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Biomedical subjects

A Mazumder

Publications and source records attributed to A Mazumder.

At least 145 records · Page 8Linked to original sources
PubMed1984

Phase I study of the adoptive immunotherapy of human cancer with lectin activated autologous mononuclear cells.

In previous in vitro studies, the authors showed that phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes (PBL) from cancer patients to generate cells that were lytic for fresh autologous tumor but not for lymphocytes or lymphoblasts. Thus, after IRB approval, a phase I clinical protocol was instituted in cancer patients who had failed all other therapy to determine the toxicity and effects, in vivo, of the infusion of large numbers of such PHA activated autologous PBL. Ten patients were treated on the protocol, six with sarcoma, one with melanoma, and three with colorectal cancer. Up to a total of 1.7 X 10(11) PBL were obtained from 7 to 15 successive leukaphereses, the cells from each leukapheresis being incubated in vitro in medium containing PHA and human AB serum for 2 days and then reinfused following the next leukapheresis 2 days later. Toxicity encountered included fever and chills in 10/10 patients, headaches in 5/10, nausea and vomiting in 3/10, and requirement for erythrocyte transfusion in 8/10. No evidence for autoimmune disease, abnormal serum chemical or coagulation studies, or pulmonary emboli was found. 111Indium trafficing studies showed distribution of infused cells mainly to the spleen and liver, with some accumulation in the lungs and tumor especially after repeated infusions. In 9/10 patients, activated PBL were detected in the peripheral circulation by the sixth leukapheresis. Evidence for this was found by assaying the incorporation of tritiated thymidine (3H-Tdr) into, and lysis of fresh tumor cells by, unstimulated PBL from successive leukaphereses. No tumor regression was seen in these patients with bulk disease. These studies demonstrated that large numbers of PHA-activated PBL can be safely obtained and infused into humans, achieving an increase in the number of circulating activated cells with evidence of migration of cells to tumor, lungs, liver and spleen. Further studies of the use of activated lymphocyte infusion in conjunction with chemotherapy in humans are in progress.

Adult↗
PubMed1984

Successful immunotherapy of natural killer-resistant established pulmonary melanoma metastases by the intravenous adoptive transfer of syngeneic lymphocytes activated in vitro by interleukin 2.

In previous in vitro studies, we have shown that murine splenocytes or cancer patient lymphocytes incubated in IL-2 become lytic for fresh syngeneic or autologous tumors. We have now performed the adoptive transfer of such lymphokine-activated killer (LAK) cells in a murine B16 metastasis model to test their in vivo efficacy. 1 X 10(8) LAK cells, infused intravenously into C57BL/6 mice with established B16 pulmonary metastases, led to a marked decreased in the number of lung nodules and improved survival. LAK cells administered 3 d after amputation of a tumor-bearing limb also decreased the incidence of spontaneous pulmonary metastases. LAK cells generated from tumor-bearer splenocytes had effects equivalent to those from normal animals, and this antimetastatic effect of the LAK cells did not require the prior administration of cyclophosphamide or other immunosuppressants. Fresh or unstimulated splenocytes had no effect. The antitumor effectors and precursors in vivo and in vitro were Thy-1+. The lymphokine required for the activation appeared to be interleukin 2 (IL-2), since incubation in partially purified supernatants from PMA pulsed EL-4 or Con A-pulsed splenocytes or purified Jurkat IL-2 led to the generation of LAK cells equally active in vivo. The use of IL-2-activated cells may provide a valuable method for the adoptive therapy of human neoplasms as well.

Animals↗
PubMed1983

Lymphokine-activated killer cell phenomenon. II. Precursor phenotype is serologically distinct from peripheral T lymphocytes, memory cytotoxic thymus-derived lymphocytes, and natural killer cells.

