Differentiation of antitumor-specific cytotoxic T lymphocytes from autologous tumor infiltrating lymphocytes in non-Hodgkin's lymphomas

HLA specificities are associated with prognosis in IGHV-mutated CLL-like high-count monoclonal B cell lymphocytosis

Introduction

Molecular alterations leading progression of asymptomatic CLL-like high-count monoclonal B lymphocytosis (hiMBL) to chronic lymphocytic leukemia (CLL) remain poorly understood. Recently, genome-wide association studies have found 6p21.3, where the human leukocyte antigen (HLA) system is coded, to be a susceptibility risk region for CLL. Previous studies have produced discrepant results regarding the association between HLA and CLL development and outcome, but no studies have been performed on hiMBL.

Aims

We evaluated the role of HLA class I (-A, -B and -C) and class II (-DRB1 and -DQB1) in hiMBL/CLL susceptibility, hiMBL progression to CLL, and treatment requirement in a large series of 263 patients diagnosed in our center with hiMBL (n = 156) or Binet A CLL (n = 107).

Results

No consistent association between HLA specificities and hiMBL or CLL susceptibility was found. With a median follow-up of 7.7 years, 48/156 hiMBLs (33%) evolved to asymptomatic CLLs, while 16 hiMBLs (10%) and 44 CLLs (41%) required treatment. No HLA specificities were found to be significantly associated with hiMBL progression or treatment in the whole cohort. However, within antigen-experienced immunoglobulin heavy-chain (IGHV)-mutated hiMBLs, which represents the highest proportion of hiMBL cases (81%), the presence of HLA-DQB1*03 showed a trend to a higher risk of progression to CLL (60% vs. 26%, P = 0.062). Moreover, HLA-DQB1*02 specificity was associated with a lesser requirement for 15-year treatment (10% vs. 36%, P = 0.012).

Conclusion

In conclusion, our results suggest a role for HLA in IGHV-mutated hiMBL prognosis, and are consistent with the growing evidence of the influence of 6p21 on predisposition to CLL. Larger non-biased series are required to enable definitive conclusions to be drawn.

HLA specificities are related to development and prognosis of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease influenced by genetic and environmental factors. The role of the HLA system in tumor antigen presentation could be involved in susceptibility and disease control. We analyzed the phenotypic frequencies of HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 in 250 DLBCLs, comparing them with 1940 healthy individuals. We also evaluated the influence of HLA polymorphisms on survival in those patients treated with curative intention using cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)-like regimen without (n = 64, 26%) or with (n = 153, 61%) rituximab. DLBCL patients have a higher phenotypic frequency of HLA-DRB1*01 (29% vs 19.5%, P = .0008, Pc = .0104) and a lower frequency of HLA-C*03 (6.4% vs 17.9%, P < .0005, Pc = .007) compared with healthy individuals. Irrespective of the age-adjusted International Prognostic Index, those patients receiving a CHOP-like plus rituximab regimen and carrying the HLA-B44 supertype had worse 5-year progression-free (54% vs 71%, P = .019) and 5-year overall (71% vs 92%, P = .001) survival compared with patients without this supertype. Our data suggest that some HLA polymorphisms influence the development and outcome of DLBCL, allowing the identification of an extremely good-risk prognostic subgroup. However, these results are preliminary and need to be validated in order to exclude a possible population effect.

Peripheral T cells of patients with B cell non-Hodgkin's lymphoma show a shift in their memory status

BACKGROUND

Tumor-infiltrating T cells have a positive influence on the clinical course of B cell non-Hodgkin's lymphoma (NHL). T cells in the peripheral blood of patients with B cell NHL, however, have so far rarely been examined.

METHODS

Using flow cytometry we examined lymphocyte subpopulations and numbers of naïve/memory T cell subtypes among peripheral T cells of patients with B cell NHL (N=22), patients with metastasized solid tumors (N=27), and healthy controls (N=20). In addition, we analyzed the intracellular content of effector molecules granzyme B and perforin and expression of the T cell receptor zeta chain.

RESULTS

We observed increased percentages of potentially highly cytotoxic CD8+CD56+ T cells in the peripheral blood of patients with NHL. Both, patients with NHL and patients with solid tumors showed a much higher expression of the chemokine receptors CCR4 and CCR5 on their T cells than healthy controls, suggesting a polarization of their T cells following stimulation with antigen and/or cytokines in vivo. Furthermore, patients with B cell NHL and patients with solid tumors had far lower percentages of naïve CD45RA+CCR7+ T cells than healthy controls and, in the case of CD4+ T cells, patients with solid tumors. In contrast, patients with B cell NHL showed markedly increased levels of memory effector CD45RA-CCR7- CD4(+) T cells when compared to healthy controls and patients with metastasized solid tumors. Patients with NHL also showed elevated levels granzyme B within CD8(+) T cells, indicating that the increase in memory effector cells was of functional relevance.

