Showing papers on "Cytotoxic T cell published in 1981"

F4/80, a monoclonal antibody directed specifically against the mouse macrophage

Abstract: A hybridoma clone which secretes a macrophage (MΦ)-specific monoclonal antibody, F4/80, was produced by fusing spleen cells from a rat hyperimmunized with cultured thioglycollate-induced mouse peritoneal MΦ with a mouse myeloma, NS1. Binding of antibody to primary cells and cell lines was detected by radioimmune indirect binding assay, autoradiography or fluorescence-activated cell sorter analysis. F4/80 binds to mouse MΦ from the peritoneal cavity or other sources, blood monocytes, MΦ derived from bone marrow precursors in culture and MΦ-like cell lines, but not to other cells, including polymorphonuclear leukocytes, lymphocytes or fibroblasts. F4/80 does not bind to MΦ via Fc receptors, is not cytotoxic and is of the rat IgG2b subclass. Since F4/80 binds to all MΦ defined by adherence, morphology and immune phagocytosis, it provides a new marker to define the MΦ in the mouse. Large differences in expression of antigen F4/80 were found, depending on intraperitoneal stimulation, time in culture and stage of maturation. Immunoprecipitation experiments demonstrated that the antigen F4/80 is part of a component of Mr 160000 which is synthesized by the MΦ and, at least in part, exposed on the cell surface.

Type C virus particles in a cord T-cell line derived by co-cultivating normal human cord leukocytes and human leukaemic T cells

Abstract: A recent nationwide survey of the lymphocyte subpopulations of leukaemia and lymphoma in Japan has disclosed a high incidence of adult T-cell leukaemia (ATL)1. One of the striking features of this disease is the clustering of patients in the southwestern part of Japan1,2. We have established a continuous culture line of leukaemic T cells from a patient with ATL3,4. This cell line, MT-1, was found to carry type C virus particles and ATL-associated antigens (ATLA) which specifically reacted with sera from all ATL patients and about 25% of healthy adults in the endemic area5. We report here that by co-culture of ATL cells from a female patient and normal human cord leukocytes from a male infant, a T-cell line of cord leukocyte origin was established. Numerous type C virus particles as well as ATLA were detected in this cell line.

A differentiation antigen of human NK and K cells identified by a monoclonal antibody (HNK-1).

Abstract: A monoclonal IgM antibody (HNK-1) was produced against a membrane antigen from the cultured T cell line, HSB-2 By indirect immunofluorescence, this antibody reacted with certain human cultured T cell lines (HSB-2 and MOLT-4 but not MOLT-3) but not with other lines of B cell or phagocytic cell origin HNK-1 reacted with 151 +/- 71% of normal blood lymphocytes but was unreactive with monocytes, granulocytes, erythrocytes, and platelets HNK-1+ cells separated by a fluorescence-activated cell sorter (FACS) were a homogeneous population of medium sized lymphocytes with abundant neutrophilic cytoplasm containing azurophilic granules HNK-1+ cells were nonadherent, surface Ig-, mostly FcIgG receptor+ and both positive and negative for demonstrable sheep erythrocyte (E) rosetting capability Cell suspensions enriched for E-rosetting T cells and depleted of FcIgG receptor+ cells contained few (6%) HNK-1+ cells Depletion of HNK-1+ cells from blood mononuclear cell populations by complement (C) mediated lysis greatly reduced NK activity against K-562 target cells and K cell lytic activity against antibody-coated chicken red blood cells Treatment with HNK-1 alone or C alone did not affect these activities When the FACS was utilized to separate HNK-1+ and HNK-1- cells from 6 individuals, the HNK-1+ cell population contained almost all of the NK and K cell function The monoclonal antibody HNK-1 thus defines the first differentiation antigen shown to be selectively expressed on human NK and K cells

Characteristics of human large granular lymphocytes and relationship to natural killer and K cells

