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Biomedical subjects

H Oettgen

Publications and source records attributed to H Oettgen.

7 recordsLinked to original sources
PubMed1987

Requirements for activation of human peripheral blood T cells by mouse monoclonal antibodies to CD3.

The present study was undertaken in an attempt to reconcile the conflicting results concerning the signals required for the activation of human resting T cells by antibodies to the T-cell receptor/CD3 complex (Ti/CD3). For this purpose we have used highly purified peripheral blood T cells, depleted of monocytes and of preactivated Ia + T cells, to the extent that they were unable to proliferate to interleukin 2 (IL-2) alone or to optimal doses of phytohemagglutinin (PHA). To further minimize the contribution of contaminating monocytes, we used the anti-CD3 mAb, Leu-4, and cells from Leu-4 nonresponder subjects, whose monocytes we show completely fail to bind the Leu-4 mAb. The parameters of T-cell activation which we measured were rises in intracellular free calcium ion [Ca2+]i, IL-2 receptor expression IL-2 production, and cell proliferation. Our results indicate that induction of proliferation of resting T cells requires at least two signals. Signal one is best delivered by multivalent anti-CD3 mAb, such as Leu-4 mAb covalently linked to Sepharose 4B (Seph-Leu-4), or with Leu-4 mAb and anti-mouse IgG. These reagents crosslink the CD3 receptor complex on the T cell, and result in a rise in intracellular [Ca2+]i, in expression of receptors for IL-2, and in proliferation upon addition of IL-2. In contrast, purified T cells exposed to soluble Leu-4 mAb do not exhibit a rise in intracellular [Ca2+]i, do not express receptors for IL-2, and do not proliferate upon addition of IL-2, indicating that the valency of anti-CD3 mAb is critical for the delivery of the first activation signal to the T cell. The essential step of crosslinking of CD3 antigens on T cells by anti-CD3 mAb is normally mediated by monocytes which have bound anti-CD3 mAbs via their Fc receptors. Monocytes from Leu-4 nonresponder subjects, which we show fail to bind Leu-4 mAb, fail to crosslink CD3 antigens on T cells, resulting in failure of T-cell activation. The second signal needed for the proliferation of T cells whose Ti/CD3 complexes are crosslinked is IL-2. IL-2 production by such T cells required a monocyte delivered signal, which must be delivered to these T cells simultaneously with the crosslinking of their Ti/CD3 antigens. This IL-2-inductive signal can be delivered by both Leu-4 nonresponder and Leu-4 responder monocytes, indicating that delivery of this IL-2 inductive signal is independent of anti-CD3 mAb binding by monocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Structural characterization of the TAP molecule: a phosphatidylinositol-linked glycoprotein distinct from the T cell receptor/T3 complex and Thy-1.

Here we characterize the T-cell-activating protein (TAP), an Ly-6 gene product involved in T cell activation, as a glycoprotein with a molecular weight of 10-12 kd under nonreducing conditions and 15-18 kd under reducing ones. Two of the three bands that are precipitated from metabolically labeled cells are expressed on the cell surface and can be recovered from the supernatants of cells treated with a phosphatidylinositol-specific phospholipase C. Thus TAP appears to be attached to the cell membrane via this lipid. Precisely the same anchorage is observed for the activating Thy-1 molecule, and is therefore of particular interest as a potentially novel linkage involved in membrane signal transduction.

Antigens, Surface↗
PubMed1985

Human interferon alpha in malignant lymphoma and Hodgkin's disease. Results of the American Cancer Society trial.

Forty-nine patients with non-Hodgkin's lymphoma or Hodgkin's disease were entered into a multi-institutional phase II trial to evaluate the antitumor activity of human interferon alpha, prepared from buffy coats. Interferon alpha was administered intramuscularly in doses of 1 X 10(6) u, 3 X 10(6) u or 9 X 10(6) u daily for 30 days. Objective partial responses were seen in 3 of 18 patients with nodular lymphoma, all at the 9 X 10(6) u dose. Interferon alpha was not observed to be of therapeutic benefit in the other subtypes of non-Hodgkin's lymphoma or Hodgkin's disease. The major toxicities consisted of fatigue, fever, myalgias and weight loss. Serum interferon levels obtained 3 to 4 hours after injection varied widely, even among patients treated at the same dose level. Despite the relatively low doses of interferon used and the brief period of administration, this study extends the earlier observations of the antitumor effect of interferon in nodular lymphoma. These results are discussed in relation to the cumulative experience in human lymphoma using alpha interferons induced in human leukocytes and those produced in bacteria by recombinant DNA techniques.

Adolescent↗
PubMed1985

The T3/T cell receptor complex: antigenic distinction between the two 20-kd T3 (T3-delta and T3-epsilon) subunits.

Clonally distributed (clonotypic) antigen receptors on human T lymphocytes (alpha and beta chains) are associated with three invariable T3 polypeptide chains (T3 gamma, delta and epsilon), together forming the T3/T cell receptor complex. Monoclonal antibodies prepared against the two 20-kd T3 polypeptide chains demonstrated that T3-delta and T3-epsilon are distinct polypeptide chains. Only one monoclonal antibody (anti-T3-delta chain) reacted with the T cell surface as judged by indirect immunofluorescence, and by its mitogenicity for quiescent peripheral blood lymphocytes. Immunohistological staining and immunoprecipitation experiments showed that both the T3-delta and T3-epsilon chains are T cell-specific. As seen with the anti-alpha/beta chain reagent WT-31, anti-T3-delta chain monoclonal antibodies stained medullary thymocytes more intensely than cortical thymocytes, whereas the difference between the staining of cortical and medullary thymocytes was generally not apparent with anti-T3-epsilon chain antibodies. Because of this specificity and their ability to react with both the denatured and the native forms of each polypeptide chain, these new monoclonal reagents will be useful tools in studies of the biosynthesis and cell surface expression of the T3/T cell receptor complex during normal and malignant thymic differentiation.

Antibodies, Monoclonal↗
PubMed1975

T-cell deficiency in patients with squamous cell cancer of the head and neck.

Cellular immunity was assessed in patients with operable squamous cell cancer of the head and neck using in vivo skin tests and in vitro lymphocyte stimulation tests. An expansion of a previous study continued to show that 30 per cent of patients with T1N0M0 lesions were DNCB-negative and that with more advanced lesions there was further impairment. A similar finding was observed in the blastogenic response to phytohemagglutinin and concanavalin A but not pokeweed mitogen. Overall, 40 per cent of patients with resectable cancer had a significant depression of the blastogenic responses to conconavalin A and phytohemagglutinin. This depression ranged from 15 per cent in patients with T1N0M0 lesions to 71 per cent in those with T3N0M0 lesions. Although this depression was more severe in patients with palpable cervical node metastases, it was related more to the size of the primary tumor than to the nodes per se. An exception occurred in patients with large fixed nodes in whom the depression of lymphocyte stimulation was most severe. The absolute T-cell count was also depressed in patients with head and neck cancer. This depression parallelled the lymphocyte stimulation results with phytohemagglutinin and conconavalin A and was progressive with increasing stage of disease. A correlation exists between DNCB negativity and early recurrence and shortened survival. Clinical follow-up study is too short to assess the correlation of in vitro immune function with these clinical prognostic factors.

Alcoholism↗