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Cytotoxic activity of doxorubicin “loaded” neutrophils against human mammary carcinoma (HTB-19)

Neutrophils were intra-cellularly "loaded" with the chemotherapeutic agent, doxorubicin applying a variety of incubation conditions in order to identify parameters which maximize chemotherapeutic incorporation, while simultaneously preserving optimal viability and chemotactic responsiveness. Doxorubicin "loaded" neutrophils (DLN) were produced in triplicate at different combinations of incubation conditions such as temperature (4 degrees C, 37 degrees C); duration (0, 1, 2 hours); and doxorubicin concentration (20, 40, 60 micrograms/ml). Chemotactic responsiveness of rinsed DLN preparations was subsequently assessed against the neutrophil peptide chemotactic agent, formyl methionyl leucyl phenylalanine (fMLP, 10(-6) M) utilizing a modified 96-well Boyden chemotactic chamber apparatus. Viable, fMLP-responsive DLN preparations were subsequently detected with MTT vitality staining reagent. At sub-physiological incubation temperatures (4 degrees C), profound declines in the viability of DLN preparations were detected when simultaneously incubated with doxorubicin formulated at concentrations greater than 10 micrograms/ml. In contrast, DLN preparations incubated at 37 degrees C displayed diminished viability only when incubated with doxorubicin formulated at a concentration of 60 micrograms/ml. Viable DLN populations were subsequently evaluated to determine their ability to exert in vitro cytotoxic activity against monolayer populations of human mammary carcinoma (HTB-19) propagated in a tissue culture environment. The lethal effect which DLN preparations inflicted towards HTB-19 populations was substantially greater than was observed with an equivalent population of untreated neutrophils. Maximal in vitro cytotoxic activity was detected with DLN preparations produced at 37 degrees C in the presence of doxorubicin formulated at a concentration of 40 micrograms/ml. In contrast, DLN preparations produced at an incubation temperature of 37 degrees C, and a doxorubicin concentration of 20 micrograms/ml displayed relatively lower levels of in vitro cytotoxic activity against HTB-19 monolayer populations. The degree of in vitro cytotoxic activity exerted against HTB-19 monolayer populations by DLN preparations was directly influenced by the duration of the challenge period. Maximal in vitro cytotoxic activity was observed when HTB-19 monolayer populations were challenged with DLN preparations for a period of 96-hours duration at 37 degrees C. Challenge periods of 48-hours duration produced levels of in vitro cytotoxic activity which were substantially lower than those observed for challenge periods of 96-hours duration. Optimal in vitro cytotoxic activity was recognized when DLN preparations were allowed to establish direct contact with HTB-19 monolayer populations at an estimated DLN:HTB-19 cellular ratio of approximately 5:1 (37 degrees C, CO2, 6%). Significantly less in vitro cytotoxic activity was recognized when DLN preparations were only permitted indirect cellular contact with HTB-19 monolayer populations which was achieved through the application of a semi-permeable 3 microM pore membrane partition. In vitro cytotoxic activity of DLN populations was not inhibited by the anti-oxidant agent, dimethyl sulfoxide (DMSO), but was inhibited in the presence of glutathione (GSH), superoxide dismutase (SOD), and vitamin E (alpha-tocopherol). Similarly, in vitro cytotoxic activity of DLN populations was also inhibited in the presence of sodium heparin (serine esterase inhibitor), and dexamethasone (inhibitor of neutrophil activation-degranulation phenomenon). Experimental results observed in these investigations collectively imply that the in vitro cytotoxic activity exerted by DLN preparations against HTB-19 populations is in part attributable to neutrophil-mediated cytotoxic immunity. This innate property of neutrophil populations involves their capacity to generate highly reactive oxygen "free" radical species (O2, HO, H2O2), and synthes

The influence of age on transfer factor treatment of cellular immunodeficiency, chronic fatigue syndrome and/or chronic viral infections

