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Biomedical subjects

F Indiveri

Publications and source records attributed to F Indiveri.

At least 109 records · Page 6Linked to original sources
PubMed1984

Human T cells in cord blood: abnormalities in IA antigens induction by phytohemagglutinin and in autologous mixed lymphocyte reactions.

About 25% of human T cells isolated from cord blood acquired la antigens, following stimulation with phytohemagglutinin (PHA) for 72 hr. This percentage is markedly lower than that found in PHA-activated T-cell populations (PHA-T cells) isolated from peripheral blood of adults. The low expression of la antigens by human T cells from cord blood does not reflect abnormalities in the sensitivity to PHA stimulation and/or in the kinetics of induction of la antigens. PHA-T cells from cord blood display a low stimulatory activity in autologous mixed lymphocyte reactions (MLR). The defect does not reflect a nonspecific abnormality in the stimulatory activity of PHA-T cells from cord blood, since the latter do not differ from PHA-T cells from adults in their ability to stimulate allogeneic T cells from adults. Furthermore the defect does not reflect a nonspecific abnormality in the proliferative response of T cells from cord blood, since the latter display a normal proliferative response to PHA-T cells from adults. The defect in the proliferative response is not restricted to the autologous MLR with PHA-T cells, since it was found also in autologous MLR with non-T cells as stimulators. Correlation of the temporal evolution of the abnormalities of human T cells with the maturation of the immune system may contribute to our understanding of the role of la antigens in cell-cell interactions and of the biological significance of abnormalities of autologous MLR.

Cells, Cultured↗
PubMed1984

Role of normal adherent cells in the regulation of the autologous mixed lymphocyte reactions in humans.

The effect of normal adherent suppressor cells on the blastogenesis of human T lymphocytes in the mixed lymphocyte reaction (MLR) was studied in both allogeneic and autologous combinations. Non-T cells and Ia+ T lymphocytes were used as stimulator cells in both allogeneic and autologous MLR. The addition of adherent cells to the stimulators inhibited blastogenesis of T lymphocytes in both types of MLR when the stimulator population was made up of non-T lymphocytes but did not interfere with blastogenesis when Ia+ T lymphocytes were used as stimulator cells. The present data indicate that the T lymphocytes able to respond to Ia+ T cells (in the MLR, autologous or allogeneic) may be different from those which respond to non-T lymphocytes or may be less sensitive to the regulatory function of normal adherent cells.

Cell Adhesion↗
PubMed1984

Decreased sensitivity of T lymphocytes to normal adherent suppressor cells in patients with head and neck cancer.

The sensitivity of T Lymphocytes to the inhibitory action of normal adherent cells in the mixed lymphocyte reaction (MLR) was studied in 20 subjects with head and neck cancer. T lymphocytes from cancer patients proliferated in the MLR both in the absence and in the presence of increasing numbers of autologous as well as allogeneic adherent cells, while the blastogenesis of T lymphocytes from controls was inhibited up to 70% by the addition of adherent cells to the culture. Such a lack of sensitivity to adherent cells in cancer patients occurred both in allogeneic and in autologous MLR. These observations indicate that the immunocompetence of patients with head and neck cancer may be related to a defect of macrophage-T lymphocyte interaction similar to the one described in patients with common varied immunodeficiency.

Adult↗
PubMed1984

Effect of single oral doses of prednisone and deflazacort on human lymphocyte distribution and functions. Analysis with monoclonal antibodies.

Two corticosteroids, prednisone and deflazacort, have been compared with respect to their capacity of inducing redistribution of T lymphocyte subsets, modification of expression of Ia antigens by PHA primed T cells, and inhibition of blastogenesis of T cells in autologous mixed lymphocyte reactions. Both corticosteroids were able to induce T lymphocytes depletion, increase of suppressor T cells, inhibit Ia expression upon mitogenic activation of T lymphocytes, and inhibit autologous MLRs either when non T cells or when PHA T lymphocytes were used as stimulators. We conclude that deflazacort may constitute a better glucocorticoid than prednisone for correcting the imbalance among T cells subsets, the helper T cells activity and the processes of cell-to-cell cooperation in immune diseases.

Adult↗
PubMed1983

Inhibitory effect of a low dose of prednisone on PHA-induced Ia antigen expression by human T cells and on proliferation of T cells stimulated with autologous PHA-T cells.

Administration of a small dose of prednisone markedly reduced (1) the PHA-induced expression of Ia antigens by T cells, (2) the stimulatory activity of Ia antigen-bearing T cells in autologous and allogeneic mixed lymphocyte reactions (MLRs), and (3) the proliferative response of T cells stimulated with autologous PHA-activated T cells or autologous or allogeneic non-T cells. The inhibitory effects of prednisone are reversible and are not detectable on T cells isolated from blood drawn 24 hr following prednisone administration. The kinetics of the prednisone-mediated inhibition of MLRs with autologous PHA-T cells is different from that of MLRs with autologous non-T cells. These data in conjunction with the information available in the literature suggest that the mechanisms underlying these two types of autologous MLRs are different.

Adult↗
PubMed1983

Human T lymphocytes in aging and malignancy: abnormalities in PHA-induced Ia antigen expression and in functional activity in autologous and allogeneic MLR.

