimulating Ca++ mobilization by phenylephrine, and cyclic AMP production by glucagon.

5C6-F4, a novel 100,000-dalton rat lymphocyte activation antigen defined by monoclonal antibody

Con A-activated rat thymocytes were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated 5C6-F4, reacted strongly with Con A-activated rat thymocytes and some LPS-activated rat spleen cells but not with normal thymocytes, spleen cells, or bone marrow cells of rat origin. The 5C6-F4 did not react with Con A-activated thymocytes of mouse origin. Immunoprecipitation of 5C6-F4 antigen from surface-iodinated Con A-activated rat thymocytes or LPS-activated rat spleen cells revealed its m.w. to be approximately 100,000. The kinetic studies of the expression of 5C6-F4 antigen revealed that 5C6-F4 antigen was detectable at 6 hr after Con A stimulation of rat spleen cells, whereas IL 2 receptor (IL 2R) was detectable at 12 hr. The appearance of 5C6-F4 antigen and IL 2R precede the onset of DNA synthesis of Con A-activated spleen cells. Thus, 5C6-F4 antigen is classified as early activation antigen. The 5C6-F4 inhibits the lymphocyte proliferation induced by mitogen and the IL 2-driven rat T cell proliferation. Sequential immunoprecipitation study as well as binding inhibition study indicated that the 5C6-F4 antigen is distinct from IL 2R molecule. The 5C6-F4 antigen appears to be a novel rat lymphocyte activation antigen that exhibits immunoregulatory function and also may serve as a useful marker of T cell activation.

5C6-F4, a novel 100,000-dalton rat lymphocyte activation antigen defined by monoclonal antibody

Con A-activated rat thymocytes were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated 5C6-F4, reacted strongly with Con A-activated rat thymocytes and some LPS-activated rat spleen cells but not with normal thymocytes, spleen cells, or bone marrow cells of rat origin. The 5C6-F4 did not react with Con A-activated thymocytes of mouse origin. Immunoprecipitation of 5C6-F4 antigen from surface-iodinated Con A-activated rat thymocytes or LPS-activated rat spleen cells revealed its m.w. to be approximately 100,000. The kinetic studies of the expression of 5C6-F4 antigen revealed that 5C6-F4 antigen was detectable at 6 hr after Con A stimulation of rat spleen cells, whereas IL 2 receptor (IL 2R) was detectable at 12 hr. The appearance of 5C6-F4 antigen and IL 2R precede the onset of DNA synthesis of Con A-activated spleen cells. Thus, 5C6-F4 antigen is classified as early activation antigen. The 5C6-F4 inhibits the lymphocyte proliferation induced by mitogen and the IL 2-driven rat T cell proliferation. Sequential immunoprecipitation study as well as binding inhibition study indicated that the 5C6-F4 antigen is distinct from IL 2R molecule. The 5C6-F4 antigen appears to be a novel rat lymphocyte activation antigen that exhibits immunoregulatory function and also may serve as a useful marker of T cell activation.

The psychological niche of older Japanese and Americans through auto-photography: aging and the search for peace

In an effort to understand aging cross-culturally, photography as a universal language was used to perceive the perceiver. Persons averaging seventy-three years of age from Japan and the United States were asked to describe "Who are you?" by taking (or having someone else take) six photographs. A content analysis of the photographs showed that older Japanese appear to be inward oriented (inside own territory, gardens, residence) and aesthetically oriented, while older Americans were more oriented toward other people. The results were interpreted in terms of differences in the search for peace. Peace is sought through self-harmony in the orient, but through social harmony in the occident.

Cells reacting with the monoclonal anti-IL-2 receptor antibody AMT-13 in the regenerating thymus of irradiated mice

The proportion and anatomical localization in murine thymus of T cell subpopulations, including those which are defined by the monoclonal anti-interleukin 2 (anti-IL-2) receptor antibody AMT-13, were studied by flow cytofluorometry and by immunohistochemical methods, both in irradiated and in normal mice. As a consequence of irradiation the proportion of AMT-13 positive cells and that of Lyt-1 positive cells were markedly enhanced, while the proportion of Lyt-2 positive cells was reduced. The vast majority of the AMT-13 positive cells both in normal and in irradiated thymi were located in the subcapsular area of the thymic cortex, whereas the irradiation resistant Lyt-1 positive cells were located in the medulla. These findings are compatible with the view that, similar to the developing thymus in the mouse embryo, in the regenerating adult thymus, AMT-13+ cells include the activated pro-thymocytes that repopulate the irradiated thymus.

