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Mirjam H M Heemskerk

Publications and source records attributed to Mirjam H M Heemskerk.

14 recordsLinked to original sources
PubMed2006

Efficiency of T-cell receptor expression in dual-specific T cells is controlled by the intrinsic qualities of the TCR chains within the TCR-CD3 complex.

Genetic engineering of T lymphocytes is an attractive strategy to specifically redirect T-cell immunity toward viral infections and malignancies. We previously demonstrated redirected antileukemic reactivity of cytomegalovirus (CMV)-specific T cells by transfer of minor histocompatibility antigen HA-2-specific T-cell receptors (TCRs). HA-2-TCR-transferred CMV-specific T cells were potent effectors against HA-2-expressing leukemic cells, as well as CMV-expressing cells. Functional activity of these T cells correlated with TCR cell-surface expression. In the present study we analyzed which properties of transferred and endogenous TCRs are crucial for efficient cell-surface expression. We demonstrate that expression of the introduced TCR is not a random process but is determined by characteristics of both the introduced and the endogenously expressed TCR. The efficiency of TCR cell-surface expression is controlled by the intrinsic quality of the TCR complex. In addition, we demonstrate that chimeric TCRs can be formed and that efficiency of TCR expression is independent of whether TCRs are retrovirally introduced or naturally expressed. In conclusion, introduced, endogenous, and chimeric TCRs compete for cell-surface expression in favor of the TCR-CD3 complex with best-pairing properties.

Amino Acid Sequence↗
PubMed2006

Rapid assessment of the antigenic integrity of tetrameric HLA complexes by human monoclonal HLA antibodies.

The ability of tetrameric major histocompatibility complex (MHC) class I-peptide complexes (tetramers) to detect antigen-specific T lymphocyte responses has yielded significant information about the generation of in vivo immunity in numerous antigenic systems. Here we present a novel method for rapid validation of tetrameric HLA molecules based on the presence of allodeterminants. Human monoclonal antibodies (mAbs) recognizing polymorphic determinants on HLA class I were immobilized on polystyrene microparticles and used to probe the structural integrity of tetrameric HLA class I molecules by flow cytometry. A total of 22 tetramers, based on HLA-A1, A2, A3, A24, B7 and B8 were reactive with their counterpart mAbs, thus confirming their antigenic integrity. A positive outcome of this mAb test ensures that tetrameric HLA class I can be used with greater confidence in subsequent functional assays.

Antibodies, Monoclonal↗
PubMed2006

Strong selection of virus-specific cytotoxic CD4+ T-cell clones during primary human cytomegalovirus infection.

To obtain insight into human CD4+ T cell differentiation and selection in vivo, we longitudinally studied cytomegalovirus (CMV)-specific CD4+ T cells after primary infection. Early in infection, CMV-specific CD4+ T cells have the appearance of interferon gamma (IFNgamma)-producing T-helper 1 (TH1) type cells, whereas during latency a large population of CMV-specific CD4+ CD28- T cells emerges with immediate cytotoxic capacity. We demonstrate that CD4+ CD28- T cells could lyse CMV antigen-expressing target cells in a class II-dependent manner. To clarify the clonal relationship between early and late CMV-specific CD4+ T cells, we determined their Vbeta usage and CDR3 sequences. The T-cell receptor beta (TCRbeta) diversity in the early CMV-specific CD4+ T-cell population was high in contrast to the use of a very restricted set of TCRbeta sequences in latent infection. T-cell clones found in the late CMV-specific CD4+ T-cell population could not be retrieved from the early CD4+ T-cell population, or were present only at a low frequency. The observation that dominant CMV-specific CD4+ clones during latency were only poorly represented in the acute phase suggests that after the initial control of the virus strong selection and/or priming of novel clones takes place in persistent infections in humans.

Amino Acid Sequence↗
PubMed2006

Alphabeta T-cell receptor engineered gammadelta T cells mediate effective antileukemic reactivity.

Retroviral transfer of T-cell receptors (TCR) to peripheral blood-derived T cells generates large numbers of T cells with the same antigen specificity, potentially useful for adoptive immunotherapy. One drawback of this procedure is the formation of mixed TCR dimers with unknown specificities due to pairing of endogenous and introduced TCR chains. We investigated whether gammadelta T cells can be an alternative effector population for TCR gene transfer because the gammadeltaTCR is not able to form dimers with the alphabetaTCR. Peripheral blood-derived gammadelta T cells were transduced with human leukocyte antigen (HLA) class I- or HLA class II-restricted minor histocompatibility antigen (mHag) or virus-specific TCRs. Because most gammadelta T cells do not express CD4 and CD8, we subsequently transferred these coreceptors. The TCR-transduced gammadelta T cells exerted high levels of antigen-specific cytotoxicity and produced IFN-gamma and IL-4, particularly in the presence of the relevant coreceptor. gammadelta T cells transferred with a TCR specific for the hematopoiesis-specific mHag HA-2 in combination with CD8 displayed high antileukemic reactivity against HA-2-expressing leukemic cells. These data show that transfer of alphabetaTCRs to gammadelta T cells generated potent effector cells for immunotherapy of leukemia, without the expression of potentially hazardous mixed TCR dimers.

