scholarly journals A novel 120-kD surface antigen expressed by a subset of human lymphocytes. Evidence that lymphokine-activated killer cells express this molecule and use it in their effector function.

1987 ◽  
Vol 166 (2) ◽  
pp. 319-326 ◽  
Author(s):  
M R Zocchi ◽  
C Bottino ◽  
S Ferrini ◽  
L Moretta ◽  
A Moretta
Keyword(s):  
T Cell ◽  
Cell Lines ◽  
Peripheral Blood ◽  
Cell Clone ◽  
Human Lymphocytes ◽  
Cytolytic Activity ◽  
Cell Populations ◽  
Target Cells ◽  
Lymphokine Activated Killer Cells ◽  
Effector Cells

A human cell clone (SF-16) displaying strong cytolytic activity against fresh tumor target cells was used for production of murine mAbs against surface antigens expressed by lymphokine-activated killer (LAK) cells and their peripheral blood precursors. The preliminary screening of hybridoma supernatants was performed according to the ability to bind SF-16 cells. Selected mAbs were further analyzed for their reactivity with several T and B cell lines and with peripheral blood T and non-T cell populations. A selected mAb, termed anti-LAK-1, only reacted with some T cell lines and with 15-30% of PBMC. Approximately 10-15% E-rosetting (T) cells and 40-50% E-rosette-negative cells were LAK-1+, as determined by cytofluorometric analysis. As the fluorescence distribution of LAK-1 antigen was clearly bimodal, LAK-1+ and LAK-1- cells could be separated by FACS. Positive cells were composed of large granular lymphocytes (LGL), whereas negative cells were mostly small lymphocytes and monocytes without LGL. After culture in rIL-2, purified LAK-1+ (but not LAK-1-) cells acquired the ability to lyse NK-resistant fresh melanoma target cells. In addition, only the LAK-1+ fraction of PBMC cultured for 5 d in rIL-2 lysed fresh tumor targets, thus indicating that the LAK-1 antigen is expressed also on LAK effector cells. Unlike some other LGL/NK cell markers, LAK-1 antigen is characterized by a stable expression: thus, LAK-1+ cell populations cultured for up to 20 d in rIL-2 maintained the LAK-1 antigen expression, whereas HNK-1 and, partially, CD16 were lost. Finally the cytolytic activity of LAK effector cells generated from PBMC cultured for 3 d in rIL-2 was susceptible to inhibition by the anti-LAK-1 mAb.

scholarly journals Peripheral blood lymphocytes as target cells of retroviral vector- mediated gene transfer

Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1988-1997 ◽  
Author(s):  
F Mavilio ◽  
G Ferrari ◽  
S Rossini ◽  
N Nobili ◽  
C Bonini ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Gene Transfer ◽  
Cell Lines ◽  
Peripheral Blood ◽  
Retroviral Vectors ◽  
Peripheral Blood Lymphocytes ◽  
Cell Populations ◽  
Target Cells ◽  
Specific Cell

Peripheral blood lymphocytes (PBLs) are key target cells for gene therapy of a number of inherited and acquired blood disorders. We have systematically compared four retroviral vectors, designed according to different strategies, for their efficiency in transfer and expression in human PBLs of the same reporter gene. The receptor gene used in the study codes for the human low-affinity nerve growth factor receptor (LNGFR), and is not expressed on the majority of human hematopoietic cells, thus allowing quantitative analysis of the transduced gene expression by immunofluorescence, with single cell resolution. Peripheral blood mononuclear cells (PBMCs), as well as human hematopoietic cell lines of myeloid and lymphoid origin, were transduced with the four vectors and analyzed for efficiency of gene transfer, integration and stability of vector proviruses, and LNGFR expression at both RNA and protein level. Fluorescence-activated cell sorter analysis of coexpression of LNGFR and lineage-specific cell surface markers was performed in transduced cell lines, PBLs, and T- cell clones to study gene expression on specific cell subpopulations. Although crucial differences were observed among different constructs, all retroviral vectors could transduce, under appropriate infection conditions, T-cell populations representative of the normal immune repertoire. Gene transfer and expression could be demonstrated also in circulating progenitors of mature T cells. Expression of the transduced gene was heterogeneous among cell populations infected with the different vectors, with optimal results obtained by two of the four constructs. Finally, we have devised a simple protocol based on vector- mediated gene transfer and positive immunoselection of the transduced cells that produces virtually 100% gene-modified cells. This may represent a crucial improvement in the way of designing efficacious protocols involving the use of gene-modified T lymphocytes in clinical studies.