Interleukin 2 receptors are released by cells in vitro and in vivo. I. Detection of soluble IL 2 receptors in cell culture supernatants and in the serum of mice by an immunoradiometric assay

An immunoradiometric assay (IRMA) detecting nanogram amounts of soluble mouse interleukin 2 receptors (IL 2R) is described. The IRMA is based on the finding that the two monoclonal antibodies AMT-13 and 7D4 react with two different epitopes of the mouse IL 2R molecule. As detected by IRMA, T lymphoblasts and IL 2R+ leukemic cells when incubated release IL 2R in soluble form into the culture medium. In the serum of mice inoculated with syngeneic IL 2R+ leukemic cells, growing as a solid tumor, IL 2R were detectable. The results raise the question whether circulating IL 2R are involved in down-regulation of immune responses.

Electrocochleographic study of low-tone hearing loss without vertigo

Auditory nerve action potential (AP), cochlear microphonics (CM) and summating potential (SP) were recorded from 6 patients with low-tone hearing loss without vertigo. All these cases showed high AP and -SP amplitude and satisfactory CM response. These findings resembled the electrocochleographic findings of type 1, which is an early stage of Ménière's disease. Hearing returned to normal range in half of the cases but remained hardly changed in the other half. The difference between these two groups could not be clarified electrocochleographically. On the other hand, low-tone hearing loss due to retrolabyrinthine lesion and due to familial sensorineural deafness was shown to have a low AP amplitude.

Functional analysis of mononuclear cells infiltrating into tumors. II. Differential ability of mononuclear cells obtained from various tissues to produce helper factors that are involved in the generation of cytotoxic cells

The requirement of CGF in the generation of cytotoxic cells against syngeneic tumor cells (T-9) and in the rejection of transplanted T-9 cells has been investigated. Spleen cells obtained from sensitized rats showed strong cytotoxicity against 51Cr-labeled T-9 cells upon incubation with CGF for 48 hr. Human recombinant IL 2 and rat IFN failed to generate cytotoxic cells from spleen cells of sensitized rats. CGF are produced by spleen cells upon inoculation of T-9 cells into sensitized rats as a host in vivo immune response. Production of CGF preceded the appearance of cytotoxic cells in regional lymph node and tumor tissues. In those rats, inoculated tumor cells were eventually rejected. In contrast, spleen cells failed to produce CGF upon inoculation of T-9 cells in unsensitized rats. Cytotoxic cells were not detected in unsensitized rats, and inoculated tumor grew in those rats. Thus, CGF is likely to be involved in the generation of cytotoxic cells and in the rejection of inoculated syngeneic tumor cells. A Mono Q anion-exchange column with an FPLC system allowed the chromatographic separation of CGF from IL 1, IL 2, IL 3, and CSF.

Functional analysis of mononuclear cells infiltrating into tumors. II. Differential ability of mononuclear cells obtained from various tissues to produce helper factors that are involved in the generation of cytotoxic cells

The requirement of CGF in the generation of cytotoxic cells against syngeneic tumor cells (T-9) and in the rejection of transplanted T-9 cells has been investigated. Spleen cells obtained from sensitized rats showed strong cytotoxicity against 51Cr-labeled T-9 cells upon incubation with CGF for 48 hr. Human recombinant IL 2 and rat IFN failed to generate cytotoxic cells from spleen cells of sensitized rats. CGF are produced by spleen cells upon inoculation of T-9 cells into sensitized rats as a host in vivo immune response. Production of CGF preceded the appearance of cytotoxic cells in regional lymph node and tumor tissues. In those rats, inoculated tumor cells were eventually rejected. In contrast, spleen cells failed to produce CGF upon inoculation of T-9 cells in unsensitized rats. Cytotoxic cells were not detected in unsensitized rats, and inoculated tumor grew in those rats. Thus, CGF is likely to be involved in the generation of cytotoxic cells and in the rejection of inoculated syngeneic tumor cells. A Mono Q anion-exchange column with an FPLC system allowed the chromatographic separation of CGF from IL 1, IL 2, IL 3, and CSF.

