Lymphokine-activated killer cell activity Characteristics of effector cells and their progenitors in blood and spleen.

Leukocytes in blood and spleen can be activated by interleukin 2 (IL-2) to become cytotoxic to certain tumor cell lines in vitro. Recent evidence suggests that such lymphokine-activated killer (LAK) cells can bring about the regression of solid tumors in animals and patients, under certain circumstances. Here, Ronald Herberman and colleagues from eight international laboratories, review what is known of the characteristics of LAK cell activity and conclude that most of it can be attributed to natural killer cells stimulated by IL-2.

Presence of Ti (WT31) negative T lymphocytes in normal blood and thymus.

The antigen receptor expressed on most T lymphocytes is a disulphide-linked heterodimer (Ti) that is composed of alpha-chain and beta-chain subunits. On the surface of human T lymphocytes, Ti is non-covalently associated with three invariant proteins, designated CD3-gamma, -delta, and -epsilon. It has been suggested that Ti is obligatory for CD3 expression.

Antigenic, functional, and molecular genetic studies of human natural killer cells and cytotoxic T lymphocytes not restricted by the major histocompatibility complex.

Cytotoxicity not restricted by the major histocompatibility complex (MHC) is mediated by two distinct types of lymphocyte: natural killer (NK) cells and non-MHC-restricted cytotoxic T lymphocytes (CTL). These two types of cytotoxic lymphocytes can be distinguished by antigenic phenotype, function, and molecular genetic studies. In human peripheral blood, NK cells are identified by expression of the Leu-19 and/or CD16 cell surface antigens, and lack of CD3/T cell antigen receptor (Ti) complex expression (i.

Correlation of cell surface antigen expression on human thymocytes by multi-color flow cytometric analysis: implications for differentiation.

Thymocytes undergo a complex series of phenotypic and genotypic changes during maturation in the thymus. This dynamic process involves qualitative and quantitative changes in the expression of certain cell surface differentiation antigens. In this study, we have directly examined the relationship of T cell differentiation antigen expression on normal human thymocytes by using multi-color immunofluorescence and multi-parameter flow cytometric analysis.

Bacterial activation of human natural killer cells. Characteristics of the activation process and identification of the effector cell.

We showed previously that contact of human peripheral blood lymphocytes with glutaraldehyde-fixed Salmonella bacteria augmented their cytotoxic capacity against NK-sensitive targets. We have now analyzed the characteristics of the activation and also identified the subsets of lymphocytes responding to bacterial contact. Blocking of protein synthesis with cyclohexamide totally abrogated bacterial induction of activated killing (AK), whereas inhibition of DNA synthesis with mitomycin C did not significantly affect the capacity of lymphocytes to respond to bacterial contact.

Distinct epitopes on the T cell antigen receptor of HPB-ALL tumor cells identified by monoclonal antibodies.

The T cell antigen receptor is a approximately 90,000 dalton disulfide linked heterodimer that is non-covalently associated with the CD3 complex. Prior studies have demonstrated that anti-CD3 or -Ti antibodies can mimic antigen and induce cellular proliferation and the secretion of lymphokines. An early event in activation via CD3/Ti is a rapid increase in concentration of intracellular Ca2+ levels.

Dissection of the lymphokine-activated killer phenomenon. Relative contribution of peripheral blood natural killer cells and T lymphocytes to cytolysis.

In vitro culture of human peripheral blood lymphocytes in IL-2 results in the generation of cytotoxic cells that can lyse fresh and cultured solid tumor cells, as well as hematopoietic tumor cell lines, without deliberate immunization or MHC restriction. This has been referred to as the lymphokine activated killer (LAK) phenomenon. Here, we show that the majority of this activity is mediated by NK cells that express the Leu-19 (NKH-1) antigen, but do not express CD3.

Human CD3+ T lymphocytes that express neither CD4 nor CD8 antigens.

CD3+ T lymphocytes expressing neither CD4 nor CD8 antigens exist in normal human peripheral blood in low frequency (approximately 3% of lymphocytes). The CD3+,4-,8- phenotype was stably maintained after in vitro culture in IL-2. Culture of CD3+,4-,8- cells in only rIL-2 generated cytotoxic T cells that lysed NK-sensitive and NK-insensitive tumor cell targets without MHC restriction.

The relationship of CD16 (Leu-11) and Leu-19 (NKH-1) antigen expression on human peripheral blood NK cells and cytotoxic T lymphocytes.

We examined the antigenic and functional characteristics of human peripheral blood lymphocytes that differentially express the CD16 (Leu-11) and Leu-19 (NKH-1) antigens. Leu-19 is a approximately 220,000 daltons protein expressed on approximately 15% of freshly isolated peripheral blood lymphocytes. Within the Leu-19+ subset, three distinct populations were identified: CD3-,CD16+,Leu-19+ cells; CD3+,CD16-,Leu-19+ cells; and CD3-,CD16-,Leu-19bright+ cells.

Evidence for three types of human cytotoxic lymphocyte.