T lymphocytes from patients with solid tumors and from aged donors are abnormal in their expression of Ia antigens following in vitro stimulation with phytohemagglutinin (PHA). Ia antigens were not detected on PHA-activated T lymphocytes from 15 of 27 patients with solid tumors. The abnormality in T lymphocytes from 25 donors older than 60 years was evidenced by a reduction in the percentage of T cells acquiring Ia antigens following stimulation with suboptimal amounts of PHA and by a delayed appearance of those antigens. In both groups of donors the defect in Ia antigen expression by PHA-activated T cells did not correlate with the reduced [3H]thymidine uptake. PHA-activated T cells from aged donors and from patients with solid tumors were poorly stimulatory in autologous and allogenic mixed lymphocyte reactions. Furthermore, T lymphocytes from these two groups of donors displayed a reduced proliferative response to autologous non-T cells, but a normal proliferative response to allogeneic PHA-activated T cells and to non-T cells from control subjects.

Adult↗
PubMed1983

Role of distinct domains of Ia antigens in autologous and allogeneic mixed lymphocyte reactions.

Murine monoclonal antibodies (MoAb) to distinct determinants of human Ia antigens and low doses of prednisone induce different effects on the autologous mixed lymphocyte reaction (MLR), stimulated by PHA-T cells or by non-T cells, and on allogeneic MLRs. These results suggest that distinct domains of Ia antigens and/or mechanisms are involved in these types of MLRs.

Antibodies, Monoclonal↗
PubMed1982

Immunogenicity of serum HLA antigens in allogeneic combinations.

Immunization of patients with chronic renal insufficiency with plasma from selected donors elicited lymphocytotoxic antibodies. Analysis of these antibodies with Fab2 blocking assays showed that they are directed to HLA-A,B and to Ia-like antigens. These results indicate that serum HLA antigens are immunogenic in allogeneic combinations.

Animals↗
PubMed1981

Stimulation of human T lymphocytes by PHA-activated autologous T lymphocytes: analysis of the role of Ia-like antigens with monoclonal antibodies.

Human T lymphocytes activated with PHA express Ia-like antigens and acquire the ability to stimulate autologous T lymphocytes in mixed lymphocyte reaction. This reaction is immunological in nature since it has specificity and memory. Ia-like antigens play a role in the stimulation of T lymphocytes by autologous PHA-T lymphocytes since monoclonal antibodies to Ia-like antigens can significantly, although not completely, inhibit the stimulation.

Antibodies↗
PubMed1981

Characterization of human null cells isolated from peripheral lymphocytes by a simultaneous double-rosetting procedure.

Human null cells were isolated from peripheral blood lymphocytes (PBL) by differential centrifugation on a Ficoll-Hypaque gradient of the PBL following simultaneous rosetting with erythrocyte indicators specific for B and T lymphocytes. Specifically, the T lymphocytes were rosetted with 2-aminoethylisothiuronium bromide-treated sheep erythrocytes (ShE), whereas the B lymphocytes were either rosetted with ShE coated with xenoantibodies against human gamma globulin or first sensitized with monoclonal antibodies to human Ig-like antigens and then rosetted with ShE coated with xenoantibodies against mouse gamma globulin. Approximately 90% of the lymphocytes isolated were null cells that did not bear detectable B-cell markers-that is, surface immunoglobulin and/or Ia-like antigens-or T-cell markers-that is, ShE receptors. The large majority of the null cells expressed receptors for the IgG Fc fragment (53-93%), C3 component (65-92%) and monkey erythrocytes (60-91%) but lacked receptors for the IgM Fc fragment and murine erythrocytes. The null cells exhibited high natural killer cell activity and antibody-dependent cellular cytotoxicity and were two- to four-fold active than the total PBL and the T-enriched cell fractions. The null cells, however, did not respond to stimulation with phytohaemagglutinin and failed to function as either stimulators or responders in an unidirectional mixed lymphocyte reaction.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1981

Persistence of cytotoxic antibodies to HLA-A,B,C antigens and to Ia-like antigens in parous women.

Cytotoxic antibodies to HLA-A,B,C and to Ia-like antigens were detected in about 8% of sera drawn from 1312 women several years after their last pregnancy. In the majority of sera anti Ia-like antigen antibodies were not associated with anti HLA-A,B,C antibodies. Persistence of both types of antibodies was not correlated with the number of pregnancies and with the time interval between the last immunizing stimulus and the drawing of the sample. Testing of the sera with a panel of HLA typed lymphocytes identified 20 sera specific for HLA-A,B alloantigens and 7 specific for Ia-like alloantigens.

Antibodies↗
PubMed1980

[Antibody response to histocompatibility antigens in hemodialysis patients subjected to planned whole-blood transfusions].

In hemodialysis patients planned whole blood transfusions from single donors, induce the formation of anti HLA A, B, C and DR cytotoxic antibodies. The percentage of immunization, however, is lower than that observed in healthy subjects immunized following a similar transfusional schedule. This observation may reflect the existence in some patients of an impairment of the immune response to histocompatibility antigens. The production of lymphocytotoxic antibodies appear to be associated with severe graft rejections while anti HLA antibodies detected only by an indirect rosette assai don't seem to play a significant role in the outcome of the transplants.

Adolescent↗