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Biomedical subjects

H Blomgren

Publications and source records attributed to H Blomgren.

At least 163 records · Page 9Linked to original sources

Regulation of lymphocyte proliferation by soluble products released by stimulated human lymphocytes.

Human lymphocytes pulsed with phytothaemagglutinin (PHA) release mitogenic factors and other lymphokines upon subsequent incubation in fresh medium. Such active supernatants (SUPs) were assayed for their capacity to modify the DNA synthetic response of human lymphocytes exposed to various mitogenic stimuli. Both non-fractionated peripheral lymphocytes and preparations of fractionated T cells were stimulated by active SUPs to DNA synthesis. In contrast, active SUPs reduced the responses of lymphocytes to allogeneic cells, PPD tuberculin and PHA. These reductions were most evident at the end of the culture periods. The results suggest that soluble products released by stimulated lymphocytes activate suppressor lymphocytes which inhibit proliferative responses of lymphocytes.

Humans↗

Evidence that nonspecific inhibitors are induced by soluble products of activated human lymphocytes.

Cultures of lymphocytes stimulated by polyclonal mitogens or specific antigens exhibit an initial wave of cell proliferation followed by a decline which has been explained by the activation of suppressor T cells. This article presents the first results aiming at testing the possibility that the suppressor cells are activated by soluble products released by stimulated lymphocytes. It was found that the supernatants of PHA-activated human lymphocytes stimulate lymphocytes to DNA synthesis with peak responses occurring on day 5 independent of the cell concentration in the cultures. In contrast, the kinetics of lymphocyte responses to phytomitogens or in the mixed lymphocyte culture were found to be dependent on cell concentration; peak responses were delayed at decreasing cell concentrations. The results support the view that certain lymphokines released in stimulated lymphocyte cultures induce suppressor cells and that biologically active concentrations are reached earlier at high cell densities.

Cells, Cultured↗

Interferon and spontaneous cytotoxicity in man. II. Studies in patients receiving exogenous leukocyte interferon.

The spontaneous cytotoxicity of peripheral lymphoid cells from five tumor patients was measured before and at various times after the first injection of human leukocyte interferon (IF). Four of the patients' lymphocytes exhibited cytotoxicity before the IF injection. After injection of IF there was an initial decrease in cytotoxicity, followed by an increase to 1.5-5 times above the preinjection level, the peak being reached at 12 hours. Thereafter the spontaneous cytotoxicity decreased but usually remained elevated for 24 hours after the injection. The lymphocytes of the fifth patient had very low spontaneous cytotoxicity before the injection of IF, and this did not markedly change afterwards. The proportion of E-rosette forming cells seemed to decrease slightly in all patients after the injection, followed by a normalization at 24-48 hours.

Adolescent↗

Depressed responder and stimulator capacities of peripheral lymphocytes from patients with advanced breast cancer in the mixed lymphocyte culture.

Peripheral lymphoid cells of patients with carcinoma of the breast were examined for reactivity (responders) against allogeneic lymphoid cells in the one-way mixed lymphocyte culture. The latter cells were also tested for response against the patients' lymphocytes (stimulators). The responder and stimulator capacities of lymphoid cells of patients with advanced cancer were found to be significantly reduced compared to cells from healthy subjects. Such defects were not observed in disease-free women previously treated for primary carcinoma of the breast. The results support the view that there is an abnormality of the lymphocyte-monocyte pool of cells in patients with advanced cancer.

Antigens↗

Influence of an M-locus difference on the cellular and humoral immunological reactivity against H-2 determined antigens of the mouse.

Studies were initiated to determine whether an immune response to the Mls antigen of C3H mice could modify responses of CBA lymphocytes (H-2-compatible) to a foreign H-2 complex. CBA lymphocytes, partially tolerant to the C3H-determined Mls antigen, generated less effector cell activity against C57Bl cells (H-2-incompatible) than lymph node cells from normal CBA donors when infused into irradiated C3H X C57Bl hosts. Effector cell activity was measured as the capacity of the cells in the irradiated spleens to inhibit CBA X C57Bl bone marrow proliferation. In contrast, immunization of CBA mice with C3H X C57Bl cells yielded lower antibody titers against C57Bl cells than immunization with CBA X C57Bl cells. Furthermore, preinjection of CBA mice with C3H X CBA cells strongly reduced the capacity of the animals to produce antibodies against C57Bl cells. Thus, these data support the conclusion that an immune response to a foreign Mls antigen may either enhance or suppress an immune response to H-2-incompatible cells.