The mode of action of the calcium ionophore A23187 on T cell proliferation. I. The ionophore does not replace lymphokines but acts via induction of IL-2 production on IL-2 responsive cells

The two compounds, the calcium ionophore A23187 and phorbol myristate acetate (PMA), which are not mitogenic for mouse thymocytes, induce proliferation when added in combination to thymocyte cultures. Short exposure to PMA renders the cells responsive to IL-2, added exogeneously. The cells rendered IL-2-responsive by PMA are enriched in the more mature peanut agglutinin (PNA)-negative population. The ionophore does not render PNA-negative thymocytes IL-2-responsive, but induces proliferation of PMA-pulsed PNA-negative thymocytes. PMA-pulsed PNA-negative thymocytes proliferating in response to either exogeneous IL-2 or ionophore express IL-2 receptors. However, the ionophore does not mimic IL-2 action but acts indirectly by induction of both IL-2 production and of IL-2 receptor expression via IL-2. This view is based on the following findings: 1) IL-2 could be detected in supernatants derived from PMA-preactivated thymocytes incubated with the ionophore; 2) The IL-2-induced proliferation, as well as the ionophore-induced proliferation, was specifically blocked by a monoclonal anti-IL-2-receptor antibody; 3) The proliferation induced by exogeneous IL-2, as well as that induced by the ionophore, could be specifically inhibited by metabolically blocked T lymphoblasts carrying IL-2 receptors competing with the responder cells for the available IL-2 added or produced in the system.

A case of biliary cystadenocarcinoma with recurrent jaundice. Diagnostic evaluation of computed tomography

A 73-year-old male patient with biliary cystadenocarcinoma and episodes of recurrent jaundice is reported. This very rare tumor was suggested as a possible diagnosis by the computed tomographic findings showing intrahepatic cystic masses with septations and papillary projections. The diagnosis of the mucin-producing tumor was supported by aspiration of mucinous bile with a cannule inserted endoscopically via the major duodenal papilla. The computed tomographic findings and the diagnosis were verified by pathologic studies made on the material obtained surgically. The mucinous bile is assumed to have been responsible for the recurrent jaundice.

Inhibition of IL 2-dependent proliferation of rat T lymphoblasts by the monoclonal antibody ART62 which reacts with MHC class 1 antigens

During the course of studies designed to obtain monoclonal antibodies (mAb) that recognize the rat interleukin 2 receptor, a mouse IgG1 mAb (ART62) was identified which inhibits the interleukin 2 (IL 2)-dependent proliferation of rat T lymphoblasts without affecting the binding of IL 2 to such cells. In order to characterize the cell surface components that react with the mAb ART62, T lymphoblasts were surface-labeled with 125I, and the radioactive molecules were immunoprecipitated by the antibody analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The mAb ART62 precipitated two major components of 48,000 m.w. and 12,000 m.w., respectively, which were different from those which react with the anti-IL 2-receptor antibody ART18, a molecule of 50,000 to 55,000 m.w. Sequential immunoprecipitation studies revealed that the mAb ART62 reacts with the MHC class 1 antigen that reacts with the classical anti-rat MHC class 1 mAb OX18, and vice versa. In contrast to the mAb ART62, OX18 that does not affect and several other mAbs known to inhibit the rat MLR failed to inhibit IL 2-dependent proliferation of rat T lymphoblasts. In contrast to the anti-IL 2 receptor antibody ART18, ART62 effectively inhibited IL 2-driven proliferation even when added to cells already committed to proliferate by IL 2-IL 2 receptor interaction. These data raise the possibility that MHC class 1 antigens could be involved in the chain of reactions mediating the signals required for cell proliferation.

Inhibition of IL 2-dependent proliferation of rat T lymphoblasts by the monoclonal antibody ART62 which reacts with MHC class 1 antigens

During the course of studies designed to obtain monoclonal antibodies (mAb) that recognize the rat interleukin 2 receptor, a mouse IgG1 mAb (ART62) was identified which inhibits the interleukin 2 (IL 2)-dependent proliferation of rat T lymphoblasts without affecting the binding of IL 2 to such cells. In order to characterize the cell surface components that react with the mAb ART62, T lymphoblasts were surface-labeled with 125I, and the radioactive molecules were immunoprecipitated by the antibody analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The mAb ART62 precipitated two major components of 48,000 m.w. and 12,000 m.w., respectively, which were different from those which react with the anti-IL 2-receptor antibody ART18, a molecule of 50,000 to 55,000 m.w. Sequential immunoprecipitation studies revealed that the mAb ART62 reacts with the MHC class 1 antigen that reacts with the classical anti-rat MHC class 1 mAb OX18, and vice versa. In contrast to the mAb ART62, OX18 that does not affect and several other mAbs known to inhibit the rat MLR failed to inhibit IL 2-dependent proliferation of rat T lymphoblasts. In contrast to the anti-IL 2 receptor antibody ART18, ART62 effectively inhibited IL 2-driven proliferation even when added to cells already committed to proliferate by IL 2-IL 2 receptor interaction. These data raise the possibility that MHC class 1 antigens could be involved in the chain of reactions mediating the signals required for cell proliferation.

