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Biomedical subjects

J M Zarling

Publications and source records attributed to J M Zarling.

At least 37 records · Page 2Linked to original sources

T-cell responses to human immunodeficiency virus (HIV) and its recombinant antigens in HIV-infected chimpanzees.

Peripheral blood lymphocytes from chimpanzees infected for 3 months to more than 3 years with human immunodeficiency virus (HIV) had normal T-cell proliferative responses after stimulation with a variety of recall antigens and mitogens, indicating that HIV infection does not cause detectable immunological impairment in chimpanzees. This finding contrasts with that obtained in HIV-infected humans, who often have impaired T-cell reactivity. Peripheral blood lymphocytes from most HIV-infected chimpanzees that were studied also had strong proliferative responses to purified HIV as well as to HIV envelope glycoproteins isolated from the virus, to recombinant HIV envelope glycoproteins gp120 and gp41, and to HIV gag protein p24. The HIV-specific T-cell responses in HIV-infected chimpanzees may contribute to prevention of the development of acquired immunodeficiency syndrome in this species.

Acquired Immunodeficiency Syndrome↗

Human cytotoxic T cell clones directed against herpes simplex virus-infected cells. IV. Recognition and activation by cloned glycoproteins gB and gD.

Results of studies in mice and clinical observations in man indicate that T cell-mediated immunity is important in resistance to herpes simplex virus (HSV) infections. This study was undertaken to elucidate the viral antigen specificity of human HSV-immune T cells. Purified HSV-1 glycoproteins gB-1 and gD-1, cloned and expressed in mammalian cells, were found to stimulate proliferation of, and interleukin 2 (IL 2) production by, peripheral blood lymphocytes (PBL) of HSV seropositive individuals, indicating the presence of memory T cells to gB-1 and gD-1 in individuals with serologic evidence of immunity to HSV. Second, T cell clones, generated by stimulation of PBL with HSV-1, were found to recognize gB-1 or gD-1, as evidenced by the ability of the clones to proliferate in response to stimulation with gB-1 or gD-1 in the absence of exogenous IL 2. Third, HSV-specific T cell clones, lytic for HSV-1 or both HSV-1- and HSV-2-infected autologous target cells, were generated after stimulation of PBL with purified cloned gB-1 or gD-1. Our findings, that human HSV-specific T cells can recognize and be activated by HSV subunit antigens gB-1 or gD-1, imply that these glycoproteins play a role in human T cell-mediated immunity to HSV and support the contention that a gB-1 or gD-1 subunit vaccine may be protective in man.

Antigens, Viral↗

Oncostatin M: a growth regulator produced by differentiated histiocytic lymphoma cells.

A polypeptide termed oncostatin M, which inhibits the replication of A375 melanoma and other human tumor cells, but not normal human fibroblasts, has been isolated from serum-free supernatants of U-937 histiocytic lymphoma cells that have been induced to differentiate into macrophage-like cells following treatment with the phorbol ester phorbol 12-myristate 13-acetate. No such growth inhibitory activity is detected in the supernatant of untreated U-937 cells, indicating that the protein is induced or increased in expression in the phorbol ester-induced differentiated cells. Oncostatin M is stable between pH 2 and 11 and after heating for 1 hr at 56 degrees C but is not stable at 90 degrees C. Purification of oncostatin M has been achieved by gel chromatography and reversed-phase HPLC, using sequentially acetonitrile and n-propanol in the presence of aqueous trifluoroacetic acid. The apparent molecular weight of oncostatin M is approximately 18,000, as determined by gel chromatography, and 28,000, as determined by polyacrylamide gel electrophoresis. The amino-terminal amino acid sequence of the purified polypeptide has been determined. No substantial sequence homology between oncostatin M and other proteins was found, including other tumor cell inhibitory proteins produced by mononuclear cells. Oncostatin M, therefore, appears to represent a distinct cell growth regulator.

Amino Acid Sequence↗

Herpes simplex virus (HSV)-specific human T-cell clones recognize HSV glycoprotein D expressed by a recombinant vaccinia virus.

