The direction of the conditioned natural killer cell response can be re-directed with indomethacin and/or handling

Cyclophosphamide has Long-Term Effects on Proliferation in Olfactory Epithelia

Chemotherapy patients often experience chemosensory changes during and after drug therapy. The chemotherapy drug, cyclophosphamide (CYP), has known cytotoxic effects on sensory and proliferating cells of the taste system. Like the taste system, cells in the olfactory epithelia undergo continuous renewal. Therefore, we asked if a single injection of 75 mg/kg CYP would affect cell proliferation in the anterior dorsomedial region of the main olfactory epithelium (MOE) and the vomeronasal organ (VNO) from 0 to 125 days after injection. Both epithelia showed a decrease in Ki67-labeled cells compared to controls at day 1 and no Ki67+ cells at day 2 postinjection. In the sensory layer of the MOE, cell proliferation began to recover 4 days after CYP injection and by 6 days, the rate of proliferation was significantly greater than controls. Ki67+ cells peaked 30 days postinjection, then declined to control levels at day 45. Similar temporal sequences of initial CYP-induced suppression of cell proliferation followed by elevated rates peaking 30-45 days postinjection were seen in the sustentacular layer of the MOE and all 3 areas (sensory, sustentacular, marginal) of the VNO. CYP affected proliferation in the sensory layer of the MOE more than the sustentacular layer and all 3 areas of the VNO. These findings suggest that chemotherapy involving CYP is capable of affecting cell renewal of the olfactory system and likely contributes to clinical loss of function during and after chemotherapy.

Breast cancer patients have improved immune and neuroendocrine functions following massage therapy

OBJECTIVES

Women with breast cancer are at risk for elevated depression, anxiety, and decreased natural killer (NK) cell number. Stress has been linked to increased tumor development by decreasing NK cell activity. The objectives of this study included examining massage therapy for women with breast cancer for (1) improving mood and biological measures associated with mood enhancement (serotonin, dopamine), (2) reducing stress and stress hormone levels, and (3) boosting immune measures.

METHODS

Thirty-four women (M age=53) diagnosed with Stage 1 or 2 breast cancer were randomly assigned postsurgery to a massage therapy group (to receive 30-min massages three times per week for 5 weeks) or a control group. The massage consisted of stroking, squeezing, and stretching techniques to the head, arms, legs/feet, and back. On the first and last day of the study, the women were assessed on (1) immediate effects measures of anxiety, depressed mood, and vigor and (2) longer term effects on depression, anxiety and hostility, functioning, body image, and avoidant versus intrusive coping style, in addition to urinary catecholamines (norepinephrine, epinephrine, and dopamine) and serotonin levels. A subset of 27 women (n=15 massage) had blood drawn to assay immune measures.

RESULTS

The immediate massage therapy effects included reduced anxiety, depressed mood, and anger. The longer term massage effects included reduced depression and hostility and increased urinary dopamine, serotonin values, NK cell number, and lymphocytes.

CONCLUSIONS

Women with Stage 1 and 2 breast cancer may benefit from thrice-weekly massage therapy for reducing depressed mood, anxiety, and anger and for enhancing dopamine, serotonin, and NK cell number and lymphocytes.

NK cell and CTL activities can be raised via conditioning of the CNS with unrelated unconditioned stimuli

Poly I:C, an inducer of interferon alpha and beta, and arecoline, a cholinergic muscarinic agonist, were used as unconditioned stimuli in conjunction with camphor odor to condition the augmentation of natural killer (NK) cell and cytotoxic T lymphocyte (CTL) activities. This observation suggested that two unrelated unconditioned stimuli might be used to associate the signals, and induce mediators at recall that can raise natural killer cell activity. In animals stimulated with an alloantigen to induce CTL, we observed that either poly I:C or arecoline conditioned association, and recall with the same CS raised CTL activity. It appears that conditioning with different substrates can raise either native (NK cell activity) or acquired (CTL activity) immunity. The studies suggest that communication between the CNS and NK cells or CTL appear to take place through a common pathway(s).

Psychoneuroendocrine immunology: site of recognition, learning and memory in the immune system and the brain

