Low doses of interferon alpha result in more effective clinical natural killer cell activation

Identification of a prognostic classifier based on EMT-related lncRNAs and the function of LINC01138 in tumor progression for lung adenocarcinoma

Purpose: This study aimed to develop a prognostic indicator based on epithelial-mesenchymal transition (EMT)-related long noncoding RNAs (lncRNAs) and explore the function of EMT-related lncRNAs in malignant progression in lung adenocarcinoma (LUAD).

Materials and methods: A LUAD dataset was acquired from The Cancer Genome Atlas (TCGA) to identify prognostic EMT-related lncRNAs via differential expression analysis and univariate Cox regression analysis. Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression analysis was utilized for variable selection and model construction. The EMT-related prognostic index (ERPI) was calculated according to the model and served as a classifier to divide LUAD individuals into high-ERPI and low-ERPI groups. A nomogram incorporating ERPI and clinicopathological variables was constructed. TCGA-LUAD, GSE50081, and GSE31210 were used to test the predictive capacity of the ERPI and nomogram. The characteristics of the tumor microenvironment (TME) were evaluated via the ESTIMATE, TIMER, and ssGSEA algorithms. Gene set variation analysis (GSVA) and ssGSEA were used to annotate the functions of the high-ERPI and low-ERPI groups. CCK8, transwell assay, wound-healing assay, and clone formation assay were conducted to clarify the biological functions of prognostic EMT-related lncRNAs.

Results: Ninety-seven differentially expressed EMT-related lncRNAs were identified, 15 of which were related to overall survival (OS). A prognostic signature was constructed based on 14 prognostic EMT-related lncRNAs to calculate the ERPI of each patient, and the predictive ability of ERPI was verified in TCGA, GSE50081, and GSE31210. The low-ERPI group survived longer and had a lower percentage of patients in advanced stage than the high-ERPI group. The nomogram had the highest predictive accuracy, followed by ERPI and stage. Patients with low ERPI had higher infiltration degree of immune cells and stronger immune responses than those with high ERPI. A series of in vitro experiments demonstrated that knockdown of LINC01138 dampened variability, proliferation, and motility of A549 and H460 cells.

Conclusion: Our study developed a prognostic classifier with robust prognostic performance and clarified the biological functions of LINC01138 in LUAD, aiding in making individual treatments for patients with LUAD and dissecting the mechanism of oncogenesis.

Loss of type I IFN responsiveness impairs natural killer cell antitumor activity in breast cancer

Competent type I IFN signaling is the lynchpin of most immune surveillance mechanisms and has recently proven critical to the efficacy of several anticancer agents. Expression of the type I IFN receptor, IFNAR, underpins type I IFN responsiveness in all cells and facilitates the activation and cytotoxic potential of lymphocytes, while loss of IFNAR on lymphocytes has previously been associated with tumor progression and poor patient survival. This study underscores the importance of intact type I IFN signaling to NK cells in the regulation of tumorigenesis and metastasis, whereby ablation of NK cell IFNAR1 impairs antitumor activity and tumor clearance. Using a preclinical model of triple negative breast cancer, we identified that intact IFNAR on NK cells is required for an effective response to type I IFN-inducing immunotherapeutics that may be mediated by pathways associated with NK cell degranulation. Taken together, these data provide a rationale for considering the IFNAR status on NK cells when devising therapeutic strategies aimed at inducing systemic type I IFN signaling in breast cancer.

Interferons in cancer immunoediting: sculpting metastasis and immunotherapy response

Interferons (IFNs) are pleiotropic cytokines critical for regulation of epithelial cell functions and for immune system regulation. In cancer, IFNs contribute to tumor-intrinsic and -extrinsic mechanisms that determine the quality of antitumor immunity and response to immunotherapy. In this Review, we focus on the different types of tumor IFN sensitivity that determine dynamic tumor-immune interactions and their coevolution during cancer progression and metastasis. We extend the discussion to new evidence supporting immunotherapy-mediated immunoediting and the dual opposing roles of IFNs that lead to immune checkpoint blockade response or resistance. Understanding the intricate dynamic responses to IFN will lead to novel immunotherapeutic strategies to circumvent protumorigenic effects of IFN while exploiting IFN-mediated antitumor immunity.

Interferons α and β in cancer: therapeutic opportunities from new insights

Over the past decade, preclinical and clinical research have confirmed the essential role of interferons for effective host immunological responses to malignant cells. Type I interferons (IFNα and IFNβ) directly regulate transcription of >100 downstream genes, which results in a myriad of direct (on cancer cells) and indirect (through immune effector cells and vasculature) effects on the tumour. New insights into endogenous and exogenous activation of type I interferons in the tumour and its microenvironment have given impetus to drug discovery and patient evaluation of interferon-directed strategies. When combined with prior observations or with other effective modalities for cancer treatment, modulation of the interferon system could contribute to further reductions in cancer morbidity and mortality. This Review discusses new interferon-directed therapeutic opportunities, ranging from cyclic dinucleotides to genome methylation inhibitors, angiogenesis inhibitors, chemoradiation, complexes with neoantigen-targeted monoclonal antibodies, combinations with other emerging therapeutic interventions and associations of interferon-stimulated gene expression with patient prognosis - all of which are strategies that have or will soon enter translational clinical evaluation.

Beyond the vicious cycle: The role of innate osteoimmunity, automimicry and tumor-inherent changes in dictating bone metastasis

Bone metastasis is a fatal consequence of a subset of solid malignancies that fail to respond to conventional therapies. While a myriad of factors contribute to osteotropism and disseminated cell survival and outgrowth in bone, efforts to inhibit tumor cell growth in the bone-metastatic niche have largely relied on measures that disrupt the bi-directional interactions between bone resident and tumor cells. However, the targeting of isolated stromal interactions has proven ineffective to date in inhibiting bone-metastatic progression and patient mortality. Osteoimmune regulation is now emerging as a critical determinant of metastatic growth in the bone microenvironment. While this has highlighted the importance of innate immune populations in dictating the temporal development of overt bone metastases, the osteoimmunological processes that underpin tumor cell progression in bone remain severely underexplored. Along with tumor-intrinsic alterations that occur specifically within the bone microenvironment, innate osteoimmunological crosstalk poses an exciting area of future discovery and therapeutic development. Here we review current knowledge of the unique exchange that occurs between bone resident cells, innate immune populations and tumor cells that leads to the establishment of a tumor-permissive milieu.

Interferon related pericarditis: Review

AIM

To conduct a review of “interferon related pericarditis”.

METHODS

We searched MEDLINE, EMBASE, Cinahl, and the Cochrane Database from the earliest available date through September 2016. A search strategy using the Medical Subject Headings and text keywords “interferon” and ”pericarditis” were used.

RESULTS

Nine case reports were eligible for the present study. Six of 8 cases were women and the mean age was 43.8 ± 13.8 years with chronic hepatitis C in 6 cases, malignant melanoma in 2 cases and chronic myelogenous leukemia in 1 case. The patients complained of chest pain in 6 cases, dyspnea in 5 cases and edema in 2 cases. Pericardial friction rub was heard in 3 of 9 cases. Congestive heart failure occurred in 3 of 9 cases. Two mechanisms for pericarditis were demonstrated, one is autoimmune included lupus like syndrome in 2 cases and the other is cardio toxicity in 4 cases. Treatment of interferon related pericarditis is discontinuation of Interferon treatment. Four of 9 cases were treated with prednisone and 4 with nonsteroidal anti-inflammatory drugs.

