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Biomedical subjects

S Gillis

Publications and source records attributed to S Gillis.

At least 253 records · Page 14Linked to original sources
PubMed1979

The in vitro generation and sustained culture of nude mouse cytolytic T-lymphocytes.

In addition to allowing for the long-term culture of both murine and human cytolytic T lymphocytes, T-cell growth factor (TCGF) functions as the key proliferation-inducing second signal in both T-cell antigen sensitization and mitogenesis. The observation that thymocytes responded normally to T-cell mitogens in the presence of TCGF, prompted the investigation of the effect of TCGF on nude mouse lymphocyte responses in vitro. We found that spleen, lymph node, and bone marrow cells, isolated from nude mice, were incapable of producing TCGF yet responded normally to T-cell mitogen sensitization provided stimulation was conducted in the presence of TCGF. Nude mouse spleen cells were also capable of responding to alloantigen sensitization in mixed lymphocyte cultures (NLMC) conducted in the presence of TCGF. Thy-1 antigen-positive cells harvested from TCGF-supplemented nude mouse MLC effectively mediated the cytolysis of alloantigen-specific target cells as tested in standard 51Cr-release assays. Cytolytic nude mouse effector cells have remained in TCGF-dependent culture for over 3 mo during which they have continued to mediate significant levels of alloantigen-specific cytolytic reactivity. These results suggest that prothymocytes present in nude mice are capable of responding to immunologic stimuli by differentiating, in vitro, into cytolytic T lymphocytes and that furthermore, a major function of the thymus may be to effect the maturation of TCGF-producing cells.

Animals↗
PubMed1979

Monoclonal cytolytic T-cell lines.

Monospecific cloned cytolytic T-lymphocyte lines have been created utilizing T-cell growth factor. The clones were found to retain their cytolytic specificity after prolonged culture and monospecific function was demonstrated by subcloning procedures. Thus, detailed studies of the phenotypic and functional characteristics of monospecific, homogeneous, cytolytic T lymphocytes will now be possible.

Animals↗
PubMed1978

Long-term culture of human antigen-specific cytotoxic T-cell lines.

Long-term cultures of human cytotoxic T-cell lines (H-CTLL) were established. H-CTLL cells were strictly dependent on growth upon a T-cell growth factor (TCGF) produced by phytohemagglutinin-stimulated normal human peripheral blood lymphocytes. H-CTLL cells were maintained in TCGF-dependent exponential proliferative culture for over 4 mo during which time they continued to mediate stimulator antigen-specific cytotoxicity as measured by a 4-h 51Cr-release assay. H-CTLL cells recovered from cryopreserved stocks and re-established in long-term culture demonstrated similar high levels of antigen-specific cytotoxicity. H-CTLL cells were 95--100% E-rosette positive and expressed normal T and Ia-like cell surface markers. The ability to sustain differentiated antigen-specific T-effector cells in long-term culture may provide a new means for the study of both the mechanism and regulation of T-cell-mediated immunity.

Antigens↗
PubMed1978

The detection of a spleen focus-forming virus neoantigen by lymphocyte-mediated cytolysis.

The existence of a nonvirion tumor-associated cell surface antigen (TASA) on cells transformed with Friend (FLV) on Rauscher (RLV) leukemia virus has been difficult to demonstrate. Antisera raised against classically defined Friend- Moloney-Rauscher antigenic determinants have been shown to react with virus structural proteins coded for by genetic information contained in the lymphatic leukemia or helper (LLV) virus genome. The recent development of nontrans-formed fibroblast cell lines which contain the replication-defective spleen focus-forming virus (SFFV) genome, free of replicating LLV, has allowed investigation of an SFFV-specific antigen. We have applied the techniques of mixed tumor-lymphocyte culture stimulation followed by lymphocyte-mediated cytolysis assays to search for the cell surface expression of an antigen coded expressly by SFFV genetic information. SFFV nonproducer-immune, in vitro activated spleen cells were capable of effecting the lysis of SFFV-containing BALB/c 3T3 and Fischer rat epithelial, cloned cell lines. Normal BALB/c 3T3 and BALB/c 3T3 cells infected with three types of ecotropic LLV were unaffected. Syngeneic FLV and RLV-induced murine leukemia cells were also killed by SFFV nonproducer-immune lymphocytes. In addition, Kirsten sarcoma virus-transformed, replication-defective and replication-rescued BALB/c 3T3 fibroblasts were not susceptible to SFFV antigen-directed cytolysis. Antibody-dependent complement-mediated cytolysis assays using monospecific goat antisera confirmed that SFFV nonproducers lacked cell surface expression of virion structural proteins. These observations suggest that the antigen detected in LMC experiments was not coded for by genetic information contained in the helper component of FLV, and that it represents a true SFFV-specific cell surface antigen. Based upon the recent molecular evaluation of the SFFV genome as consisting of both xenotropic and ecotropic virus sequences, it appears reasonable that xenotropic genetic information may be responsible for expression of the SFFV- specific antigen. Since the replication-defective SFFV genome is also responsible for the malignant transformation associated with FLV-induced erythroleukemia, one might postulate that gene sequences capable of programming transformation may also code for the TASA detected in these studies.