CONCLUSIONS

These findings indicate a marked shift in the composition of peripheral T cells of patients with B cell NHL from naïve to memory effector-type cells.

Impairment of death-inducing signalling complex formation in CD95-resistant human primary lymphoma B cells

Multiple mechanisms exist by which tumour cells can escape CD95-mediated apoptosis. Previous studies by our laboratory have shown that primary B cells from non-Hodgkin's Lymphoma (B-NHL) were resistant to CD95-induced cell death. In the current study, we have analysed the mechanisms underlying CD95 resistance in primary human lymphoma B cells. We report that FADD (FAS-associated death domain protein) and caspase-8 were constitutively expressed in lymphoma B cells and that the CD95 pathway was blocked upstream to caspase-8 activation. However, caspase-8 was processed and functional after treatment with staurosporine (STS). We found that the expression levels of FLICE (FADD-like interleukin-1 beta-converting enzyme)-Inhibitory Protein (c-FLIP) and Bcl-2-related proteins were heterogeneous in B-NHL cells and were not related to CD95 resistance. Finally, we report the absence of a CD95-induced signalling complex [death-inducing signalling complex (DISC)] in lymphoma B cells, with no FADD and caspase-8 recruitment to CD95 receptor. In contrast, DISC formation was observed in CD95-resistant non-tumoural (NT) B cells. Therefore, we propose that the absence of DISC formation in primary lymphoma B cells may contribute to protect these cells from CD95-induced apoptosis.

Differentiation of anti-tumour cytotoxic T lymphocytes from autologous peripheral blood lymphocytes in non-Hodgkin's lymphomas

We have previously reported that specific anti-tumour cytotoxic T cells (CTL) can be differentiated from tumour-infiltrating lymphocytes (TIL) in non-Hodgkin's lymphoma. We found that the combination of interleukin (IL)-1, IL-2 and IL-12 was very efficient for expansion of CD8+ T-cell receptor (TCR)alphabeta+ T cells and for development of their ability to specifically lyse tumour cells. In this study, we investigated whether anti-tumour T cells could be generated from the peripheral blood of patients using the culture protocol developed for TIL. Autologous T cells and tumour B cells from five patients were included in this study. It was found that polyclonal anti-tumour cytotoxic effector cells were generated when cultured in the presence of IL-1beta, IL-2 and IL-12. Interestingly, tumour cells were lysed by perforin/granzyme-mediated cytolysis and not by CD95-mediated apoptosis. By performing inhibition experiments, it was observed that both CD8+ and CD4+ T cells were responsible for the cytotoxic effect and that they were able to recognize malignant B cells by either a major histocompatibility complex (MHC)-restricted or MHC-non-restricted mechanism. Intriguingly, in addition to interferon-gamma and tumour necrosis factor-alpha, IL-10 was secreted continuously during culture. The source of patient T cells used for the generation of anti-tumour CTL should be based on the results obtained with peripheral blood lymphocytes and TIL.

Differentiation of antigen-presenting cells (dendritic cells and macrophages) for therapeutic application in patients with lymphoma

The recent clinical trial in lymphoma using tumor antigen-loaded DCs (Hsu et al, Nature Med 1996; 2: 52) demonstrates the efficiency of the use of professional antigen presenting cells (APCs) for taking up, processing and presenting tumor protein in a vaccine strategy in cancer. However, the production of large quantities of clinical grade APCs remains to be resolved. Here, we describe that both dendritic cells (DCs) and macrophages (MOs) can be efficiently differentiated in large numbers from lymphoma patients in spite of their disease and previous therapy. These cells were produced using the VAC and MAK cell processors according to standard operating procedures. DCs and MOs were differentiated from circulating monocytes in gas permeable hydrophobic bags, with 2% autologous serum and in the presence of GM-CSF and IL-13 or GM-CSF alone, respectively. DCs and MOs were then purified by counter flow centrifugation. Phenotypic, morphological and functional analysis showed that cells differentiated from patients with lymphoma present quite similar features to DCs and MOs produced from monocytes of healthy donors. Moreover, we show that MOs, when combined with CD20 antibody (Rituximab), can efficiently engulf tumor cells and propose that a such combination could be used for initiating a clinical trial in lymphoma. Thus, the possibility of producing functional DC and MOs in large amounts in conditions compatible with therapeutic application will allow the development of new immune strategies to eradicate lymphoma.