Human cytotoxic T-cell (CTL) clones that lyse autologous cells infected with herpes simplex virus (HSV) type 1 or 2 were generated by stimulating lymphocytes with a recombinant vaccinia virus (recombinant vaccinia-gD-1 virus) that expresses HSV type 1 glycoprotein D (gD-1). Furthermore, CTL clones generated with HSV type 1 or with cloned gD-1 lysed autologous cells infected with the recombinant vaccinia-gD-1 virus. Our findings thus showed that gD serves as a target antigen for human CTLs and that a recombinant vaccinia-gD virus activates HSV-specific human CTL.

Antigens, Viral↗

Human cytotoxic T cell clones directed against herpes simplex virus-infected cells. III. Analysis of viral glycoproteins recognized by CTL clones by using recombinant herpes simplex viruses.

Human cytotoxic T cell (CTL) clones specific for herpes simplex virus (HSV) type 1- and type 2-infected cells were generated and were analyzed with regard to the viral glycoproteins they recognize on autologous HSV-infected cells. By use of target cells infected with wild-type HSV strains, a gC deletion mutant of HSV-1, and HSV-1 X HSV-2 intertypic recombinants, some HSV-1-specific CTL clones were found to be directed against L region-encoded gA/B-1, and others against S region-encoded glycoproteins (gD-1 or gE-1). Some HSV-2-specific clones were found to be directed against L region-encoded gC-2, whereas others were directed against S region-encoded glycoproteins (gD-2, gE-2, or gG). These findings provide direct evidence that several HSV glycoproteins that are expressed on the surface of HSV-infected cells serve as recognition structures for human HSV-specific CTL.

Clone Cells↗

Human cytotoxic T cell clones directed against herpes simplex virus-infected cells. II. Bifunctional clones with cytotoxic and virus-induced proliferative activities exhibit herpes simplex virus type 1 and 2 specific or type common reactivities.

Human cytotoxic T lymphocyte (CTL) clones directed against herpes simplex virus (HSV)-infected cells were generated after stimulation of peripheral blood lymphocytes (PBL) with HSV type 1 (HSV-1) and HSV type 2 (HSV-2). These CTL clones were studied with regard to HSV type specificity and with regard to whether they also express helper cell activity. Some clones, generated after stimulation with HSV-1, were cytotoxic for autologous cells infected with either HSV-1 or HSV-2 ("HSV type common clones"), whereas other clones lysed HSV-1-infected cells only ("type-specific clones"). Similarly, after HSV-2 stimulation, both HSV-2 specific and HSV type common clones were obtained, indicating the heterogeneity of human cytotoxic T cells to HSV. All CTL clones tested were found to be bifunctional in that they also proliferated in response to stimulation with HSV. The HSV type specificity of the proliferative response was identical to that of the cytotoxic activity of the clones. An HSV type common clone, when stimulated with either HSV-1 or HSV-2, and an HSV-1 specific clone, when stimulated with HSV-1 but not with HSV-2, produced a factor, presumably interleukin 2 (IL 2), which induced proliferation of CTLL, an IL 2-dependent T cell line, providing evidence that our HSV-directed CTL clones also express helper cell activity. CTL clones that we previously reported were restricted in cytotoxic activity by HLA class II DR-1 or MB-1 antigens were found, in this study, to be restricted in proliferative response to HSV by these same HLA antigens. These results suggest that our bifunctional T cell clones directed against HSV may recognize the same viral antigenic determinants and the same HLA antigens for both cytotoxic and virus-induced proliferative activities. This is the first demonstration of human HSV type specific and HSV type common T cell clones and HSV specific T cell clones with both cytotoxic and helper cell activities.

Antigens, Viral↗

Impaired natural killer activity in patients with chronic lymphocytic leukemia is associated with a deficiency of azurophilic cytoplasmic granules in putative NK cells.