scholarly journals Peripheral blood lymphocytes as target cells of retroviral vector- mediated gene transfer

Blood ◽  
1994 ◽  
Vol 83 (7) ◽  
pp. 1988-1997 ◽  
Author(s):  
F Mavilio ◽  
G Ferrari ◽  
S Rossini ◽  
N Nobili ◽  
C Bonini ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Gene Transfer ◽  
Cell Lines ◽  
Peripheral Blood ◽  
Retroviral Vectors ◽  
Peripheral Blood Lymphocytes ◽  
Cell Populations ◽  
Target Cells ◽  
Specific Cell

Abstract Peripheral blood lymphocytes (PBLs) are key target cells for gene therapy of a number of inherited and acquired blood disorders. We have systematically compared four retroviral vectors, designed according to different strategies, for their efficiency in transfer and expression in human PBLs of the same reporter gene. The receptor gene used in the study codes for the human low-affinity nerve growth factor receptor (LNGFR), and is not expressed on the majority of human hematopoietic cells, thus allowing quantitative analysis of the transduced gene expression by immunofluorescence, with single cell resolution. Peripheral blood mononuclear cells (PBMCs), as well as human hematopoietic cell lines of myeloid and lymphoid origin, were transduced with the four vectors and analyzed for efficiency of gene transfer, integration and stability of vector proviruses, and LNGFR expression at both RNA and protein level. Fluorescence-activated cell sorter analysis of coexpression of LNGFR and lineage-specific cell surface markers was performed in transduced cell lines, PBLs, and T- cell clones to study gene expression on specific cell subpopulations. Although crucial differences were observed among different constructs, all retroviral vectors could transduce, under appropriate infection conditions, T-cell populations representative of the normal immune repertoire. Gene transfer and expression could be demonstrated also in circulating progenitors of mature T cells. Expression of the transduced gene was heterogeneous among cell populations infected with the different vectors, with optimal results obtained by two of the four constructs. Finally, we have devised a simple protocol based on vector- mediated gene transfer and positive immunoselection of the transduced cells that produces virtually 100% gene-modified cells. This may represent a crucial improvement in the way of designing efficacious protocols involving the use of gene-modified T lymphocytes in clinical studies.

Transfer of Human T-Cell Receptors (TCR) Containing Murine Chimeric Constant Beta-Gamma-Chain Sequences Reduces the Risk of Mixed Heterodimers and Shows Enhanced in Vitro-Accumulation of TCR-Tranduced Effector Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3583-3583
Author(s):  
Angela Krackhardt ◽  
Xiaoling Liang ◽  
Ingrid G Schuster ◽  
Luise U Weigand ◽  
Elfriede Eppinger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Therapeutic Approach ◽  
Cell Clone ◽  
Target Cells ◽  
Malignant Diseases ◽  
Effector Cells ◽  
T Cell Clone