CD3 Complex↗
PubMed2006

Designer T cells by T cell receptor replacement.

T cell receptor (TCR) gene transfer is a convenient method to produce antigen-specific T cells for adoptive therapy. However, the expression of two TCR in T cells could impair their function or cause unwanted effects by mixed TCR heterodimers. With five different TCR and four different T cells, either mouse or human, we show that some TCR are strong--in terms of cell surface expression--and replace weak TCR on the cell surface, resulting in exchange of antigen specificity. Two strong TCR are co-expressed. A mouse TCR replaces human TCR on human T cells. Even though it is still poorly understood why some TCRalpha/beta combinations are preferentially expressed on T cells, our data suggest that, in the future, designer T cells with exclusive tumor reactivity can be generated by T cell engineering.

Animals↗
PubMed2005

Impact of peptides on the recognition of HLA class I molecules by human HLA antibodies.

MHC class I molecules expressed on cell surfaces are composed of H chain, beta2-microglobulin and any of a vast array of peptides. The role of peptide in the recognition of HLA class I by serum HLA Abs is unknown. In this study, the solid-phase assay of a series (n = 11) of HLA-A2-reactive, pregnancy-induced, human mAbs on a panel (n = 12) of recombinant monomeric HLA-A2 molecules, each containing a single peptide, revealed peptide selectivity of the mAbs. The flow cytometry membrane staining intensities on the HLA-A2-transduced cell line K562, caused by these mAbs, correlated with the number of monomer species detected by the mAbs. Flow cytometry staining on HLA-A2-bearing cell lines of a variety of lineages was indicative of tissue selectivity of these HLA-A2 mAbs. This tissue selectivity suggests that the deleterious effect on allografts is confined to alloantibodies recognizing only HLA class I loaded with peptides that are derived from tissue-specific and household proteins. Since Abs that are only reactive with HLA loaded with irrelevant peptides are expected to be harmless toward allografts, the practice of HLA Ab determination on lymphocyte-derived HLA deserves reconsideration.

Antibodies, Monoclonal↗
PubMed2005

Pretransplantation CMV-specific T cells protect recipients of T-cell-depleted grafts against CMV-related complications.

We have studied cytomegalovirus (CMV) immunity in 17 CMV-positive recipients of T-cell-depleted or T-cell-replete grafts. In recipients of T-cell-replete grafts, the patient's CMV-specific T-cell response was completely ablated. Because primary anti-CMV responses were rare during the first year, immunity depended essentially on the transfer of donor CMV-specific T cells and, therefore, on the CMV positivity of the donor. In the recipients of T-cell-depleted grafts, CMV-specific cytotoxic T cells were of recipient origin in 2 patients who underwent transplantation with CMV-negative donors and in 3 of 8 patients who underwent transplantation with CMV-positive donors, and they were of mixed or donor origin in the other 5 patients studied. Recipient CMV-specific T cells responded vigorously to antigen ex vivo and persisted for several years without replenishment by donor cells. Furthermore, they appeared to have a protective effect because CMV-related complications were absent in the patients with CMV-specific T cells of recipient origin. Clinical outcomes of a cohort of 91 patients corroborated the experimental results. Patients with recipient T cells in their blood were protected regardless of the donor immune status. Hence, when a T-cell depletion protocol is used that favors the survival of recipient T cells, the patient's pretransplantation CMV-specific immunity protects against posttransplantation CMV-related complications.

Adult↗
PubMed2005

Adult and cord blood T cells can acquire HA-1 specificity through HA-1 T-cell receptor gene transfer.