Abstract: Recent evidence, has demonstrated an association between a subpopulation of peripheral blood mononuclear cells, morphologically identified as large granular lymphocytes (LGL), and natural killer (NK) activity. We have now evaluated more directly the role of LGL in both NK activity and antibody- dependent cellular cytotoxicity (ADCC), by using highly enriched populations of LGL, obtained by centrifugation of peripheral blood mononuclear cells on Percoll discontinuous density gradients. Both spontaneous and interferon- augmented NK and ADCC activities were exclusively associated with the LGL- enriched, low density fractions. The majority of LGL formed conjugates with NK-susceptible and antibody-coated target cells. Approximately 20 percent of small conventional lymphocytes also formed conjugates with the target cells for NK, but this was not associated with cytotoxic activity. Virtually all LGL were found to have receptors for the Fc portion of IgG (FcγR). The frequency of LGL among blood leukocytes was 2-6 percent. LGL could be enriched to an average purity of 95 percent by combining discontinuous density gradient centrifugation with subsequent adsorptions of the low density fractions on monolayers of immobilized immune complexes. About 50 percent of LGL were found to be FcγR-bearing T cells (T(G)), forming low affinity rosettes with sheep erythrocytes at 4 degrees C. Only 10-20 percent of LGL formed high affinity rosettes with sheep erythrocytes at 29 degrees C. LGL could be enriched to a purity of more than 90 percent by depleting high affinity rosette-forming cells from low density Percoll fractions. LGL were only a subpopulation of T(G) cells, because some lymphocytes with conventional morphology also adhered to the immobilized immune complex monolayers and formed high affinity rosettes with sheep erythrocytes. Separation of these cells from LGL by discontinuous density gradient centrifugation indicated that they are not cytotoxic, suggesting a morphological and functional subdivision of T(G) cells. The verification in this study that virtually all human NK and K cells have a characteristic morphology adds a useful parameter to the monitoring of human lymphocytes, and the ability to purify these cells by simple physical procedures should be invaluable in their further characterization.

The rapid isolation of clonable antigen‐specific T lymphocyte lines capable of mediating autoimmune encephalomyelitis

Abstract: The isolation and propagation of functional antigen-specific lines of T lymphoblasts is described. These lines were found to recognize foreign or self antigens in association with accessory cells of syngeneic major histocompatibility complex genotype. Intravenous inoculation of a T cell reactive only against myelin basic protein led to development of clinical paralysis in syngeneic rats. Thus, it is possible to study biological function as well as antigen specificity using T cell lines.

Antigen-inducible, H-2-restricted, interleukin-2-producing T cell hybridomas. Lack of independent antigen and H-2 recognition

Abstract: We developed a method for production of antigen-specific, H-2-restricted T cell hybrids. The tumor cell partner in the fusions was itself a T cell hybrid, FS6-14.13.AG2 (or its derivatives), which could be induced to produce the growth factor, interleukin-2 (IL-2), in response to a challenge with concanavalin A, but had no known antigen specificity. The normal T cell partner in the fusions was a population of lymph node T cell blasts that had been highly enriched in antigen-specific, H-2-restricted T cells by in vivo immunization, followed by in vitro challenge with antigen and clonal expansion in IL-2-containing medium. These fusions produced hybrids that grew constitutively in culture. A sizable proportion of the hybrids demonstrated the ability to produce IL-2 in response to a challenge with specific antigen presented by irradiated spleen cells of the appropriate H-2 type. Four cloned antigen/H-2-specific hybrid lines were produced. AO-40.10 responded to chicken ovalbumin (OVA) when presented by I-A(k)-bearing cells. DC1.18.3 responded to the apo form of beef cytochrome c when presented with I-A(d). AODK-10.4 responded to keyhole limpet hemocyanin (KLH) presented with I-A (d). AODK-1.16 also responded to KLH presented by a product of the I region of H-2(d), but the data were consistent with either a product of the I-J-I-E(d) region or a combinatorial molecule with elements from both I-A(d) and I-E(d)/I-C(d). Coincidentally, AO-40.10 was shown to have an unexpected alloreactivity with a product of H-2(b) mapping to the K-I-A region. These hybrids should prove invaluable as sources of monoclonal material for the study of the receptor(s) on T cells with H-2-restricted antigen specificities. We also generated T cell hybrids with two antigen/H-2 specificities by fusing an azaguanine-resistant clone of AO-40.10 to normal T cells with a different antigen/H-2 specificity. Many of the hybrids retained reactivity to OVA plus H-2(a) and to the second antigen/H-2 combination. None reacted to either OVA plus the second H-2 type or to the second antigen plus H-2(a). One of these hybrids was successfully cloned to produce the line AOFK- 11.11.1. It retained the ability to recognize OVA plus I-A(k) inherited from one parent, and KLH plus IA(f) inherited from the other. It did not recognize OVA plus IA(f) or KLH plus I-A(k). These results have some bearing on models describing the nature of T cell receptors for antigen recognized in association with H-2 products. They do not support models in which antigen and H-2 are recognized separately by two independent T cell receptors.

