Enhancement of natural killer cell activity in mice by treatment with a thymic factor

Summary The administration of a thymic factor, thymostimulin (TP-1), to mice resulted in considerable augmentation of natural killer (NK) cell activity as measured in a short-term assay against ⁵¹Cr-labeled YAC-1 target cells. Conditions suitable for detection of the thymostimulin-induced boosting of NK included multiple daily exposures to TP-1 (50 g/kg), and peak levels of reactivity were observed at 2–4 days after discontinuation of treatment. A strict age-dependency of the effect was also observed, with optimal augmentation of NK-cell activity when TP-1 was administered to mice at 4–6 weeks of age. The effect was not limited to TP-1 treatment but was also observed on administration of another thymic factor (thymosin ₁). The activated cells responsible for the increased natural cell-mediated cytotoxicity appeared to be typical murine NK cells, judging by both functional and antigenic criteria.     

Tumor microenvironments,the immune system and cancer survival

The study of cancer immunology has recently been reinvigorated by the application of new research tools and technologies, as well as by refined bioinformatics methods for interpretation of complex datasets. Recent microarray analyses of lymphomas suggest that the prognosis of cancer patients is related to an interplay between cancer cells and their microenvironment, including the immune response.     

Circulating immune complexes in cervical cancer patients as detected by C1q binding

In a retrospective study in women with cervical cancer, circulating immune complex levels were measured by radioimmunoprecipitation with 125I-C1q. Sera from 46 patients with cervical cancer and 35 normal controls were examined. Significantly higher levels of immune complexes were detected in cancer patients compared with controls. Mean value of binding capacity in patients was 49.8%, and by contrast, in the controls was 27.4% (two-tail test = 0). Increases in tumor mass were associated with high levels of circulating immune complexes. The presence of immune complexes in circulation statistically correlated with disease activity, however, the assay used still had limited value for diagnosis or aiding in therapeutic decisions. Nevertheless, the future holds promise for such uses.     

The immune system as key to cancer treatment: Triggering its activity with microbial agents

Traditional methods such as chemotherapy and radiation therapy offer only limited success in treating cancer. Part of the reason is related to our misunderstanding of what cancer is: it is not the cause but the consequence of a weakened living system. Localized cellular stress, caused by toxins, mutagens or radiation, coupled with a weakened systemic response or inability to support or defend the cells that are under attack, cause these cells to revert to an ancient, unicellular mode of survival, therefore cutting links with the overarching organism and defend themselves from the threat as if they were individual entities. We hypothesize that strengthening the organism, specifically the immune system, is a more promising approach toward a cure for cancer than attempting to exterminate cancer cells. The hypothesis can be tested by experiments that are designed to strengthen the immune system by both traditional means (e.g., ingestion of natural substances known to increase the activity of the immune system, such as fruits, vegetables, and nuts), diminish immune system inhibitors released by cancer cells (e.g., TGF-β), and by the injection of heat-killed or genetically altered pathogenic bacteria to trigger a massive response (fever response) of the immune system into the affected area and compare those results to traditionally used methods.     

Enhancement of innate immune system in monocot rice by transferring the dicotyledonous elongation factor Tu receptor EFR

The elongation factor Tu (EF-Tu) receptor (EFR) in cruciferous plants specifical y recognizes the N-terminal acetylated elf18 region of bacterial EF-Tu and thereby activates plant immunity. It has been...     

Cellular elements of the immune system in the larynx cancer, SEM study

Observations that certain primary tumors (solid ones) are infiltrated by cells which participate in immune responses tend us to examine this problem in spontaneously growing larynx carcinoma (ca. planoepitheliale). Our observations in SEM revealed within but also in surrounding of cancer infiltrations the presence of cellular elements belonging to the immune system like: lymphocytes, monocytes and macrophages. The most numerous of them, lymphocytes, are brought to the surrounding and tumor's territory by very rich vascular network (angiogenesis phenomenon). Bidirectional transmigration of the lymphocytes, observed mainly within the postcapillary venules, takes place through the cytoplasm of endothelial cells. It is most probably that they are lymphocytes of T-type which are involved in a cell mediated mechanisms of the immune response against a tumor. The lymphocytes are responsible also for the presence of monocytes and especially macrophages within a tumor's territory. These facts suggest that the human organism, in certain degree, is able to fight against malignant tissue by similar mechanisms which are involved in the rejection of the graft.     

Enhancement of delayed cutaneous hypersensitivity in untreated cancer patients given a short-term oral treatment with C 1821

Summary C 1821 is a purified glycoprotein extract of Klebsiella pneumoniae serotype 2 with immunomodulating properties in animals (in vivo and in vitro) and in humans (in vitro). The compound is devoid of any apparent toxicity when given orally. The aim of the present work was to evaluate the effects of a short term oral administration of C 1821 on delayed cutaneous hypersensitivity to recall antigens in untreated cancer patients (mostly lymphomas). Consecutive patients were alternately allocated to receive C 1821 or placebo for 14 days. C 1821 restored and significanty (P<0.02) enhanced skin reactions, as shown using the Multitest system.     