Abstract Abstract 3583 Poster Board III-520 Introduction Adoptive transfer of T-cell receptor (TCR)-transduced T cells may represent an attractive and promising novel approach to specifically treat malignant diseases and has been previously successfully applied in the clinic. This approach promises the availability of sufficient numbers of effector cells with defined specificity for any tumor-associated antigen as also TCR from T cells with specificity for tumor-associated self antigens usually deleted in the autologous host may be isolated from an allorestricted or xenorestricted environment. We have previously identified the HLA-A2-allorestricted T-cell clone (SK22) with specificity for a peptide derived from Formin-like protein 1 (FMNL1) restrictedly expressed in hematopoietic tissue and overexpressed in diverse leukemias and other malignant tissue. SK22 demonstrated specific cytotoxicity against FMNL1-overexpressing cells as EBV-transformed B cells, lymphoma cell lines and native malignant cells derived from patients with chronic lymphocytic leukemia whereas healthy tissue was mainly spared. The TCR of this T cell clone may therefore represent a suitable tool for the treatment of diverse malignant diseases using TCR-transduced T cells. However, there are different concerns which need to be addressed to further improve this therapeutic approach. First, the formation of heterodimers between endogenous TCR chains and transduced TCR chains derived from receptors with low interchain affinity may abrogate specific TCR function and harbours a particular risk for unknown specificities. Although a number of TCR chain modifications has been previously applied to solve this problem further improvements are necessary. Second, longterm survival of TCR-transduced T cells has been demonstrated to be critical for the effectivity of this approach and novel approaches are needed. Methods and Results We have isolated the TCR-chain genes of the FMNL1-specific T cell clone SK22 and cloned them into the retroviral vector pMP71. Transduction of unmodified TCR-chain genes of SK22 in CD8α-transfected TCR-deficient Jurkat76 cells resulted in multimer-positive cells indicating that correct TCR-chain genes have been isolated. However, peripheral blood mononuclear cells (PBMC) transduced with these native TCR chains did neither show TCR expression nor specific T-cell function suggesting that TCR SK22 represents a weak TCR with low interchain affinity. Expression and function of this TCR could be significantly improved by current optimization strategies as codon-optimization and murinization of constant chains. Effector cells transduced with these optimized TCR chain genes showed reactivity against transformed cells of different origin whereas non-transformed HLA-A2 positive target cells as lung fibroblasts, embryonic cardiomyocytes, CD4- and CD8-positive T cells as well as activated PBMC were not recognized. However, substantial mispairing persisted despite of murinization of constant chain sequences. Using human TCR chain genes containing murinized chimeric constant βγ-chains previously reported to exert improved signaling in murine T cells and cell lines, we created a hybrid TCR with high functional efficiency after transfer in human effector cells. Moreover, usage of murinized chimeric constant βγ-chains of SK22 clearly reduced the formation of heterodimers in human PBMC. In addition, we observed enhanced in vitro-accumulation of CD8- and CD4-positive cells expressing the transgenic receptor when optimized murinized chimeric constant βγ-chains in comparison to optimized murinized constant β-chains without γ-chain sequences were used. These results could be confirmed after transfer of two alternative TCR with specificities for HER2/neu and GP100 containing murinized chimeric constant βγ-chains. Conclusion These data show that transfer of the optimized TCR SK22 may be an attractive therapeutic tool for the treatment of malignancies of hematologic and other origin. Moreover, the transfer of TCR chain genes containing optimized murinized chimeric constant βγ-chains may have a significant impact on the improvement of safety and efficiency of this therapeutic approach. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Direct demonstration of the clonogenic potential of every human peripheral blood T cell. Clonal analysis of HLA-DR expression and cytolytic activity.

1983 ◽  
Vol 157 (2) ◽  
pp. 743-754 ◽  
Author(s):  
A Moretta ◽  
G Pantaleo ◽  
L Moretta ◽  
J C Cerottini ◽  
M C Mingari
Keyword(s):  
T Cells ◽  
T Cell ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Cell Populations ◽  
Target Cells ◽  
Flow Cytofluorometry ◽  
Hla Dr ◽  
Clonogenic Potential ◽  
Precursor Frequency