BACKGROUND AND OBJECTIVES: Minor histocompatibility antigen (mHag)-specific graft-versus-leukemia reactivities are observed following unselected donor lymphocyte infusion for the treatment of relapse after HLA-matched mHag-mismatched stem cell transplantation (SCT). Adoptive transfer of donor-derived ex vivo-generated HA-1-specific oligoclonal T cells or HA-1 peptide patient vaccination are currently being explored as curative tools for stem cell based immunotherapy of hematologic malignancies. Another treatment modality to eradicate residual leukemic cells after SCT is the transfer of the HA-1 hematopoietic-specific T-cell receptor (TCR) into cells from the stem cell donor. This strategy would be particularly useful in case of relapse after cord blood transplantation (CBT) and is explored in this study. DESIGN AND METHODS: HLA-A2(neg) adult peripheral blood and cord blood mononuclear cells were transduced with the genes encoding the HA-1 alpha and beta TCR chains derived from established HA-1 specific cytotoxic T lymphocyte clones. RESULTS: The T cells transduced with HA-1 TCR alpha beta showed consistent marker gene expression, but low staining with HLA-A2/HA-1 tetrameric complexes. They did, however, show hematopoietic-restricted cytolytic activity against HLA-A2(pos)/HA-1(pos) target cells, including leukemic cells. INTERPRETATION AND CONCLUSIONS: The low level of HA-1-specific tetramer staining of HA-1 TCR alpha beta transduced T cells may be caused by hybrid TCR formation of the transferred TCRalpha and beta chains with endogenous TCR alpha and beta chains. This may cause unwanted alloreactivity and requires attention. The HA-1 TCR alpha beta transduced T cells show that the HA-1 TCR can be functionally transferred into donor mononuclear cells, which can be exploited in immunotherapeutic settings of SCT and CBT for hematologic malignancies.

Adult↗
PubMed2004

Reprogramming of virus-specific T cells into leukemia-reactive T cells using T cell receptor gene transfer.

T cells directed against minor histocompatibility antigens (mHags) might be responsible for eradication of hematological malignancies after allogeneic stem cell transplantation. We investigated whether transfer of T cell receptors (TCRs) directed against mHags, exclusively expressed on hematopoietic cells, could redirect virus-specific T cells toward antileukemic reactivity, without the loss of their original specificity. Generation of T cells with dual specificity may lead to survival of these TCR-transferred T cells for prolonged periods of time in vivo due to transactivation of the endogenous TCR of the tumor-reactive T cells by the latent presence of viral antigens. Furthermore, TCR transfer into restricted T cell populations, which are nonself reactive, will minimize the risk of autoimmunity. We demonstrate that cytomegalovirus (CMV)-specific T cells can be efficiently reprogrammed into leukemia-reactive T cells by transfer of TCRs directed against the mHag HA-2. HA-2-TCR-transferred CMV-specific T cells derived from human histocompatibility leukocyte antigen (HLA)-A2+ or HLA-A2- individuals exerted potent antileukemic as well as CMV reactivity, without signs of anti-HLA-A2 alloreactivity. The dual specificity of these mHag-specific, TCR-redirected virus-specific T cells opens new possibilities for the treatment of hematological malignancies of HLA-A2+ HA-2-expressing patients transplanted with HLA-A2-matched or -mismatched donors.

Amino Acid Sequence↗
PubMed2003

Redirection of antileukemic reactivity of peripheral T lymphocytes using gene transfer of minor histocompatibility antigen HA-2-specific T-cell receptor complexes expressing a conserved alpha joining region.

Donor-derived T lymphocytes directed against minor histocompatibility antigens (mHags) exclusively expressed on cells of the hematopoietic lineages can eliminate hematologic malignancies. Transfer of T-cell receptors (TCRs) directed against these mHags into T lymphocytes may provide a strategy to generate antileukemic T cells. To investigate the feasibility of this strategy the TCR usage of mHag HA-2-specific T-cell clones was characterized. Thirteen different types of HA-2-specific T-cell clones were detected, expressing TCRs with diversity in TCR alpha- and beta-chain usage, however, containing in the TCR alpha chain a single conserved gene segment J alpha 42, indicating that J alpha 42 is involved in HA-2-specific recognition. We transferred various HA-2 TCRs into T lymphocytes from HLA-A2-positive HA-2-negative individuals resulting in T cells with redirected cytolytic activity against HA-2-expressing target cells. Transfer of chimeric TCRs demonstrated that the HA-2 specificity is not only determined by the J alpha 42 region but also by the N-region of the alpha chain and the CDR3 region of the beta chain. Finally, when HA-2 TCRs were transferred into T cells from HLA-A2-negative donors, the HA-2 TCR-modified T cells exerted potent antileukemic reactivity without signs of anti-HLA-A2 alloreactivity. These results indicate that HA-2 TCR transfer may be used as an alternative strategy to generate HA-2-specific T cells to treat hematologic malignancies of HLA-A2-positive, HA-2-expressing patients that received transplants from HLA-A2-matched or -mismatched donors.

Amino Acid Sequence↗
PubMed2003

Hematopoiesis-restricted minor histocompatibility antigens HA-1- or HA-2-specific T cells can induce complete remissions of relapsed leukemia.

