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Biomedical subjects

E Braakman

Publications and source records attributed to E Braakman.

At least 19 recordsLinked to original sources
PubMed1992

Heterodimeric complex formation with CD8 and TCR by bispecific antibody sustains paracrine IL-2-dependent growth of CD3+ CD8+ T cells.

During physiologic activation of mature CD8+ T cells, TCR and CD8 bind to the same Ag-complexed MHC class I molecule. Thereby, close proximity is induced between CD8 and the TCR/CD3 complex. During this engagement, CD8 may deliver TCR-independent signals via its associated protein tyrosine kinase, p56lck. We studied the potential biologic effects of close association between CD8 and TCR/CD3 complexes by using a bispecific antibody (bsAb) directed against both TCR and CD8 molecules. This hybrid hybridoma (quadroma)-produced bsAb binds as a monomeric molecule to CD3+ CD8+ but not CD3+ CD4+ T cells. The bsAb proved capable of inducing the cytotoxic effector function of cloned CD3+ CD8+ T cells but not of CD3+ CD4+ T cells. When the bsAb was presented to resting T cells by monocytes, proliferation of the CD3+ CD4+ but not the CD3+ CD8+ subset of T lymphocytes was induced. Parental anti-TCR antibody induced vigorous growth of cells of both subsets. Essentially identical results were obtained when bsAb was presented in an immobilized fashion. The unresponsiveness of the CD3+ CD8+ T cells with respect to mitogenesis could be restored by exogenous rIL-2. The data suggest that bsAb-induced activation differs from activation by monospecific anti-TCR antibody. The former appears to more closely mimic physiologic Ag-induced signaling, because it leads to a similar paracrine IL-2-dependent growth pattern. The bsAb may, therefore, be instrumental in studying T cell signaling pathways, in particular the role of CD8-associated p56lck therein.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1992

Optimization of culture conditions for activation and large-scale expansion of human T lymphocytes for bispecific antibody-directed cellular immunotherapy.

We investigated the optimal culture conditions (i.e., activation procedure, medium composition and type of culture vessel) for rapid in vitro expansion of large numbers (greater than 5 x 10(9) of blood T lymphocytes. These expanded lymphocytes can be targeted to be cytotoxic to ovarian carcinoma cells with a bispecific monoclonal antibody (BsAb) specific for CD3 and for the ovarian carcinoma-associated antigen MOv18. Both phytohemagglutinin (PHA) and monoclonal antibody (MAb) CD3 induced rapid T-cell proliferation, although the growth kinetics after PHA activation were slightly faster. A 50-fold increase in cell number was obtained after 14 and 16 days for PHA and CD3 MAb, respectively. The induction of BsAb-directed cytolysis was faster after CD3 MAb than after PHA activation of lymphocytes, but became similar around day 20. A mixture of media consisting of 78% RPMI 1640, 20% AIM-V and 2% human plasma (Mix-med) yielded better results than 100% AIM-V medium. Culture of lymphocytes in polyolefin bags, compared with tissue culture flasks, or cryopreservation did not affect lymphocyte yield and function. In most cultures the proportion of CD8+ lymphocytes increased, suggesting a growth advantage of CD8+ over CD4+ lymphocytes in this culture system. A protocol employing PHA activation, Mix-med and polyolefin bags has been used successfully to activate and expand blood lymphocytes for the first 5 patients entered into a phase-I/II clinical trial for the intraperitoneal treatment of ovarian carcinoma using CD3 x anti-MOv18 BsAb-directed T lymphocytes.

Antibodies, Monoclonal↗
PubMed1992

Genetic correction of cultured T cells from an adenosine deaminase-deficient patient: characteristics of non-transduced and transduced T cells.

T lymphocytes derived from peripheral blood of a patient with adenosine deaminase (ADA) deficiency were expanded in vitro. The human ADA (hADA) gene was introduced into these replicating ADA- T cells with the use of an amphotropic recombinant retrovirus carrying the hADA gene. Subsequently, infected T cells were selected on the basis of their ADA expression, by exposure to a combination of the toxic agent xylofuranosyl-adenine and the specific ADA inhibitor 2'-deoxycoformycin. CD4+ and CD8+ T cells could be infected and selected with equal efficiencies. The genetically modified T cells were shown to contain intact copies of the provirus and to express normal levels of hADA. As expected, uninfected T cells from the ADA-deficient patient displayed an increased sensitivity to 2'-deoxyadenosine. Following genetic modification, however, this sensitivity was restored to normal levels in both CD4+ and CD8+ T cells. The introduction of the hADA gene into the genome of the in vitro expanded T cells did not alter their phenotype, proliferative capacity or cytotoxic potential. These characteristics were identical to those of T cells derived from healthy individuals. These findings are of critical importance for the clinical application of hADA gene-transducted T cells.