In an attempt to determine the clonogenic properties of human peripheral blood T cells, we have developed a limiting dilution microculture system using phytohemagglutinin (PHA) as T cell activator and supernatant from PHA-stimulated spleen cultures as a source of T cell growth factors. The frequencies of cells capable of extensive proliferation under these culture conditions were 0.52-0.73, 0.98-1.11, and less than 0.02 in peripheral blood mononuclear, E-rosette-positive, and E-rosette-negative cell populations, respectively. The clonogenic potential of virtually all T cells was confirmed in experiments using single cells isolated by micromanipulation. Clone size ranged between 5 and 30 X 10(4) cells on day 14 of culture. The same microculture system was used to determine the precursor frequency of all cytolytic T lymphocytes (CTL-P). As assessed by a lectin-dependent 51Cr release assay, the CTL-P frequency in purified T cell populations ranged between 0.30 and 0.34. In comparison, the precursor frequency of T cells capable of lysing K562 target cells was ranging between 0.14 and 0.16. Parallel analysis of individual clonal cultures for both lytic activities showed that 50% of the clones exhibiting lectin-dependent lysis were also active against K562 target cells. All of the proliferating clones expressed HLA-DR antigens, although to a varying degree as assessed by flow cytofluorometry. Given the high cloning efficiency of this culture system, it appears now possible to determine the precursor frequencies of the various classes of functional cells in T cell populations.

Re-Engineering γ δ T Cells by α β T Cell Receptor Gene Transfer Creates Potent Effector Cells with Anti-Leukemic Reactivity.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1288-1288
Author(s):  
Lars T. van der Veken ◽  
Renate S. Hagedoorn ◽  
Marleen M. van Loenen ◽  
Roel Willemze ◽  
J.H. Frederik Falkenburg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Gene Transfer ◽  
Peripheral Blood ◽  
Cytokine Production ◽  
Target Cells ◽  
Facs Analysis ◽  
Effector Cells ◽  
Tetramer Binding ◽  
Potent Effector

Abstract Retroviral transfer of T cell receptors (TCRs) to peripheral blood derived T cells generates large numbers of T cells with the same antigen specificity, which can potentially be used for adoptive immunotherapy. One drawback of this procedure is the formation of mixed α β TCR dimers with unknown specificities due to pairing of endogenous and introduced TCR chains. To completely prevent the formation of mixed TCR dimers by TCR gene transfer to α β T cells we investigated whether γ δ T cells can serve as alternative host T cells for α β TCR transfer, since the γ δ TCR is not capable of forming dimers with the α β TCR. Peripheral blood derived γ δT cells were isolated by immunomagnetic bead isolation and subsequent FACS sorting, resulting in >99% pure populations of γ δT cells. The isolated γ δT cells were retrovirally transduced with three different TCRs specific for the hematopoietic minor histocompatibility antigen (mHag) HA-2 in the context of HLA-A2, for CMV-pp65 in the context of HLA-B7, or for the HLA class II restricted mHag DBY. The TCR-transduced γ δT cells expressed both the introduced TCRs and the endogenous γ δTCR at their cell surface as determined by FACS analysis. When γ δT cells transduced with the HLA class I restricted HA-2-TCR or CMV-TCR were stained with tetramers, only the CMV-TCR expressing γ δT cells but not the HA-2-TCR expressing γ δT cells were capable of strong antigen specific tetramer binding. In contrast, functional analysis indicated that all TCR-transduced γ δT cells specifically recognized peptide pulsed target cells leading to target cell lysis and IFNγ and IL-4 production, indicating that while the avidity of the HA-2-TCR engineered γ δT cells was insufficient for strong antigen specific tetramer binding, the avidity was high enough for the specific recognition of peptide pulsed target cells. However, the functional reactivity of the TCR-transduced γ δT cells against target cells presenting endogenously processed antigens was low. FACS analysis indicated that most γ δT cells lacked the expression of the coreceptors CD4 and CD8. Therefore, we investigated whether introduction of the relevant coreceptor could enhance the functionality of the redirected γ δT cells. Co-transfer of the CD8α β coreceptor to the HA-2-TCR and CMV-TCR transferred γ δT cells turned them into effective, antigen specific tetramer binders. Furthermore, expression of CD8α β by the HA-2-TCR and CMV-TCR transduced γ δT cells and CD4 by the DBY-TCR transduced γ δT cells generated powerful effector cells exerting high levels of antigen specific lysis of both peptide pulsed target cells and target cells presenting endogenously processed antigen. In addition, coreceptor expressing TCR-engineered γ δT cells produced high amounts of IFNγ and IL-4 when stimulated with peptide pulsed target cells or endogenously processed antigen. To investigate the anti-leukemic reactivity of TCR-transferred γ δT cells, we determined the antigen specific cytotoxicity and cytokine production against primary CML and AML cells by γ δT cells equipped with the HA-2-TCR and CD8α β . We observed both antigen specific cytolytic activity and cytokine production against both CML and AML cells expressing the hematopoiesis specific mHag HA-2, while HLA-A2+ leukemic cells lacking expression of the HA-2 mHag were not recognized. These data demonstrate that transfer of α β TCRs to γ δT cells generated potent effector cells for immunotherapy of leukemia, without the expression of potentially hazardous mixed TCR dimers.

