Inhibition of natural killer activity in emotional stress and elimination of this phenomenon by interferon inducer

The authors provide the data on the effect of emotional painful stress (EPS) of varying duration on the activity of natural killers (NK) of August rats' spleen 1 to 9 days after exposure to stress is discontinued. The activity of NK was tested against target cells K 562 labeled with 51Cr in a 14-hour test. The effect of stress was found to depend on the duration of the stressor reaction. 1 1/2- and 3-hour stress activated NK, while prolonged 6-hour stress suppressed the activity of natural killers within the first 2 days, followed by the recovery by day 7-9 of the activity of lymphocytes having natural cytotoxicity. Tiloron, a synthetic inducer of endogenous interferon, corrected the post-stressor depression of NK activity.     

Interleukin-2 restoration of the activity of natural killers during stress

Interleukin 2 used in vitro and in vivo induces effectively the recovery of cytotoxic activity of natural killers and lectin-dependent cellular cytotoxicity effectors in stress-immobilized CBA mice. This lymphokin can be used for correction of stressor depression in the cells of the natural anti-tumor resistance system.     

The natural killer and fungicidal activity of the peripheral blood mononuclear cells in candidiasis

The activity of natural killers and the capacity of peripheral blood mononuclears for the extracellular killing of Candida cells in patients with different forms of candidiasis has been determined in the radiometric test with the use of targets labeled with 3H-uridine RNAase and in the fungicidal test. On the basis of the data thus obtained the conclusion has been made that in candidiasis changes in the activity of natural killers and fungicidal capacity depend on the severity of the disease and the stage of the process. Linear correlation between the activity of natural killers and fungicidal capacity in candidiasis patients at the stage of exacerbation and in healthy persons is absent.     

The effect of electromagnetic radiation with extremely high frequency and low intensity on cytotoxic activity of human natural killer cells]

EHF electromagnetic radiation under short-time action suppresses the cytotoxical activity of the natural killer cells from granulocyte fraction and peripheral blood of healthy volunteers; the observed effect is non-linear. Under the long-time irradiation of the natural killer cells from the mononuclear fraction of blood, the suppressing effect gets a practically linear character after the 20-30 minutes action. Under the long-time irradiation of peripheral blood the insignificant stimulation of natural killers was observed. It is assumed that the radiation applied can suppress the cytotoxic activity of the natural killers, breaking the normal metabolic pathway of phosphatidylinositphosphate.     

Electrokinetic and functional characteristics of natural killers in mice

Using adsorption methods and elimination of Thy-1+ lymphocytes, the null cell fraction was obtained. The electrophoretic mobilities of unfractionated splenocytes and different fractions of lymphoid cells and null fractions (to which the natural killers belong) were measured with "Parmoquant-2" device. Simultaneously, the natural killer activity of unfractionated splenocytes and null cell fractions was examined.     

Immune system of the blowworm Calliphora vicina (diptera, calliphoridae) as a source of medicines

Study of mechanisms of cellular and humoral immunity of larvae of the blowworm Calliphora vicina has revealed three groups of pharmacologically active substances perspective for use in medicine--alloferons, allostatins, and antimicrobial peptides. Alloferons--the family of peptides of C. vicina stimulating selectively the cytotoxic activity of natural killers of the evolutionary ancient group of immunocompetent cells playing the key role in the system of mammalian antiviral and antitumor immunity. Alloferons are used in medicine for treatment of herpes-viral infections and viral hepatitis B. Allostatins-synthetic peptides combining structural characteristics of alloferons and some mammalian immunologically active proteins. Allostatins, like alloferons, produce stimulating effects on cytotoxic activity of natural killers and interferon production, but differ from them by pronounced adjuvant properties--the ability to enhance immune recognition of alien antigens. At present, allostatins are used to increase resistance of skin and mucosae to viral infections; in future, they might also find use in immunotherapy of cancer and other diseases. Another protein and peptide group perspective for use in medicine serve as antimicrobial peptides in immune response of larvae C. vicina. The study of the agent containing defensins, cecropins, diptericins, and praline-enriched C. vicina peptides shows the drugs of this type to be of great interest as the tool for treatment and prevention of infections caused by antibiotic-resistant bacteria.     

