Low doses of rIL2 after autologous bone marrow transplantation induce a "prolonged" immunostimulation of NK compartment in high-grade non-Hodgkin's lymphomas

The Future of Natural Killer Cell Immunotherapy for B Cell Non-Hodgkin Lymphoma (B Cell NHL)

Natural killer (NK) cells have played a critical—if largely unrecognized or ignored—role in the treatment of B cell non-Hodgkin lymphoma (NHL) since the introduction of CD20-directed immunotherapy with rituximab as a cornerstone of therapy over 25 years ago. Engagement with NK cells leading to lysis of NHL targets through antibody-dependent cellular cytotoxicity (ADCC) is a critical component of rituximab’s mechanism of action. Despite this important role, the only aspect of B cell NHL therapy that has been adopted as standard therapy that even indirectly augments or restores NK cell function is the introduction of obinutuzumab, a CD20 antibody with enhanced ability to engage with NK cells. However, over the last 5 years, adoptive immunotherapy with effector lymphocytes of B cell NHL has experienced tremendous growth, with five different CAR T cell products now licensed by the FDA, four of which target CD19 and have approved indications for some subtype of B cell NHL—axicabtagene ciloleucel, brexucabtagene autoleucel, lisocabtagene maraleucel, and tisagenlecleucel. These T cell-based immunotherapies essentially mimic the recognition, activation pathway, and cytotoxic machinery of a CD19 antibody engaging NK cells and lymphoma targets. Despite their efficacy, these T cell-based immunotherapies have been difficult to implement because they require 4–6 weeks of manufacture, are costly, and have significant toxicities. This renewed interest in the potential of cellular immunity—and the manufacturing, supply chain, and administration logistics that have been addressed with these new agents—have ignited a new wave of enthusiasm for NK cell-directed therapies in NHL. With high safety profiles and proven anti-lymphoma efficacy, one or more new NK cell-directed modalities are certain to be introduced into the standard toolbox of NHL therapy within the next few years, be it function-enhancing cytokine muteins, multi-domain NK cell engagers, or adoptive therapy with expanded or genetically modified NK cells.

Maintenance biotherapy with interleukin-2 and interferon for metastatic renal cell cancer

The term maintenance immunotherapy comprises at least two different therapeutic approaches: the continuation of immunotherapy beyond disease progression and the use of chronic immunotherapy after the achievement of an initial response (or disease stabilization) with more intensive treatment modalities, such as chemotherapy. The former therapeutic approach was proposed in renal cell carcinoma some years ago relying on several immunological considerations. Some years later, we have learned that it is feasible and endowed with a favorable therapeutic index; furthermore, its immunologic effects are well described and reproducible, and it has antitumor activity. However, due to the lack of adequate randomized Phase III studies, the actual impact of this treatment strategy on patient survival has not yet been proved. The rationale of this treatment, its immunological and clinical results, as well as its pitfalls and perspectives, will be presented and discussed in this review.

Changes in Lymphocyte Count Induced by Repeated Cycles with Low-Dose Interleukin-2 and Interferon-α in 146 Patients with Renal Cell Carcinoma

Aims and Background

The exact mechanism by which recombinant interleukine-2 and interferon-a modulate the immunological response, inducing long-term responses in metastatic renal cell carcinoma, is still not clear. The aim of the study was to analyze the modifications in peripheral blood lymphocytes during cycles of low-dose immunotherapy as a marker of the biological response to the treatment in 146 patients with renal cell carcinoma (advanced and localized disease).

Methods and Study Design

Peripheral blood lymphocytes were evaluated before and after every cycle of treatment.

Results

We found a statistically significant overall difference between pre- and post-cycle values (mean increase of 39%). The differences between pre- and post-cycle lymphocyte counts for each cycle were significant. Also, the post-cycle lymphocyte count of each cycle remained higher than the baseline value. Furthermore, pre-cycle lymphocyte counts of each cycle were still higher than the baseline value, with no difference between a pre-cycle lymphocyte mean value and the other one (except that between the first and second cycle). From the end of each cycle, but before starting the next one, the absolute value of lymphocytes fell on the average by 15–30%, concurring with the fact that, even starting from pre-cycle values higher than baseline, the immune system remains sensitive to chronically repeated stimulation by immunotherapy. We also found that non-metastatic patients had a higher number of peripheral blood lymphocytes than metastatic patients, whereas the latter had a lower immune response to therapy.

Conclusions

The results support the idea that “maintenance” immunotherapy may not develop resistance over time in terms of biological response and thus may have a role as chronic therapy in combination with other drugs such as target therapy. We suppose that the immune system of patients with metastases is in a state of relative impairment, resulting in less sensitivity to immunostimulating agents.