scholarly journals The natural killer-related receptor for HLA-C expressed on T cells from CD3+ lymphoproliferative disease of granular lymphocytes displays either inhibitory or stimulatory function

Blood ◽  
1996 ◽  
Vol 87 (6) ◽  
pp. 2369-2375 ◽  
Author(s):  
A Cambiaggi ◽  
AM Orengo ◽  
R Meazza ◽  
S Sforzini ◽  
PL Tazzari ◽  
...  
Keyword(s):  
T Cell ◽  
Natural Killer ◽  
Cell Line ◽  
Cell Clone ◽  
Molecular Form ◽  
Lymphoproliferative Disease ◽  
Cytolytic Activity ◽  
Target Cells ◽  
T Cell Clone ◽  
Granular Lymphocytes

Four patients with lymphoproliferative disease of granular lymphocytes (LDGL) coexpressing CD3 and the natural killer (NK)-related “p58” receptor for HLA-C alleles were studied. These CD3+p58+ LDGLs have been detected among a series of 44 CD3+ LDGLs analyzed. Two patients with LDGL (GI and BA) expressed only the p58 molecule defined by the GL-183 and CH-L monoclonal antibodies (MoAbs), while the cases of patients PU and MA also coexpressed the molecular form identified by EB6 anti-p58 MoAb. Three LDGL cases (GI, MA, and PU) displayed the CD8+4-CD16+ T- cell receptor (TCR)alpha/beta+ phenotype, while one patient (BA) was CD8+4+CD16+ TCRalpha/beta+. Freshly isolated granular lymphocytes (GL) from these cases displayed cytolytic activity in an anti-CD3 MoAb- triggered redirected killing assay against the Fcgamma-receptor+ (Fcgamma-R+) P815 target cell line. Lysis of P815 target cells, triggered by an anti-CD3 or by anti-CD16 MoAb, could be inhibited by the addition of anti-p58 MoAb in three fresh or interleukin (IL)-2- cultured GL tested (GI, MA, and PU). Triggering of cytotoxicity against the HLA-DR+ Fcgamma-R+ Daudi cell line induced by appropriate superantigens could also be inhibited by anti-p58 MoAb in patients PU and GI with LDGL. These data indicate that activation through the CD16, CD3, and TCR molecules can be modulated by p58 receptors in these LDGLs. On the contrary, IL-2-expanded cells of patient BA were induced to lyse P815 target cells by anti-p58 MoAb. In addition, anti-p58 MoAB enhanced anti-CD16 MoAb triggered lysis and did not inhibit activation via CD3. These data indicate that, in this particular patient with LDGL, p58 displays a stimulatory effect on cell triggering, rather than the typical inhibitory effect previously observed in p58+ T-cell clones derived from healthy donors. The anti-p58 MoAb did not induce CA++ mobilization in p58+ LDGLs and in a p58+CD3+ normal T-cell clone equipped with inhibitory p58 molecules, while Ca++ mobilization could be observed in cultured GL from patient BA, which could be activated by anti-58 MoAb. These findings suggest that stimulatory and inhibitory p58 molecules are equipped with different signal transducing properties, thus contributing to a better knowledge of the normal counterpart.

scholarly journals Alloreactive cloned T cell lines. I. Interactions between cloned amplifier and cytolytic T cell lines.