Animals↗
PubMed1978

The effect of T cell growth factor on the generation of cytolytic T cells.

The development of cytotoxic effector cells through primary allogeneic mixed tumor-lymphocyte culture (MTLC) was found to be accompanied by the production of T cell growth factor (TCGF). Addition of supplemental TCGF to MTLC resulted in the generation of significantly greater quantities of effector cells, and these effector cells displayed augmented cytotoxic activity. The TCGF-induced effect could not by duplicated by the addition of fresh medium or a mitogenic concentration of concananvalin A. Although TCGF augmented the proliferation of antigen-nonreactive cells, antigen-reactive cells appeared to be preferentially stimulated by TCGF. Finally, it was shown that depletion of TCGF from MTLC resulted in an impairment of proliferation and differentiation of cytotoxic effector cells. These findings demonstrate that soluble factors are involved in the regulation of in vitro cell-mediated immune responses in an analogous manner to similar factors that have been shown to regulate humoral immune responses. Therefore, the forces affecting TCGF production may modulate the amplitude of a T cell-mediated cytolytic response.

Animals↗
PubMed1978

T cell growth factor: parameters of production and a quantitative microassay for activity.

Several soluble factors have recently been associated with the proliferation and differentiation of thymus-derived lymphocytes. One of these factors present in medium conditioned by T cell mitogen-stimulated lymphocytes has the ability to promote the long-term culture of normal and antigen-specific cytotoxic T cells. We report a method to test for this proliferative stimulus in the form of a sensitive microassay based upon the tritiated-thymidine incorporation of continuous murine tumor-specific cytotoxic T cell lines (CTLL). The microassay requires microliter quantitites of sample fluid and is amenable to quantitative analysis. This highly reproducible, quantitative assay for T cell growth factor (TCGF) has allowed investigation as to the kinetics of TCGF generation and has revealed that T lymphocytes are required for its production. Further investigation has supported the notion that this nonspecies-specific factor is actively removed from tissue culture medium by the proliferation of either T cell mitogen-activated lymphocytes or CTLL.

Animals↗
PubMed1977

In vitro generation of tumor-specific cytotoxic lymphocytes. Secondary allogeneic mixed tumor lymphocyte culture of normal murine spleen cells.

In vivo or in vitro immunity to murine leukemia virus (MuLV)-induced leukemia cells which do not effectively produce virus, has been difficult to demonstrate. Because immunizations with allogeneic murine leukemia cells have been used to confer syngeneic tumor immunity to virus- producing cells, we attempted to generate lymphocytes, cytotoxic to syngeneic nonproducer leukemia cells, by stimulating normal murine spleen cells with allogeneic nonproducer leukemia cells in mixed tumor lymphocyte culture (MTLC) reactions in vitro. Secondary allogeneic MTLC of normal C57BL/6 or DBA/2 spleen cells effectively produced syngeneic tumor-specific cytotoxic lymphocytes. Target cells lysed in lymphocyte- mediated cytolysis (LMC) assays, included both Friend and Rauscher virus- induced syngeneic murine leukemia cells and chemically-induced hematopoietic tumor cells. Syngeneic tumor cells were lysed regardless of whether they produced infectious MuLV or expressed viral antigens gp-71, p-30, or p-12 at the cell surface. Syngeneic normal cells (thymus, lymph node, or Concanavalin A-stimulated spleen cells) used as targets in LMC assays were uneffected by lymphocytes harvested from secondary allogeneic MTLC. Several other in vitro culture treatments including secondary syngeneic MTLC and repetitive mixed lymphocyte culture stimulations were incapable of generating tumor-specific cytotoxic lymphocytes. Based upon these results, we propose that secondary MTLC stimulation of normal spleen cells with allogeneic nonproducer leukemia cells selects for the proliferation of two subpopulations of antigen-specific cytotoxic lymphocytes. The population capable of effecting syngeneic tumor cell lysis is directed against tumor-associated cell surface antigens which may be distinct from viral structural proteins or glycoproteins. The growth of these tumor-specific cytotoxic lymphocytes may be enhanced by a soluble allogeneic effect factor produced by the proliferation of the second subpopulation of lymphocytes generated in repetitive allogeneic MTLC, namely those lymphocytes with specificities directed against differing histocompatibility antigens.

Animals↗
PubMedDate not supplied

Cloning, sequence and expression of human interleukin-2 receptor.