Increase in NK-activity using superlow doses of the immunomodulator cycloferon

A possibility of rising the antitumor activity of natural killers using various doses of the immunomodulator cycloferon was evaluated. A direct correlation has been revealed between the killer activity and the cycloferon dose. However, on a decrease in cycloferon concentrations by several orders, as compared with commonly accepted doses, this correlation changed for inverse. A possible mechanism of this effect is discussed in addition to practical significance of the obtained results.     

Dynamics of the activity of the normal mouse spleen killers after partial splenectomy

The activity of natural killers from the mouse spleen was determined by 51Cr clearance from labeled target cells (YAC-1) at different times after resection of the two-thirds of the spleen. In the early periods after operation, there was a decrease in the natural cytotoxic activity of splenocytes followed by a relatively rapid rise for 8 days until the maximum exceeding the cytotoxicity of intact spleen cells was reached. However, the total lytic potential of the regenerating spleen did not return to normal during 28 days.     

Killer-yeast strains with a broad spectrum of action: a search among collection strains and preliminary classification

Killer strains were looked for among certain yeast species belonging to five spore-forming genera (Hansenula, Pichia, Kluyveromyces, Williopsis and Zygowilliopsis) and one imperfect genus (Candida). 171 killers were found among 272 strains, and many of them had a high activity and a broad action spectrum. These as well as S. cerevisiae K1 and K2 killers (173 killers all in ail) were classified according to differences in their activity and the spectra of action on susceptible strains. Thirty-four groups belonging to 13 classes were isolated.     

Effects of the removal of olfactory bulbs on the appearance and then on the latency of the "mouse-killing reaction" in the rat of the Wistar SM strain

The 20% of male 5-6 month-old Wistar rats SM prove to be natural killers. A four-month long insulation of "surely non-killer" rats has not allowed to notice a mouse-killing behaviour in any animal. The total bilateral removal of olfactory bulbs in "non-killer rats" causes a "mouse-killing behaviour" in all the animal 24 hours after the operation, but with a latency of response that has proved different in the various rats. Precisely, while 24 hours and 15 days after the bulb operation the rats can be distinguished into "rapid killers" and "slow killers", after 30 days all the animals become "rapid killers" with a remarkably shortened period of mouse-killing latency (1 - 60 seconds).     

Activity of human natural killer cells against target cells possessing different sensitivity to interferon]

The cytotoxic activity of peripheral blood natural killers (NK) against target cells (TC) J-96 and L-929 with high sensitivity to interferon (IFN) action, J-41 and MCB resistant to IFN action and line K-562 labelled by H3-uridine was studied in 14 hrs cytotoxic test. It has been shown that human TC J-96 didn't differ from the J-41 in their sensitivity to NK cytotoxicity and they are strongly resistant to NK than TC K-562. The murine TC L-929 as the human TC didn't differ from the MCB in their sensitivity to NK lysis and had also the same sensitivity to NK as the K-562 cells.     

Action of T-activin on human natural killer activity in vitro

The activity of natural killers (NK) from human peripheral blood was determined by 3H-uridine test using target cells K-562. T-activin effect on the activity of human NK in vitro depended on two parameters: the preparation dose and effector/target cells ratio. The inhibitory effect of T-activin was observed with high doses and increased E/T ratio, while the activating effect was noted with low doses and reduced E/T ratio. This can be attributed to the heterogeneity of NK population, different functional role of high and low doses of thymic factors and the development of NK as T-cell precursors.     

Influence of Enterobacter toxin on the cellular immunity

Study of dynamics of formation of spontaneous and mitogen (phytohemagglutinin - PHA, concanavalin A - ConA)-activated blast lymphocytes showed increase of number of transforming T-lymphocytes under the influence of Enterobacter cloacae thermolabile enterotoxin. Itwas noted that PHA mainly stimulated mitosis of T-cell population, ConA - of natural killers, whereas enterotoxin stimulated mitotic activity of both cell types.     