1980 ◽  
Vol 151 (4) ◽  
pp. 876-895 ◽  
Author(s):  
A L Glasebrook ◽  
F W Fitch
Keyword(s):  
T Cell ◽  
Cell Lines ◽  
Cytolytic Activity ◽  
Surface Proteins ◽  
Target Cells ◽  
Spleen Cells ◽  
T Cell Clones ◽  
Cell Clones ◽  
T Cell Lines ◽  
Cytolytic Cell

Several T cell clones have been derived by limiting dilution of secondary mixed leukocyte culture cells stimulated by H-2- and M locus (Mls)-disparate spleen cells. When examined for the expression of cytolytic activity and the ability to proliferate, these cell clones can be classified into two major categories. One type of cell is noncytolytic; when cultured with irradiated spleen cells, such clones proliferate in response to Mls determinants. Some, but not all, of these clones express Lyt-1 alloantigens. The other type of cell is cytolytic; these clones do not proliferate when cultured with irradiated allogeneic spleen cells unless supernatant fluid (SF) is added. These cytolytic clones express Lyt-2 alloantigens. Some cytolytic clones are specific for H-2Kd and others for H-2Dd alloantigens. Still other cytolytic cell clones exhibit cross-reactive lysis of different H-2-bearing tumor and Con A blast target cells. Noncytolytic T cell clones, when stimulated by Mls antigens, were examined for their ability to promote proliferation of cytolytic T cell clones. All of the noncytolytic cell clones tested were able to promote proliferation of cytolytic cell clones with the concomitant expression of cytolytic activity directed toward the original stimulating alloantigen (H-2d). Amplification of cytolytic activity was dependent upon stimulation of the noncytolytic amplifier T cell clones by Mls antigens. Specific alloantigen (signal 1), however, was not required for proliferation of the cytolytic cell clones; the amplifying signal (signal 2), delivered by the amplifier cell clones, was sufficient alone to promote proliferation of the cytolytic cell clones. Whereas proliferation of the amplifier cells was radiosensitive, the generation of the soluble amplifying signal was radioresistant. Amplification of cytolytic activity was observed when either amplifier cells were physically separated from responding cytolytic cells in Marbrook cultures or when cytolytic cells were cultured with SF collected from amplifier cell cultures. The amplifying factors were neither antigen specific nor strain specific and could be produced by Lyt-1- cells. The availability of cloned T cell lines that retain specific biologic function offers unique opportunities to characterize cell surface proteins and cell-cell interactions.

scholarly journals A clone-specific monoclonal antibody that inhibits cytolysis of a cytolytic T cell clone.

1983 ◽  
Vol 157 (3) ◽  
pp. 921-935 ◽  
Author(s):  
D W Lancki ◽  
M I Lorber ◽  
M R Loken ◽  
F W Fitch
Keyword(s):  
Monoclonal Antibody ◽  
T Cell ◽  
Bone Marrow Cells ◽  
Cytotoxic T Lymphocyte ◽  
Cell Clone ◽  
Lymphocyte Culture ◽  
Cytolytic Activity ◽  
Target Cells ◽  
Region Gene ◽  
T Cell Clone

Monoclonal antibody 384.5 specifically inhibited cytolysis of P-815 target cells by cloned L3 cytotoxic T lymphocyte (CTL) effector cells. The lytic activity of other cloned CTL that have other distinct specificities was not affected. Antibody 384.5 did not inhibit the cytolytic activity of bulk populations of C57BL/6 mixed lymphocyte culture (MLC) cells. Concanavalin A-facilitated cytolysis by T cell clone L3 but not T cell clone B18 was inhibited by antibody 384.5, whereas phytohemagglutinin-facilitated cytolysis by L3 cells was not strongly inhibited. Antibody 384.5 binds specifically to L3 cells but not to several other T lymphocytes clones, or to a detectable portion of populations of primary MLC cells, normal spleen, thymus, lymph node, or bone marrow cells. In contrast, C57BL/6 anti-B10.A(5R) secondary MLC cells (genetically enriched for reactivity against the H-2Dd region gene products) contained a small population which reacted with the antibody 384.5. The determinant detected by antibody 384.5 was susceptible to trypsin treatment, and was reexpressed after overnight incubation. These results suggest that the monoclonal antibody 384.5 detects an endogenously synthesized clone-specific determinant associated with the cytolytic activity of the L3 CTL clone. These properties make antibody 384.5 an attractive candidate for an antibody that reacts with the antigen-recognition site of a cytolytic T cell antigen receptor.