T lymphocytes, essential for the generation of a normal immune response, require the presence of the lymphokine interleukin-2 (IL-2) in order to proliferate. Cells that respond to IL-2 possess a surface receptor glycoprotein specific for this lymphokine. We have recently purified and chemically characterized the IL-2 receptor from both phytohaemagglutinin-activated human T cells and the human T-cell lymphoma HUT-102 (ref. 5). From the NH2-terminal protein sequence obtained in that study, we have now used synthetic oligonucleotides to probe a complementary DNA library, prepared from HUT-102 messenger RNA, for the presence of cDNA clones that might code for the IL-2 receptor. Two cDNA clones were isolated which had closely related DNA sequences. Interestingly, only one coded for an active receptor when transfected into COS-7 cells. This clone contained a 216-base pair (bp) insert that was not present in the other clone. The insert was flanked by an 8-bp direct repeat reminiscent of a transposable element, and appeared to code for a region of marked structural homology to the NH2-terminal region of the receptor molecule.

Amino Acid Sequence↗
PubMedDate not supplied

Cloning, sequence and expression of two distinct human interleukin-1 complementary DNAs.

Two distinct but distantly related complementary DNAs encoding proteins sharing human interleukin-1 (IL-1) activity (termed IL-1 alpha and IL-1 beta), were isolated from a macrophage cDNA library. The primary translation products of the genes are 271 and 269 amino acids long, although expression in Escherichia coli of the carboxy-terminal 159 and 153 amino acids produces IL-1 biological activity.

Amino Acid Sequence↗
PubMedDate not supplied

The cell surface receptors for interleukin-1 alpha and interleukin-1 beta are identical.

Interleukin-1 (IL-1) is a factor that can induce proliferation of murine T lymphocytes and can elicit a variety of other biological responses. These include bone resorption, fibroblast proliferation, acute phase protein release from hepatocytes, cartilage breakdown and fever. This spectrum of activities is consistent with a role for IL-1 as a mediator of inflammation. Recently, sequence data have shown that there are at least two members of the IL-1 family; these distantly related proteins have been termed IL-1 alpha and IL-1 beta. We have found previously that both murine T cells and fibroblasts possess a relative molecular mass (Mr) approximately 80,000 (80K) plasma membrane receptor for human IL-1 beta. We show here that the receptor for IL-1 alpha on both murine and human cells is identical to that for IL-1 beta. This result raises the issue of what separation, if any, there might be between the biological activities of IL-1 alpha and IL-1 beta.

Animals↗
PubMedDate not supplied

Abnormal cervical cytology: a risk factor for endometrial cancer recurrence.

The objective of this study was to evaluate the relationship between cervical cytology, histologic type, and risk of endometrial cancer recurrence. We performed a retrospective study of patients undergoing surgery for endometrial carcinoma. Risk factors for recurrence including histology, tumor grade, nodal status, myometrial invasion, peritoneal washings, stage, and cervical cytology were assessed. Abnormal cervical cytology was defined as the presence of any endometrial cells on Pap smear. Papillary serous and clear cell carcinomas were considered high-risk histologies. Univariate and multivariate analyses of risk factors for recurrence were performed. Thirty-nine (9%) patients developed recurrent endometrial cancer. More patients with abnormal Pap smears recurred (12% versus 4%, P < 0.05). For endometrioid adenocarcinoma, abnormal cervical cytology occurred in 61% and 7% recurred, while with high-risk histologies, 84% had abnormal cervical cytology and 19% recurred (P < 0.05). Other significant predictors of recurrence on univariate analysis were myometrial invasion, nodal status, washings, stage, and histology. On multivariate analysis, only nodal status remained a significant predictor of recurrence. Abnormal cervical cytology is associated with increased risk of endometrial cancer recurrence. Abnormal cervical cytology occurs more frequently in high-risk histologies, which are known to have a higher risk of recurrence. On multivariate analysis, only nodal spread remains a significant predictor of recurrence.

Carcinoma↗
PubMedDate not supplied

Massive intracranial bleeding requiring emergency splenectomy in a patient with CMV-associated thrombocytopenia.

We describe a previously healthy male patient, with severe immune thrombocytopenic purpura (ITP) following CMV infection which was refractory to steroids and intravenous immunoglobulin, who developed massive intracranial bleeding. Despite an extremely low platelet count (2x10(9)/liter) which was refractory to platelet transfusions, successful emergency splenectomy was performed, with rapid resolution of the thrombocytopenia. Bleeding complications are extremely rare in viral-associated ITP. Emergency splenectomy should be considered in the presence of life-threatening bleeding when other modalities fail to produce a rise in the platelet count. Infection with CMV should be ruled out in cases of severe, treatment-resistant ITP.

Cerebral Hemorrhage↗