This study was undertaken to gain further insight into the severely impaired natural killer (NK) activity we and others have previously observed in patients with chronic lymphocytic leukemia (CLL). Normal individuals' NK cells are large granular lymphocytes (LGL) that (A) bind to and lyse NK-sensitive cells, including K562, (B) express receptors for the Fc portion of IgG (FcR+ cells), and (C) express cell surface antigens reactive with monoclonal antibodies OKM1, 9.6, and OKT11A. We thus examined lymphocytes depleted of monocytes and B cells, from 6 CLL patients and 6 normal individuals, that were identified on the basis of binding to K562, expressing OKM1, or expressing receptors for the Fc portion of IgG. In the CLL patients studied, lymphocytes that bind to K562 cells, as well as OKM1+ cells isolated by fluorescence activated cell sorting, were morphologically similar to LGL of normal individuals, with the exception that more than 75% of the patients' cells were deficient in azurophilic cytoplasmic granules, which typify normal individuals' LGL. Furthermore, although the percentages of the patients' FcR+ cells reactive with OKT11A, 9.6 and OKM1 were very similar to those of normals, the majority of the patients' FcR+ cells were deficient in azurophilic granules and lacked NK activity. These findings indicate that the impaired NK activity in CLL patients is associated with cells that are phenotypically and morphologically NK cells, but which lack azurophilic granules that are thought to play a role in NK-mediated lysis.

Antibodies, Monoclonal↗

Human cytotoxic T cell clones directed against herpes simplex virus-infected cells. I. Lysis restricted by HLA class II MB and DR antigens.

In contrast to general findings that mouse and human cytotoxic T lymphocytes (CTL) are restricted in cytotoxic activity by major histocompatibility complex (MHC) class I antigens, we previously found that some herpes simplex virus (HSV) type I-infected cells that shared no HLA class I antigens with the HSV-1-stimulated lymphocytes were lysed. In this study, we addressed the question of the role of HLA antigens in human T cell-mediated lysis of HSV-1-infected cells by generating clones of HSV-1-directed CTL from two HSV-1-seropositive individuals. CTL clones that lysed autologous HSV-1-infected lymphoblastoid cell lines (LCL), but not natural killer-sensitive K562 cells or uninfected or influenza virus-infected LCL, were tested for cytotoxicity against a panel of allogeneic HSV-1-infected LCL. Clone KL-35 from individual KL lysed only HSV-1-infected LCL sharing the HLA class II MB1 antigen with KL. With all four CTL clones isolated from individual PM, only HSV-1-infected LCL sharing DR1 with PM were lysed. Monoclonal antibody s3/4 (directed against MB1 ), but not TS1/16 or B33 .1 (directed against a DR framework determinant), blocked lysis of autologous HSV-1-infected cells by KL-35. In contrast, B33 .1, but not s3/4, blocked lysis of autologous HSV-1-infected cells by the PM CTL clones but not by KL-35. Together, these results indicate that our five human CTL clones which are directed against HSV-1-infected cells, and which are all OKT3+, OKT4+, OKT8-, are restricted in lytic activity by HLA class II MB and DR antigens. These results suggest that the HLA D region-encoded class II antigens may be important in the recognition and destruction of virus-infected cells by human CTL.

Antibodies, Monoclonal↗

Human anti-lymphoma responses generated in vitro and in vivo following sensitization with allogeneic leukocytes.

Peripheral blood lymphocytes (PBL) from a patient with poorly differentiated lymphocyte lymphoma (PDLL), after stimulation for 7 days with X-irradiated allogeneic lymphocytes pooled from three or ten donors (poolx), were cytotoxic for autologous lymphoma cells. Some clones lytic for autologous lymphoma cells, that were derived from this patient's pool-stimulated cells, resembled cytotoxic T lymphocytes (CTL), while other clones resembled natural killer (NK)-like cells in that they also lysed NK-sensitive HLA-negative K562 cells. In a second patient with more advanced PDLL, PDL cultured with T-cell growth factor (which is produced following stimulation with mitogens or alloantigens) lysed autologous lymphoma cells. On the basis of these in vitro findings, we asked whether IV transfusions with X-irradiated allogeneic leukocytes would result in anti-lymphoma responses in vivo. Ten days after transfusions with X-irradiated leukocytes from four unrelated donors, the first patient's two previously palpable nodes were no longer palpable and he remained in complete clinical remission for 6 months. The second patient had a temporary partial remission with dramatic reduction in size of multiple cervical and axillary nodes within 2 weeks after receiving the leukocyte transfusions.