CONCLUSION

Interferon related pericarditis still remains uncertain. Treatment of interferon related pericarditis rests mainly on early recognition and drug discontinuation. Interferon related pericarditis was treated with steroid and/or nonsteroidal anti-inflammatory drugs.

Recurrent Pericarditis, an Unexpected Effect of Adjuvant Interferon Chemotherapy for Malignant Melanoma

Drug-induced pericarditis is a well-described cardiac pathology that can result from a variety of medications; however, interferon-mediated pericarditis is extremely rare. We present a case of a young female with recurrent pericarditis due to interferon therapy. The role of interferon in adjuvant chemotherapy is well known and yields good effect, but this case highlights the very uncommon phenomena of interferon induced pericarditis and the significant distress it can cause.

The Use of Registries to Improve Cancer Treatment: A National Database for Patients Treated with Interleukin-2 (IL-2)

Registries evaluating un-randomized patients have provided valuable information with respect to a therapy's utility, treatment practices, and evolution over time. While immunotherapy for cancer has been around for more than three decades, data collection in the form of a registry has not been undertaken. The authors believe that establishing a registry to study HD IL-2 immunotherapy, which has been the only systemic therapy producing long term unmaintained remissions for advanced kidney cancer and melanoma for over 20 years, will be an important resource in understanding the impact of immunotherapy with HD IL-2 in a rapidly changing therapeutic environment. Optimizing administration and improving selection of appropriate patients likely to benefit from HD IL-2 immunotherapy are two of many benefits to be derived from this endeavor.

Interferons and their stimulated genes in the tumor microenvironment

Constitutive expression of interferons (IFNs) and activation of their signaling pathways have pivotal roles in host responses to malignant cells in the tumor microenvironment. IFNs are induced by the innate immune system and in tumors through stimulation of Toll-like receptors (TLRs) and through other signaling pathways in response to specific cytokines. Although in the oncologic context IFNs have been thought of more as exogenous pharmaceuticals, the autocrine and paracrine actions of endogenous IFNs probably have even more critical effects on neoplastic disease outcomes. Through high-affinity cell surface receptors, IFNs modulate transcriptional signaling, leading to regulation of more than 2,000 genes with varying patterns of temporal expression. Induction of the gene products by both unphosphorylated and phosphorylated STAT1 after ligand binding results in alterations in tumor cell survival, inhibition of angiogenesis, and augmentation of actions of T, natural killer (NK), and dendritic cells. The interferon-stimulated gene (ISG) signature can be a favorable biomarker of immune response but, in a seemingly paradoxical finding, a specific subset of the full ISG signature indicates an unfavorable response to DNA-damaging interventions such as radiation. IFNs in the tumor microenvironment thus can alter the emergence, progression, and regression of malignancies.

Safety and effectiveness of interferon alpha-2a in treatment of patients with Behçet's uveitis refractory to conventional treatments

PURPOSE

To evaluate the intermediate-term safety and effectiveness of interferon alpha-2a (IFNalpha2a) in patients with Behçet's uveitis (BU) refractory to corticosteroids and immunosuppressive agents.

DESIGN

Open, nonrandomized, uncontrolled, interventional, prospective study.

PARTICIPANTS

Fifty-three patients (106 eyes) with active, vision-threatening BU who failed to respond to conventional treatments.

INTERVENTION

In 53 patients, acute inflammation was suppressed with effective prednisolone dosage (1-2 mg/kg/day, tapered to 10 mg within 4-6 weeks). The patients were treated with IFNalpha2a 4.5 million international units (MIU) 3 times per week for the first 3 months followed by IFNalpha2a 3 MIU 3 times per week for the next 3 months. Observation or other treatment methods were performed according to the decision tree developed for this study.

MAIN OUTCOME MEASURES

Remission and complete response (primary outcome measures), frequency of uveitis attacks, visual acuity (VA), and adverse effects (secondary outcome measures).

RESULTS

During 2 years of follow-up (median 65 months, range 12-130 months), compliance with the therapy was excellent. At the end of 1-year follow-up, treatment response was obtained in 45 of 53 patients (84.9%). The mean attack rate of 3.6+/-1.1 per year (range, 2-8) decreased to 0.56+/-0.75 (range, 0-4) per year (P=0.001). Visual acuity improved (> or = 0.2 logarithm of the minimum angle of resolution units from initial VA) in 30 eyes (28.3%) and worsened in 12 eyes (11.3%). Five patients (9.4%) did not respond to the initial treatment, and 3 patients (5.6%) developed severe adverse effects, including psoriasis, epileptic seizure, and extreme tiredness. Fifteen patients (28.3%) were off treatment for all the medications and disease free for 28+/-13.1 months (range, 12-50 months).

CONCLUSIONS

These results suggest that IFNalpha2a may be a valuable treatment option in BU that is refractory to corticosteroids and conventional immunosuppressive agents. The possible role of IFNalpha2a as a first-line agent in BU should be validated in randomized controlled clinical trials against newly described biologic agents.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Intratumoral dendritic cells and chemoradiation for the treatment of murine squamous cell carcinoma

Dendritic cells are potent antigen-presenting cells that have been shown to have significant antitumor effects in vitro and in vivo. However, the therapeutic efficacy of dendritic cells as an immunotherapeutic treatment has been limited by both immunologic tolerance and active immunosuppression in the tumor microenvironment. To address this problem, we examined the ability of concurrent systemic chemotherapy and local, fractionated radiation to augment intratumoral dendritic cell injections in a mouse model of squamous cell carcinoma. Intratumoral injections of dendritic cells alone did not have a significant antitumor effect in mice with squamous cell carcinoma flank tumors, but the addition of chemoradiation resulted in significant tumor regression. Concurrent chemoradiation alone resulted in slower tumor growth, but no complete tumor regressions. The combination of chemoradiation and intratumoral dendritic cell injections resulted in improved survival and complete tumor regression in 30% mice. Mice with complete tumor regression were partially resistant to the repeat challenge with relevant tumor 60 days after treatment. These findings were partially dependent on the presence of CD4 T cells, CD8 T cells, and natural killer cells. Chemoradiation may augment intratumoral dendritic cell injections through increased intratumoral apoptosis and decreased intratumoral regulatory T cells. This work suggests a possible role for the use of intratumoral dendritic cell therapy with more traditional chemoradiation strategies.

Regulation of activated CD4+ T cells by NK cells via the Qa-1-NKG2A inhibitory pathway

The ability of natural-killer cells to regulate adaptive immunity is not well understood. Here we define an interaction between the class Ib major histocompatibility complex (MHC) molecule Qa-1-Qdm on activated T cells responsible for adaptive immunity and CD94-NKG2A inhibitory receptors expressed by natural-killer cells by using Qa-1-deficient and Qa-1 knockin mice containing a point mutation that selectively abolishes Qa-1-Qdm binding to CD94-NKG2A receptors. The Qa-1-NKG2A interaction protected activated CD4+ T cells from lysis by a subset of NKG2A+ NK cells and was essential for T cell expansion and development of immunologic memory. Antibody-dependent blockade of this Qa-1-NKG2A interaction resulted in potent NK-dependent elimination of activated autoreactive T cells and amelioration of experimental autoimmune encephalomyelitis. These findings extend the functional reach of the NK system to include regulation of adaptive T cell responses and suggest a new clinical strategy for elimination of antigen-activated T cells in the context of autoimmune disease and transplantation.