From the study of tumor cell immunogenicity to the generation of antitumor cytotoxic cells in non-Hodgkin's lymphomas

The question of the immunogenicity of non-Hodgkin's lymphoma (NHL) B cells has been investigated in an attempt to support the development of new immunotherapeutic treatments for this disorder, which remains resistant to conventional treatments in most cases. In the present review, we report and discuss our new findings in the field of NHL B cell immunogenicity. One aspect of our work is the description of the expression and functions of membrane molecules associated with antigen presentation. The expression levels of adhesion molecules was measured, and the relevance of this expression to the sensitivity of malignant B cells to cell-mediated lysis was studied. Since the T cell response relies on the expression of both HLA class I and II molecules, we also investigated whether or not these molecules were present at the surface of NHL B cells. Subsequently, we asked whether antitumor CTL and LAK cells could be developed and analyzed the mechanisms of cell lysis involved. Since the generation of a T cell response requires the expression of the costimulatory molecules CD80 and CD86, we investigated their in vivo expression and their modulation in vitro during contact with responding T lymphocytes. The understanding of the immunogenicity of NHL B cells has enabled us to develop a new culture protocol to induce antitumor specific autologous CTL. The originality of NHL B cells--unlike most other tumor cells--is to be able to function as antigen presenting cells (APC) and to activate a T cell response in the absence of other professional APC. Over the next few years, these findings should allow the generation of anti-NHL specific T cells for adoptive immunotherapy and for the identification of NHL-associated antigens.

Development of lymphoproliferative disorder of granular lymphocytes in association with hairy cell leukemia

Lymphoproliferative disorder of granular lymphocytes (LDGL) is a low grade T-cell disease characterized by clonal expansion of large granular lymphocytes of either T cell or natural killer (NK) cell lineage that express the cytotoxic T-cell/NK cell antigens CD16, CD56 and/or CD57. LDGL has been described in association with other malignancies, leading to theories of a common abnormal stem cell as well as development of the LDGL as an immune response to a primary tumor. We have studied 32 patients with hairy cell leukemia (HCL). In 15 patients (47%) we detected an increase in cells expressing cytotoxic T-cell/NK cell antigens. In 10(31%) patients these cells were of T cell lineage, while 5 patients (16%) had increased NK-cells. T cell clonality was detected by PCR in all cases with increased cytotoxic T-cells in which adequate DNA was obtained from peripheral blood. Since in 2 patients the LDGL was not present at diagnosis but developed during follow up, our data suggests that clonal LDGL may develop in response to the HCL. The significance of LDGL in the setting of HCL and flow cytometric evaluation of HCL versus LDGL will be discussed.

Role of autologous CD4+ T cell clones in human B non-Hodgkin's lymphoma: aborted activation and G1 blockade induced by cell-cell contact

This article describes the study of the functional relationship between auto-tumor-reactive CD4(+) T cell clones (TCC) and autologous malignant B cells. Four auto-tumor-reactive CD4(+) TCC were derived from tumor-infiltrating T lymphocytes (TIL-T) from a freshly isolated human follicular lymphoma by the following technique: total CD4(+) TIL-T were negatively purified by an immunomagnetic procedure, then CD4(+) TCC were obtained by limiting dilution in the presence of IL-2 and autologous non-irradiated follicular lymphoma cells as feeders. After expansion, these CD4(+) TCC were co-cultured with non-irradiated autologous malignant B cells. All four TCC were activated by B lymphoma cells and proliferated, as assessed by CD25 expression and cell cycle analysis. Activation and proliferation of B lymphoma cells were studied in response to activated CD4(+) T cells. Although all four TCC were able to induce B lymphoma cell activation (Ki-67 antigen induction and CD40 up-regulation), cells were subsequently blocked in G1 phase. Activation of B-NHL cells was mediated by TCR-HLA class II interaction, as shown by a blocking experiment using an anti-CD4 monoclonal antibody (mAb). Since anti-CD40 mAb with or without IL-4 did not induce proliferation of B lymphoma cells in contrast to normal B cells, we suggest that the blockade in G1 phase is due to the presence of abnormalities in B lymphoma cells. This is the first evidence that autologous reactive CD4(+) TCC can engage follicular lymphoma B cells to enter the cell cycle and induce an aborted activation stage.