Cells, Cultured↗

Depletion of human NK cells with monoclonal antibodies allows the generation of cytotoxic T lymphocytes without NK-like cells in mixed cultures.

In vitro stimulation of human mononuclear cells with x-irradiated autologous lymphoblastoid cell line (LCL) or allogeneic normal cells in mixed leukocyte cultures (MLC) was previously shown to result in the generation of OKT3+ OKT8+ cytotoxic T lymphocytes (CTL) lytic for allogeneic and autologous LCLs and also of natural killer- (NK) like cells that are OKT3- and primarily OKT8- and are lytic for HLA- NK-sensitive K562 cells. The origin of the NK-like cells was not previously known because, although the majority of fresh human NK cells react with monoclonal antibodies OKM1 and B73.1, lymphocytes bearing these markers are not detected several days after the onset of MLC, when NK-like cells are present. In this study, experiments were undertaken to determine whether NK-like cells generated after stimulation with x-irradiated pooled allogeneic normal cells (poolx) or with autologous LCL are derived from cells expressing antigens reactive with monoclonal antibodies OKM1 or B73.1, which react with fresh NK cells. Mononuclear cells, depleted of monocytes, were stained with OKM1 or B73.1 and fluorescein-labeled goat anti-mouse IgG. Lymphocytes depleted of OKM1+ or B73.1+ cells, by fluorescence-activated cell sorting, and lymphocytes that were stained but not sorted were stimulated for 7 days with either poolx or autologous LCL. The generation of NK-like activity was decreased at least 90% after depletion of cells reactive with OKM1 or B73.1, whereas the generation of CTL against autologous and allogeneic LCL was minimally affected. These findings show that NK-like cells generated in MLC are derived from cells that express the phenotype of fresh NK cells (OKM1+ or B73.1+) and that CTL can be generated in cultures in which relatively little NK-like activity is concomitantly detected, by depleting NK cells with monoclonal antibodies before stimulation.

Animals↗

LY-2+ effectors cytotoxic for syngeneic tumor cells: generation by allogeneic stimulation and by supernatants from mixed leukocyte cultures.

The present study was aimed at gaining insight into means by which stimulation of mouse spleen cells with allogeneic normal cells in mixed leukocyte cultures (MLC) can result in the generation of effector cells cytotoxic for syngeneic tumor or transformed cells. Stimulation of lymphocytes from BALB/c or C3H mice for 5 days with cells from mice of every allogeneic strain tested, in medium containing mouse serum and lacking xenogeneic serum, resulted in the activation of effectors cytotoxic for syngeneic cells transformed spontaneously or by SV40, polyoma or adenovirus. In each experiment, all of the syngeneic transformed cell lines, as well as clones derived from these lines, were lysed to the highest degree by effectors obtained from the same culture, and therefore stimulated with cells from the same allogeneic strain. Although the particular allogeneic sensitizing strain that induced the highest cytolytic activity varied between experiments, effectors obtained from the culture with the highest cell recovery always exhibited the greatest cytotoxicity against all the syngeneic transformed cells and clones. Lysis was mediated predominantly by Ly-2+ effectors; total lytic units of cytotoxicity recovered after treatment with monoclonal anti-Ly-2 antibody and complement (C) were reduced by 85 to 90% compared to cells treated with C alone. Lysis of syngeneic tumor cells by the allosensitized effectors in cytotoxicity assays was not inhibited by the addition of unlabeled "blocking" lymphocytes from the allogeneic strain used for sensitization. In addition, it was found that lymphocytes cultured without stimulating cells for 5 days in medium supplemented with supernatants from secondary MLC that are known to contain high levels of lymphokines, mediated high levels of cytotoxicity on all the transformed cells tested, but lacked detectable cytotoxic activity for syngeneic or allogeneic Con A blasts. The MLC supernatant-activated effectors that lyse the transformed cells are phenotypically CTL, because treatment with anti-Ly-2 and C reduced lytic activity by approximately 75%. Taken together, these findings suggest that the generation in MLC of Ly-2+ effector cells cytotoxic for syngeneic transformed cell lines might not be due, in some cases, to lymphocyte responses to particular alloantigens on the stimulating cells that are cross-reactive with "alien" histocompatibility antigens on transformed cells, but rather is due to effector cell activation by lymphokines produced during allogeneic stimulation.