Positive and negative regulation of Natural Killer cells: therapeutic implications

Natural Killer (NK) cells can mediate numerous anti-tumor and anti-viral effector functions as well as play important immunoregulatory roles in various disease states. Promoting the ability of NK cells to respond in an immunotherapeutic setting has often been sought by the addition of NK cell-stimulating factors. However, such therapies are often found to be insufficient, which may in part be due to the presence of inhibitory influences on the NK cell. NK cells can respond to a plethora of cytokines which are generated by numerous cell types and these interactions can markedly affect NK cell survival and activity. NK cells also possess multiple activating and inhibiting receptors which can alter their function. Whether the NK cell will become activated or not can depend on a complex balance of activating and inhibitory signals received by the cell and modulation of these signals may shift the balance on NK activation. This review discusses the various activating and inhibitory stimuli which can act on NK cells, and suggests that future NK cell-based therapies consider not only activating stimuli but also removal of possible inhibitory elements which could prevent optimal NK cell function and/or survival.

Reduction of recurrent HSV disease using imiquimod alone or combined with a glycoprotein vaccine

The aim of this study is to evaluate the effects of an immune modulator, imiquimod, given alone or in combination with an HSV vaccine on HSV immune responses and as immunotherapy of a genital recurrence model. After recovery from primary genital HSV infection, animals were randomized to placebo, 21 days of imiquimod plus a placebo vaccine, or 21 days of imiquimod plus an HSV-2 glycoprotein vaccine. Placebo or HSV vaccine was given in the footpad on days 16 and 37 after HSV-2 genital inoculation. Daily imiquimod or placebo was given subcutaneously in the shoulder on days 16 through 37. Genital recurrences were monitored and HSV specific NK activity, IL-2 response and ELISA antibody were assayed. For the entire 15 week observation period, imiquimod alone reduced recurrences 62.6%, while addition of HSV vaccine to imiquimod reduced recurrences 80.6% compared to placebo/placebo. The duration of significant recurrence reduction was more notable with the addition of vaccine. Imiquimod alone significantly reduced the weekly HSV recurrent disease in the first 10 weeks (53-94% reduction, mean 75.9%), as did imiquimod plus HSV-vaccine (71-98% reduction, mean 89.5%). In weeks 10-15, imiquimod alone reduced recurrences significantly only in week 10 (20-53% reduction, mean 33%), whereas the addition of vaccine extended the significant recurrence reduction to 14 weeks (44-71% reduction, mean 56.8%). The recurrence reduction is correlated to an increased HSV-induced in vitro IL-2 response and NK activity against HSV targets in treated groups. Both imiquimod and the imiquimod/vaccine combination significantly reduced genital HSV recurrences, but the combination extended the duration and extent of protection for recurrences compared to imiquimod alone. Enhanced HSV specific immune responses correlated to the protection.

Mild hyperthermia modulates biological activities of interferons

A significant enhancement of antiviral activity of human IFN-alpha, -beta and -gamma and murine IFN-gamma is observed when cells are treated with mild hyperthermia (39 degrees C) during antiviral assays. Treatment of primary human fibroblast cells with mild hyperthermia for 4 and 24 hours prior to interferon antiviral assays (pre-assay hyperthermia) further enhances interferon antiviral activity. An enhancement of interferon induced enzyme, 2,5-oligoadenylate synthetase, is also observed in cells treated with interferon and mild hyperthermia. This increase in enzyme activity is, in part, responsible for the observed increase in interferon antiviral activity with hyperthermia. Besides antiviral activity, mild hyperthermia also increases interferon antiproliferative activity on different tumour cells beyond its effect at normal physiological temperatures. On the other hand, mild hyperthermia decreases human interferon production in both human and murine cells when challenged with a viral or non-viral inducer. Also, mild hyperthermia suppresses interferon-mediated enhancement of natural killer (NK) cell activity in human and murine cells. The findings demonstrate that, although mild hyperthermia has suppressive effects upon interferon production and NK cell activity, it significantly increases both antiviral and antiproliferative activities of all three human interferons. These observations have direct bearing upon clinical utilization of exogenously administered interferons to late stage cancer patients who for the most part have a weaker immune system. In these patients, the antiviral and antiproliferative efficacies of administered interferon can be enhanced by combining interferon and hyperthermia.

Interferon alfa-2b, colchicine, and benzathine penicillin versus colchicine and benzathine penicillin in Behçet's disease: a randomised trial

BACKGROUND

Sight-threatening eye involvement is a serious complication of Behçet's disease. Extraocular complications such as arthritis, vascular occlusive disorders, mucocutaneous lesions, and central-nervous-system disease may lead to morbidity and even death. We designed a prospective study in newly diagnosed patients without previous eye disease to assess whether prevention of eye involvement and extraocular manifestations, and preservation of visual acuity are possible with combination treatments with and without interferon alfa-2b.

METHODS

Patients were randomly assigned 3 million units interferon alfa-2b subcutaneously every other day for the first 6 months plus 1.5 mg colchicine orally daily and 1.2 million units benzathine penicillin intramuscularly every 3 weeks (n=67), or colchicine and benzathine penicillin alone (n=68). The primary endpoint was visual-acuity loss. Analysis was by intention to treat.

FINDINGS

Significantly fewer patients who were treated with interferon had eye involvement than did patients who did not receive interferon (eight vs 27, relative risk 0.21 [95% CI 0.09-0.50], p<0.001). Ocular attack rate was 0.2 (SD 0.62) per year with interferon therapy and 1.02 (1.13) without interferon therapy (p=0.0001). Visual-acuity loss was significantly lower among patients treated with interferon than in those without interferon (two vs 13, relative risk 0.13 [95% CI 0.03-0.60], p=0.003). Arthritis episodes, vascular events, and mucocutaneous lesions were also less frequent in patients treated with interferon than in those not receiving interferon. No serious side-effects were reported.

INTERPRETATION

Therapy with interferon alfa-2b, colchicine, and benzathine penicillin seems to be an effective regimen in Behçet's disease for the prevention of recurrent eye attacks and extraocular complications, and for the protection of vision.

Autoimmunity induced by interferon-alpha therapy for chronic viral hepatitis

Type I interferons, which are mostly alpha-interferons (either as single agents or in combination with antiviral drugs), are currently the standard therapy for chronic viral hepatitis B, B/D, and C. Side-effects are not uncommon and include exacerbation of pre-existing autoimmune disorders or the de novo induction of autoimmunity. These adverse effects are attributed to the immunomodulatory properties of type I interferons, and should be distinguished from autoimmunity associated with chronic viral hepatitis in which interferon treatment may indeed be beneficial. The major autoimmune side-effects of interferon therapy for chronic viral hepatitis are thyroid or liver disease. Therefore, screening for thyroid antibodies and auto-antibodies indicative of autoimmune hepatitis both before, during, and after interferon therapy is strongly recommended. The presence of high concentrations of thyroid auto-antibodies or antibodies associated with autoimmune hepatitis can be contraindicative to interferon therapy. However, treatment is not contraindicated in viral hepatitis (in particular chronic hepatitis C) associated with autoimmune phenomena--including low-titer thyroid antibodies or other non-organ specific auto-antibodies. If interferon-induced autoimmunity occurs, the necessity of therapy has to be balanced carefully against the risks of autoimmune disease. Further research is needed to identify the factors which determine susceptibility to interferon-associated autoimmunity in individual patients.