N-acetylcysteine reduces susceptibility of transformed and embryonic cells to lytic activity of natural killer cells

Changes in the sensitivity of several transformed and embryonic cells to the lytic activity of natural killers (NK) due to N-acetylcysteine (NAC) has been studied. We found that epidermoid carcinoma A431 cells and murine hepatoma MH22a cells, as well as the transformed mouse fibroblasts 3T3-SV40 treated with 10 mM NAC that we investigated previously normalized their phenotype to the various extent. Like normal cells these cells exposed to NAC are not recognized and destroyed by NK. Murine embryonic fibroblasts (MEFs) similar to transformed cells were destroyed by NK. MEFs treated with 10 mM NAC lost their susceptibility to NK, as did transformed cells. The loss of cell sensitivity to NK cytolytic activity was accompanied by the reorganization of the actin cytoskeleton and generation of well-pronounced stress-fibers.     

Flow laser cytometry for evaluation of the human immune system

Some flow laser cytometry (FLC) techniques intended for studies of the immune system cells are reviewed. A widespread analytical method is the phenotyping of lymphocytes by the markers they express. The use of FLC permits the evaluation of practically all functional parameters of immunocompetent cells. Thus, to analyze their ingestive and microbicidal activity fluorochrome-labeled microorganisms are used. The apploication of indicator dyes makes it possible to evaluate calcium mobilization and formation of active forms of oxygen. FLC is used for the identification of cytokines inside the cell and in the medium. The authors propose tests for the analysis of the proliferative activity of lymphocytes, the cytotoxicity of natural killers, the evaluation of apoptosis and protein processing with monocytes/macrophages.     

Immunological and morphological properties of fibroblasts transformed in vitro. II. The change in the susceptibility of FC3H3 cells to lymphocytes--natural killers and macrophages during their selection for malignancy

The previous report contained the information on obtaining in vitro continuous cell lines of embryonic fibroblasts of mice of 4 genotypes, including C3H. In this paper, data on the degree of lysis of some derivatives of FC3H3 cells by natural killers and macrophages are given. It was shown that normal cells were not lysed by these effectors unlike cells which overcame Hayflick's limit and got minimum malignancy in vitro. However, it was established that the in vivo selection of cells for high tumorigenicity resulted in the formation of tumor cells resistant to lymphocytes--natural killers and macrophages.     

Delayed hypersensitivity and nonspecific cellular immunity. The cytotoxic activity of macrophages, natural and antibody-dependent killer cells

The experiment on (BALB/cXC57BL)F1 mice, showing a high level of delayed hypersensitivity (DH) when sensitized with BCG vaccine and Staphylococcus aureus strain B-243, has demonstrated the influence of such sensitization and DH reaction induced by the injection of a specific antigen (old tuberculin or staphylococcal phagolysate) into the sensitized animals on the cytotoxicity of macrophages, natural killers (NK) and antibody-dependent killers (ADK). Sensitization with BCG vaccine alone results in an insignificant rise in the activity of these effector cells, and sensitization with S. aureus produces no changes at all. The pronounced activation of the cytotoxicity of macrophages, NK and, to a lesser extent, ADK has been observed in DH reaction induced by the injection of a specific antigen into the sensitized mice. In the course of DH reaction a rise in the activity of NK and ADK not only against tumor target cells, but also against microbial ones (Candida albicans and S. aureus) has been found to occur.     

Idiotype-specific inactivation by xenogeneic antisera of T killers but not of T-MIF producers immune to H-2 complex antigens

Following appropriate absorption rabbit serum to CBA anti-C57BL/6 lymph node cells (rabbit ISS) and rat serum to enriched CBA anti-C57BL/6 T killers (rat ISS) selectively inhibited the activity of K-anti-b T killers but did not affect T killers of other specificities (K-anti-d, d-anti-b). Rabbit ISS did not suppress the capacity of CBA anti-C57BL/6 (K-anti-b) T cells to produce MIF. Under the same conditions, anti-Thy-1.2 serum inactivated killers and K-anti-b MIF-producers. The findings indicate that the killers and MIF-producers immune to the antigens of H-2 complex constitute different subpopulations of T cells, which appear to carry nonidentical sets of idiotypes.     

Relationship between the number of erythrocytes with micronuclei and immunologic status in humans

26 persons, having high level of erythrocytes with micronuclei were distinguished among clinically healthy people. While examining their health changes were registered in the systolic and pulse pressures, number of T-suppressors and T-helpers, natural killers, level of immunoglobulins and immune complexes, phagocytosis activity and peroxidases reaction of the leukocytes. Increase in the level of the cytogenetic aberrative lymphocytes was observed in all the cases. DNA-reparative synthesis was reduced only in 5 persons.