Animals↗

Deficiency of natural killer cell activity in patients with chronic lymphocytic leukemia.

Natural killer (NK)6 cell activity of peripheral blood lymphocytes against human leukemia cell lines was measured in patients with chronic B-cell lymphocytic leukemia (CLL) and age- and sex-matched controls. In order to remove the leukemia cells that interfere with the in vitro assay we (1) isolated lymphocytes that form rosettes with sheep red blood cells (SRBC) or (2) lysed the CLL cells with a monoclonal anti-B cell antibody and complement. NK activity in either lymphocyte preparation from nine of 10 patients with advanced disease was not detectable and, when calculated in terms of lytic units per ml of blood, as at least seven times lower than in controls; only one of these patients exhibited activity within the control range. Two patients with early disease had measurable, but low, NK-cell activity. Prolongation of the NK cell assay from 6 to 18h gave rise to significant killing in the CLL patients lacking NK cell activity in the 6-h assay; however, the activity still was six times lower than in controls. Treatment of leukemia cell-depleted lymphocytes from CLL patients with human fibroblast interferon or the interfeon inducer poly 1:C enhanced NK-cell activity in the two early stage patients but this treatment was ineffective in three later stage patients. The percentage of cells with characteristics of NK cells, i.e. those with receptors for SRBC and Fc-portion of IgG, was four times higher in CLL patients and the percentage of lymphocytes binding to NK-sensitive target cells was equal to that in controls despite the fact that, in the majority of patients, lysis of the target cells by the lymphocytes does not ensue. The NK deficiency may be responsible for the increased incidence of secondary malignancies in CLL patients.

Aged↗

Stimulation with autologous lymphoblastoid cell lines: lysis of Epstein-Barr virus-positive and -negative cell lines by two phenotypically distinguishable effector cell populations.

Human lymphocytes, stimulated in vitro for 6 days with x-irradiated or glutaraldehyde-treated autologous Epstein-Barr (EB) virus-transformed lymphoblastoid cell lines (LCL), are cytotoxic for autologous and allogeneic EB+ LCLs as well as for several EB- cell lines that are also susceptible to lysis by interferon-activated natural killer (NK) cells. To determine whether the apparent nonspecific lysis mediated by LCL-stimulated cells is due to a mixture of effector cells directed against different target cells, advantage was taken of our recent finding that monoclonal antibody OKT8 reacts with human cytotoxic T lymphocytes but not with NK cells or NK-like cells generated in mixed leukocyte cultures. The depletion of OKT8+ cells from LCL-stimulated cultures by treatment with OKT8 and complement abolished or markedly depleted cytotoxicity against all EB+ target cells tested, whereas cytotoxicity against EB-, NK-sensitive cell lines including K562, MOLT-4 and HSB-2 was not or only minimally reduced. These results indicate that stimulation with autologous LCL results in the generation of OKT8+ cytotoxic T lymphocytes that lyse EB virus-transformed LCL and OKT8- NK-like cells that lyse EB-, NK-sensitive cells.

Antibodies, Monoclonal↗

Sensitization of lymphocytes against pooled allogeneic cells. II. Characterization of effector cells cytotoxic for autologous lymphoblastoid cell lines.