Type I interferons

Type I interferons (IFNs) constitute a family of structurally related proteins that are all derived from the same ancestral gene and act on a common cell-surface receptor. Contrary to many other cytokines, the production of type I IFNs is not a specialized function, and all cells in the organism can produce them, usually as a result of induction by viruses, via the formation of double-stranded RNA. Type I IFNs are indeed responsible for the first line of defense during virus infection and act through the induction of a great number of proteins. Of these, at least thirty have been characterized, and there are probably many more. In addition to their direct antiviral effect, type I IFNs exert a wide variety of other activities, such as for example the induction of various cytokines and the stimulation of different effector cells of the immune system. Due to these pleiotropic effects, recombinant interferons are used in the clinic to treat a variety of diseases, among which cancer, viral hepatitis and multiple sclerosis.

Common cancers--immunotherapy and multidisciplinary therapy: Parts III and IV

The refractoriness of many solid tumors to cytotoxic chemotherapy has led to the exploration of new therapeutic modalities, including immunotherapy. Immunotherapy does not have a direct cytotoxic effect on the cancer cell but is an attempt to promote rejection of the tumor by the host, chiefly through the cellular arm of the immune system. The clinical success with immunotherapy (primarily adoptive immunotherapy) among patients with unresectable malignant melanoma and cancer of the kidney has not been marked by the large numbers of patients responding but by occasional dramatic effectiveness of therapy for these cancers, which usually are refractory to chemotherapy. Long-lasting responses and even complete disappearance of all known metastases are possible for a small percentage of patients with melanoma or renal cell carcinoma who undergo immunotherapy. A reasonable approach for patients with good performance status (no symptoms or ambulatory with symptoms but not bedridden) is entrance to clinical trials, especially trials examining adoptive or active immunotherapy for melanoma or adoptive immunotherapy for renal cancer. The overall treatment of patients with cancer has changed. Primary-care physicians detect almost all cancers. The days when "taking it out" is the best we could offer a patient are over. As we learn more about the use of adjuvant or neoadjuvant chemotherapy and radiation therapy, it is likely one or both of these modalities will be incorporated into the treatment of additional solid tumors previously managed solely with surgical resection. Increasingly, additional therapy is being given for earlier-stage disease as we define how to maximize the potential for cure with minimal toxicity. Many new therapies are on the horizon, including the use of noncytotoxic treatments as an adjunct to a surgical procedure. Such therapies include the use of angiogenesis inhibitors, tumor vaccines, and immunotherapy. Now and in the future, patients will be best served when treated in an environment that can integrate medical, surgical, and radiation oncology actively.

Phase I study combining tumor necrosis factor with interferon-alpha and interleukin-2

We evaluated the effects of the addition of escalating doses of tumor necrosis factor (TNF) to two fixed doses and schedules of a combination of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) to determine the maximum tolerated dose of this three-cytokine combination and its feasibility as an outpatient regimen. Eighteen patients with metastatic cancer were enrolled. Each course consisted of 3 consecutive weeks of treatment with IFN-alpha 9 x 10(6) IU/m2/day intramuscularly (i.m.) or subcutaneously (s.c.) days 1, 3, and 5 each week for 3 weeks plus IL-2 continuous infusion 1 x 10(6) IU/m2/day (group A) or 3 x 10(6) IU/m2/day (group B) days 1-5 each week for 3 weeks. TNF was administered only during the first week of each course intravenously (i.v.) for 2 h on days 1-5. The dose of TNF was escalated (40, 80, 120 micrograms/m2) in cohorts of 3 patients. The most common side effects were fever, chills, and fatigue in all patients. Grade 3-4 toxicity included anemia (3 patients), thrombocytopenia (1 patients), arrhythmia (2 patients), pulmonary edema (3 patients),- and weight loss (1 patient). Five patients withdrew from study due to toxicity. The combination of the three cytokines is feasible as an outpatient regimen in one of the following combinations: (a) TNF 80 micrograms/m2/day as 2-h infusion on days 1-5 + IL-2 1 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks, or (b) TNF 40 micrograms/m2/day as a 2-h infusion on days 1-5 + IL-2 3 x 10(6) IU/m2/day continuous infusion on days 1-5 for 3 weeks + IFN-alpha 9 x 10(6) IU/m2/day s.c. or i.m. on days 1, 3, and 5 for 3 weeks.

Bleomycin-induced lung injury is enhanced by interferon-alpha

We have evaluated the effect of intraperitoneal (I.P.) injection of human recombinant interferon-2alpha (IFN-alpha) on Bleomycin-induced pulmonary injury in hamsters. Pulmonary injury was induced by a single intratracheal (I.T.) instillation of Bleomycin (Bleo). Six groups of male Syrian hamsters were treated as follows: 1) I.T. Bleo and daily I.P. injections of low-dose interferon-alpha (2 x 10(4) U), 2) I.T. Bleo and daily I.P. injections of high-dose interferon-alpha (10(5) U), 3) I.T. Bleo and I.P. injections of saline, 4) I.T. saline and I.P. low-dose IFN-alpha, 5) I.T. saline and I.P. high-dose IFN-alpha, 6) I.T. saline and I.P. saline. Animals were sacrificed 28 days after I.T. treatment. Lung injury was evaluated histologically and biochemically. Treatment of hamsters with low-dose but not high-dose IFN-alpha significantly augmented the Bleo-induced lung injury, as determined by a semiquantitative morphological index. Lung hydroxyproline measurements were highest in Bleo-low-dose-IFN-alpha followed by Bleo-high-dose-IFN-alpha and Bleo-Sal as compared to Sal-Sal and Sal-IFN-alpha controls. These results suggest that IFN-alpha augments Bleo-induced lung injury but that this effect is complex and does not follow a simple-dose-response pattern.

Weekly 5-fluorouracil and interferon-alfa-2b in metastatic cancer

Twenty-four patients with advanced cancer were treated with 5-Fluorouracil 600 mg/m2 intravenously and interferon-alfa-2b 3 MU subcutaneously both given weekly for 6 weeks followed by a 2-week hiatus. The median age of patients treated on this study was 66 years. Mild to moderate leukopenia, nausea/emesis, and anemia were the most common toxicities. There were no treatment-related deaths and only 1 episode of grade IV toxicity (leukopenia in a patient who was receiving concurrent radiation therapy). Two complete responses, 7 partial responses and 1 prolonged minor response (pancreas cancer--12+ months) have been seen. Weekly 5-FU and interferon is well-tolerated and shows activity in selected patients with advanced cancer.

Effects of type I-interferons on human thyroid epithelial cells derived from normal and tumour tissue

Long term interferon (IFN) therapy is frequently associated with side effects which affect the thyroid gland such as hypothyroidism and thyroiditis. We have therefore tested the ability of type I-IFNs to exert direct effects on primary cultures of human thyroid epithelial cells: (i) Type I-IFNs (IFN-alpha 2b and IFN-omega) inhibit cell proliferation as determined by [3H]thymidine incorporation with a half-maximal effect at approximately 1 ng/ml (50 pM). Inhibition of cell growth is observed in cells derived from normal thyroid as well as neoplastic tissue (autonomous and non-secreting adenoma; follicular, papillary and anaplastic carcinoma). (ii) Over a similar concentration range, type I-IFNs suppressed thyroglobulin release by thyroid cells. (iii) IFN-alpha 2b stimulated surface expression of major histocompatibility class (MHC) I but not MHC II molecules, while IFN-gamma enhanced the expression of both MHC I and MHC II molecules. This effect of IFN-gamma, but not that of IFN-alpha 2b was antagonized by suramin. (iv) Incubation of thyroid cells with IFN-alpha 2b also resulted in increased cell surface levels of the intercellular adhesion molecule 1 (ICAM-1). These findings demonstrate that type I-IFNs directly affect thyroid function and explain related side effects of these cytokines. In addition, our results provide a rational basis for the possible use of type I-IFNs in the treatment of patients with advanced thyroid cancer for whom no therapeutic alternative exists.