Culture of human peripheral blood lymphocytes (PBL) in partially purified and lectin-free interleukin 2 results in the generation of cytotoxic effector cells which have the unique property of lysing natural killer (NK)-resistant fresh human tumor cells. We have termed these effector cells "lymphokine- activated killer" cells (LAK). LAK are generated from both normal and cancer patients' PBL and are able to lyse both autologous and allogeneic tumor cells from all histologic tumor types tested. Our previous studies suggested that the LAK phenomenon was distinct from either the cytotoxic thymus-derived lymphocyte (CTL) or NK systems based on a variety of criteria. This study reports that the cell type involved is also distinct, as determined by phenotypic characteristics. The LAK effector cell phenotype was analyzed in parallel with alloimmune CTL, and LAK were found to be similarly susceptible to the monoclonal anti-T cell antibodies OKT-3 or OKT-8 plus complement. In contrast the LAK precursor was not susceptible to the OKT-3 or Leu-1 antibodies plus complement, while the ability to generate alloimmune CTL was totally obliterated when tested using the same PBL responder population; in fact, generation of LAK was found to be augmented five- to sixfold, clearly suggesting that LAK precursor cells are not T lymphocytes as defined by these antibodies. LAK precursors were found to be abundant in NK cell-enriched Percoll gradient fractions, which had been depleted of the 29 degrees C E- rosetting "high affinity" T cells. However, LAK precursors were found to be distinct from the majority of NK cells since lysis of fresh PBL with the monoclonal antibodies OKM-1, Leu-7, or OKT-11 significantly depleted or totally eliminated NK activity, while subsequent activation of the remaining cells generated high levels of LAK and in some cases augmented levels of LAK. LAK precursors were found to be distributed in the thymus, bone marrow, spleen, lymph node, and thoracic duct in addition to the PBL. Therefore, while the cell(s) responsible for activation and expression of LAK activity have some common features with the classic T cell-mediated CTL and NK cell systems, the LAK precursor cells are clearly distinct as determined by phenotype analysis using monoclonal antibodies and complement, and at present must be classified as a "null" cell.

Animals↗
PubMed1983

Lysis of fresh human solid tumor cells by autologous lymphocytes activated in vitro by allosensitization.

We have previously demonstrated that cancer patients' peripheral blood lymphocytes (PBL) allosensitized against single or pool normal donor PBL are capable of lysing fresh autologous tumor cells in a 4-h 51Cr-release assay. In this report, we present further investigations into this phenomenon. These alloactivated killer cells (A-AK cells) lysed autologous and allogeneic tumors and allogeneic but not autologous PBL. Furthermore, cold target inhibition studies demonstrated that autologous and allogeneic tumors were lysed by the same effector cells. Multiple metastases from the same patient were equivalently lysed by these A-Ak cells. The presence of adherent cells and proliferation of the precursors were necessary to generate A-AK cells, although the effector cell itself was radioresistant and nonadherent. The effects of allosensitization were enhanced by the addition of lectin-free interleukin-2 preparations to the in vitro culture by partial depletion of adherent cells prior to sensitization. The A-Ak effector cell was OKT3+, OKT8+, OKT4-, OKM1- and could be generated by just 3 days of allosensitization. The precursors for A-Ak cells could be separated from NK cells on percoll gradients and lysis could be generated from thoracic duct lymphocytes, a population devoid of NK cells. The phenotype of the majority of the precursor cells was OKT3+, OKT4-. Theses alloactivated PBL could be expanded in crude or lectin-free interleukin-2 without loss of cytotoxicity for fresh autologous tumor cells. Activated T cells represent a population of on-NK cells with broad lytic specificity for fresh tumor cells. Such cells may be of value in the adoptive immunotherapy of human solid tumors and may play a role in immune surveillance.

Antigens, Surface↗
PubMed1983

Lysis of fresh natural killer-resistant tumor cells by lectin-activated syngeneic and allogeneic murine splenocytes.