PD-1+ immune cell infiltration inversely correlates with survival of operable breast cancer patients

The programmed death-1 (PD-1) molecule is mainly expressed on functionally “exhausted” CD8⁺ T cells, dampening the host antitumor immune response. We evaluated the ratio between effective and regulatory T cells (Tregs) and PD-1 expression as a prognostic factor for operable breast cancer patients. A series of 218 newly diagnosed invasive breast cancer patients who had undergone primary surgery at Ruijin Hospital were identified. The influence of CD8⁺ cytotoxic T lymphocytes, FOXP3⁺ (Treg cell marker), and PD-1⁺ immune cell counts on prognosis was analyzed utilizing immunohistochemistry. Both PD-1⁺ immune cells and FOXP3⁺ Tregs counts were significantly associated with unfavorable prognostic factors. In bivariate, but not multivariate analysis, high tumor infiltrating PD-1⁺ cell counts correlated with significantly shorter patient survival. Our results suggest a prognostic value of the PD-1⁺ immune cell population in such breast cancer patients. Targeting the PD-1 pathway may be a feasible approach to treating patients with breast cancer.     

Prediction of prognosis of patients with lung cancer in combination with the immune score

Purpose: The host’s immune response to malignant tumor is fundamental to tumorigenesis and tumor development. The immune score is currently used to assess prognosis and to guide immunotherapy; however, its association with lung cancer prognosis is not clear.Methods: Clinical features and immune score data of lung cancer patients from The Cancer Genome Atlas were obtained to build a clinical prognosis nomogram. The model’s accuracy was verified by calibration curves.Results: In total, 1005 patients with lung cancer were included. Patients were divided into three groups according to low, medium, and high immune scores. Compared with patients in the low immune score group, the disease-free survival (DFS) of patients in medium and high immune score groups was significantly longer; the hazard ratio (HR) and 95% confidence interval (95% CI) were 0.77 [0.60–0.99] and 0.74 [0.60–0.91], respectively. The overall survival (OS) of patients in the medium and high immune score groups was significantly longer than in the low immune score group; the HR and 95% CI were 0.74 [0.57–0.96] and 0.69 [0.55–0.88], respectively. A clinical prediction model was established to predict the survival prognosis. As verified by calibration curves, the model showed good predictive ability, especially for predicting 3-/5-year DFS and OS.Conclusion: Patients with lung cancer with medium and high immune scores had longer DFS and OS than those in low immune score group. Patient prognosis can be effectively predicted by the clinical prediction model combining clinical features and immune score and was consistent with actual clinical outcomes.     

Enhancement of the citrus immune system provides effective resistance against Alternaria brown spot disease

In addition to basal defense mechanisms, plants are able to develop enhanced defense mechanisms such as induced resistance (IR) upon appropriate stimulation. We recently described the means by which several carboxylic acids protect Arabidopsis and tomato plants against fungi. In this work, we demonstrate the effectiveness of hexanoic acid (Hx) in the control of Alternaria brown spot (ABS) disease via enhancement of the immune system of Fortune mandarin.     

Netrin-1 concentrations in patients with advanced gastric cancer and its relation with treatment

Context: Netrin-1 is found to be elevated and usable as a diagnostic biomarker in many human cancers.

Objectives: We evaluated serum Netrin-1 concentrations in patients with advanced gastric cancer compared with those in a healthy group.

Material and methods: Thirty patients with advanced gastric cancer and thirty healthy people were included in the study. Serum netrin-1 concentrations were measured by quantitative ELISA method in both groups.

Results: The mean serum Netrin-1 concentrations were found to be significantly higher in patients with gastric cancer than in healthy controls. The mean serum Netrin-1 concentrations were found to be significantly higher in patients with gastric cancer before the beginning of chemotherapy when compared after the completion of third cycle.

Discussion and conclusion: Our results indicated that netrin-1 concentrations elevated in advanced gastric cancer compared to a healthy control group and netrin-1 concentrations decreased with chemotherapy.     

Induction of an immune network cascade in cancer patients treated with monoclonal antibodies (ab1)

The antitumor effector functions of unconjugated monoclonal antibodies (mAb) in cancer therapy are not fully understood. Direct cytotoxic mechanisms such as antibody-dependent cellular cytotoxicity, complement-dependent cytolysis and apoptosis have been suggested. Induction of anti-idiotypic (ab₂) and anti-anti-idiotypic (ab₃) antibodies as well as the corresponding T cells (T₂ and T₃) has also been proposed to be of therapeutic significance. In this study induction of an immune network cascade in ten patients with colorectal carcinoma, treated with mAb 17-1A (ab₁) was assessed. After treatment, all ten patients had anti-idiotypic antibodies and anti-anti-idiotypic antibodies with ab₁-like binding specificity while only five of ten patients had T cells corresponding to ab₃ (T₃) as assessed by a proliferation assay (DNA synthesis), and an assay of interferon production (ELISPOT) (Enzyme-linked immuno SPOT) in vitro or by a delayed-type hypersensitivity reaction in vivo. Purified T cells from four of the five patients with a positive T₃ test responded with DNA synthesis after stimulation using human anti-mAb 17-1A anti-idiotypic monoclonal antibodies. These four patients had a clinical response showing a tumor reduction after therapy, while all six patients lacking a proliferative response failed to show tumor regression. Induction of a cell-mediated immune network cascade might accordingly be an important anti-tumor effector function of mAb and should be considered in the future design of mAb-based therapy protocols in cancer patients.     