Rat lymphoid cell lines producing human T cell leukemia virus. II. Constitutive expression of rat interleukin 2 receptor

Three rat lymphoid cell lines (TARS-1, TARL-2, and TART-1) (12) transformed by human T cell leukemia/lymphoma virus I (HTLV-I) had rearrangement of the beta chain gene of the T cell antigen receptor, and had integrated proviral DNA from HTLV-I in their genomes. As is the case with adult T cell leukemia (ATL)-derived human T cell lines transformed by HTLV-I, these rat cell lines unequivocally expressed interleukin 2 (IL-2) receptor, as determined by radiolabeled IL-2 binding. By Scatchard plot analysis, one of the cell lines, TART-1, proved to have high affinity receptors (Ka = 1.3 X 10(11)/M and 8.8 X 10(9)/M). Rat IL-2 receptor, not human IL-2 receptor, was expressed on HTLV+ rat cell lines, as demonstrated by the fact that they expressed antigens reactive with monoclonal antibodies (ART-18) against rat IL-2 receptor, but not with anti-Tac antibodies. The collective evidence indicates that the endogenous IL-2 receptor gene is activated in human and rat lymphoid cell lines with HTLV-I production. The mechanism of abnormal IL-2 receptor expression in HTLV infection is discussed.

Nucleotide sequence of mouse IL-2 receptor cDNA and its comparison with the human IL-2 receptor sequence

We have cloned cDNA encoding the mouse interleukin-2 (IL-2) receptor from a murine T cell line, CTLL using human IL-2 receptor cDNA as probe. COS 7 cells transfected with the cDNA expressed the antigen recognized by the monoclonal antibody against the murine IL-2 receptor. The cDNA identified 4 species of mRNA (4.5, 3.5, 2.2 and 1.5 kb) of the mouse IL-2 receptor in CTLL cells. Difference in the length of mRNA seems to be ascribed to the variable length of the 3' untranslated sequence. Total nucleotide sequence (approximately 1400 bp) of this cDNA was determined and compared with the human receptor. The nucleotide and amino acid sequences of the IL-2 receptor are 70% and 60%, respectively, homologous in average between the two species. The comparison has revealed several conserved regions localized to particular exons such as transmembrane and cytoplasmic portions, suggesting that these regions are important for receptor function and its regulation.

Direct demonstration that the monoclonal antibody AMT-13 and interleukin 2 bind to the same molecule

125I-labeled surface molecules from mouse T lymphoblasts were fractionated by affinity supports coupled with recombinant interleukin 2 (IL2) and the monoclonal antibody (mAb) AMT-13. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that two molecules of approximately 55 kDa and of approximately 180 kDa were bound in both cases. Sequential precipitation and SDS-PAGE analysis of the precipitated molecules revealed that only the approximately 55-kDa molecule eluted from AMT-13 mAb support was rebound to IL2 affinity support. In addition, IL2 inhibited specifically the binding of 125I-labeled AMT-13 mAb to T lymphoblasts. Thus the results directly demonstrate that the a approximately 55-kDa cell surface molecule represents the IL2-binding protein and that the mAb AMT-13 reacts with this molecule.

Production of Listeria-specific rat T-cell clones and role of interleukin-2 receptors in regulation of Listeria-dependent T-cell clone growth in vitro

Splenic T lymphocytes from rats immunized with the facultative intracellular bacterium Listeria monocytogenes were cloned by the limiting-dilution technique in the presence of accessory cells, heat-killed L. monocytogenes as antigen, and conditioned medium containing interleukin-2. The cloned rat T-cells were Listeria-specific cells, and their proliferation depended on class II-restricted antigen presentation by accessory cells. As demonstrated by their reactivity to the monoclonal antibody W3/25, the clones were of helper cell phenotype. Cloned-cell proliferation depended on repeated (or continuous) exposure to antigen. When antigen was omitted from the system, cell growth subsided over time, and cells finally ceased to grow. By the use of the monoclonal antibody ART-18, which recognizes the interleukin-2 receptor, it was shown that cessation of growth was accompanied by the disappearance of interleukin-2 receptors from the cell surface. The addition of antigen to the culture resulted in the reexpression of interleukin-2 receptors and concomitant resumption of proliferation.