This paper demonstrates that lectin-activated lymphocytes of selected mouse strains can lyse fresh autologous or allogeneic tumor cells but not the fresh normal cells tested in short-term 51Cr release assays. Murine splenocytes, incubated with concanavalin A for 3 days, lysed tumor cells from fresh syngeneic P815 mastocytoma, 102 methylcholanthrene sarcoma, and FBL3 lymphoma; fresh allogeneic 3LL lung carcinoma and MethA sarcoma; and tissue-cultured YAK cells in 18-hr51Cr release assays. Natural killer cells in fresh splenocyte preparations only lysed tissue-cultured YAK cells and not the other targets. Syngeneic and allogeneic lymphoblasts, lung, or liver cells were not lysed by the concanavalin A-activated killer (CAK) cells. The induction of cytotoxicity by concanavalin A incubation was abrogated by alpha-methylmannoside in the 3-day incubation, but not in cytotoxicity assay. Radiosensitive cells and adherent cells were necessary for the generation of CAK cells. The CAK effectors themselves were radioresistant, nonadherent, and mostly Thy 1+ and Ly 2+. The CAK phenomenon may be mediated by lymphokine production by an Ly 1+ cell, since depletion of Ly 1+ cells prior to activation abrogates CAK induction, and the ability of numerous mouse strains (and nude mice) to generate CAK cells correlated with their ability to produce Interleukin 2. The biological and therapeutic role of these cells is currently being investigated in murine syngeneic primary and metastatic tumor models.

Animals↗
PubMed1983

Characterization of the lysis of fresh human solid tumors by autologous lymphocytes activated in vitro with phytohemagglutinin.

Human peripheral blood lymphocytes (PBL), obtained from patients with a variety of malignancies, when incubated in vitro with phytohemagglutinin (PHA), lysed fresh autologous tumors during a short-term 51Cr-release assay. These PHA-activated killer (PAK) cells produced maximum lysis of tumor cells by 4 to 8 hr of co-cultivation. PHA incubation induced the generation of cells lytic for autologous and allogeneic tumors but not autologous or allogeneic PBL. Cold target inhibition studies demonstrated that autologous and allogeneic tumors of various histologic types all shared the determinants recognized by PAK cells. Some adherent cells were necessary for generation of these PAK, but higher numbers were suppressive. Augmentation of tumor cell lysis was seen when adherent cells were partially removed before PHA activation. The PAK effector cell was OKT3+, OKT8+. The precursor cell of the PAK was separated from natural killer (NK) cells on Percoll gradients and was generated from thoracic duct lymphocytes, a population devoid of NK cells. Furthermore, the phenotype of the majority of the precursor cells was OKT3+, OKM1-. Activation by PHA for 2 days was found to be an efficient and convenient method for generating lymphoid cells lytic for fresh autologous human tumor. The biologic and possible therapeutic role of these cells is currently being investigated.

Cell Adhesion↗
PubMed1982

Lymphokine-activated killer cell phenomenon. Lysis of natural killer-resistant fresh solid tumor cells by interleukin 2-activated autologous human peripheral blood lymphocytes.

Activation in lectin-free interleukin 2 (IL-2) containing supernatants of peripheral blood mononuclear leukocytes (PBL) from cancer patients or normal individuals resulted in expression of cytotoxicity toward 20 of 21 natural killer (NK)-resistant fresh solid tumor cells tested. Fresh solid tumor cells were resistant to NK-mediated lysis in 10 autologous patients' PBL-tumor interactions, and from 17 normal individuals tested against 13 allogeneic fresh tumors. Culture of PBL in IL-2 for 2-3 d was required for the lymphokine activated killers (LAK) to be expressed, and lytic activity toward a variety of NK-resistant fresh and cultured tumor targets developed in parallel. Autologous IL-2 was functional in LAK activation, as well as interferon-depleted IL-2 preparations. Irradiation of responder PBL before culture in IL-2 prevented LAK development. Precursors of LAK were present in PBL depleted of adherent cells and in NK-void thoracic duct lymphocytes, suggesting that the precursor is neither a monocyte nor an NK cell. LAK effectors expressed the serologically defined T cell markers of OKT.3, Leu-1, and 4F2, but did not express the monocyte/NK marker OKM-1. Lysis of autologous fresh solid tumors by LAK from cancer patients' PBL was demonstrated in 85% of the patient-fresh tumor combinations. Our data present evidence that the LAK system is a phenomenon distinct from either NK or CTL systems that probably accounts for a large number of reported nonclassical cytotoxicities. The biological role of LAK cells is not yet known, although it is suggested that these cells may be functional in immune surveillance against human solid tumors.