Induction of an immune network cascade in cancer patients treated with monoclonal antibodies (ab1)

The antitumor effector functions of unconjugated monoclonal antibodies in cancer therapy are complex. Direct cytotoxic mechanisms such as antibody-dependent cellular cytotoxicity, complement-dependent cytolysis and apoptosis have been suggested. Induction of anti-idiotypic (ab₂) and anti-anti-idiotypic (ab₃) antibodies as well as T cell (T₂ and T₃ respectively) responses have also been proposed to be of clinical importance. In this study induction of an immune network cascade in patients with colorectal carcinoma, treated with mAb 17-1A (ab₁) was assessed. All patients developed anti-idiotypic antibodies (ab₂) of the IgG class after treatment with ab₁ and four of nine patients showed induction of mouse Ig reactive T cells [a proliferative response to F(ab)₂ fragments of ab₁]. Patients with such a T cell response developed anti-anti-idiotypic antibodies (ab₃), while those lacking the T cell reactivity failed to mount an ab₃ response. Three of four patients with a T cell response achieved a tumor response to mAb therapy. Thus, all responding patients belonged to the group of individuals developing ab₃. Induction of mAb(ab₁)-reactive T cells as well as an immune network cascade might be important antitumor effector functions of mAb and should be considered in the future design of mAb-based therapy protocols in cancer patients.     

The prognostic significance of immune changes in patients with renal cancer,melanoma and colorectal cancer,treated with interferon α2b

 In the present study we evaluated the response rate and the immunorestorative properties of interferon α2b (IFnα2b) administered to patients with advanced renal cell carcinoma (RCC), melanoma (MEL) or colorectal cancer (CC). We studied the immune status and correlated it with clinical responses. Thirty-five patients with advanced RCC, and 14 with MEL were treated with recombinant INFα2b. The dose was increased progressively from 5×10⁶ IU/day in the first week (three times every week) to 10×10⁶ IU/day in the second week and thereafter to 15×10⁶ IU/day subcutaneously. In patients with CC INFα2b was given at 5×10⁶ IU/day every other day (three times every week); these patients also received (together with INF) leucovorin 200 mg m^–2 day^–1 in a 1-h i. v. infusion every week, and mid-infusion 400 mg/m² 5-FU was administered as an intravenous bolus every week. The response rate was as follows: for RCC, 6 patients achieved partial response (PR), 10 stable disease (SD), and 21 progressed (PD); for MEL, 5 patients achieved PR and 9 PD; for CC, 6 achieved PR, 5 SD, and 9 PD. In all patients blood was withdrawn prior to INFα2b treatment and then monthly. T lymphocytes, after isolation from peripheral blood, were tested for proliferation in the autologous mixed-lymphocyte reaction and allogeneic mixed-lymphocyte reaction, interleukin-2 (IL-2) production, expression of IL-2 receptors during the allogeneic-mixed-lymphocyte reaction, and the production of IL-1 by peripheral blood monocytes. Striking increases were demonstrated in all parameters 2 months after treatment with INFα2b. In comparison to normal controls, all patients with the malignant neoplasms presented decreased (>45%) mean values of the immunological parameters under investigation (P 0.0001). Responders (patients with RCC, MEL, and PR) presented lower mean values of all the parameters studied than did non-responders (P 0.0001). Patients with CC presented the lowest mean values of the parameters than did the other patients (RCC, MEL) (P 0.0001). After therapy with INFα2b, patients with RCC experiencing PR showed a mean increase of more than 30% (P 0.0001). Patients with SD showed a mean increase of about 20% (P 0.0001), and those with PD showed a 6% increase in the immunological parameters under investigation. Patients with MEL experiencing PR showed a mean increase of more than 30% and patients with PD a decrease of more than 10% (P 0.0001). All patients, regardless of the clinical response, achieved an increase of more than 60% (P 0.0001). Administration of IFNα2b resulted in a marked potentiation of a deficient cellular immune response in vitro in those patients with RCC and MEL who responded to the treatment. On the other hand, non-responders demonstrated a decrease in the examined parameters and, in some, deterioration of the already depressed immunological functions was observed. This observation can have prognostic significance regarding clinical response of INF. In contrast, our findings show that the immune stimulation associated with INFα treatment in all our CC patients did not predict an improved clinical outcome. There are several theoretical explanations for this discrepancy. Received: 30 November 1996 / Accepted: 25 June 1996