Adenosine Deaminase↗
PubMed1992

CD16 on human gamma delta T lymphocytes: expression, function, and specificity for mouse IgG isotypes.

We examined the expression, the signal transduction capacity and mouse IgG-isotype specificity of CD16 on human gamma delta T cells. CD16 is expressed by the majority of gamma delta T cells in peripheral blood and by part of the gamma delta T cell clones. The amount of CD16 expressed on gamma delta T cell clones varied considerably with passaging of the cells, but was always significantly less than on freshly isolated gamma delta T cells. Like CD16 on CD3- CD16+ natural killer (NK) cells, CD16 on gamma delta T cells can act as an activation site triggering cytotoxic activity. CD16+ gamma delta T cell clones exerted antibody-dependent cellular cytotoxicity (ADCC) which could be blocked by anti-CD16 mAb. ADCC activity of gamma delta T cell clones was also inhibited by anti-CD3 mAb, suggesting a functional linkage between the CD16 and CD3 activation pathways. MAb directed against CD16 induced lysis of Fc gamma R+ target cells by CD16+ gamma delta T cell clones. The mouse IgG-isotype specificity of CD16 on gamma delta T cells was analyzed using isotype switch variants of a murine anti-glycophorin A mAb in EA rosette assays, and was found to be identical to that of CD16 on CD3- CD16+ NK cells, i.e., highest affinity for mIgG2a, intermediate affinity for mIgG2b, and undetectable binding of mIgG1-sensitized erythrocytes. CD16 was partly modulated from the cell surface of both gamma delta T cells and NK cells after rosette formation with mIgG2a-sensitized erythrocytes, indicating that the rosette formation was indeed mediated via the CD16 molecule.

Animals↗
PubMed1991

Engineering T lymphocyte antigen specificity.

Targeting of immune cells by bispecific antibodies has proven to be a powerful tool for the investigation of cellular cytotoxicity, lymphocyte activation and induction of cytokine production, as well as to represent an innovative form of immunotherapy for the treatment of cancer. The hallmark of this approach is the use of the specificity of monoclonal antibodies to join target and immune cells by virtue of the dual specificity of bispecific antibodies for the two entities. More precisely, the bispecific antibody has two different binding sites, which are capable of recognizing tumor associated antigens on the one hand and lymphocyte activation sites on the other. This process of crosslinking results in the activation of the lymphocyte and triggering of its lytic machinery, as well as lymphokine production. A major advantage of this therapeutic modality is, that use is made of the normal cellular immune defence system and therefore is only associated with minor toxicity. The distinct lymphocyte populations, which can be used for adoptive immunotherapy and the various bispecific antibody preparations, as well as the chimeric immunoglobulin/T cell receptor construction, are the major topics of this review.

Animals↗
PubMed1991

T cell targeting in cancer therapy.

Targeting of immune cells by bispecific antibodies has proven a powerful tool for the investigation of cellular cytotoxicity, lymphocyte activation and induction of cytokine production, as well as to represent an innovative form of immunotherapy for the treatment of cancer. The hallmark of this approach is the use of the specificity of monoclonal antibodies to join target and immune cells by virtue of the dual specificity of bispecific antibodies for the two entities. More precisely the bispecific antibody has two different binding sites, which are capable of recognizing tumor associated antigens on the one hand and lymphocyte activation sites on the other. This process of crosslinking results in the activation of the lymphocyte and triggering of its lytic machinery, as well as lymphokine production. A major advantage of this therapeutic modality is, that use is made of the normal cellular immune defence system and therefore is only associated with minor toxicity. The distinct lymphocyte populations, which can be used for adoptive immunotherapy and the various bispecific antibody preparations, as well as the chimeric immunoglobulin/T cell receptor construction are the major topics of this review.

Antibodies, Monoclonal↗
PubMed1991

Expression of CD45 isoforms by fresh and activated human gamma delta T lymphocytes and natural killer cells.