Studies on interleukin 2 receptor expression and IL-2 production by murine T cell lymphomas

In order to study the possible role of the T-lymphocyte growth factor, Interleukin 2 (IL-2), and/or of the IL-2 receptor in the autonomous growth of leukaemic cells, 15 mouse leukaemic cell lines of various aetiology were analyzed for (i) IL-2 receptor expression and (ii) for the capacity to secrete IL-2. Several but not all of the cell lines tested were IL-2 receptor positive. The cells constitutively expressing IL-2 receptors at their surface could not be stimulated to secrete IL-2. Cell producing and secreting IL-2 did not express detectable amounts of IL-2 receptors at their surface. It has been demonstrated that proliferation of the leukaemic cells was independent of exogenous IL-2. The monoclonal anti-IL-2 receptor antibody AMT-13 inhibited IL-2 dependent proliferation of activated normal T-lymphocytes but failed to inhibit the growth of IL-2 receptor expressing leukaemic cells. The results argue against the autocrine stimulation hypothesis but do not exclude the possibility of involvement of functionally altered IL-2 receptors on autonomous cell growth.

Immunohistochemical localization of cells reacting with monoclonal antibodies directed against the interleukin-2 receptor of murine, rat and human origin

Recently, species specific monoclonal antibodies, directed against the interleukin-2 (IL-2) receptor of murine, rat and human origin, have been produced. In this study we demonstrate with immunohistological methods that cells reacting with these antibodies are present in normal primary and secondary lymphatic organs. The cells are exclusively localized in T cell-dependent areas, and their number increased as a result of immunization.

Detection and localization by the monoclonal anti-interleukin 2 receptor antibody AMT-13 of IL 2 receptor-bearing cells in the developing thymus of the mouse embryo and in the thymus of cortisone-treated mice

During embryonic development of the mouse, before expressing classical T cell markers, the blast cells colonizing the thymus react with the monoclonal antibody AMT-13 shown previously to detect interleukin 2 receptors. The proportion of AMT-13+ cells decreases as gestation time increases. On the other hand, the proportion of Thy-1+, Lyt-1+ and Lyt-2+ cells increases during ontogenesis. On the 19th day of gestation when the thymus architecture is comparable to the adult thymus, the AMT-13+ cells become localized in the subcapsular area of the cortex. In the adult thymus after cortison treatment the regenerating cells express the AMT-13 antigen. The AMT-13 antigen presumably the interleukin 2 receptor is the first marker of the early embryonic thymocytes reported until now that may be related to cellular function.

Studies on the interleukin-2 receptor, its generation and dynamics using monoclonal anti-interleukin-2 receptor antibodies

There is increasing evidence suggesting that the monoclonal antibodies ART-18, AMT-13 and anti-Tac recognize species-specific antigenic determinants of the interleukin-2 (IL-2) receptors of rat, mouse and human origin, respectively. In order to compare directly the molecules (glycoproteins) recognized by these antibodies, concanavalin A (ConA) activated T-lymphocytes of the respective species were surface labeled with 125I, after which the materials immunoprecipitated by the appropriate anti-IL-2 receptor antibodies were subjected to SDS-PAGE analysis. The noncross-reacting antibodies ART-18 and AMT-13 both precipitated a 50-55-kD molecule. The anti-Tac-reactive material (the putative human IL-2 receptor) is considerably different (60-65 kD) from those precipitated by antibodies ART-18 and AMT-13 (the putative rat and mouse IL-2 receptors). An indirect binding assay using the anti-mouse IL-2 receptor antibody AMT-13 showed that, after addition of ConA to spleen cell cultures, T-lymphocytes expressed IL-2 receptors before the onset of the ConA-induced DNA synthesis. The ConA-induced expression of the IL-2 receptor is apparently a transient event. IL-2 receptor bearing cells progressively lost their receptors (within 6 days) when recultured in the absence of ConA. Cells re-exposed to ConA regained IL-2 receptors. Short exposure of T-cells (thymocytes) to ConA or the nonmitogenic compound phorbol myristate acetate (PMA) is not sufficient to trigger IL-2 receptor expression. Murine thymocytes incubated with PMA for 30 min or with ConA for 4 hr (mitogen-pulsed T-cells) failed to bind the anti-IL-2 receptor antibody AMT-13 and to absorb IL-2 activity present in semipurified IL-2 preparations, but they proliferated vigorously in response to the same IL-2 preparations. The IL-2 preparations, when absorbed with thymocytes, lost: (1) the capacity to generate IL-2 receptors, and (2) the capacity to induce proliferation of mitogen-pulsed cells; but they retained the capacity to induce proliferation of T-lymphoblasts. These results suggest the existence of a factor, IL-2 receptor inducing factor (RIF), present in the IL-2 preparations. It is postulated that RIF is a prerequisite for the acquisition of IL-2 receptors and consequently for IL-2 responsiveness by lectin-activated cells.