Interleukin-2 augments natural killer cell activity.

Abstract: The lymphokine interleukin-2 (IL-2; also termed T-cell growth factor) causes the proliferation of activated T-cell clones1,2. Effector T-cell lines exhibiting suppressor, helper and cytotoxic activities have been established by growth of appropriately stimulated cells in IL-2-containing medium3,4. In addition, IL-2 has been shown to provide requisite T-cell ‘help’ in a number of in vitro immune response assays, including the generation of cytotoxic T cells from thymocyte (and nude spleen cell) cultures5 and the induction of erythrocyte-specific antibody in T cell-deficient populations6. We report here a further activity of IL-2, one previously attributed solely to interferon—the ability to augment the cytotoxic activity of natural killer (NK) cells. This conclusion was reached from the observation that preparations of IL-2, which lacked interferon, caused a rapid increase in NK cell activity. This ability to augment cytotoxity was removed from IL-2 preparations, not only by absorption with IL-2 receptor bearing cells, but also by precipitation with a monoclonal antibody directed against IL-2.

Evolutionary conservation of surface molecules that distinguish T lymphocyte helper/inducer and cytotoxic/suppressor subpopulations in mouse and man

Abstract: We describe the biochemical properties and cell surface distributions of three human T cell antigens (Leu-1, Leu-2a, and Leu-2b) which we postulate to be the homologues of the Lyt-1, Lyt-2, and Lyt-3 antigens that distinguish functional T cell subsets in the mouse. Leu-l, like Lyt-1, is on all thymocytes and peripheral T cells and is present in greater amounts on the helper/inducer subset than on the cytotoxic/suppressor subset. Both antigens increase in parallel fashion during T cell maturation in the thymus and each antigen is carried on a single 67,000-molecular weight (relative) (M(r)) polypeptide chain. Surprisingly, Leu-1 and Lyt-1 each are also expressed in readily detectable amounts on some B celI Ieukemias but not detectably so on normal B cells. Leu-2a and Leu-2b are antigens found only on suppressor/cytotoxic cells in the human and are very similar to the murine Lyt-2 and Lyt-3 antigens. In both species, the two antigens are on the same disulfide- linked multimeric molecules. Disulfide-bond reduction in both species yields subunits of similar size and charge. Lyt-3 and Leu-2b are extremely sensitive to trypsin digestion on viable cells whereas Lyt-2 and Leu-2a are much less so. A different membrane antigen, Leu-3, is an exclusive marker of the helper/inducer subset in man. No mouse homologue for this 55,000-M(r) protein is known. The maintenance of the homologous molecules on functionally distinct T cell subpopulations in two evolutionarily distant species suggests that the Lyt and Leu antigens perform essential functions for the cells on which they are found.

Lysis of Fresh and Cultured Autologous Tumor by Human Lymphocytes Cultured in T-Cell Growth Factor

Abstract: 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 51 Cr 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 auto-reactive 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.

A monoclonal antibody discriminating between subsets of T and B cells.

Abstract: A description is given of a rat anti-mouse hybridoma antibody, JIId, which reacts with erythrocytes, neutrophils, greater than 90% of thymus cells, and most B cells JIId does not have detectable activity for mature T cells, pluripotential stem cells, platelets, or cells of the monocyte-macrophage lineage Although the JIId antigen is present on 90 to 95% of typical small B lymphocytes, pretreatment of spleen cells with JIId plus complement has no effect on secondary IgG antibody responses; by contrast, primary IgM responses and proliferative responses to lipopolysaccharide are substantially reduced Unlike the precursors of IgG antibody-producing cells (AFC), IgG AFC per se are strongly JIId-positive Rapid acquisition of the JIId antigen also applied to the early progeny of pluripotential stem cells

Use of Monoclonal Antibodies to T-Cell Subsets for Immunologic Monitoring and Treatment in Recipients of Renal Allografts

Abstract: Using monoclonal antibodies and flow cytometry, we serially monitored lymphocyte subpopulations in renal-allograft recipients treated with either conventional immunosuppression or a monoclonal antibody. In 29 patients given conventional suppression, highly significant correlations between changes in T-cell subsets and rejection were noted. Normal or elevated ratios of OKT4 (helper/inducer) to OKT8 (suppressor/cytotoxic) cells were associated with rejection unless the donor was HLA identical or the total number of T cells was extremely low. In patients with low ratios, rejection seldom occurred. Two patients treated with OKT3 monoclonal antibody for acute rejection had rapid disappearance of OKT3-reactive cells from the peripheral blood and prompt reversal of rejection. The use of monoclonal antibodies allows the precise determination of changes in T-cell subsets and promises the development of therapeutic protocols that can be designed to manipulate selected lymphocyte populations. (N Engl J Med....