Naive and primed alpha beta T cells can be distinguished on the basis of their differential expression of CD45RA and CD45RO, respectively. The present study indicates that these CD45-isoforms also identify naive and primed maturational stages of gamma delta T cells and natural killer (NK) cells. In peripheral blood, all V gamma 9-V delta 2 gamma delta T cells reportedly express CD45RO whereas all V delta gamma delta T cells lack CD45RO. Here, we show that these CD45RO- V delta gamma delta T cells all express CD45RA and the CD45RO+ V.9-V delta 2 gamma delta cells lack expression of CD45RA. The V delta T cells acquired CD45RO expression and lost part of their surface CD45RA, following in vitro activation with phytohaemagglutinin or IL-2. Also the CD3-CD16+ NK cells in peripheral blood that are uniformly CD45RA+ CD45RO- completely converted to the CD45RA-CD45RO+ phenotype upon in vitro activation. Moreover, all cloned V.9-V delta 2 and V delta 1 T cells and NK cells express CD45RO and lack expression of CD45RA. Our results strongly suggest that CD45RA and CD45RO are genuine markers for naive and primed lymphocytes that represent distinct differentiation lineages.

Antigens, CD↗
PubMed1990

Recognition by human V gamma 9/V delta 2 T cells of a GroEL homolog on Daudi Burkitt's lymphoma cells.

All human gamma delta T cells coexpressing the products of the variable (V) region T cell receptor (TCR) gene segments V gamma 9 and V delta 2 recognize antigens from mycobacterial extracts and Daudi cells. Exogenous and endogenous ligands on the cell surface, homologous to the groEL heat shock family, induced reactivities that resembled superantigen responses in this major subset of human peripheral blood gamma delta T cells. Stimulation of human V gamma 9/V delta 2 T cells is not restricted by human leukocyte antigens (HLA), including nonpolymorphic beta 2-microglobulin (beta 2M)-associated class Ib molecules. These data may be important for understanding the role of gamma delta T cells in autoimmunity and in responses to microorganisms and tumors.

Antigen-Presenting Cells↗
PubMed1990

Human V gamma 9-V delta 2 T cell receptor-gamma delta lymphocytes show specificity to Daudi Burkitt's lymphoma cells.

Peripheral blood TCR-gamma delta cells with different functional V gamma or V delta gene rearrangements represent two nonoverlapping subsets. The major subset uses the V gamma 9 and the V delta 2 gene segments and the minor subset the V delta 1 gene segments in its functional TCR rearrangement. Upon in vitro activation, these TCR-gamma delta lymphocytes display MHC-unrestricted lytic activity, against a wide variety of tumor cells of distinct histologic origin. Here we show that fresh TCR-gamma delta lymphocytes that express a V gamma 9-V delta 2 encoded TCR display a specific proliferative response to Daudi, Burkitt's lymphoma cells. Moreover, cloned V gamma 9-V delta 2 lymphocytes show the capacity to lyse Daudi cells, whereas none of the cloned V gamma 1 TCR-gamma delta lymphocytes shows such specificity. Nucleotide diversity at the V-D-J junction of the TCR-V delta 2 gene did not contribute to this Daudi cell specificity. Comparison of the MHC-unrestricted cytolytic capacities of the V gamma 9-V delta 2 and the V delta 1 clones using a panel of distinct types of tumor target cells showed that on average, the level of MHC unrestricted lysis of V gamma 9-V delta 2 clones against these tumor cells exceeded that of V delta 1 clones. However, in contrast to all these tumor cell lines, only the Daudi cells showed such an absolute distinction in susceptibility to lysis by V gamma 9-V delta 2 and V delta 1 clones. V gamma 9-V delta 2 clones that were generated with a stimulator cell other than Daudi did not lyse their stimulator cells but nevertheless showed specific cytolysis of Daudi cells. The specific proliferation to and cytolysis of Daudi cells of the entire V gamma 9-V delta 2 subpopulation of TCR-gamma delta lymphocytes is reminiscent of a superantigen response.

Base Sequence↗
PubMed1990

ICAM- melanoma cells are relatively resistant to CD3-mediated T-cell lysis.