Induction of CD16+ CD56bright NK cells with antitumour cytotoxicity not only from CD16- CD56bright NK Cells but also from CD16- CD56dim NK cells

The aim of this study was to examine the effect of cytokines on different subsets of NK cells, while especially focusing on CD16(-) CD56(dim) cells and CD16(-) CD56(bright) cells. When human peripheral blood mononuclear cells (PBMC) were cultured with a combination of IL-2, IL-12 and IL-15 for several days, a minor population of CD56(bright) NK cells expanded up to 15%, and also showed potent cytotoxicities against various cancer cells. Sorting experiments revealed that unconventional CD16(-) CD56(+) NK cells (CD16(-) CD56(dim) NK cells and CD16(-) CD56(bright) NK cells, both of which are less than 1% in PBMC) much more vigorously proliferated after cytokine stimulation, whereas predominant CD16(+) CD56(dim) NK cells proliferated poorly. In addition, many of the resting CD16(-) CD56(bright) NK cells developed into CD16(+) CD56(bright) NK cells, and CD16(-) CD56(dim) NK cells developed into CD16(-) CD56(bright) NK cells and also further into CD16(+) CD56(bright) NK cells by the cytokines. CSFE label experiments further substantiated the proliferation capacity of each subset and the developmental process of CD16(+) CD56(bright) NK cells. Both CD16(-) CD56(dim) NK cells and CD16(-) CD56(bright) NK cells produced large amounts of IFN-gamma and Fas-ligands. The CD16(+) CD56(bright) NK cells showed strong cytotoxicities against not only MHC class I (-) but also MHC class I (+) tumours regardless of their expression of CD94/NKG2A presumably because they expressed NKG2D as well as natural cytotoxicity receptors. The proliferation of CD16(+) CD56(bright) NK cells was also induced when PBMC were stimulated with penicillin-treated Streptococcus pyogenes, thus suggesting their role in tumour immunity and bacterial infections.

Low-dose total body irradiation augments the therapeutic effect of interleukin-2 in a mouse model for metastatic malignant melanoma

BACKGROUND

Low-dose total body irradiation (LTBI) is known for its antitumor immune modulatory effects. Moreover, there is theoretical ground suggesting that combining LTBI with interleukin-2 (IL-2) will have a synergistic immune-mediated antitumor effect. However, the use of LTBI in combination with IL-2 or other forms of immunotherapy has not been tested before.

AIM OF THE WORK

To test the efficacy of combining LTBI and IL-2 in controlling lung metastases in a murine model for malignant melanoma compared to IL-2 alone.

MATERIAL AND METHODS

Ten-week-old female C57BL/6 mice were inoculated intravenously (on day 0) with 1 million B16F1 malignant melanoma cells. The mice received either no treatment (control group), LTBI alone (single fraction of 0.75 Gy), IL-2 treatment alone (30,000 CU x 2 daily for 5 consecutive days), or a combination of LTBI and IL-2. LTBI was given on day +7 and IL-2 treatment started day +8. On day +14, the mice were sacrificed and the lungs were removed and analyzed for tumor burden. Lung sections were also tested for tumor-infiltrating cells using immunohistochemical staining. Peripheral blood and splenic cells were collected and tested for the percentage of the various lymphocytic subsets using immunostaining and flow cytometry.

RESULTS

Tumor burden expressed as the percentage of lung area occupied with metastases (+/- 1 SD), was the same in the control group (8.1 +/- 4.9%), and in the group receiving LTBI alone (8.3 +/- 4.5%). Tumor burden was reduced to 6.4% (+/- 3.4%) in the IL-2 alone group (P = 0.3) and further reduced to 3% (+/- 1%) in the combined treatment group (P = 0.004). The difference in tumor burden between the IL-2 alone group and the combined treatment group was statistically significant (P = 0.006). The combined treatment caused a significant increase in the number of natural killer (NK) cells and macrophages infiltrating the metastatic sites. This was associated with a significant increase in the percentage of CD122+ (IL-2R beta) cells and NK cells in both peripheral blood and spleens.

CONCLUSION

We conclude that combining LTBI and IL-2 treatment is synergistic and therapeutically more effective than IL-2 alone. The data points to NK cells and macrophages as likely major effectors of the synergistic outcome of the combined treatment. This observation may have important clinical implications in the treatment of patients with metastatic malignant melanoma.

Long-term immunotherapy with low-dose interleukin-2 and interferon-alpha in the treatment of patients with advanced renal cell carcinoma

BACKGROUND

The objective of this study was to evaluate response, toxicity, and immunologic effects of an original immunotherapy schedule based on repeated cycles of low doses of recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFNalpha) in patients with metastatic renal cell carcinoma (mRCC).

METHODS

Fifty patients who underwent nephrectomy received therapeutic cycles consisting of subcutaneous rIL-2 for 5 days per week and intramuscular rIFNalpha twice weekly for 4 consecutive weeks. The cycle was regularly repeated indefinitely at 4-month intervals in all patients, irrespective of their response. rIL-2 (1 x 10(6) IU/m(2)) was administered every 12 hours on Days 1 and 2 and once per day on Days 3-5 of each week; rIFNalpha (1.8 x 10(6) IU/m(2)) was given on Days 3 and 5. Toxicity was graded according to the World Health Organization (WHO) criteria. Forty percent of the patients had only one metastatic disease site at the time of treatment. The Kaplan-Meier method was used to estimate survival, and an analysis of variance was used to evaluate the effects on leukocytes and lymphocyte subsets over time.