Stimulation of human lymphocytes in mixed leukocyte culture (MLC) with x-irradiated pooled allogeneic normal cells (poolx) was previously shown to result in generation of effector cells cytotoxic for autologous Epstein-Barr virus- (EBV) transformed lymphoblastoid cell lines (LCL). This study was undertaken to determine whether lysis of the autologous EBV- transformed LCL cells by pool-stimulated cells is mediated by cytotoxic Tc lymphocytes (Tc) or natural killer- (NK) like cells, both of which are generated in MLC. In the first series of experiments, proliferating cells were eliminated by treatment of pool-stimulated cells with 5 X 10(-5) M 5-bromodeoxyuridine (BUdR) and light. The remaining cells failed to lyse allogeneic normal lymphocytes and autologous LCL cells, whereas cytotoxicity against NK-sensitive K562 leukemia cells was retained. In the second series of experiments, pool-stimulated effector cells were treated with monoclonal anti-human Tc cell antibodies, OKT3 or OKT8, and complement (C). The cells recovered after antibody and C treatment were diminished in their ability to lyse allogeneic normal lymphocytes as well as autologous LCL cells, whereas their cytotoxicity against K562 leukemia cells was unaffected. These combined results provide strong evidence that lysis of autologous LCL cells by lymphocytes stimulated with pooled allogeneic normal cells is mediated by Tc rather than NK-like cells.

Bromodeoxyuridine↗

Phenotypes of human natural killer cell populations detected with monoclonal antibodies.

In our recent studies, human natural killer (NK) cell activity was found to be decreased 2- to 4-fold after treatment of monocyte-depleted peripheral mononuclear cells with monoclonal antibody OKM1 and complement (C). The present study was undertaken to determine whether there is an additional population of NK cells that is OKM1-, since treatment with OKM1 and C decreased, but did not eradicate, NK cell activity. Treatment of lymphocytes with monoclonal antibody OKT11A, which reacts with all sheep red blood cell rosetting lymphocytes, and C also decreased NK cell activity. Although approximately 90% of OKT11A+ cells are OKT3+, NK cell activity resides within the OKT11A+ cell population, which is OKT3- since OKT3-cell depletion fails to decrease NK cell activity. Double fluorescence analysis of OKT3-depleted lymphocytes revealed that 54% of the OKM1+ cells are OKT11A- and 45% of the OKT11A+ cells are OKM1-, thus demonstrating that within the OKT3-depleted population, approximately one-half the OKM1+ cells are OKT11A- and vice versa. Treatment of lymphocytes with OKM1 together with OKT11A and C decreased NK cell activity against 3 NK-sensitive leukemia lines--K562, MOLT-4, and HSB-2--more than did treatment with either antibody alone; virtually no lytic activity was retained after elimination of OKM1+ and OKT11A+ cells. The results thus provide strong evidence that there is at least 2 populations of human NK cells; one is OKM1+ and the other is OKT11A+

Animals↗

Monoclonal antibodies which distinguish between human NK cells and cytotoxic T lymphocytes.

Although it is widely accepted that T cells have a major role in specific tumour immunity, there is now much evidence that natural killer (NK) cells, which exist in many species and spontaneously lyse certain tumour cells in vitro, provide early resistance against tumour growth. Human NK-cell activity can be augmented in vitro by interferon and its inducers, including polyinosinic:polycytidylic acid (poly I:C); furthermore, NK-like activity is generated in mixed leukocyte cultures (MLCs) as is specific cytotoxic T-cell (Tc) activity. When effector cells generated in human MLCs lyse allogeneic or autologous virus-transformed or tumour cells, it has been difficult to evaluate the relative contributions of Tc and NK-like cells to the lysis because the latter, like T cells, can form rosettes with sheep erythrocytes and react with xenogeneic anti-human thymocyte serum. We report here that monoclonal antibodies against human mononuclear cell subpopulations can distinguish Tc from NK and NK-like cells. OKT3 or OKT8 monoclonal antibodies (reactive with virtually all or a subset of T cells, respectively) with complement (C') ablate MLC-generated Tc activity against allogeneic normal cells but do not decrease lysis of HLA-negative, NK-sensitive K562 leukaemia cells by NK, poly I:C-activated NK or MLC-activated NK-like cells. In contrast, OKM1 monoclonal antibody (reactive with a low proportion of non-adherent mononuclear cells as well as macrophages) with C' causes marked diminution of NK and poly I:C-activated NK-cell activity.

Animals↗