The primary activation pathway of T cells is via the T-cell receptor (TCR)/CD3 complex, which is functionally interrelated with various accessory molecules. We examined the contribution of the lymphocyte-function-associated antigen-I/intercellular adhesion molecule 1 (LFA-1/ICAM-1) interaction to CD3/TCR-mediated lysis by cytotoxic T lymphocytes (CTL). We used ICAM-I-or+ tumor cell lines as target cells and anti-CD3- or anti-LFA-1 containing hetero-cross-linked monoclonal antibody (MAb) to bridge CTL and target cells and simultaneously to activate CTL. The ICAM-1- melanoma-derived cell line IgR39 was relatively resistant to CD3-mediated lysis by both TCR alpha beta + and TCR gamma delta + CTL, when compared with ICAM-1+ cell lines. Induction of ICAM-1 on the membrane of IgR39 cells by tumor necrosis factor (TNF) rendered these cells more susceptible to CD3-mediated lysis. Anti-ICAM-1 MAb inhibited this TNF-enhanced susceptibility to lysis, directly demonstrating that the induction of ICAM-1 was critical in the TNF-induced increase in susceptibility to lysis of IgR39 cells. CTL formed less efficient conjugates with the ICAM-1- cells as compared to ICAM-1+ cells. Both spontaneous and CD3-induced conjugate formation as well as CD3-mediated lysis of ICAM-1- tumor cells by CTL were enhanced by the addition of anti-LFA-1 containing hetero-cross-linked MAb, thereby mimicking the LFA-1/ICAM-1 interaction between CTL and target cells. Soluble anti-CD18 MAb inhibited CD3-mediated lysis of ICAM-1- target cells by CTL without affecting their conjugate formation. Anti-LFA-1 MAb added after conjugate formation still inhibited lysis of both ICAM-1+or- tumor cells. Taken together, these findings suggest that the LFA-1/ICAM-1 interaction co-activates CD3/TCR-mediated lysis by CTL through both an enhanced CTL-target cell binding and the delivery of post-conjugate costimulatory signals.

Antibodies, Monoclonal↗
PubMed1990

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

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.

Antibodies, Monoclonal↗
PubMed1990

Interleukin-2. The experience of the Rotterdam Cancer Institute; Daniel den Hoed Kliniek.

Between October 1987 and October 1989 we have treated 110 patients with advanced solid tumors with recombinant interleukin-2 (rIL2) based immunotherapy. In renal cell cancer we have studied rIL2 alone, rIL2 combined with rIL2 activated lymphocytes (LAK), and in an ongoing study rIL2 and LAK and alpha-interferon (alpha IFN). There is suggestive evidence of increasingly good results in these consecutive studies. In melanoma the combination of rIL2 and chemotherapy was investigated, followed by an ongoing study of rIL2 and alpha IFN. In these studies rIL2 has been administered as a continuous intravenous infusion of 18 x 10(6) International Units/m2/day for 5 days (18 x 10(6) IU = 3 x 10(6) Cetus Units = 6.9 Biological Response Modifiers Program (BRMP) Units). Patients with non-small cell lung cancer are entered in a phase I-II study of rIL2 and alpha IFN. The rIL2 administration differs from the above mentioned schedule in that rIL2 is given at a maximum dose of 6 x 10(6) IU/m2/day for 28 days on an outpatient basis. In a phase I study we have searched for the maximum tolerated dose of a daily time 4 schedule of rIL2. In the second part of this study a daily time 4 schedule, every week for 4 weeks is being investigated. Finally, we are investigating the safety and efficacy of local regional administration of rIL2 in patients with head and neck cancer, mesothelioma, and liver metastasis of colorectal cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Lymphocyte leukocyte function-associated antigen 1 interacting with target cell intercellular adhesion molecule 1 co-activates cytolysis triggered via CD16 or the receptor involved in major histocompatibility antigen-unrestricted lysis.