Interleukin 2 receptors on an insulin-specific T cell line: dynamics of receptor expression

Long-term cultured T blasts with specificity for bovine insulin (BK-BI-1.2), which cease growing in IL 2 supplemented medium and require periodic antigenic challenge to resume proliferation, were selected as a model system to analyze the regulation of the growth of activated T cells. The use of AMT-13, a monoclonal antibody (mAb) directed at the murine IL 2 receptor, in indirect binding experiments and in FACS analysis allowed us to examine the time-dependent expression of IL 2 receptors on BK-BI-1.2 blasts after antigenic stimulation. The data reveal a transitory expression of IL 2 receptors, attaining maximal levels on day 2 after antigenic induction and having declined to low levels by day 6. mAb 10-2.16, reactive with I-Ak, did not inhibit T cell-proliferative capacity when the cells were subcultured in IL 2. This result suggests that, once induced to maximal levels by antigen, the transitory expression of IL 2 receptors on the descendent cells is not dependent on the continual presence of antigen-presenting cells. Thus, the progressive loss of IL 2 receptors apparently is not due to a mechanism operating by clearance of receptors from the cell surface on completion of each cell cycle, leading to dependency of the descendent cells on repeated contact with antigen for renewed receptor expression. The disappearance of IL 2 receptors from the surface of antigen-stimulated T cells might provide a basis for the control of immunologic specificity in vivo.

Interleukin 2 receptors on an insulin-specific T cell line: dynamics of receptor expression

Long-term cultured T blasts with specificity for bovine insulin (BK-BI-1.2), which cease growing in IL 2 supplemented medium and require periodic antigenic challenge to resume proliferation, were selected as a model system to analyze the regulation of the growth of activated T cells. The use of AMT-13, a monoclonal antibody (mAb) directed at the murine IL 2 receptor, in indirect binding experiments and in FACS analysis allowed us to examine the time-dependent expression of IL 2 receptors on BK-BI-1.2 blasts after antigenic stimulation. The data reveal a transitory expression of IL 2 receptors, attaining maximal levels on day 2 after antigenic induction and having declined to low levels by day 6. mAb 10-2.16, reactive with I-Ak, did not inhibit T cell-proliferative capacity when the cells were subcultured in IL 2. This result suggests that, once induced to maximal levels by antigen, the transitory expression of IL 2 receptors on the descendent cells is not dependent on the continual presence of antigen-presenting cells. Thus, the progressive loss of IL 2 receptors apparently is not due to a mechanism operating by clearance of receptors from the cell surface on completion of each cell cycle, leading to dependency of the descendent cells on repeated contact with antigen for renewed receptor expression. The disappearance of IL 2 receptors from the surface of antigen-stimulated T cells might provide a basis for the control of immunologic specificity in vivo.

A rat monoclonal antibody that binds specifically to mouse T lymphoblasts and inhibits IL 2 receptor functions: a putative anti-IL 2 receptor antibody

To obtain an anti-interleukin 2 (IL 2) receptor antibody, we immunized rats with phorbol myristate acetate-pulsed mouse T lymphoblasts. The spleen cells of the rats were fused with rat myeloma cells. Several stable clones of hybridoma cells were obtained that produced monoclonal antibodies (mAb) reacting specifically with mouse T lymphoblasts. One of these mAb, AMT-13, showed characteristics of a putative anti-IL 2 receptor antibody. As tested by FACS analysis, the mAb AMT-13 binds to murine T lymphoblasts or to IL 2-dependent T cell lines, but not to B lymphoblasts, thymocytes, splenocytes, lymph node cells, or bone marrow cells. The mAb AMT-13 inhibited in a species-specific and dose-dependent manner: i) the capacity of mouse T lymphoblasts to absorb IL 2 activity, and ii) the capacity of mouse T lymphoblasts to proliferate in response to IL 2. The function of T lymphoblasts of rat origin was not affected by the mAb AMT-13. The time course of the acquisition by mitogen-stimulated spleen cells of the capacity to absorb IL 2 activity was paralleled by that of their capacity to bind the mAb AMT-13. Preliminary biochemical analysis of the antigen recognized by AMT-13 revealed a major component with an apparent m.w. of 50,000 to 60,000. According to these data, the mAb AMT-13 seems to be directed against an antigenic determinant of the murine IL 2 receptor molecule.