Interferon as adjunctive treatment for non-metastatic renal cell carcinoma

OBJECTIVE

To investigate the effect of recombinant alpha 2b-interferon therapy on natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) in the peripheral blood in patients with renal cell carcinoma who had undergone radical nephrectomy.

PATIENTS AND METHODS

Between January 1988 and June 1989, 20 patients (14 men and six women, mean age 59 years, range 43-80) received interferon (IFN) therapy following radical nephrectomy for renal cell carcinoma. Thirteen patients had stage I disease, one had stage II and six had stage III; none had metastases.

RESULTS

There was a significant increase in NK activity at 5 and 7 months after starting IFN therapy but there was no increase in ADCC.

CONCLUSIONS

Low doses of IFN administered long-term increased NK activity in patients with renal cell carcinoma. This finding should be helpful in designating protocols for randomized studies of post-operative IFN administration as adjuvant therapy.

Modulation of 2',5'-oligoadenylate synthetase in patients treated with alpha-interferon: effects of dose, schedule, and route of administration

The interferon (IFN)-induced intracellular enzyme 2',5'-oligoadenylate (2-5A) synthetase was measured in extracts of peripheral mononuclear cells isolated from patients receiving a 300-fold range of doses of alpha interferon (IFN-alpha). The range of enzyme induction was 2.3- to 5.7-fold. The maximum fold increase varied from individual to individual as did the dose required for maximum enzyme stimulation. The magnitude and endurance of the enzyme response was a function of IFN dose and was unrelated to the duration of treatment or number of injections or to the route of administration. The enzyme assay was a more sensitive indicator of IFN administration than was measurement of the level of circulating IFN. These results substantiate the potential of a clinical 2-5A synthetase assay for monitoring IFN treatment.

Interferons: Pleiotropic cellular modulators

Interferons play a key role in host response as pleiotropic modulators of cell function. As induced proteins, interferons contrast with other physiologic regulators such as glucocorticoids which are produced relatively continuously. Antitumor effects have been suggested to be principally the result of two mechanisms: a direct effect on the functional capacity or antigenic composition of tumor cells or an indirect effect on modulation of immunological effector cell populations with tumor specificities. Over the past decade, interferons have been established as therapeutically useful molecules for malignant and viral diseases.

Treatment of malignant ascites due to recurrent/refractory ovarian cancer: the use of interferon-alpha or interferon-alpha plus chemotherapy in vivo and in vitro

Intraperitoneal treatment with interferon (IFN) for malignant ascites due to advanced ovarian carcinoma refractory to chemotherapy gave an objective response rate of 36% (7/19 patients treated). In vitro studies demonstrated that cytotoxicity of peripheral blood monocytes/macrophages was stimulated by IFN. However, peritoneal exudate cells obtained after intraperitoneal treatment with interferon were not stimulated to kill autologous tumour cells. Clinical response was therefore most probably due to a direct inhibitory effect of IFN on growth of malignant cells rather than due to an immune modulatory effect. Using a newly established ovarian cancer cell line (UWOV1), synergy between the growth inhibitory/antitumour effects of IFN and cisplatin was demonstrated at clinically achievable concentrations of each agent. IFN plus cisplatin proved to be more effective than intraperitoneal cisplatin alone in control of peritoneal carcinomatosis. The response rate was 5/7 (77%) for combined modality therapy vs. 2/9 (22%) for intraperitoneal chemotherapy alone. Both in vitro and in vivo studies suggest a role for interperitoneal therapy for control of refractory ascites in ovarian cancer.

Preliminary trial of nonrecombinant interferon alpha in recurrent squamous cell carcinoma of the head and neck

Fourteen patients with recurrent squamous cell carcinoma of the head and neck (SCCHN) were treated with 10 x 10(6) U of nonrecombinant interferon alpha (IFN) intramuscularly (IM) daily for 3 days every 28 days. There were 11 men and 3 women, with ages ranging from 48 to 74 years. Patients had previously been treated with surgery (9 patients), radiotherapy (13 patients), or chemotherapy (8 patients). All patients had measurable disease by physical exam and radiologic evaluation and a performance status of less than or equal to 2 (ECOG). Patients were treated for a minimum of 3 months and continued on therapy until disease progression. The dose and treatment schedule of IFN was well-tolerated. Toxicities included low-grade fever, mild anorexia, and malaise. Treatment was stopped in 1 patient due to the development of atrial fibrillation. One death occurred as a complication of aspiration pneumonia 2 weeks following the onset of therapy and was not felt to be related to IFN therapy. Of the 14 patients treated, there was 1 complete response (30+ months) of a base of tongue primary. Two patients had stabilization of disease (SD, 8 and 12 months). One patient had a mixed response with resolution of subcutaneous nodules. The remaining 10 patients died of progressive disease. Immunological assessment was performed on 8 patients. The 1 patient who had a complete response was noted to have markedly low pretreatment natural killer (NK) cell activity and a subsequent sharp rise in activity after initial treatment. We conclude that low-dose cyclic IFN is well-tolerated in patients with recurrent SCCHN and has potential antitumor activity.

A phase I trial of alpha-interferon in combination with pentostatin in hematologic malignancies

Pentostatin, a novel inhibitor of adenosine deaminase, has shown activity in various lymphoid malignancies of both the T and B cell lineage. This agent has unique side effects and in general myelosuppression has been mild. Interferon has both antiviral and antineoplastic properties. This agent has shown activity in hairy cell leukemia, chronic granulocytic leukemia, low grade lymphoma, and myeloma. Side effects from interferon are in general dissimilar to those that have been seen with pentostatin and in particular myelosuppression has not been a major toxicity with low doses of interferon. This current trial explored the combination of pentostatin and interferon in hematologic malignancies. Fifteen patients were enrolled in this phase I trial at a fixed dose of pentostatin of 4 mg/m2 biweekly and interferon at doses of 0.5, 1, 2, or 4 million units/m2 of interferon. At the first three dose levels of interferon nausea and vomiting were the predominant toxicity and appeared to worsen with time on study. Fatigue also was seen at the lowest level of interferon and was severe enough to cause two individuals to discontinue the study medications. At higher dose levels of interferon, myelosuppression, nausea and vomiting, and fatigue were the predominant toxicities. One patient with hairy cell leukemia had a complete response and a second patient with T cell cutaneous lymphoma had a partial response which lasted for 6 to 7 weeks. The maximum tolerated dose of interferon with pentostatin in this patient population was four million units/m2.