Regulation of the production of immune interferon and cytotoxic T lymphocytes by interleukin 2.

Abstract: The activation of alloantigen-specific cytotoxic T lymphocyte precursors is dependent upon the presence of both macrophages and helper T cells or regulatory molecules derived from these facilitative cells. Three biochemically distinct helper factors have been identified: interleukin 1 (macrophage-derived), Interleukin 2 (T cell derived), and immune interferon. All 3 factors are found in supernatants of mixed lymphocyte cultures (MLC), however, the removal of macrophages from these cultures completely ablates the production of these factors as well as the induction of cytotoxic T lymphocytes (CTL). The addition of IL 2 to these macrophage-depleted MLC restores the ability of responder T cells to: 1) bypass the requirement for macrophage soluble function, 2) produce immune interferon, and 3) generate CTL. The kinetics and dose response of immune interferon production in response to IL 2 correlates with the generation of CTL. The production of immune interferon as well as the generation of CTL requires T cells, alloantigen, and IL2. Furthermore, the induction of CTL by IL2 was neutralized by the addition of anti-immune interferon. These data suggest that: 1) the regulation of immune interferon production is based on a T to T cell interaction mediated by IL 2, and 2) immune interferon production may be required for IL 2 induction of CTL. These findings are consistent with the hypothesis that the induction of CTL involves a linear cell-factor interaction in which IL 1 (macrophage-derived) stimulates T cells to produce IL 2, which in turn stimulates other T cells to produce immune interferon and become cytotoxic.

Analysis of T lymphocyte subsets in cytomegalovirus mononucleosis.

Abstract: Lymphocyte proliferative responses to mitogens and herpes virus antigens are diminished during cytomegalovirus (CMV) mononucleosis. We analyzed peripheral blood T lymphocytes from patients in the acute and convalescent phases of CMV mononucleosis using monoclonal antibodies directed against the T helper and the T cytotoxic-suppressor cell subsets. Acute CMV infection is associated with a reversal in the normal ratio of helper to suppressor T lymphocytes with relative and absolute decreases in T helper cells and corresponding increases in T suppressor cells. These alterations in T lymphocyte subsets are accompanied by diminished lymphocyte responses to the mitogen concanavalin A (Con A). During convalescence, helper T lymphocytes increase, suppressor T lymphocytes decrease, and Con A responses return to normal.

Distribution of T cell subsets in human lymph nodes

Abstract: A series of T cell-specific monoclonal antibodies was used to determine the location of T lymphocyte subpopulations in frozen sections of human lymph nodes by means of an immunoperoxidase technique. The majority of cells in the paracortical regions were reactive with anti-T1 and anti-T3 antibodies, which define all mature peripheral T cells. In contrast, the majority of cells within primary follicles were unreactive with anti-T1 and anti-T3 antibodies, but were reactive with anti-Ia and anti-IgM antibodies. In addition, a substantial number of T1+, T3+ cells were found in the germinal centers of secondary follicles on the capsular side. The vast majority of T1+, T3+ cells in the paracortex and the follicles were reactive with anti-T4 antibody, which defines inducer/helper T cells. Only a minority of cells in these areas were reactive with anti-T5 and anti-T8 antibodies, which define cytotoxic/suppressor cells. No lymphocytes were stained with anti-T6 antibody, which reacts with a majority of thymocytes but not with peripheral T cells. Scattered cells in the paracortex showed staining for Ia antigen in an irregular dendritic pattern. The findings demonstrate that the major T cell population found within human lymph node bears the mature T1+, T3+, T4+ phenotype characteristic of inducer T cells. Moreover, the location of this population indicates that they play a role in the induction of B cell differentiation in vivo.

Identification of a macrophage antigen-processing event required for I-region-restricted antigen presentation to T lymphocytes.

