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H Holte

Publications and source records attributed to H Holte.

77 records · Page 5Linked to original sources
PubMed1987

The activation-associated antigen 4F2 predicts patient survival in low-grade B-cell lymphomas.

Expression of the activation-associated 4F2 antigen, transferrin receptor and interleukin-2 (IL-2) receptor on suspended cells from 75 biopsied low-grade non-Hodgkin lymphomas (L-NHL) of B-cell origin was correlated to patient survival, clinical prognostic parameters and estimated DNA synthesis. 4F2 antigen expression correlated significantly with poor patient survival, high DNA synthesis and transferrin receptor expression. Transferrin receptor expression was associated with high DNA synthesis and treatment response, but not with patient survival. On the other hand, IL-2 receptor was correlated neither to patient survival nor to other studied markers for cell activation, but seemed to be expressed on certain subsets of lymphomas. We suggest that monoclonal antibody (MAb) against the activation-associated 4F2 antigen could be used to select patients with L-NHL for aggressive chemotherapy.

Antibodies, Monoclonal↗
PubMed1987

Activation of human B cells: alternate options for initial triggering and effects of nonmitogenic concentrations of anti-IgM antibodies on resting and activated cells.

The monoclonal antibody 1F5, which is reactive with the CD20 (Bp 35) pan-B cell antigen, was shown to activate resting human peripheral blood B cells into the middle to late G1 phase of the cell cycle. However, in contrast to F(ab')2 fragments of polyclonal anti-mu, 1F5 synergized only weakly with B cell growth factor (BCGF) for DNA synthesis in these cells. We provide evidence that the CD20 molecule and surface immunoglobulin represent two alternative activation pathways in resting B cells. We also show that anti-immunoglobulins, during co-stimulation with BCGF, may play an important role in G1 as well as for the initial cell triggering. Thus, anti-mu in nonmitogenic concentrations was shown to provoke distinct effects on 1F5-pretreated G1 cells, as monitored by increases in cellular volumes as well as in cytoplasmic Ca2+ levels. Moreover, anti-mu could increase c-myc mRNA levels in 1F5-primed cells, implying that c-myc expression can be regulated in G1 as well as during the initial G0 to G1 transition. Partially purified human BCGF neither induced G1 entry in resting peripheral blood cells nor primed the cells for DNA synthesis. The finding that BCGF did not influence c-myc mRNA levels in resting or in activated B cells suggests that its mitogenic action does not involve the c-myc function.

Antibodies, Anti-Idiotypic↗
PubMed1987

Downregulation of c-myc RNA is not a prerequisite for reduced cell proliferation, but is associated with G1 arrest in B-lymphoid cell lines.

We related the effects of c-myc expression on the ability of growth inhibitors to block the cells in the G0/G1 phase of the cell cycle. In two different B-cell lines, there was an association between the accumulation of cells in the middle to late G1 phase of the cell cycle and a rapid transient downregulation of c-myc mRNA levels. The phorbol ester TPA and the adenylate cyclase activator forskolin reduced the c-myc RNA, levels and after 3 days of treatment a proportion of the cells accumulated in G1. In contrast, neither interferon-gamma, tumor necrosis factor-alpha nor the monoclonal antibody 33-1 against DQ major histocompatibility antigens changed the cell-cycle distribution or regulated the c-myc RNA levels. Yet, all five growth inhibitors reduced the proliferation to approximately the same extent. The growth reduction was not accompanied by definite differentiation, as judged by the absence of the B-cell differentiation marker B1 (CD20).

B-Lymphocytes↗
PubMed1987

Transforming growth factor type beta (TGF beta) inhibits G1 to S transition, but not activation of human B lymphocytes.

Type beta transforming growth factor (TGF beta) is a polypeptide that may influence the growth of a variety of cell types in a positive or negative fashion. In this study we show that TGF beta markedly inhibits DNA synthesis in normal and neoplastic human B lymphocytes stimulated to proliferate with anti-immunoglobulins and B-cell growth factor (BCGF). Although TGF beta was needed during the initial 12 h of the culture to promote optimal inhibition, we found that it had little or no effect on several early to intermediate parameters of cell activation [( Ca2+]i increase, c-myc mRNA increase, cellular enlargement, RNA increase, and the increase in the expression of the 4F2 activation antigen). In contrast, TGF beta almost completely blocked the induction of transferrin receptor expression, which normally occurs in the late G1 phase of the cell cycle. Therefore, we conclude that TGF beta treatment leads to arrest of the cells in the middle to late G1 phase, prior to transferrin receptor expression.

Antibodies, Anti-Idiotypic↗