Animals↗

Subpopulations of cells involved in the human mixed lymphocyte culture response.

Various subpopulations of human peripheral lymphoid cells were tested for their role in the mixed lymphocyte culture (MLC) response. Preparations of lymphocytes enriched for T cells, separated by a rosette sedimentation technique, were usually found to exhibit higher MLC responses than preparations enriched for B cells. The relatively high responses of B-cell-enriched preparations could largely be explained by contaminating T cells (approximately 5%) whose MLC reactivities were strongly enhanced by autologous non-T lymphocytes. Cell preparations enriched for B cells were found to be more potent stimulations of MLC responses than T-cell-enriched preparations in most responder-stimulator cell combinations. An MLC response could only be elicited in the presence of cells with characteristics of monocytes/macrophages. These cells could be derived from either the responder or the stimulator.

B-Lymphocytes↗

Activated mouse lymphocyte release factors which modulate the proliferative responses of other lymphocytes.

Supernatants of mouse lymphocyte cultures briefly exposed to phytomitogens or various antigens may contain factors---lymphokines--which are mitogenic for lymphocytes in the absence of any additional stimulatory agents. Whether such supernatants can modulate the proliferative responses of lymphocytes exposed to phytomitogens or allogeneic cells is the subject of the present investigation. Active supernatants were obtained from cultures of either mouse lymph node cells incubated with concanavalin A bound to Sepharose or allogeneic cells for 24 h. Both types of active supernatants reduced the 3H-thymidine uptakes of lymph node cells and cortisone-resistant--medullary--thymocytes in response to various phytomitogens and allogeneic cells. In contrast, normal suspensions of mouse thymocytes, containing both cortical and medullary lymphocytes, exhibited stimulations higher than anticipated. The results indicate that activated lymphocytes may release factors which reduce proliferative responses of some lymphocytes, presumably immunologically mature T cells, and enhance the responses of other lymphocytes which are relatively immature.

Animals↗

Effect of radiation therapy on the mitogenic response of in vitro irradiated human lymphocytes to phytohaemagglutinin.

Irradiation of human peripheral lymphocytes in vitro reduces their capacity to be triggered to DNA-synthesis by PHA in a two-dose shaped fashion suggesting the presence of one relatively radiation sensitive and one relatively resistant cell population. Intracavitary and external radiation therapy for carcinoma of the uterus and vagina, which reduced the lymphocyte counts by approximately 66 per cent, did not significantly change the ratio of these subpopulations, indicating that PHA-reactive cells cannot be grouped into radiation sensitive and resistant subpopulations.

Cells, Cultured↗

Effect of bleomycin on peripheral lymphocytes.

Five patients with carcinoma of the penis receiving radiation therapy and injections of Bleomycin were examined to determine whether Bleomycin affects the peripheral pool of lymphoid cells. Total lymphocyte counts were not decreased, but transient reduction of the frequency of thymus-dependent cells occurred in 3 patients. The responses of the lymphocytes to phytomitogens and PPD were temporarily decreased these 3 patients. In 2 subjects the phytomitogen reactivity of the lymphocytes was improved after treatment.

Adult↗

Prognostic relevance of immunologic variables in breast carcinoma.

A series of 203 consecutive patients with operable carcinoma of the breast was analysed with regard to correlations between a set of immunologic and clinical variables existing at the time of the diagnosis. No major correlations were revealed between immunologic variables on the one hand and clinical features or the course of the disease on the other. The well-known prognostic relevance of tumour size, involvement of the axilla and the histological grade of malignancy was evident.

Autoantibodies↗

Blood lymphocyte subpopulations in breast cancer patients following radiotherapy.

Both T and non-T lymphocytes decreased immediately following radiotherapy in breast cancer patients. The relative depletion of non-T lymphocytes, however, was more marked than that of T cells. 3 years later the number and the proportion of non-T lymphocytes was higher than immediately after radiotherapy, while T lymphocytes were still depressed. The proportion of cells with membrane-associated Ig was higher in patients 3 years following radiotherapy than in non-treated patients and healthy controls. There was no difference in the proportion of T and non-T lymphocytes between patients with and without metastases, respectively.

Breast Neoplasms↗