Claude Kasten-Sportes

Allogeneic Lymphocytes Induce Tumor Regression of Advanced Metastatic Breast Cancer

PURPOSE Allogeneic T lymphocytes can induce regression of metastatic breast cancer through an immune-mediated graft-versus-tumor (GVT) effect in murine models. To determine if a clinical GVT effect exists against metastatic breast cancer, allogeneic lymphocytes were used as adoptive cellular therapy after a reduced-intensity chemotherapy conditioning regimen and allogeneic hematopoietic stem-cell transplantation (HSCT) from human leukocyte antigen-matched siblings. PATIENTS AND METHODS Sixteen patients with metastatic breast cancer that had progressed after treatment with anthracyclines, taxanes, hormonal agents, and trastuzumab, received allogeneic HSCT. The reduced-intensity transplant conditioning regimen consisted of cyclophosphamide and fludarabine. To distinguish an immunological GVT effect from any antitumor effect of cytotoxic chemotherapy in the transplant-conditioning regimen, allogeneic T lymphocytes were removed from the stem-cell graft and were subsequently administered late postallogeneic HSCT. Allogeneic lymphocytes containing 1 x 10(6), 5 x 10(6), and 10 x 10(6) CD3(+) cells/kg were infused on days +42, +70, and +98 post-allogeneic HSCT, respectively. RESULTS Objective tumor regressions occurred after day +28 post-allogeneic HSCT in six patients and were attributed to allogeneic lymphocyte infusions. Two of these responding patients had disease progression post-allogeneic HSCT before subsequent tumor regression. Tumor regressions occurred concomitantly with the establishment of complete donor T-lymphoid engraftment, were associated with the development of graft-versus-host disease (GVHD), and were abrogated by subsequent systemic immunosuppression for GVHD. CONCLUSION Allogeneic lymphocytes can induce regression of advanced metastatic breast cancer. These results indicate that an immunological GVT effect from allogeneic lymphocytes exists against metastatic breast cancer and provide rationale for further development of allogeneic cellular therapy for this largely incurable disease.

Human CTLs to Wild-Type and Enhanced Epitopes of a Novel Prostate and Breast Tumor-Associated Protein, TARP, Lyse Human Breast Cancer Cells

Vaccine therapy for prostate and breast cancer may have potential for treating these major causes of death in males and females, respectively. Critical to the development of tumor-specific vaccines is finding and characterizing novel antigens to be recognized by CD8+ T cells. To define new CD8+ T-cell tumor antigens, we determined two wild-type HLA-A2 epitopes from a recently found tumor-associated protein, TARP (T-cell receptor γ alternate reading frame protein), expressed in prostate and breast cancer cells. We were also able to engineer epitope-enhanced peptides by sequence modifications. Both wild-type and enhanced epitopes induced peptide-specific CD8+ T-cell responses in A2Kb transgenic mice. In vitro restimulation of human CD8+ T cells from a prostate cancer patient resulted in CD8+ T cells reactive to the peptide epitopes that could lyse HLA-A2+ human breast cancer cells (MCF-7) expressing TARP. Epitope-specific human CD8+ T cells were also enumerated in patients’ peripheral blood by tetramer staining. Our data suggest that HLA-A2-binding TARP epitopes and enhanced epitopes discovered in this study could be incorporated into a potential vaccine for both breast and prostate cancer.

Establishment of early donor engraftment after reduced-intensity allogeneic hematopoietic stem cell transplantation to potentiate the graft-versus-lymphoma effect against refractory lymphomas