Adolescent↗
PubMed1982

Development of long-term cell lines and lymphoid clones reactive against murine and human tumors: a new approach to the adoptive immunotherapy of cancer.

We have investigated the use of T-cell growth factor (TCGF) to isolate and grow, in long-term culture, lymphoid cells with immunologic reactivity directed against syngeneic murine and autologous human tumors. Splenocytes from mice immune to a methylcholanthrene-induced sarcoma were expanded in TCGF, both before and after in vitro mixed lymphocyte-tumor cultures, and expressed high levels of cytotoxicity for fresh syngeneic solid tumor cells. Cloned lines have been isolated with a high level of specific lysis for the immunizing tumor. Similar studies of cytotoxic reactivity to a syngeneic FBL-3 lymphoma have given rise to long-term cytotoxic cell lines growing in TCGF capable of curing mice with disseminated lymphoma in adoptive transfer studies. Exposure to TCGF, of human peripheral lymphoid cells from cancer-bearing patients, results in the development of cytotoxicity to autologous fresh tumor. We have used clonal analysis by limiting dilution techniques to isolate individual cloned cells with this autologous antitumor reactivity. Infusion to autologous cytotoxic cells expanded 10,000-fold in TCGF and labeled with 111In into three cancer patients resulted in cell localization initially to the lung and subsequently to the liver and spleen. The application of these techniques for the cloning and expansion of antitumor T-lymphoid cells in TCGF has offered a new approach to adoptive immunotherapy.

Animals↗
PubMed1982

Lysis of fresh human solid tumors by autologous lymphocytes activated in vitro with lectins.

Human peripheral blood lymphocytes (PBL), obtained from patients with a variety of cancers, were incubated in vitro with phytohemagglutinin, concanavalin A, and crude or lectin-free T-cell growth factors. The lectin-activated PBL of nine patients were capable of lysing fresh autologous tumor during a 4-hr 51Cr release assay. Multiple metastases from the same patient were equivalently lysed by these activated autologous PBL. No lysis of fresh PBL or lectin-induced lymphoblast cell targets was seen, although tumor, PBL, and lymphoblast cells were shown to be equally lysable using allosensitized cells. The activated cells could be expanded without loss of cytotoxicity in crude or lectin-free T-cell growth factors. The generation of cells lytic to fresh autologous tumor was dependent on the presence of adherent cells, although the lytic cell itself was not adherent. Proliferation was not involved in the induction of lytic cells since equal lysis was induced in irradiated and nonirradiated lymphocytes. Lectin was not required in the lytic assay, and the addition of alpha-methyl-D-mannoside to concanavalin A-activated lymphoid cells did not increase the lysis of fresh tumor cells. Activation by lectin for 3 days appears to be an efficient and convenient method for generating human cells lytic to fresh autologous tumor. These lytic cells may be of value for studies of the cell-mediated lysis of human tumor and possibly for tumor immunotherapy as well.

Breast Neoplasms↗
PubMed1981

Characterization of rat colonic epithelial cell populations.

Colonic epithelial cells from male Sprague-Dawley rats were isolated by incubating everted colon with hyaluronidase suspended in Puck's saline F with an average cell yield of 120 x 10(6). These cells were fractionated by discontinuous Ficoll gradient and by short-term cell culture techniques. Centrifugation of isolated cells on discontinuous Ficoll gradient (15-35%) yielded populations differing in their proliferative activity. Additionally, a short-term cell culture technique was standardized to fractionate these cells according to their proliferating activity as judged by their DNA synthesis and thymidine kinase activity. Viability of these cells were judged by trypan blue exclusion, capacity to oxidize glucose and incorporation of precursors into protein DNA, RNA and glycoproteins. These fractionated cells were examined and identified by cytological studies. Cells showing proliferative activity sedimented at heavier regions of the Ficoll gradient, and the majority of these cells attached to the surface under conditions of short-term culture. Columnar mature absorptive cells and mucus-secreting goblet cells that showed very little proliferative activity sedimented at lighter zones of the Ficoll gradient and a major portion of these cells failed to attach by the cell culture method.