Natural killer (NK) cells lyse a broad spectrum of tumor-cell lines and virus-infected cells, they are MHC unrestricted and they are detectable in unimmunized subjects: cytotoxic T cells (CTL) have fine antigen specificity, are MHC restricted and are usually detectable only after they multiply on exposure to antigen. Here Lewis Lanier and Joseph Phillips argue that these functional criteria do not adequately distinguish types of cytotoxic cell. They propose a classification based on recognition structure, which identifies three distinct effector cells.

NK cell function in a patient with IgM monoclonal antibody against myelin-associated glycoprotein.

Anti-Leu 7 antibody reacts with determinants on a subset of natural killer (NK) cells and myelin-associated glycoprotein (MAG). In a patient patient with peripheral neuropathy and IgM autoantibodies against MAG, we found the distribution and functions of NK cells to be normal.

Function and cell distribution of KC-1, a novel natural killer cell-associated antigen.

Natural killer (NK) cell have been implicated in immune responses to tumor and viral antigens. We describe here a monoclonal antibody, anti-KC-1, that blocks lysis of NK targets by fresh but not activated NK cells. Anti-KC-1 has no effect on cytotoxic T lymphocyte activity or on antibody-dependent cellular cytotoxicity.

Lectin-dependent and anti-CD3 induced cytotoxicity are preferentially mediated by peripheral blood cytotoxic T lymphocytes expressing Leu-7 antigen.

Monoclonal antibodies against the CD3 antigen and certain lectins can induce interleukin 2 dependent antigen-specific T cell clones to mediate non-antigen specific cytotoxicity. On the basis of this observation, we predicted that it may be possible to identify cytotoxic T lymphocytes (CTL) in peripheral blood without knowing the antigen specificity of these in vivo primed CTL. By using this strategy, peripheral blood lymphocytes were separated into low and high-density fractions on Percoll gradients and were tested for cytotoxic activity in the presence or absence of concanavalin A (Con A) or anti-Leu-4 antibody.

Human natural killer cells isolated from peripheral blood do not rearrange T cell antigen receptor beta chain genes.

The lineage of NK cells and their relationship to T lymphocytes have been controversial issues. Since rearrangement of the T cell antigen receptor beta chain genes occurs early in the ontogeny and differentiation of all T cells, this can be used as an unequivocal marker to discriminate T from non-T lymphocytes. Recent studies (16-18) examining T cell antigen receptor gene rearrangement and expression in certain IL-2-dependent NK cell lines and leukemias have revealed that some lines rearrange C beta genes, whereas others do not.

Human thymic and peripheral blood non-MHC-restricted cytotoxic lymphocytes.

We propose that non-MHC-restricted cytotoxicity is mediated by two distinct types of lymphocyte: NK cells and a unique subset of cytotoxic T-lymphocytes (CTLs). Herein, we review experimental data to support the hypothesis that NK cells and non-MHC-restricted CTLs use different recognition structures and arise from distinct lineages. Furthermore, we demonstrate that non-MHC-restricted CTLs can be generated in vitro by culturing thymocytes in recombinant interleukin-2 (rIL-2).

Functional properties of a unique subset of cytotoxic CD3+ T lymphocytes that express Fc receptors for IgG (CD16/Leu-11 antigen).

A subset of peripheral blood T lymphocytes coexpressing CD3 and IgG Fc receptors (FcR) (CD16/Leu-11 antigen) have been identified, isolated, and functionally characterized. The CD3+, CD16+ cells were established in short-term culture using growth medium containing interleukin 2 (IL-2). Both the freshly isolated cells and the cultured cell line stably expressed the CD3+, CD16+ phenotype.

Molecular characterization of the murine T cell antigen receptor and associated structures.

Previous studies have demonstrated that the T cell antigen-specific receptor is a disulfide-linked heterodimer with subunits of 40-48 kilodaltons. We have produced a series of antiserums and monoclonal antibodies to epitopes carried by the molecule, including clonotypic epitopes specific to individual T lymphomas as well as epitopes shared by different T cell lines. Using these reagents we have isolated the heterodimers from a variety of T cells for comparison of primary structure via two-dimensional peptide mapping.

Antigens associated with the activation of murine mononuclear phagocytes in vivo: differential expression of lymphocyte function-associated antigen in the several stages of development.

Two well-characterized antigens [Mac-1 and lymphocyte-function-associated antigen (LFA-1)], expressed on a variety of leukocytes, are members of a family of surface proteins associated with multiple recognition functions. To analyze expression of these proteins during macrophage development, we utilized both radioimmunoassay and flow cytometry. As previously reported, Mac-1 is expressed on murine macrophages in all stages of development.

p150/95, Third member of the LFA-1/CR3 polypeptide family identified by anti-Leu M5 monoclonal antibody.

Monoclonal antibody (mAb) anti-Leu M5 reacts with a two-chain molecule composed of a 150-kDa alpha subunit noncovalently associated with a 95-kDa beta subunit and probably is specific for an epitope on the 150-kDa alpha chain. This p150/95 antigen is the third member of a family of polypeptides sharing a common 95-kDa beta chain, which includes the lymphocyte function-associated antigen LFA-1 (p177/95) and complement receptor CR3 (Mo1/MAC-1/OKM1; p165/95) antigens. Sequential immunoprecipitation with anti-p95 beta chain mAb specifically removed the antigens detected by anti-LFA-1, anti-CR3 and anti-Leu M5 mAb.