Biological and clinical effects of interferon-beta ser at two doses

To assess biological response, therapeutic activity, and side effects, a randomized, double-blind trial of two doses of interferon-beta ser (IFN-beta ser), differing by 20-fold 4.5 and 90 x 10(6) units), was undertaken in 64 patients with metastatic renal carcinoma. Patients were treated intravenously with injections daily for 10 days with an 11-day rest before treatment was reinitiated. The trial confirmed the relatively good toleration of IFN-beta ser; in the first cycle only 4/63 patients had anorexia of moderate or greater severity. Median weight change over the duration on study was -1.5 kg; in the first cycle only 7% of patients had performance status decline greater than 1 level. Statistically significant changes (p less than 0.05) occurred in granulocytes, lymphocytes, calcium, cholesterol, alkaline phosphatase, and aspartate transferase (AST); however, except for AST, overall clinical differences in the two doses were not great. Of 60 patients evaluated, 1 developed neutralizing antibody. When assessed 24 h after IFN-beta ser at 4.5 x 10(6) units, significant (p less than 0.05) augmentation had occurred in beta 2-microglobulin, HLA-DR, and HLA-DQ expression on monocytes, 2',5'-oligoadenylate (2-5A) synthetase in peripheral mononuclear cells, and natural killer (NK) and K cells functional activity. Although the 90 x 10(6) unit dose also resulted in stimulation of these responses, little additional augmentation of biological response occurred at the higher dose. Except for a decline in monocyte HLA-DR expression, biological responses remained increased at both doses over the 10-day period of treatment. However, no objective regressions of metastatic disease occurred. In view of objective responses in metastatic renal carcinoma in other trials with IFN-beta ser, consideration should be given to alternative schedules.

The effect of recombinant interferon-alpha on lymphocyte subpopulations and HLA-DR expression on liver tissue of HBV-positive individuals

Interferon-alpha (IFN-alpha) has been reported to be beneficial in the treatment of chronic active hepatitis occurring as a result of hepatitis B virus (HBV) infection. Treatment with IFN-alpha has been proposed as a means of reducing the high rate of allograft infection in clinical liver transplantation in patients transplanted for HBV-related chronic active hepatitis and cirrhosis who are positive for hepatitis B surface antigen (HBsAg). We obtained resected whole livers from two groups of patients who received liver transplants. Group A consisted of 11 patients who were HBsAg+ but were not treated with IFN-alpha, and group B consisted of 10 patients who were also HBsAg+ but received IFN-alpha therapy for 29.4 +/- 5.6 days prior to orthotopic liver transplantation. No differences between the two groups existed in terms of a variety of demographic and clinical characteristics. The liver tissue was stained with monoclonal antibodies to cell surface antigens unique to different mononuclear cell populations by the avidin-biotin-immunoperoxidase technique to determine the effect of IFN-alpha on the lymphocyte subsets as well as HLA antigen expression on liver-infiltrating mononuclear cells. The number of HLA-DR+ lymphocytes in the liver was significantly increased (P less than 0.005) within the portal areas in group B compared with that found in group A (84 +/- 14 versus 33 +/- 5 per one high-power field). Moreover, the intensity of the HLA-DR antigen expression on lymphocytes in the portal areas (P less than 0.02) and in the hepatic lobule (P less than 0.05) was greater in group B than in group A. The number of natural killer (NK) cells was increased in the portal areas (P less than 0.05) of group B compared with group A. These alterations in the lymphocyte and NK cell populations present in the liver in response to IFN-alpha therapy presumably reflect an IFN-alpha-induced enhancement of the immune response to virus-infected cells.

Modulation of lymphoid cell sensitivity to interferon by thyroid hormones

The possibility of increasing the responsiveness of lymphoid cells to Interferon (IFN) was investigated by studying the effect of the in vitro preincubation of spleen cells from young mice with thyroid hormone prior to the administration of IFN on their Natural Killer (NK) activity. Both physiological concentrations of T4 or T3 are able to significantly increase the boosting action of IFN on NK cells. The increase in IFN-responsiveness is observable at various IFN concentrations and the peak level of IFN-induced NK activity is reached with less than a half-optimal IFN concentration after T4 pretreatment. The effect of T4 on the IFN-sensitivity of NK cells requires a very short time, being already fully expressed after only 30 min, with minor increments at more prolonged incubation times. These results indicate for the first time the possibility of modulating the in vitro sensitivity to IFN by a hormonal approach.

Lymphokines and cytokines as cancer treatment. Immunotherapy realized

Human proteins with identified effects on host responses to malignant cells have been established as effective therapeutic techniques in cancer. Lymphokines, products of activated cells of the immune system, have pleiotropic biochemical and cellular effects. These include stimulation of immune effector cell proliferation, augmentation of cytotoxicity of immune effector cells for tumor cell targets, enhancement in antigen-recognition potential by monocytes, and modulation of tumor-associated antigen expression on neoplastic cells. Interferons (IFN) and interleukin-2 (IL-2), purified to homogeneity, can induce regression of metastatic malignancy. Recombinant DNA technology has facilitated large-scale production of these and other lymphokines and cytokines. It has also made possible analyses of physical structures of the molecules themselves and has enabled creation of mutated molecules with specific, desired substitutions in their amino acid sequence. Monoclonal antibodies, directed at tumor-associated antigens, can augment antibody-dependent cell-mediated cytotoxicity and can selectively deliver cytotoxic techniques to malignant cells. Molecules that modify the host resistance to malignant disease also have potential to augment effectiveness of other cancer treatment techniques. Lymphokines, cytokines, and monoclonal antibodies, all products of biotechnology, have resulted in fulfillment of the promise of the immune system for inhibition of growth of human malignancy.

New therapeutic strategies in the treatment of murine diseases induced by virus and solid tumors: biology and implications for the potential treatment of human leukemia, AIDS, and solid tumors

Understanding the biology and treatment of various cancers (including leukemia) and immunodeficiency disorders is still an ongoing and experimental process. Animal models have been and continue to be important to this process. This review will focus in on work by ourselves and others that have used murine models assessing the effects in vivo of the Friend virus complex (FVC, composed of a spleen focus forming virus and a murine leukemia helper virus) and solid tumors with metastatic potential in order to evaluate new and innovative therapies. These therapies include radiation, hyperthermia, and newly recognized naturally occurring biomolecules termed cytokines. These cytokines include, but are not limited to, the interferons, the tumor necrosis factors, the interleukins, the hematopoietic colony stimulating factors, lactoferrin and E-type prostaglandins. For example, it has been found that lactoferrin, when administered early enough, prolongs the survival of mice injected, but not yet infected, with the FVC. Of even greater potential usefulness is that mice already infected with the FVC can be completely rescued from death by treatment with split low dosage (150 cGy) total body irradiation. Irradiation treatment was associated with restoration of the T helper to T suppressor cell ratio, natural killer cell activity and marrow proliferative responses to the mitogens PHA and con A which were compromised by the FVC. More recent studies in our laboratory have demonstrated the potential of the interleukins and colony stimulating factors to decrease the metastatic potential of the B16 melanoma and the Lewis Lung Carcinoma cell lines. The cytokines can act in greater than additive fashion and combinations of therapies are possible. This review is meant to increase the awareness of these investigative animal models and the new types of combination therapies that can then be used as the basis for future clinical trials evaluating therapeutic efficacy.