Abstract: The mechanism of macrophage-antigen handling was studied using a system that involves the quantitation of the antigen-specific binding of Listeria monocytogenes-immune T cells to macrophages. Specific T cells did not bind to native antigen. Because the specific binding of T cells to macrophages could be measured during a short (5- to 15-min) interaction, it was possible to follow the temporal development of a T cell-binding substrate with increasing time of antigen-macrophage interaction. In contrast to the rapid (5-min) uptake of Listeria by macrophages, the development of T cell-binding ability required a 30- and 60-min period of antigen-macrophage interaction. During this processing period, Listeria organisms bound to the macrophage surface were ingested and partially catabolized. Unlike antigen uptake, antigen processing was a temperature-dependent and energy-requiring event. Although macrophages treated with paraformaldehyde before antigen processing did not develop T cell-binding activity, macrophages treated with paraformaldehyde after a 60-min antigen-processing period retained T cell-binding ability. The kinetics of antigen catabolism correlated with antigen processing, and inhibition of antigen catabolism was associated with a corresponding inhibition of antigen processing for T cell binding. Anti-Ia antibodies had no effect on Listeria uptake of catabolism. These results supply direct evidence for a macrophage-antigen processing event relevant to T cell recognition of antigen.

Thymus-dependent membrane antigens in man: Inhibition of cell-mediated lympholysis by monoclonal antibodies to TH2 antigen

Abstract: In prior studies a heteroantiserum to a surface membrane component termed TH2 was used to define two subsets of human T cells (TH2+ and TH2-), which were found to express distinct sets of activities in vitro. In the present studies we prepared monoclonal antibodies to surface determinants that are restricted to T cells belonging to each of these two subsets. Two antibodies, termed αLeu-2a and αLeu-2b, which seem to define the same surface antigen identified by the original TH2 antiserum, reacted with 57-84% of thymocytes and 22-46% of the erythrocyte-rosette-forming cells (ERF-C) in peripheral blood. Two other monoclonal antibodies, termed αLeu-3a and αLeu-3b, reacted with the same subpopulation of thymocytes (78-89%) and peripheral blood ERF-C (47-78%) but, unlike αLeu-2a and αLeu-2b, did not exhibit cross-blocking; i.e., labeling cells with αLeu-3a did not inhibit the subsequent binding of αLeu-3b. T cells reactive with αLeu-2a were shown to be unreactive with αLeu-3a, indicating that two separate subpopulations of T cells, Leu-2 (formerly TH2+) and Leu-3 (TH2-) T cells, were thereby defined. These two T cell subsets make up the subpopulation of ERF-C (80-95%) previously defined by a monoclonal antibody to a T cell membrane antigen (Leu-1) that has a thymus-dependent distribution on normal lymphocytes but is expressed by some surface-immunoglobulin-positive (sIg+) leukemic lymphocytes. None of the Leu antibodies reported here reacted with sIg+, Leu-1+ leukemic cells, nor did they react with normal hematopoietic cells or lymphoid cells that had surface markers characteristic of B cells. Studies of the blocking effects of Leu antibodies on killing in cell-mediated lympholysis by effector T cells were carried out in the absence of complement. These experiments established the following points: (i) αLeu-2a abolished the killing by cytotoxic T cells of allogeneic phytohemagglutinin-stimulated blasts, (ii) inhibition of killing by αLeu-2b was markedly less than inhibition by αLeu-2a, and (iii) other antibodies, including αLeu-1, αLeu-3a, and αLeu-3b, had little or no effect on killing in cell-mediated lympholysis. The relevance of these findings to prior studies done in the mouse and in man are discussed.

Studies of a human T lymphocyte antigen recognized by a monoclonal antibody

Abstract: A monoclonal antibody (designated L17F12) detects an antigen present on 95-100% of human peripheral T lymphocytes, the majority of thymocytes, and acute lymphocytic leukemia T cells but not B cells, B-cell lines, or monocytes. Examination of frozen tissue sections by the immunoperoxidase method revealed that the cells expressing this antigen were found predominantly in the medulla of thymus and in T-cell zones of lymph node and spleen. The antigen recognized by L17F12 was associated with a cell-surface glycoprotein of 67,000 daltons. L17F12 was used to isolate this molecule from human thymocytes, normal peripheral T cells, leukemic T cells, and T-cell lines. Expression of this antigen on normal T cells was not diminished by prolonged exposure in vitro to various T-cell stimuli. In the absence of complement, L17F12 bound to T cells without altering proliferative functions, thus enabling rapid purification of functionally intact T cells. In the presence of complement, L17F12 was cytolytic for T cells, providing the basis for depletion of T cells from heterogeneous populations. These data suggest that the monoclonal antibody L17F12 recognizes a specific T-cell differentiation protein. This antibody will be useful in studies of the human immune system.