Donor lymphocyte infusion (DLI) into patients with a relapse of their leukemia or multiple myeloma after allogeneic stem cell transplantation (alloSCT) has been shown to be a successful treatment approach. The hematopoiesis-restricted minor histocompatibility antigens (mHAgs) HA-1 or HA-2 expressed on malignant cells of the recipient may serve as target antigens for alloreactive donor T cells. Recently we treated three mHAg HA-1- and/or HA-2-positive patients with a relapse of their disease after alloSCT with DLI from their mHAg HA-1- and/or HA-2-negative donors. Using HLA-A2HA-1 and HA-2 peptide tetrameric complexes we showed the emergence of HA-1- and HA-2-specific CD8(+) T cells in the blood of the recipients 5-7 weeks after DLI. The appearance of these tetramer-positive cells was followed immediately by a complete remission of the disease and restoration of 100% donor chimerism in each of the patients. Furthermore, cloned tetramer-positive T cells isolated during the clinical response specifically recognized HA-1 and HA-2 expressing malignant progenitor cells of the recipient and inhibited the growth of leukemic precursor cells in vitro. Thus, HA-1- and HA-2-specific cytotoxic T lymphocytes emerging in the blood of patients after DLI demonstrate graft-versus-leukemia or myeloma reactivity resulting in a durable remission. This finding implies that in vitro generated HA-1- and HA-2-specific cytotoxic T lymphocytes could be used as adoptive immunotherapy to treat hematological malignancies relapsing after alloSCT.

Bone Marrow Cells↗
PubMed2002

Functional role of alternatively spliced deoxycytidine kinase in sensitivity to cytarabine of acute myeloid leukemic cells.

Development of resistance to cytarabine (AraC) is a major problem in the treatment of patients with acute myeloid leukemia (AML). Inactivation of deoxycytidine kinase (dCK) plays an important role in AraC resistance in vitro. We have identified inactive, alternatively spliced dCK forms in leukemic blasts from patients with resistant AML. Because these dCK-spliced variants were only detectable in resistant AML, it was hypothesized that they might play a role in AraC resistance in vivo. In the current study, the biologic role of the alternatively spliced dCK forms in AraC resistance was further investigated by retroviral transductions in rat leukemic cells. Introduction of inactive, alternatively spliced dCK forms into AraC-resistant K7 cells, with no endogenous wild-type (wt) dCK activity, could not restore AraC sensitivity, whereas wt dCK fully restored the AraC-sensitive phenotype. Transfection of alternatively spliced dCK forms into AraC-sensitive KA cells, as well as in human leukemic U937 cells and in phytohemagglutinin-stimulated T cells, did not significantly change sensitivity toward AraC. In addition, cotransduction of wt dCK with alternatively spliced dCK in K7 cells did not result in altered sensitivity to AraC compared with K7 cells only transduced with wt dCK. These data indicate that the alternatively spliced dCK forms cannot act as a dominant-negative inhibitor on dCK wt activity when they are coexpressed in a single cell. However, a cell expressing alternatively spliced dCK forms that has lost wt dCK expression is resistant to the cytotoxic effects of AraC.

Acute Disease↗
PubMed2002

Mesenchymal stem cells promote engraftment of human umbilical cord blood-derived CD34(+) cells in NOD/SCID mice.

OBJECTIVE: Mesenchymal stem cells (MSC) have been implicated as playing an important role in hematopoietic stem cell engraftment. We identified and characterized a new population of MSC derived from human fetal lung. In cotransplantation experiments, we examined the homing of MSC as well as the effect on engraftment of human umbilical cord blood (UCB)-derived CD34(+) cells in NOD/SCID mice. MATERIALS AND METHODS: Culture-expanded fetal lung-derived CD34(+) cells were characterized by immune phenotyping and cultured under conditions promoting differentiation to osteoblasts or adipocytes. Irradiated (3.5 Gy) NOD/SCID mice (n = 51) were transplanted intravenously with 0.03 to 1.0 x 10(6) UCB CD34(+) cells in the presence or absence of 1 x 10(6) culture-expanded fetal lung-derived MSC, irradiated CD34(-) cells, B cells, or with cultured MSC only. RESULTS: Culture-expanded fetal lung CD34(+) cells were identified as MSC based on phenotype (CD105(+), SH3(+), SH4(+), CD160(+)) and their multilineage potential. Cotransplantation of low doses of UCB CD34(+) cells and MSC resulted in a three-fold to four-fold increase in bone marrow engraftment after 6 weeks, whereas no such effect was observed after cotransplantation of irradiated CD34(-) or B cells. Homing experiments indicated the presence of MSC in the lung, but not in the bone marrow, of NOD/SCID mice. CONCLUSIONS: We identified a population of MSC derived from human fetal lung. Upon cotransplantation, MSC, but not irradiated CD34(-) or B cells, promote engraftment of UCB CD34(+) cells in bone marrow, spleen, and blood by mechanisms that may not require homing of MSC to the bone marrow.

Adipocytes↗