A rat monoclonal antibody that binds specifically to mouse T lymphoblasts and inhibits IL 2 receptor functions: a putative anti-IL 2 receptor antibody

To obtain an anti-interleukin 2 (IL 2) receptor antibody, we immunized rats with phorbol myristate acetate-pulsed mouse T lymphoblasts. The spleen cells of the rats were fused with rat myeloma cells. Several stable clones of hybridoma cells were obtained that produced monoclonal antibodies (mAb) reacting specifically with mouse T lymphoblasts. One of these mAb, AMT-13, showed characteristics of a putative anti-IL 2 receptor antibody. As tested by FACS analysis, the mAb AMT-13 binds to murine T lymphoblasts or to IL 2-dependent T cell lines, but not to B lymphoblasts, thymocytes, splenocytes, lymph node cells, or bone marrow cells. The mAb AMT-13 inhibited in a species-specific and dose-dependent manner: i) the capacity of mouse T lymphoblasts to absorb IL 2 activity, and ii) the capacity of mouse T lymphoblasts to proliferate in response to IL 2. The function of T lymphoblasts of rat origin was not affected by the mAb AMT-13. The time course of the acquisition by mitogen-stimulated spleen cells of the capacity to absorb IL 2 activity was paralleled by that of their capacity to bind the mAb AMT-13. Preliminary biochemical analysis of the antigen recognized by AMT-13 revealed a major component with an apparent m.w. of 50,000 to 60,000. According to these data, the mAb AMT-13 seems to be directed against an antigenic determinant of the murine IL 2 receptor molecule.

Partial characterization of the putative rat interleukin 2 receptor

T lymphoblasts of rat origin were (a) surface labeled with 125I and (b) internally labeled with 3H-marked sugars. Cell lysates were purified by immunoabsorption using the putative anti-rat interleukin 2 (IL2) receptor monoclonal antibody ART18 . The purified material was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoretic analysis. Two specific membrane components were detected: a 50-kDa major and a 36-kDa minor component in reducing and a 45-kDA major and a 72-kDa minor component in nonreducing conditions, respectively. Both components were found to be susceptible to trypsinization and to neuraminidase treatment. 3H-labeled sugars were incorporated into the major component. The results indicate that the rat IL2 receptor is either a 50-kDa glycoprotein or a 36-kDa molecule, or that both components are part of the receptor molecule.

Studies on T lymphocyte activation. II. Monoclonal antibody inhibiting the capacity of rat T lymphoblasts to absorb and to respond to IL-2: an anti-IL-2 receptor antibody?

We describe the production and some of the properties of a monoclonal antibody which inhibits binding of Interleukin 2 (IL-2) to rat T lymphoblasts as well as the capacity of these lymphoblasts to proliferate in response to IL-2 of rat or murine origin. According to these criteria, the antibody seems to be directed against an antigenic determinant on the IL-2 receptor. The antibody, obtained from hybridomas derived from mice immunized with phorbol-myristate-acetate-pulsed rat T lymphoblasts, exhibited species specificity, indicating that IL-2 receptors of various species are not necessarily identical, even if they can respond to IL-2 from different species.

The characteristics of a monoclonal antibody that binds specifically to rat T lymphoblasts and inhibits IL 2 receptor functions

In order to obtain an anti-interleukin 2 (IL 2) receptor antibody, we immunized mice with phorbol myristate acetate-pulsed rat T lymphoblasts. The spleen cells of the mice were fused with myeloma cells. Several stable clones of hybridoma cells were obtained that produced monoclonal antibodies (mAb) reacting specifically with rat T lymphoblasts. Only one of these mAb, the mAb ART18, showed characteristics of a putative anti-IL 2 receptor antibody. This mAb was produced on a large scale, purified, and characterized. As tested by a binding assay, 125I-labeled mAb ART18 bound to rat T lymphoblasts (7.5 X 10(4) binding sites per cell), but not to thymocytes or spleen cells of rat origin, or to lymphoblasts, thymocytes, or spleen cells of murine origin. Only marginal binding to lipopolysaccharide-stimulated rat lymphoblasts was detected. The mAb ART18 inhibited in a species-specific and dose-dependent manner i) the capacity of rat T lymphoblasts to absorb IL 2 activity and ii) the capacity of rat T lymphoblasts to proliferate in response in IL 2. The function of T lymphoblasts of murine origin was not affected by the mAb ART18. The time course of the acquisition by mitogen-stimulated spleen cells of the capacity to absorb IL 2 activity was paralleled by that of their capacity to bind 125I-labeled mAb ART18. According to these data, the mAb ART18 seems to be directed against an antigenic determinant of the IL 2 receptor molecule.