Inducer T lymphocytes synthesize a factor that stimulates proliferation of cloned mast cells

Abstract: Inducer T lymphocytes activate other cells to divide and express new function. Known target cells include other lymphocytes and haematopoietic stem cells1. We now provide evidence that the inducer T cell acts on another important target population: mast cells. Mast cells have a central role in the expression of immediate hypersensitivity and are also prominent in T-cell mediated reactions of the delayed type2–7. Because the proliferation of differentiated cells is often regulated by soluble growth factors, we examined an inducer T-cell clone for its ability to stimulate mast cell proliferation. We report here that cloned Ly1+2− inducer T cells produce a factor that selectively induces morphologically and karyotypically normal mouse mast cell clones to proliferate. We therefore suggest that inducer T cells may regulate mast cell numbers by releasing a soluble growth factor that stimulates them to divide. Because mast cell products also affect certain T-cell functions8–10, mast cell-T cell interactions may comprise part of an immunoregulatory circuit.

Biological properties of an influenza A virus-specific killer T cell clone. Inhibition of virus replication in vivo and induction of delayed-type hypersensitivity reactions.

Abstract: We tested two biological properties of a continuously growing mouse cytotoxic T cell line, L4, which is specific for influenza A virus and has been cloned and recloned many times. We previously reported that L4 cells are H-2 restricted and cross-reactive for all type A influenza viruses, whereas they do not recognize type B influenza viruses. They bear Thy-1 and Lyt-2 markers. In the present study, we show that L4 cytotoxic T cells protect mice against a lethal influenza infection on transfer to syngeneic recipients, and reduce virus titers in the lungs of mice challenged with a heterologous type A influenza virus. This provides further support for the active role of cytotoxic T cells in limiting virus replication in influenza infection. We could also demonstrate that the cloned cytotoxic T cells induce a delayed-type hypersensitivity skin reaction in the footpads of mice challenged with live or inactivated influenza virus. This reaction can be observed at 24 h, but has declined by 48 h. A clone of cells derived from L4 that has lost its cytotoxic potential and its ability to recognize infected cells did not induce a delayed-type hypersensitivity reaction in the presence of virus. Thus, cytotoxic T cells actively killing influenza virus-infected cells are able to induce a delayed-type hypersensitivity skin reaction to homologous and heterologous type A influenza viruses.

Activation of human T lymphocyte subsets: helper and suppressor/cytotoxic T cells recognize and respond to distinct histocompatibility antigens.

Abstract: This study was directed at determining the major histocompatibility complex (MHC) antigens recognized by helper (Leu-3) and suppressor-cytotoxic (Leu-2) T lymphocyte subsets in man. These 2 subsets were isolated from peripheral blood with monoclonal antibodies and challenged in vitro with various stimuli. Only Leu-3 cells proliferated in response to autologous nonrosetting cells and soluble antigens, suggesting that helper but not suppressor-cytotoxic T cells recognize autologous HLA-DR antigen. Furthermore, only Leu-3 T cells responded to allogeneic DR antigen; this was shown in reactions between 2 siblings who were HLA-identical except for a single disparity at HLA-DR caused by a crossover event. Leu-3 cells activated in primary allogeneic mixed leukocyte reactions (MLR) responded equally in secondary allogeneic MLR to the priming cells and to cells that were identical at HLA-DR but discordant at HLA-A, B, and C to the priming cell. The antigens responsible for stimulating Leu-2 cells in allogeneic MLR were not identified, although the results are compatible with a role for HLA-A and B antigens and exclude a dominant role for HLA-DR. These data indicate that the helper and suppressor-cytotoxic T cell subsets in man respond differentially to MHC antigens in a manner analogous to the murine Lyt-2- 3- and Lyt-2+ 3+ populations.