A group of 222 patients suffering from cellular immunodeficiency (CID), frequently combined with chronic fatigue syndrome (CFS) and/or chronic viral infections by Epstein-Barr virus (EBV) and/or cytomegalovirus (CMV), were immunologically investigated and treated with transfer factor (TF). The age range was 17-77 years. In order to elucidate the influence of aging on the course of the disease and on treatment, 3 subgroups were formed: 17-43 years, 44-53 years, and 54-77 years. Six injections of Immodin (commercial preparation of TF by SEVAC, Prague) were given in the course of 8 weeks. When active viral infection was present, IgG injections and vitamins were added. Immunological investigation was performed before the start of therapy, and subsequently according to need, but not later than after 3 months. The percentages of failures to improve clinical status of patients were in the individual subgroups, respectively: 10.6%, 11.5% and 28.9%. The influence of increasing age on the percentage of failures to normalize low numbers of T cells was very evident: 10.6%, 21.2% and 59.6%. In individuals uneffected by therapy, persistent absolute lymphocyte numbers below 1,200 cells were found in 23.1%, 54.5% and 89.3% in the oldest group. Statistical analysis by Pearson's Chi-square test, and the test for linear trend proved that the differences among the individual age groups were significant. Neither sex, nor other factors seemed to influence the results. The results of this pilot study show that age substantially influences the failure rate of CID treatment using TF. In older people, it is easier to improve the clinical condition than CID: this may be related to the diminished number of lymphocytes, however, a placebo effect cannot be totally excluded.

Clinical significance of autologous tumor killing (ATK) activity and its induction therapy in human cancer

The activity of blood lymphocytes to kill autologous freshly isolated tumor cells tested at the time of surgery predicts a favorable clinical course in patients who have primary localized solid tumor and receive curative operation. The strong correlation of autologous tumor killing (ATK) activity with disease-free interval and total survival indicates that ATK activity is a meaningful prognostic indicator and provides evidence for immunological control of tumor growth and metastasis. Although there is no direct evidence that ATK lymphocytes play a critical role in regression of tumor and prevention of tumor regrowth, the lack of ATK activity in patients who relapsed and died may not result from other factors related to their poor performance status, immune functions and tumor characteristics. Clinical trials with ATK induction therapy resulted in an improvement of the clinical outcome in patients who naturally have no such potential. The data indicate that the presence of both natural and induced ATK activity is strongly associated with long-term survival. In addition, adoptive transfer of BRM-induced ATK effector cells resulted in prolongation of survival time even in patients with documented metastatic tumors. Thus, considerable emphasis should be placed on a strategy that induces ATK activity in vivo. Such an approach may provide a new focus for cancer immunotherapy.

Tissue distribution and cellular distribution of liposomes encapsulating muramyltripeptide phosphatidyl ethanolamide: Tissue and cellular distribution of LE-MTPPE

In previous studies it was shown that administration of liposome-encapsulated MTPPE (LE-MTPPE) led to resistance against Klebsiella pneumoniae infection. To get more insight in the cell types that are involved in this by LE-MTPPE induced antibacterial resistance, the tissue distribution of liposomes encapsulating MTPPE and the distribution over the cells in the main target organs were investigated. After intravenous injection of the liposomes in mice a substantial amount was recovered from liver and spleen and a smaller amount from the lung. In the liver 83% of the liposomes was taken up by the macrophages. In the spleen also most liposomes were taken up by macrophages of the red and white pulp as well as by dendrocytes. The liver and spleen were also the organs in which, after intravenous inoculation, K. pneumoniae was trapped. It was observed that cells containing LE-MTPPE often had not taken up bacteria. Most bacteria, about 73%, were found in cells not containing liposomes. The capacity of the liposome-containing cells to take up bacteria did not change with time. This suggests that the by LE-MTPPE immunostimulating effect is due to the production of cytokines by the cells that take up LE-MTPPE. These cytokines might stimulate other cells to the killing of bacteria.

Open Access