The characteristics of a monoclonal antibody that binds specifically to rat T lymphoblasts and inhibits IL 2 receptor functions

In order to obtain an anti-interleukin 2 (IL 2) receptor antibody, we immunized mice with phorbol myristate acetate-pulsed rat T lymphoblasts. The spleen cells of the mice were fused with myeloma cells. Several stable clones of hybridoma cells were obtained that produced monoclonal antibodies (mAb) reacting specifically with rat T lymphoblasts. Only one of these mAb, the mAb ART18, showed characteristics of a putative anti-IL 2 receptor antibody. This mAb was produced on a large scale, purified, and characterized. As tested by a binding assay, 125I-labeled mAb ART18 bound to rat T lymphoblasts (7.5 X 10(4) binding sites per cell), but not to thymocytes or spleen cells of rat origin, or to lymphoblasts, thymocytes, or spleen cells of murine origin. Only marginal binding to lipopolysaccharide-stimulated rat lymphoblasts was detected. The mAb ART18 inhibited in a species-specific and dose-dependent manner i) the capacity of rat T lymphoblasts to absorb IL 2 activity and ii) the capacity of rat T lymphoblasts to proliferate in response in IL 2. The function of T lymphoblasts of murine origin was not affected by the mAb ART18. The time course of the acquisition by mitogen-stimulated spleen cells of the capacity to absorb IL 2 activity was paralleled by that of their capacity to bind 125I-labeled mAb ART18. According to these data, the mAb ART18 seems to be directed against an antigenic determinant of the IL 2 receptor molecule.

[Comparative study on cefmetazole and cefazolin in the treatment of suppurative otitis media]

Cefmetazole (CMZ) was compared to cefazolin (CEZ) for efficacy and safety in the treatment of suppurative otitis media (including acute otitis media and chronic otitis media in acute aggravating stage) under well controlled clinical trials. The therapeutic effects were analyzed statistically in 172 patients (82 administered CMZ, 90 administered CEZ). The adverse reactions were also analyzed statistically in 199 patients (CMZ 99, CEZ 100) in whom the judgement was possible. 1. The efficacy rate of CMZ (72.3% for good to excellent response) was assessed by physicians in charge to be similar to that of CEZ (59.3%). This was the same being assessed by the committee, too (CMZ 64.6%, CEZ 56.7%). 2. When patients were classified into 2 groups (acute otitis media, chronic otitis media in acute aggravating stage) with respect to diagnosis, statistically significant difference in clinical efficacy assessed by physicians in charge was observed in the cases with chronic otitis media (CMZ, CEZ). In addition, the improvements of flares on the drum membrane and the mucous membrane of eardrum were significantly better in the CMZ group than in the CEZ group. 3. Bacteriologically, 16 cases (19.8%) of S. aureus were resistant to CEZ, while only 1 case (1.2%) to CMZ. CMZ was judged to be effective in 5 of the 6 cases in which CEZ-resistant strains were detected. 4. Side effects were found in 2 cases (2.0%) treated with CMZ: one complained of retching and abdominal pain and the other developed skin eruption. On the other hand, only 1 case (1.0%) developed skin eruption in the CEZ group. These results suggest that CMZ is a new antibiotic agent which is highly valuable in the treatment of suppurative otitis media.

Chitin: an immunological adjuvant and a polyclonal B-lymphocyte activator

Chitin, a linear beta 1-4 linked poly-N-acetylglucosamine, enhanced the in vivo immune response of normal mice to sheep red blood cells, but not that of mice with thymic aplasia (nude mice). The compound is mitogenic for murine B lymphocytes but not for thymocytes or splenic T lymphocytes. Similarly to well-known polyclonal B-lymphocyte activators; e.g. lipopolysaccharide, chitin induces differentiation of B lymphocytes into antibody-forming cells in vitro.

Treatment of postoperative respiratory distress syndrome

We have studied 45 patients with postoperative adult respiratory distress syndrome (ARDS) who were treated by mechanical ventilation during the last four years. This period was divided into two periods, and the mortality and progress after treatment were analysed. The overall, mortality was 56%. In the first period this rate was as high as 76%, while in the second period this rate improved to 43%. This improvement in the second period was thought to have resulted from aggressive cardiorespiratory treatment and the diminution of infection. According to the course of ARDS after treatment, four types could be classified. Type 1 showed rapid improvement in respiratory function. Type 2 showed gradual improvement. Type 3 showed relapse of respiratory failure. Type 4 resisted mechanical ventilation. Patients of types 3 and 4 had extremely poor prognoses. Stricter management to avoid infection, specific treatment of multiple organ failure (which was seen frequently) seemed advantageous. High frequency positive pressure ventilation (HFPPV) may have some role in improving the respiratory function of the patients with ARDS.