Eradication of disseminated murine leukemia by chemoimmunotherapy with cyclophosphamide and adoptively transferred immune syngeneic Lyt-1+2- lymphocytes

Abstract: The phenotype of T cells therapeutically effective in immunotherapy of advanced Friend virus-induced (FBL) leukemia in vivo and cytotoxic to FBL in vitro was determined. Mice bearing disseminated FBL leukemia were successfully treated by a combination of cyclophosphamide and adoptive transfer of syngeneic immune lymphocytes. Therapeutic efficacy was largely dependent on the presence of Lyt-1+2- T cells in the transferred cells, whereas cells cytotoxic to FBL tumor in vitro were derived from the Lyt-1+2+ and Lyt-1-2+ subsets. Thus, the predominate cell required to eradicate tumor in adoptive chemoimmunotherapy was not cytolytic to tumor in vitro. Potentially, the Lyt-1+2- cell may operate in vivo as an amplifier cell rather than by a direct anti-tumor effect. Elimination of the Lyt-1+ population with alpha-Lyt-1 and complement prevented the generation of significant cytotoxic responses during both primary in vitro sensitization to alloantigens and in vitro sensitization of tumour-primed cells. The capacity of Lyt-1+ cell-depleted population to generate cytotoxic responses was partially reconstituted by addition, at the initiation of culture, of interluekin 2, a T cell growth factor derived from Lyt-1+2- cells, which contain the CTL and CTL precursors, were nearly as effective in vitro as unseparated immune cells. If the remaining effector cells (i.e., Lyt-1+2- T cells) function in vivo predominantly as amplifier cells, than the tumour-bearing host must be capable of making a positive contribution to the outcome of therapy.

Analysis of T cell function in autoimmune murine strains. Defects in production and responsiveness to interleukin 2.

Abstract: In the studies reported here, we have analyzed the production and consumption of T cell growth factor, more recently termed interleukin 2 (IL-2), as well as some cell-mediated immune functions, in murine strains [MRL, BXSB, NZB, and (NZB x NZWF1] manifesting systemic lupus erythematosus (SLE)-like syndromes. Young (4-6 wk) or old (4-8 mo) autoimmune or normal mice were studied and compared with regard to the following T cell functions in vitro after stimulation with concanavalin A (Con A): (a) mitogenic response; (b) IL-2 levels in culture supernates; and (c) the ability to respond to and adsorb IL-2. In addition, proliferative activity in the allogeneic mixed leukocyte culture and frequency of alloreactive cytotoxic T lymphocyte precursors (CTLp) were analyzed in some of these strains. Reduced Con A-induced mitogenic responses and IL-2 production appeared at 3-6 wk of age in the early, severe SLE developing strains MRL-Mp-lpr/lpr (MRL/l) and male BXSB and progressed thereafter. Similar defects appeared at a later stage in MRL/Mp-+/+ and (NZB x NZW)F1 hybrid mice, which develop late disease. Detailed analysis of cells from the enlarged lymph nodes and spleens of older MRL/l mice demonstrated that such cells: (a) responded poorly to Con A or allogeneic stimulator cells, even in the presence of exogenous IL-2; (b) did not suppress IL-2 production by normal spleen cells; (c) were relatively incapable of adsorbing or inactivating IL-2; and (d) had a markedly reduced anti-H-2b CTLp frequency in the mesenteric lymph nodes but a normal one in spleen. These results indicate that the proliferating Thy-1.2+, Lyt-1+ T cells in MRL/l mice are defective in their responses to mitogenic stimuli, in IL-2 production, and in expression of acceptor sites for IL-2. The relevance of these defects to the MRL/l disease as well as to the role of IL-2 in autoimmunity in general remains to be determined.

Ia+ T cells in synovial fluid and tissues of patients with rheumatoid arthritis.

Abstract: Markedly elevated levels of T cells expressing Ia antigens were found in the synovial membranes and synovial fluids of patients with rheumatoid arthritis. The primary increase in expression of the Ia antigens was on the OKT 8+ (suppressor/cytotoxic) T cell subset. In addition, the total percentage of OKT 8+ T cells in intraarticular sites was usually greater than levels in peripheral blood. Small numbers of OKT 4+ (helper/inducer) cells bearing Ia antigens were also identified. The characteristic increase in the Ia+ T cells in peripheral blood was not encountered in most patients treated with D-penicillamine.

Antibodies to membrane structures that distinguish suppressor/cytotoxic and helper T lymphocyte subpopulations block the mixed leukocyte reaction in man.