Animals↗
PubMed1981

Lysis of fresh and cultured autologous tumor by human lymphocytes cultured in T-cell growth factor.

Human lymphocytes derived from the peripheral blood of patients with a variety of cancers were grown in T-cell growth factor (TCGF) and tested in a 4-hr 51Cr microcytotoxicity assay against fresh and cultured autologous tumor, autologous cultured skin fibroblasts, and autologous fresh peripheral blood lymphocytes. Lymphocytes grown in TCGF caused significant lysis of autologous cultured tumor and fibroblasts but caused little lysis of fresh autologous peripheral blood lymphocytes in all of seven patients tested. This lytic activity against autologous cultured cells was not dependent on the source of serum used in culturing the lymphoid cells or the targets. Lymphoid cells grown in TCGF also were capable of causing selective lysis of fresh autologous tumor cells that had never been in culture in five of nine patients. Lymphoid cells growing in lectin-free TCGF caused selective lysis of autologous tumor in five of seven patients. These observations demonstrate that peripheral lymphoid cells grown in TCGF can be lytic for autologous cultured and autologous fresh tumor compared to the lysis of fresh autologous peripheral blood lymphocytes. The fact that these autoreactive cells, lytic for tumor, may be expanded to large numbers in TCGF suggests a possible role for these cells in studies of the control of the cytotoxic response of activated cells to tumor and possibly in the immunotherapy of tumors as well.

Adult↗
PubMed1981

Lysis of human solid tumors by autologous cells sensitized in vitro to alloantigens.

Human lymphocytes sensitized in vitro to allogeneic single-donor cells as well as to pools of allogeneic donor cells were evaluated for their cytotoxic potential against autologous fresh solid tumor cells, autologous tissue-cultured tumor and fibroblasts, fresh peripheral blood lymphoid cells (PBL), and Con A blasts of PBL. Using 4-hr 51Cr release assays, pool-sensitized effector cells lysed autologous tissue-cultured tumor and fibroblast targets in 4 of 4 experiments. Similarly, in 2 of 2 experiments with single-donor allosensitized effectors, autologous tissue-cultured tumor was lysed. No lysis of fresh PBL was seen. Significant lysis of fresh autologous tumor target cells was seen in 10 of 12 experiments with pool-sensitized effectors, though, again, no lysis of autologous PBL was observed. No lysis of autologous Con A blasts was seen in 2 of 2 experiments. Fresh tumor cells, PBL, and Con A blasts appeared equally lysable, since they were equally lysed by effector cells specifically sensitized to alloantigens present on these cells. Cold target inhibition studies demonstrated that cultured tumor and fibroblasts but not PBL shared the determinants recognized by pool-sensitized cells.

Animals↗
PubMed1978

DNA synthesis and thymidine kinase activity of rat colon epithelial cells fractionated by discontinuous Ficoll gradient.

Epithelial cells from colons of adult Sprague-Dawley rats were fractionated on a discontinuous Ficoll gradient at low centrifugal forces (170 x g) for approximately 60 minutes. Epithelial cells were separated into three distinct zones, whereas cell debris, yeast, and bacteria remained at the top of the gradient. The percentage of cells in each zone was inversely related to the density of the gradient. More than 95% of the cells were morphologically intact and viable (excluded trypan blue). Cells sedimenting at higher densities of Ficoll exhibited higher thymidine kinase activity and DNA synthesis, suggestive of active cell division. The cells sedimenting at lower densities of Ficoll showed the least thymidine kinase activity and DNA synthesis, properties that are compatible with those of mature absorptive cells. Tall columnar cells with vesicular nuclei were predominant in the fraction sedimenting at the lowest density (top fraction). At higher densities (middle and lower fractions), most of the cells were short and columnar with basally located condensed dark-staining nuclei.

Animals↗