RESULTS

A total of 241 cycles were administered. One patient achieved a complete response, and five patients achieved a partial response. Five patients had stable disease, and 30 patients had progressive disease. Nine patients were not evaluable for response. The overall response rate was 12% (95% confidence interval, 3-21%) on the basis of an intent-to-treat analysis. The 36-month survival probability for all 50 patients was 47%. Treatment-related toxicity was limited to WHO Grades 1 and 2. Both lymphocyte and eosinophil levels significantly increased after all cycles (by 42% and 353%, respectively). The treatment also induced significant increases in the CD25 positive (24%), CD56 positive (28%), and CD3 negative/CD56 positive (54%) lymphocyte subsets.

CONCLUSIONS

Long-term, repeated treatment with low doses of rIL-2 and rIFNalpha is feasible in patients with mRCC. The schedule induces clinical response rates and survival probabilities are similar to those obtained using higher doses.

Transgenic expression of CD40L and interleukin-2 induces an autologous antitumor immune response in patients with non-Hodgkin's lymphoma

The malignant B cells of non-Hodgkin's lymphoma (B-NHL cells) express peptides derived from tumor-specific antigens such as immunoglobulin idiotypes, and also express major histocompatibility complex antigens. However, they do not express co-stimulatory molecules, which likely contributes to their protection from host antitumor immunity. To stimulate NHL-specific immune responses, we attempted to transfer the human CD40 ligand (hCD40L) gene to B-NHL cells and enhance their co-stimulatory potential. We found that an adenoviral vector encoding human CD40L (AdhCD40L) was ineffective at transducing B-NHL cells because these cells lack the coxsackievirus B-adenovirus receptor and alpha(v) integrins. However, preculture of the B-NHL cells with the human embryonic lung fibroblast line, MRC-5, significantly up-regulated expression of integrin alpha(v)beta 3 and markedly increased their susceptibility to adenoviral vector transduction. After prestimulation, transduction with AdhCD40L increased CD40L expression on B-NHL cells from 1.3+/-0.2% to 40.8+/-11.9%. Transduction of control adenoviral vector had no effect. Expression of transgenic human CD40L on these CD40-positive cells was in turn associated with up-regulation of other co-stimulatory molecules including B7-1/-2. Transduced B-NHL cells were now able to stimulate DNA synthesis of autologous T cells. However, the stimulated T cells were unable to recognize unmodified lymphoma cells, a requirement for an effective tumor vaccine. Based on previous results in an animal model, we determined the effects of combined use of B-NHL cells transduced with AdhCD40L and AdhIL2 vectors. The combination enhanced initial T-cell activation and generated autologous T cells capable of specifically recognizing and killing parental (unmodified) B-NHL cells via major histocompatibility complex--restricted cytotoxic T lymphocytes. These findings suggest that the combination of CD40L and IL2 gene-modified B-NHL cells will induce a cytotoxic immune response in vivo directed against unmodified tumor cells.

Pediatric blood cell transplantation

OBJECTIVES

To provide a review of the use of blood cell transplantation (BCT) in pediatric patients, the psychological and developmental issues related to BCT, and guidelines for supportive care.

DATA SOURCES

Review articles, research studies, and book chapters pertaining to BCT in children with cancer.

CONCLUSIONS

BCT is a safe and reliable source of support after myeloablative regimens for children with disseminated disease, relapse or failure after chemotherapy, or children with high-risk features at diagnosis.

IMPLICATIONS FOR NURSING PRACTICE

The pediatric oncology nurse is an integral part of the multidisciplinary team in providing long-term care for children undergoing BCT. Astute clinical monitoring, supportive care, and management of complications is of utmost importance to recovery.

The potential role of NK cells in the separation of graft-versus-tumor effects from graft-versus-host disease after allogeneic bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) is being increasingly used for the treatment of a variety of cancers ranging from leukemias to breast cancer. However, significant obstacles currently limit the efficacy of this treatment procedure. The predominant two are the occurrence of graft-versus-host disease (GVHD) and relapse from the cancer. While regimens exist that prevent the occurrence or severity of GVHD, these same regimens also increase the rate of relapse. Conversely, most attempts to reduce the relapse rate also result in increased GVHD. The use of NK cells as an adoptive immunotherapy after BMT is attractive for several reasons. NK cells exhibit antitumor effects both in vitro and in animal models and may, therefore, promote graft-versus-tumor (GVT) effects to remove minimal residual disease after allogeneic BMT. NK cells have also been shown to promote hematopoietic engraftment and donor cell reconstitution after allogeneic BMT in mice. The effects of NK cells on hematopoiesis are believed to be due to the hematopoietic growth factors they can produce after activation. Another advantage in using NK cells is that they can prevent the occurrence of GVHD after allogeneic BMT in mice. This effect is mediated at least in part by the immunosuppressive cytokine, transforming growth factor beta (TGF-beta). BMT studies in mice also indicate that the beneficial effects of NK cells are optimal if they are administered soon after the transplant. Thereafter, NK cells and, more importantly, IL-2, which is used to activate them, are detrimental and can exacerbate the subsequent GVHD. Thus, the use of activated NK cells after allogeneic BMT may provide GVT effects without inducing GVHD.