Generation of tumoricidal effector cells with a novel potentiator: N-[4-[(4-fluorophenyl)sulfonyl]phenyl] acetamide (CL 259,763)

An effort was made to investigate the effects of a novel immunopotentiator, N-[4-[(4-fluorophenyl)sulfonyl]phenyl]acetamide (CL 259,763), on the generation of tumoricidal effector cells. It was demonstrated that a single oral dose of the compound (100-600 mg/kg) induced in mice a population of peritoneal macrophages capable of inhibiting the growth of tumor cells. These activated macrophages released proteases which seemed responsible for the tumor cell inhibition because the cytostatic activity was abrogated in the presence of protease inhibitors TLCK and aprotinin. On the other hand, addition of catalase and exogenous arginine to the culture failed to alter the effect, suggesting that hydrogen peroxide and arginase did not participate in this system. Although induction of cytolytic T-lymphocytes (CTL) reactive with syngeneic tumor cells was achievable in mice previously sensitized to the tumor, treatment with CL 259,763 rendered these animals even more responsive to tumor antigens resulting in a significant enhancement of tumor cell destruction. The compound was effective in augmenting the CTL response over a rather broad dose range of 25-200 mg/kg. In contrast to these stimulatory effects, the cytolytic activity of natural killer cells seemed not to be affected by the compound. Taken together, CL 259,763 is an orally active immunomodulator capable of inducing tumor inhibitory macrophages and potentiating CTL responses to syngeneic tumor cells and, therefore, may prove clinically useful in the treatment of neoplastic diseases.

Induced proteins in human peripheral mononuclear cells over a range of clinically tolerable doses of interferon-gamma

This study assessed biologic response modification at three different dose levels (0.15, 1.5, and 15 mg/m2) of interferon-gamma (IFN-gamma) administered by intravenous bolus three times weekly. A final total of 24 patients were evaluable. Dose-limiting toxicity occurred at the highest dose level (15 mg/m2) and included fatigue, leukopenia, and hepatotoxicity. Evaluation of biologic response modification included assessment of 2',5'-oligoadenylate (2-5A) synthetase activity in peripheral mononuclear cells, measurement of serum beta 2-microglobulin and expression of beta 2-microglobulin on monocytes, measurement of monocyte HLA Class II expression (HLA-DR, HLA-DQ), and measurement of hydrogen peroxide generation by monocytes 24 h after the first and fourth IFN-gamma treatments. Significant increases (p less than 0.05) from baseline were seen at 24 h with all parameters except H2O2 generation. Except for enhancement of HLA-DR, even the lowest dose (0.15 mg/m2) augmented synthesis of 2-5A synthetase and HLA proteins. A dose-response effect was noted for changes in serum and monocyte beta 2-microglobulin levels but not for 2-5A synthetase levels or HLA Class II antigen expression on monocytes. After 4 doses administered over 9 days, most parameters remained increased when compared to pretreatment, but were not further enhanced when compared with levels attained after the first dose. The results of this study document the efficacy of IFN-gamma for biological activation over a wide dose range and are consistent with the postulate that immunoregulatory effects of biological therapeutics can be obtained in man at doses substantially less than those that are maximally tolerated. Further documentation of biologic response parameters by IFN-gamma at low doses will be necessary to determine the importance of biologic activation in relation to antitumor activity.

In vivo effects of combination treatment with recombinant interferon-gamma and -alpha in metastatic melanoma

The toxicity and therapeutic efficacy of the combination of recombinant interferon gamma (rIFN-gamma) and alpha (rIFN-alpha) was investigated in 15 patients with metastatic melanoma. Patients were treated with an escalating dose of rIFN-gamma and a fixed dose of rIFN-alpha administered s.c. 3 times a week. The maximum dose was well tolerated. The median survival time of the patients was 7 months; no clinical remissions were observed. In the majority of cases, expression of HLA class-I and -II antigens on the patients' peripheral blood lymphocytes and monocytes increased markedly during treatment. An increase in HLA-DR expression of peripheral blood T lymphocytes was correlated with a longer survival time. This suggests that activation of T lymphocytes may have a favourable influence on the course of metastatic disease. The in vitro anti-proliferative activity of IFNs on melanoma cell lines isolated from melanoma metastases during treatment of 3 patients was determined. In contrast to the lack of in vivo anti-tumour effect in patients, both rIFN-gamma and rIFN-alpha inhibited DNA synthesis of these melanoma cell lines in vitro, combined IFNs acting synergistically. Anti-proliferative activity observed in vitro occurred at IFN concentrations below the peak serum levels achieved in vivo.

Immunosuppressive effects of recombinant interferon-alpha during long-term treatment of cancer patients

Interferons (IFN) are known to modulate immune responses in an either stimulatory or inhibitory manner. Most of the knowledge about immunomodulatory activities of IFN comes from investigations of IFN effects on cells in vitro. This study examines the influence which long-term treatment with recombinant interferon-alpha 2 exerts on immune functions in cancer patients. Serial in vitro immune function studies of peripheral blood mononuclear cells were done to determine parameters of B-cell and T-cell functions as well as natural killer (NK)-cell activity. The authors detected profound suppression of in vitro immunoglobulin synthesis and lymphocyte proliferation as well as depression of NK-cell activity during IFN treatment. All suppressed immune functions normalized on discontinuation of IFN therapy. The authors conclude from these observations that, apart from their beneficial effects, IFN produce substantial immunosuppression.

Immunological recovery and dose evaluation in IFN-alpha treatment of hairy cell leukemia: analysis of leukocyte differentiation antigens, NK and 2',5'-oligoadenylate synthetase activity

A low-dose interferon (IFN)-alpha regimen for the treatment of hairy cell leukemia (HCL) was evaluated by following changes in leukocyte differentiation antigens (LDA), natural killer cell (NK) and 2',5'-oligoadenylate (2-5A) synthetase activities. Due to hairy cells' (HC) weak expression of several antigens positive for T cells, B cells, NK cells and monocytes, the use of a double marker specific for hairy cells was needed to distinguish the different subpopulations. Analysis of LDA in peripheral blood (PB) showed a total normalization of the T cell and monocyte numbers within 90 days, the number of NK cells normalized in 90 to 180 d, whereas normalization of B cell number was seen only after 180 to 360 d of treatment. Mean pretreatment 2-5A synthetase activity was normal or low, but upon treatment the levels rose immediately to higher than normal values and remained high throughout the study. Pretreatment NK activity was low, but normalized after between 90 to 360 d, except in 2 patients with severe splenomegaly. In vitro incubation of peripheral blood mononuclear cells (PBMNC) with IFN-alpha induced activation of the NK and 2-5A synthetase activity in untreated patients, but with treatment these effects were gradually abolished, indicating an increasing effect of IFN-alpha in vivo with time. These results shows that the different PBMNC subpopulations and important immunological functions normalize with treatment. This normalization is, however, not seen until at least after 1 year of treatment, indicating that the treatment schedule should be longer. As no exhaustion to the effect of IFN was seen, as measured by the 2-5A synthetase activity, a continuing beneficial effect of treatment is anticipated. The increasing effect of IFN-alpha after the first signs of clinical effect suggests that the doses used in the present study were higher than necessary.

The role of interferons in the treatment of malignant neoplasms

Interferons (IFNs) are proteins with a wide range of biological effects. IFNs have antiviral and antiproliferative properties. They modulate both the immune system and the expression of cell phenotype. In the past decade, the IFNs have received intense clinical scrutiny. Alpha IFN is the best studied and displays activity in many neoplastic diseases; it has shown the most promise in the hematological cancers although several solid tumors, including epidemic Kaposi's sarcoma, renal cell carcinoma, and melanoma, respond. No neoplastic disease, however, has been cured by the IFNs. IFN seems to be most active in the setting of minimal residual disease, and clinical studies evaluating its role in the adjuvant setting are under way. Other areas of research include trials combining IFN with cytotoxic drugs or other biological response modifiers, and maintenance IFN to prolong remissions following successful induction therapy.