The binding of leukocyte function-associated antigen 1 (LFA-1) (CD11a/CD18) to its natural target ligand, intercellular adhesion molecule 1 (ICAM-1) (CD54), is an important step in lymphocyte adhesion to cells and its subsequent activation. We studied whether LFA-1-ICAM-1 interactions affect tumor cell susceptibility to MHC-unrestricted lysis by TCR-CD3-CD16+ natural killer (NK) and TCR gamma delta + CD3+ CD16+/- lymphocytes. Moreover, tumor target cell susceptibility to anti-CD16 mAb-triggered lysis by TCR- NK cells was investigated. Therefore, ICAM-1+ or ICAM-1- tumor cell lines were used as target cells. Two melanoma-derived cell lines expressing little or no ICAM-1 were relatively resistant to MHC-unrestricted lysis as well as anti-CD16 mAb-triggered lysis by fresh or cloned TCR- NK cells. The ICAM-1- melanoma cell line was also relatively resistant to MHC-unrestricted lysis by TCR gamma delta + clones. Tumor necrosis factor (TNF) induced ICAM-1 expression on ICAM-1- tumor cells, and simultaneously increased target cell susceptibility to MHC-unrestricted as well as to anti-CD16 mAb-triggered lysis. This enhanced level of lysis was inhibited by anti-ICAM-1 mAb. Our data demonstrate that LFA-1-ICAM-1 interactions increase MHC-unrestricted or CD16-mediated cytolysis of tumor cells. Anti-CD18 interactions increase MHC-unrestricted or CD16-mediated cytolysis of tumor cells. Anti-CD18 (LFA-1 beta) mAb inhibited MHC-unrestricted lysis of ICAM-1+ and ICAM-1- tumor cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1989

Induction of lysis by T cell receptor gamma delta+/CD3+ T lymphocytes via CD2 requires triggering via the T11.1 epitope only.

The requirements for activation of the lytic machinery through CD2 of TCR gamma delta+/CD3+ cells were examined, by utilizing bispecific heteroconjugates containing anti-CD2 mAb cross-linked to anti-DNP. Contrary to the CD2 activation requirements in TCR alpha beta+/CD3+ cells, cytotoxic activity in TCR gamma delta+/CD3+ clones and TCR-/CD3- NK cell clones can be induced by heteroconjugates containing a single anti-CD2 (OKT11.1) mAb. Activation of TCR gamma delta+/CD3+ cells via CD2 is independent of heteroconjugates binding to CD16 (Fc gamma RIII), because heteroconjugates prepared from Fab fragments induced equal levels of lysis. Moreover, anti-CD16 mAb did not inhibit triggering via CD2 in TCR gamma delta+/CD3+ cells. In TCR-/CD3- NK cells, however, induction of cytotoxicity via CD2 is co-dependent on interplay with CD16. Anti-CD3 mAb blocked the anti-CD2 x anti-DNP heteroconjugate-induced cytotoxicity of TCR gamma delta+/CD3+ cells, indicating a functional linkage between CD2 and CD3 on these cells. We conclude that induction of lysis via CD2 shows qualitatively different activation requirements in TCR gamma delta+/CD3+, TCR alpha beta+/CD3+ CTL and TCR-/CD3- NK cells.

Antibodies, Monoclonal↗
PubMed1989

Induction of tumor-cell lysis by bi-specific monoclonal antibodies recognizing renal-cell carcinoma and CD3 antigen.

Bi-specific monoclonal antibodies (MAbs) were developed by somatic hybridization of 2 mouse hybridomas, one producing MAb against the G250 renal-cell carcinoma (RCC)-associated antigen and the other against the T-cell antigen CD3 (OKT3). The dual specificity of the hybrid MAb produced by these so-called quadromas was analyzed by immunohistochemistry on tissue sections and by cytotoxicity assays with relevant target and effector cells. The bi-specific MAb could induce TCR alpha beta/CD3+ and TCR gamma delta/CD3+ cloned lymphocytes to kill RCC cells. A noteworthy finding was that the TCR alpha beta and gamma delta lymphocyte clones showed different triggering abilities. The specificity of target-cell lysis by the cytotoxic T cells (CTL) was dictated by the specificity of the G250 MAb. Control bi-specific MAb, recognizing a cell-surface structure not involved in T-cell activation, did not induce lysis. Several IgG subclass switch variants of the G250 hybridoma, i.e., IgG1, 2a, 2b and IgE, were used for somatic hybridization with the OKT3 hybridoma (IgG2a). Except for IgE, all IgG subclass combinations could equally induce cytolysis. Induction of cytolysis was inhibited only by excess OKT3 MAb. Comparison of 2 bi-specific MAb preparations of the same combination (IgG2a/1), produced by 2 quadromas derived from the same parental hybridomas after identical purification procedures, produced different amounts of bispecific MAb.

Animals↗