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B J Alter

Publications and source records attributed to B J Alter.

At least 19 recordsLinked to original sources
PubMed1990

Cellular basis of the proliferative response of human T cells to mouse xenoantigens.

Purified human T cells respond proliferatively to allogenic peripheral blood mononuclear (PBMC) stimulating cells but show no response to murine splenic stimulating cells. Two possible explanations for the lack of xenogeneic response are that human T cells, educated in a human thymus, cannot directly recognize a molecule as disparate as mouse antigen encoded by H-2 and/or that a cytokine(s) produced by the APCs is needed to allow a proliferative response and that the cytokine(s) produced by murine APC do not provide an adequate stimulus to the human T cells under these conditions. We show here that highly purified human T cells can respond directly in an antigen-specific manner to murine stimulating cells if human rIL-1 or rIL-2 or a T cell growth factor (TCGF) preparation are present in the culture. These findings demonstrate that human T cells can recognize murine antigens and that a highly significant response can be obtained if a human cytokine is present to permit that response.

Animals↗
PubMed1987

Long-term growth of lymphokine-activated killer (LAK) cells: role of anti-CD3, beta-IL 1, interferon-gamma and -beta.

Peripheral blood lymphocytes (PBL) cultured in interleukin 2 (IL 2)-containing medium in conventional tissue culture develop the ability to lyse fresh tumor cells; such cells are referred to as lymphokine-activated killer (LAK) cells. LAK activity peaks by day 5 of culture and declines rapidly thereafter. We studied culture conditions and signals that allow for long-term culture and expansion of cells with LAK activity. By culturing cells at relatively low densities and regularly replenishing medium and recombinant IL 2 (r-IL 2), LAK function is significantly higher as compared with short-term cultures, and remains present for at least 21 days while cell numbers undergo an average 100-fold expansion. By activating these cultures with anti-CD3 (OKT3) monoclonal antibody and r-IL 2, an approximately 1000-fold expansion in the cell number is obtained with maintenance of comparable levels of LAK activity. The exogenous addition of beta interleukin 1 (beta-IL 1), interferon-beta (IFN-beta) or interferon-gamma (IFN-gamma) can augment the lytic activity of cell populations expanded by anti-CD3 plus r-IL 2. These approaches may enable the in vitro generation from individual donors of much greater numbers of LAK cells for adoptive immunotherapy than can now be obtained with the 3 to 5 day in vitro culture systems.

Antibodies, Monoclonal↗
PubMed1987

Long-term culture of LAK cells: expansion and activation signals.

Long-term culture of cells in rIL2-containing medium increases LAK activity on a per cell basis and produces an average 30-100-fold expansion over 14-21 days. The stimulation of PBL with anti-CD3 results in a 300-1000-fold increase in cell number while maintaining LAK activity. Cells stimulated with anti-CD3 and cultured in rIL2 for 12 days) can be further stimulated with beta IL1, or beta IFN, producing a further increase in LAK activity. These findings have allowed us to begin understanding the role of different signals in the activation of cells with LAK activity and together with biotechnological advances will allow for the culture of large numbers of cells for experimental and therapeutic purposes.

Antibodies, Monoclonal↗
PubMed1981

Early detection and specificity analysis of human cytolytic T lymphocyte (CTL) colonies generated in soft agarose culture: a potential assay for definition of CTL defined (CD) determinants.

In this communication we describe and early, large-scale screening assay for the detection of colonies with varied cytolytic specificity. The colonies are generated in soft agarose culture from day 3 mixed lymphocyte culture (MLC) alloactivated cells. A cell mediated lympholysis (CML) assay utilizing as few as 500 target cells has made it possible to prescreen for cytolytic T lymphocyte (CTL) colonies and to test for antigen specificities as early as 11 and 14 days, respectively, after MLC priming. Large numbers of colonies, from 80 to over 150, have been prescreened against a specific sensitizing target cell, and as many as 30 CTL colonies have been simultaneously tested against a panel of multiple targets carrying defined HLA-A, -B, -C, -DR antigens to evaluate antigen specificity. All CTL colonies are lytic against the specific sensitizing target cell and do not lyse the target autologous to the responder. Some are found to be operationally specific in that they lyse only those target cells which share HLA serologically defined (SD) antigens with the sensitizing cells, and other show cytolytic patterns which are not correlated with known HLA-SD antigens. These observations support, at a much finer level of analysis, the possible distinction between SD and CTL defined (CD) determinants.

Cells, Cultured↗
PubMed1980

Cloned primed-lymphocyte-test reagents in the dissection of HLA-D.

Human T lymphocytes obtained as blasts on day 4 from a primary mixed leukocyte culture (MLC) were cloned in the presence of T cell growth factor (TCGF) and feeder cells. Parameters important in producing higher-specific-activity TCGF were evaluated; irradiation of the responding cells as well as removal of adherent cells or inclusion of indomethacin in the culture was important. In addition, the presence of an irradiated lymphoblastoid cell line (LCL) cell in the TCGF-producing system enhanced activity in the supernate. The long-term maintenance of progeny from clones was achieved by utilizing the LCL autologous with either the responding or sensitizing cells from the initial MLC as feeder cells. Under those conditions, clones could be expanded for 7 or more wk with the maintenance of PLT reactivity. Had all the cells in each clone been maintained for the full 7 wk, more than 1 X 10(10) cells could have been developed in each clone. The cloned reagents provide a higher degree of antigen-specific reactivity than do normal PLT cells. It is to be anticipated that as the requirements for cloning are made more stringent, including the recloning of the cells, these reagents will aid greatly in the dissection of the complexity attendant to HLA-D.

Clone Cells↗
PubMed1980

TCGF production for cloning and growth of functional human T lymphocytes.

In an effort to increase the potency of T cell growth factor (TCGF), several variables were examined for their effects on the production of TCGF. The following manipulations enhanced the potency of TCGF: first, the removal of adherent cells and addition of indomethacin to the producing cultures; second, irradiation with 1000 rads of the cells used to produce TCGF; and, third, the addition of Epstein-Barr virus transformed lymphoblastoid (LCL) cells. It was also noted that the addition of irradiated feeder cells increased the efficiency of limiting dilution cloning.

Cell Division↗
PubMed1979

Lyt phenotypes of responding cells in secondary alloantigen responses.

Lymphocytes responding in a "secondary" MLC-CML system, after in vitro sensitization, apparently fall into two classes with regard to their Lyt phenotype. First, are the cells that form the majority of the proliferating cells after restimulation with either I or K + I differences, which are Lyt 1-2, and second, are Tc that are Lyt 1-2+. The Lyt 1-2- proliferating cells are not cytotoxic and are lysed by treatment with anti-Thy 1.2 serum in the presence of C.

Animals↗
PubMed1979

Past, present, and future aspects of histocompatibility.

We have stressed problems attendant on studies of the MHC, ignoring non-HLA factors and their role in allograft immunity. Many other topics could have been chosen for discussion is any such overview; our selection reflects our own interests. We felt assured, however, that excellent coverage by our many colleagues of the diverse and varied aspects of histocompatibility not approached in this summary has allowed us this freedom.

Cells, Cultured↗