Reduced-intensity allogeneic hematopoietic stem cell transplantation (alloHSCT), which typically results in mixed chimerism initially after transplantation, has had limited efficacy in chemotherapy-refractory lymphomas. We hypothesized that the rapid establishment of complete donor chimerism would potentiate a graft-versus-lymphoma effect. Fifteen patients with chemotherapy-refractory lymphoma initially received induction with a conventional chemotherapy regimen (etoposide, prednisone, vincristine, cyclophosphamide, adriamycin, fludarabine [EPOCH-F]) to deplete host T cells and provide disease control prior to alloHSCT. Patients then received conditioning with fludarabine and cyclophosphamide followed by alloHSCT from HLA-matched siblings. Graft-versus-host disease prophylaxis consisted of cyclosporine alone. EPOCH-F resulted in 73% of patients having partial responses or stable disease. EPOCH-F depleted host CD4(+) T cells from a median of 235 cells/microL to 56 cells/microL. Fourteen patients underwent alloHSCT, and all had >95% donor engraftment by day 14 after transplantation. The incidence of Grade II to III acute graft-versus-host disease was 71%. There were two therapy-related deaths. There were 8 partial responses and 3 complete responses (CRs) at day 28. Five additional CRs were observed at day 100 without withdrawal of cyclosporine or donor lymphocyte infusion. The rate of CRs for all 15 patients was 60%. The 1-year progression-free survival rate from time of study entry is 67% with only 1 relapse among 9 CRs. At a median potential follow-up of 28 months, the overall survival rate is 53%. These data demonstrate that a potent and durable graft-versus-lymphoma effect can occur against chemotherapy-refractory lymphomas and suggest that this effect may be associated with rapid, complete donor chimerism after reduced-intensity alloHSCT.

Clinical “cytokine storm” as revealed by monocyte intracellular flow cytometry: correlation of tumor necrosis factor α with severe gut graft-versus-host disease

BACKGROUND & AIMS Gut graft-versus-host disease (GVHD) contributes significantly to lethality after allogeneic hematopoietic stem-cell transplantation (HSCT). In murine models, macrophage secretion of interleukin 1alpha (IL-1alpha) and tumor necrosis factor alpha (TNF-alpha) contributes to gut GVHD pathogenesis. To help characterize whether human gut GVHD has similar biological characteristics, monocyte IL-1alpha and TNF-alpha production were evaluated after HSCT. METHODS Patients with refractory hematologic malignancy (n = 17) underwent reduced-intensity conditioning, HLA-matched sibling HSCT, and cyclosporine A GVHD prophylaxis. After HSCT, monocyte IL-1alpha and TNF-alpha levels were measured using intracellular flow cytometry (IC-FCM), and results were correlated with clinical GVHD. RESULTS Incidences of acute GVHD were none (n = 3), grades I-II (n = 9), or grades III-IV (n = 5; each case with stage 2-3 gut GVHD). Posttransplantation monocyte IL-1alpha production (percentage of CD14(+)IL-1(+) cells) increased significantly from 8.7% +/- 3.7% (week 2) to 40.3% +/- 7.3% (week 4; P = 0.0065) and was not associated with GVHD severity (P = 1.00). Conversely, increases in monocyte TNF-alpha were quantitatively reduced and temporally delayed, from 0.6% +/- 0.2% (week 2) to 3.6% +/- 1.4% (week 6; P = 0.076). Most importantly, elevation of monocyte TNF-alpha level correlated with increased gut GVHD severity (P = 0.0041); increases in monocyte TNF-alpha levels typically preceded the onset of gut GVHD symptoms. CONCLUSIONS Human gut GVHD after reduced-intensity allogeneic HSCT is associated with monocyte cytokine secretion initially involving IL-1alpha, followed by TNF-alpha. Serial measurement of monocyte cytokines, in particular, TNF-alpha, by IC-FCM may represent a noninvasive method for GVHD monitoring, potentially allowing the identification of patients appropriate for early-intervention strategies.

Infectious complications and immunodeficiency in patients with human T‐cell lymphotropic virus I‐associated adult T‐cell leukemia/lymphoma

Background. Adult T‐cell leukemia/lymphoma (ATL) is a malignancy of mature T‐cells occurring in patients infected with the human T‐cell lymphotropic virus‐I. These patients frequently develop a variety of infections throughout their disease course.

Use of heparin versus lepirudin flushes to prevent withdrawal occlusion of central venous access devices

Study Objective. To determine whether lepirudin flushes are more effective than heparinized saline in preventing withdrawal occlusion of central venous access devices.