Whole blood assay for NK activity in splenectomized and non-splenectomized hairy cell leukemia patients during IFN-alpha-2b treatment

Natural killer cell (NK) activity in peripheral blood (PB) was followed longitudinally for up to 2 yr after initiation of low-dose IFN-alpha-2b therapy in nine hairy cell leukemia (HCL) patients. A whole blood NK (WB-NK) assay was employed in order to measure the NK activity per unit blood. The pretreatment WB-NK activity was consistently low, indicating that the patients' total NK activity in PB is decreased. Striking differences in WB-NK activity were observed between splenectomized and non-splenectomized patients, whereas no consistent patterns were found when using the conventional NK assay. Thus the WB-NK activity of splenectomized patients showed an immediate increase after initiation of treatment, while the activity in non-splenectomized patients decreased and remained low during the first 3-6 months. Subsequently, after reduction in spleen size, the WB-NK activity began to increase. In splenectomized patients, a second rise in WB-NK was observed after 3-6 months of therapy, coinciding with the normalisation of the peripheral blood counts. In both groups of patients incubation with IFN in vitro induced a rise in NK activity before start of treatment, which was abrogated promptly after initiation of therapy, indicating a maximal in vivo boosting of the NK cells. These differences observed indicate that the response of splenectomized and non-splenectomized HCL patients to IFN treatment should be evaluated separately.

Interferons affect oxygen metabolism in human neutrophil granulocytes

Human polymorphonuclear neutrophil granulocytes (PMN) were incubated with recombinant interferons (IFNs) and tested for O2 consumption, hydrogen peroxide formation, and chemiluminescence. N-formyl-methionyl-leucyl-phenylalanine (f-MLP, a bacterial peptide analogue) and phorbol myristate acetate (PMA, a protein kinase C activator) were used as PMN stimuli. An increase in O2 consumption after f-MLP-stimulation was seen when PMN had been incubated 2-4 h with either 1000 IU/ml IFN-alpha or 100 IU/ml IFN-gamma, but this increase in O2 consumption was not observed with 1000 IU/ml IFN-beta. Likewise, 100 U/ml IFN-gamma enhanced f-MLP stimulated chemiluminescence, whereas IFN-alpha or IFN-beta (1000 U/ml) had no detectable effects. None of the interferons affected baseline or PMA-stimulated O2 consumption and chemiluminescence, nor did they influence the H2O2-dependent oxidation of intracellular dichlorofluorescein (DCFH) (baseline, f-MLP-stimulated or PMA-stimulated). Our data indicate that some--but not all--aspects of oxygen metabolism in PMN can be affected by IFN, and that there are differences between various subtypes of IFNs regarding their neutrophil priming potential.

IFN-treatment of B16-F1 versus B16-F10: relative impact on non-adaptive and T-cell-mediated immune defense in metastatic spread

Treatment of tumor cells with interferon-gamma (IFN) frequently reduces their susceptibility towards NK cells and results in augmented expression of MHC antigens, which may increase immunogenicity of tumor cells. Depending on the relative strength of these opposing effects, i.e. escape from non-adaptive immune defense versus facilitated activation of T-cell-mediated defense, IFN-treatment may be beneficial or disadvantageous for the tumor-bearing host. This is demonstrated for the variants F1 and F10 of the B16 melanoma, which differ in metastasizing capacity. IFN-treatment of B16-F1 melanoma cells significantly reduced susceptibility towards non-adaptive immune defense, and increased metastasizing potential. On the other hand, H2K antigen expression was augmented by a factor of 50; concomitantly, lysability by CTL was increased, together with the number and expansion rate of cytotoxic T-cell precursors (CTLp) recruited after immunization with IFN-treated B16-F1. The benefit of increased antigenicity and immunogenicity outweighed the disadvantage or reduced susceptibility towards non-adaptive immune defense. B16-F10 cells were less susceptible to NK cells, expression of MHC antigens was found to be stronger and they were more immunogenic than B16-F1 cells. After IFN-treatment, susceptibility to non-adaptive immune defense was further reduced. Expression of MHC antigens as well as antigenicity and immunogenicity were only moderately augmented. As a consequence, the decreased susceptibility to non-adaptive immune defense was dominating in the tumor bearing host and could not be counterbalanced by immunization with IFN-treated B16-F10 cells. We interpret these data to show that a precise knowledge of the relative decrease in susceptibility to non-adaptive immune defense, the relative increase in MHC antigen expression, antigenicity and immunogenicity may allow a more precise prognosis of the influence of IFN on metastatic capacity in the B16 system, and eventually also in a clinical therapeutic regimen.

Correlation of immunomodulatory and therapeutic activities of interferon and interferon inducers in metastatic disease

The mechanism of therapeutic activity of recombinant murine interferon-gamma (rMu IFN-gamma) and the IFN inducer polyinosinic-polycytidylic acid solubilized with poly-L-lysine in carboxy methyl cellulose (pICLC) in treating metastatic disease was investigated by comparing effector cell augmentation with therapeutic activity in mice bearing experimental lung metastases (B16-BL6 melanoma). Effector cell functions in spleen, peripheral blood, and lung (the organ with tumor) were tested after 1 and 3 weeks of rMu IFN-gamma or pICLC administration (intravenous, three times a week). In these studies, natural killer (NK), lymphokine-activated killer (LAK), cytolytic T lymphocytes (CTL) (against specific and nonspecific targets), and macrophage tumoricidal and tumoristatic activities were measured. rM IFN-gamma and pICLC had therapeutic activity and immunomodulatory activity in most assays of immune function examined. Specific CTL activity of pulmonary parenchymal mononuclear cells (PPMC), but not in splenocytes or peripheral blood lymphocytes (PBL), during week 3 and not during week 1, correlated with the therapeutic activity of rMu IFN-gamma and of pICLC. Macrophage tumoricidal activity in PPMC, but not in alveolar macrophages, also correlated with the therapeutic activity of rMu IFN-gamma, but the opposite was true for the therapeutic activity of pICLC. NK activity of PPMC, but not of splenocytes or PBL, during week 1 correlated with the therapeutic activity of pICLC; in contrast, NK activity at any site did not correlate with the therapeutic activity of rMu IFN-gamma. LAK activity at any site did not correlate with the therapeutic activity of either agent.

Modulation of immune functions by long-term treatment with recombinant interferon-alpha 2 in a patient with hairy-cell leukemia

Serial in vitro immune function studies of peripheral blood mononuclear cells (PBMC) were carried out during the long-term treatment with recombinant interferon-alpha 2 (IFN-alpha 2) in a patient with hairy-cell leukemia (HCL). Parameters of B- and T-cell functions as well as NK-cell activity were determined. Treatment with IFN-alpha 2 is associated with temporary and long-term depression of some immune functions, but can also normalize immune responses: in vitro-induced immunoglobulin synthesis, which was normal at diagnosis, was inhibited during the first weeks of IFN therapy but subsequently rose to normal levels. Lymphocyte proliferative responses to mitogens and antigens that were markedly reduced pretherapeutically were further depressed by IFN treatment but, with the exception of pokeweed mitogen (PWM)-induced responses, normalized completely by the 15th to 17th week of treatment. Cocultivation of PBMC with monocytes from normal individuals enhanced depressed lymphocyte proliferative responses. NK-cell activity, which was low at diagnosis, did not rise to the normal range during IFN treatment, but rapidly normalized when IFN therapy was stopped. A discussion is presented on the implications of the alteration of immune functions by treatment with IFN.