Abstract: Two major subsets of human T lymphocytes that are functionally analogous to the mouse Lyt-2+ and Lyt-2- subsets have been defined by their expression of two thymus-dependent membrane antigens, Leu-2 and Leu-3. Leu-2+,3- cells have suppressor/cytotoxic functions and Leu-2-,3+ cells have helper functions. These studies were designed to determine the effects of adding IgG1 monoclonal anti-Leu-2 and anti-Leu-3 antibodies to the mixed leukocyte reaction (MLR). At high concentrations, each antibody partially inhibited the proliferative response of unseparated T cells and abolished the response of the isolated subset having the appropriate phenotype. An IgG1 monoclonal antibody to HLA-A2 and an IgG2a antibody to Leu-1, a pan-T antigen, failed to inhibited the MLR. These results suggest that the Leu-2 and Leu-3 antigens may have a direct role in the mechanism whereby T cells recognize and respond to alloantigen.

Monoclonal antibody to a novel lymphocyte function-associated antigen (LFA-1): mechanism of blockade of T lymphocyte-mediated killing and effects on other T and B lymphocyte functions.

Abstract: 14. Nonoyama, M.. and J. S. Pagano. 1971. Detection of Epstein-Barr viral genome in nonproductive cells. Nature (New Biol.) 233:103. 15. Nonoyama. M. 1975. Detection of tumor virus genomes by nucleic hybridization. Int. Rev. Exp. Pathol. 14:69. 16. Raab-Traub. N., T. Dambaugh. and E. Kieff. 1980. DNA of Epstein-Barr virus VIII. 895-8, the Prennis prototype, is an unusual deletion derivative. Cell 22:257. 17. Dambaugh. T., D. Beisel, M. Hummel, W. King, S. Ferr. A. Cheung, M. Heller. N. Raab-Traub and E. Kieff. 1980. Epstein-Barr virus (895-8) DNA.

Does OKT3 monoclonal antibody react with an antigen-recognition structure on human T cells?

Abstract: OKT3 monoclonal antibody to human T cells inhibits the target cell lysis mediated by allogeneic cytotoxic T cells and the generation of these effector cells in mixed lymphocyte culture. This marked inhibition of cell-mediated lysis is not found with other monoclonal antibodies also reactive with cell surface antigens of human T cells (OKT1, OKT4, OKT5, OKT6, OKT8, and OKT11). OKT3 antibody is mitogenic and this effect appears to require receptor activation in that it occurs at low concentrations (10(-12) M range) of OKT3 antibody, requires intact OKT3 IgG, and is inhibited by a factor(s) in human plasma. By contrast, the inhibition of allogeneic cell-mediated lysis by OKT3 antibody appears to be due to steric hindrance in that it requires higher concentrations of OKT3 antibody (10(-8) M range), Fab fragments retain approximately 10% activity, and inhibition is demonstrable in the presence of human plasma. These findings are consistent with the suggestion that OKT3 antibody reacts with the human T-cell antigen-recognition structure.

Distribution of t lymphocyte subsets in the human bone marrow and thymus: an analysis with monoclonal antibodies.

Abstract: A panel of reagents (OKT1, 3, 4, 6, 8, and 11) detects differentiation antigens expressed exclusively on HuTLA+ T lymphoid cells but absent on bone marrow precursors, such as terminal deoxynucleotidyl transferase- (TdT) positive cells, immature myeloblasts, and other myeloid/erythroid cell types In the bone marrow no transitional forms could be detected between TdT+ and T cells The BM T cells showed mostly the suppressor/cytotoxic phenotype (OKT8+) with only a few T cells of inducer type (OKT4+) Thymocyte heterogeneity was also analyzed directly in tissue sections and in double labeling assays in combination with TdT staining, a marker for cortical thymocytes Many large thymic blasts (in fetal and infant thymus) showed reactivity with OKT11--a pan-T reagent, but had only weak or negligible activity with the other antibodies Cortical thymocytes reacted strongly with OKT11, 6, 4, and 8, whereas medullary cells reacted with OKT11, 3, 4 (majority) and 8 (minority) Thus, the reactivity with these antibodies is generated in the thymus at various stages of differentiation In contrast, OKT10 (an anti-"precursor cell" reagent) reacted not only with thymocytes but also with TdT+ BM precursors, myeloblasts, and BM B lymphocytes although it was unreactive with mature peripheral lymphoid and maturing myelo/erythroid cells