Characterization of MHC Class-I Restricted TCRαβ+CD4−CD8− Double-Negative T Cells Recognizing the gp100 Antigen from a Melanoma Patient after gp100 Vaccination

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4905-4905
Author(s):  
Simon Voelkl ◽  
Tamson Moore ◽  
Michael Rehli ◽  
Michael Nishimura ◽  
Karin Fischer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class I ◽  
Peripheral Blood ◽  
Melanoma Patient ◽  
Cell Clone ◽  
Class I ◽  
Target Cells ◽  
Double Negative ◽  
T Cell Clone

Abstract The immune attack against malignant tumors requires the concerted action of CD8+ cytotoxic T lymphocytes (CTL) as well as CD4+ T helper cells. The contribution of T cell receptor (TCR)αβ+ CD4− CD8− double-negative (DN) T cells to anti-tumor immune responses is widely unknown. In previous studies, we have demonstrated that DN T cells with a broad TCR repertoire are present in humans in the peripheral blood and the lymph nodes of healthy individuals. Here we characterize a human DN T cell clone (T4H2) recognizing an HLA-A2-restricted melanoma-associated antigenic gp100-peptide isolated from the peripheral blood of a melanoma patient. Antigen recognition by the T4H2 DN clone resulted in specific secretion of IFN-γ and TNF. Although lacking the CD8 molecule the gp100-specifc DN T cell clone was able to confer antigen-specific cytotoxicity against gp100-loaded target cells as well as HLA-A2+ gp100 expressing melanoma cells. The cytotoxic capacity was found to be perforin/granzymeB-dependent. Together, these data indicate that functionally active antigen-specific DN T cells recognizing MHC class I-restricted tumor-associated antigen (TAA) may contribute to anti-tumor immunity in vivo.

scholarly journals Gamma/delta T cell clones and natural killer cell clones mediate distinct patterns of non-major histocompatibility complex-restricted cytolysis.

1990 ◽  
Vol 171 (5) ◽  
pp. 1567-1579 ◽  
Author(s):  
P Fisch ◽  
M Malkovsky ◽  
E Braakman ◽  
E Sturm ◽  
R L Bolhuis ◽  
...  
Keyword(s):  
T Cell ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Killer Cell ◽  
Target Cells ◽  
Cytotoxic Lymphocytes ◽  
Gamma Delta ◽  
T Cell Clones ◽  
Effector Cells ◽  
Cell Clones

Non-MHC-restricted killer cells are cytotoxic lymphocytes that can mediate cytolysis of most tumor targets without apparent selectivity and restriction by the MHC, particularly when activated with IL-2. These effector cells include predominantly NK cells and T cells expressing the TCR-gamma/delta. We found that TCR-gamma/delta-1+, delta TSC1-, BB3+, Ti gamma A+ T cell clones mediate a characteristic cytolytic pattern of non-MHC-restricted cytolysis that is markedly different from NK clones and alpha/beta T cell clones derived from the peripheral blood of the same normal individuals. The characteristic finding is that all BB3/Ti gamma A+ gamma/delta clones mediate strong cytolysis of Daudi cells but they do not lyse Raji cells. In contrast, NK clones from the same donors mediate strong cytolysis of both Daudi and Raji targets. Cytotoxicity by the gamma/delta clones on certain target cells such as Daudi and Molt 4 can be specifically inhibited by mAbs reactive against the TCR-gamma/delta. Therefore, the TCR-gamma/delta on these clones either directly recognizes target epitopes on some tumor targets or it is involved in the regulation of their cytotoxic function. The expression of TCR-gamma/delta products reacting with the BB3 and Ti gamma A mAbs reflects the usage of identical TCR-gamma/delta V region genes that appear to be associated with the characteristic pattern of non-MHC-restricted cytotoxicity displayed by this major subset of human peripheral blood gamma/delta cells.

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