Targeted pretransplant host lymphocyte depletion prior to T-cell depleted reduced-intensity allogeneic stem cell transplantation

Mixed chimaerism and graft rejection are higher after reduced‐intensity allogeneic stem cell transplantation (RIST) with T‐cell depleted (TCD) allografts. As host immune status before RIST affects engraftment, we hypothesized that targeted depletion of host lymphocytes prior to RIST would abrogate graft rejection and promote donor chimaerism. Lymphocyte‐depleting chemotherapy was administered at conventional doses to subjects prior to RIST with the intent of decreasing CD4+ counts to <0·05 × 109cells/l. Subjects (n = 18) then received reduced‐intensity conditioning followed by ex vivo TCD human leucocyte antigen‐matched sibling allografts. All evaluable patients (n = 17) were engrafted; there were no late graft failures. At day +28 post‐RIST, 12 patients showed complete donor chimaerism. Mixed chimaerism in the remaining five patients was associated with higher numbers of circulating host CD3+ cells (P = 0·0032) after lymphocyte‐depleting chemotherapy and was preferentially observed in T lymphoid rather than myeloid cells. Full donor chimaerism was achieved in all patients after planned donor lymphocyte infusions. These data reflect the importance of host immune status prior to RIST and suggest that targeted host lymphocyte depletion facilitates the engraftment of TCD allografts. Targeted lymphocyte depletion may permit an individualized approach to conditioning based on host immune status prior to RIST.

The interleukin-2 receptor: a target for immunotherapy.

Immune intervention began almost two centuries ago when Jenner introduced vaccination with cowpox as a means of protecting against smallpox. This form of immune intervention plays a dominant role in the prevention of human disease. Furthermore, immunological approaches including radioimmunoassays, enzyme-linked immunoassays, microfluorometry, and modern molecular immunogenetics are critical in clinical diagnosis.

Natural killer cell receptor repertoire following HLA-matched allogeneic hematopoietic stem cell transplantation

6635 Background: Following hematopoietic stem cell transplantation (HSCT), natural killer (NK) cells are among the first lymphocytes to recover, returning to normal levels within six weeks after HSCT. NK cells may mediate anti-tumor effects and regulate graft versus host disease (GVHD); modulation of the relative frequency and intensity of expression of the cytotoxic NK receptors may influence NK activity post transplant. METHODS We compared the NK receptor expression in seven patients at one month following non-myeloablative HLA-matched allogeneic HSCT with that of donors and healthy volunteers. NK cells were divided into two subsets based on expression of CD56 and CD16. Both subsets were assessed for three main classes of receptors that trigger or inhibit cytotoxicity: natural cytotoxicity receptors (NCR), killer immunoglobulin-like receptors (KIR) and C-type lectin receptors. RESULTS Compared to donors, the expression of the NCR NKp46 increased significantly in all patients, whereas NKp30 increased in the CD 56+ bright subset only in patients that developed acute GVHD. Expression of KIR receptors (CD158A, CD158B) did not change or decreased slightly. In contrast the C-type lectin receptor CD 94 was upregulated on most NK cells. The heterodimeric partners of CD94, NKG2A and NKG2C, were also increased, but the increase in frequency of cells expressing the inhibitory receptor NKG2A was greater than that of the activating receptor NKG2C. The homodimeric activating receptor NKG2D increased in all patients. No significant differences in NK receptor expression between the donors and healthy volunteers was observed Conclusions: These results demonstrate changes in the NK receptor repertoire during the early post-transplant period that may have an impact on NK cells mediated cytotoxicity. No significant financial relationships to disclose.

Perspectives in post-transplantation immunotherapy in breast cancer.

High risk and metastatic breast cancer remain a major therapeutic challenge. Although the role of high dose chemotherapy followed by stem cell transplantation (SCT) in the overall treatment strategy is not yet well defined, it is clear that new forms of therapy such as immunotherapy will be needed to cure the majority of patients with advanced disease. We review important considerations for immunotherapy in the post-transplantation period. Experimental and clinical data suggest that immunotherapy may be most effective in a state of minimal residual disease such as that achieved following SCT. However, high dose therapy and autologous SCT result in an iatrogenic immune deficiency, which compounds the suppression of the immune system associated with tumor itself. Understanding reconstitution of a functional immune system post transplantation is critical in devising clinically effective immune interventions. A review of the clinical studies of post transplant immunotherapy for breast cancer is presented including autologous and allogeneic strategies, as well as perspectives for future development.