How the interaction between the brain and immune system takes place has not been clearly defined. Because multiple changes are occurring simultaneously in all organ systems (e.g., cardiovascular, gastrointestinal, reproductive, renal, respiratory, immune, CNS), how many single systems interacts with the brain becomes extraordinarily difficult to understand. The problem boils down to developing an approach that not only allows one to study the whole organism and define the mediators of the interacting systems, but also permit one to establish the connection and physiologic relevance of the responses that are being evaluated. Conditioning, a phenomenon made popular by the work of Pavlov (1906, 1927), may provide insight into the pathways of communication between the brain and possibly any organ system of the body. Conditioning allows one to separate the afferent from the efferent circuits. That is, signals from the immune system to the CNS (IS-->CNS) can be effectively separated from signals from the CNS to immune system (CNS-->IS). This permits one to study each pathway individually. Simple, single association trial models to condition fever, natural killer (NK) cell and cytotoxic lymphocyte (CTL) activities have been developed to evaluate the pathways. Single trial learning is not new. Pavlov has observed that "The electric buzzer set going before administration of food established a conditioned alimentary reflex after only a single combination," whereas the reverse order of presentation failed to condition the animal (Pavlov 1927 p. 27). Thus, conditioning can be used to train the brain to activate the immune system and other organ systems participating in the response. During the course of the conditioned response, presumably the CNS via the hypothalamus integrates in a cohesive orderly fashion all input and output signals and coordinates the responses made by the brain to the organ systems. The odor of camphor, the conditioned stimulus (CS) can be associated with the response produced by an unconditioned stimulus (US). The unconditioned stimuli used are poly I:C to raise fever and nonimmunospecific NK cell activity or alloantigens to raise immunospecific CTL activity. The unconditioned stimulus serves only as a means to activate the immune system and unbalance the homeostasis so that a transient but new bidirectional communication loop can be established between the immune system and the CNS (IS<-->CNS). The expression of the conditioned response (i.e., elevation of fever, NK cell, or CTL activity) induced with the CS (odor stimulus) is an outcome of neural activity (CNS-->IS). This infers that during conditioning, the signals generated by the CS and US imprints a neural pathway located within the central nervous system and leaves behind a CS/US memory of the association. The immune activity (NK cell or CTL activity) which is modulated indicate that the memory pathway was activated in the brain of the animal expressing the conditioned response. The immune cells that are modulated can be considered to be casual bystander cells. These cells however must be in the proper (ready) state of activation to receive salient signals from the brain. Along with changes in the indicator cell population, other complex physiological processes are altered by the brain via sympathetic and neuroendocrine pathways to raise the fever response. These observations suggest that the physiological changes which are being evaluated such as fever, NK cell or CTL activities or perhaps blood pressure, heart rate, fat metabolism, oxygen consumption serve only as indicators (readouts), and infer that the CNS has made a coordinated reply in response to the CS signal.

Lipopolysaccharide and IL-1 alpha activate CNS pathways as measured by NK cell activity

The effect of lipopolysaccharide (LPS) on murine unstimulated and prestimulated natural killer (NK) cells and its ability to serve as an unconditioned stimulus was investigated. LPS injection induced a statistically significant increase in NK cell activity when compared with saline-treated control groups. To demonstrate the existence of communication between the peripheral immune system and the central nervous system (CNS), we used a single-trial conditioning paradigm in which camphor served as the conditioned stimulus (CS) and LPS as the unconditioned stimulus (US). Once a CS/US association is made, exposure of animals to the CS alone results in the conditioned response (i.e., increase in NK cell activity). Using 50 micrograms of LPS as the US produced a low but significant increase in NK cell activity when compared to control groups. However, 10 micrograms of LPS did not show a significant increase in NK cell activity. We also observed that interleukin-1 alpha (IL-1 alpha) injected intracisternally can serve as a US to condition a central neuroendocrine pathway. Because the dose of IL-1 alpha employed was too small to raise NK cell activity in the spleen, the NK cells themselves were formally not subjected to conditioning. These observations suggest that LPS and IL-1 alpha conditions the brain and that NK cell activity can be used as an indicator system to detect neuroendocrine signals arising from the activated pathway(s).

The use of conditioning to probe for CNS pathways that regulate fever and NK cell activity

Immune and central nervous system (CNS) interactions are complicated because afferent signals from the immune system to the CNS in response to antigens or infections may elicit an immediate efferent response to the immune system. This communication loop is required for the homeostatic regulation of the immune system. Conditioning can be used as a tool to take the communication loop apart. In conditioned animals, the conditioned stimulus can be employed later to trigger the site of the association memory located within CNS, and set off the efferent pathway. Conditioning therefore allows one to isolate and identify the potential circuits in the brain that becomes conditioned. We have conditioned a pathway in the brain which can be used to modulate core body temperature (Tc) and natural killer (NK) cell activity. The Tc and NK cell activity are used as readouts to detect the expression of the conditioned response which is taking place in the brain. Since various cytokines (IFN, IL-1 etc) that are produced by antigenic stimulation invariably raise fever, it appears that the immune system could signal the CNS with nonspecific cytokines that activate the hypothalamic-pituitary pathway to modulate core body temperature. These observations infer that the thermoregulatory pathway in the brain becomes conditioned and points to a common pathway of communication in which interferon-beta, prostaglandin E2, CRH and ACTH appear to play a role in modulating both Tc and NK cell activity.

Role of arcuate nucleus of the hypothalamus in the acquisition of association memory between the CS and US

A single trial association protocol was used to demonstrate a conditioned increase in natural killer (NK) cell activity. The signals used were odor of camphor as the conditioned stimulus (CS) and polyinosinic-polycytidylic acid (poly I:C) as the unconditioned stimulus (US). This model has been used to dissect the underlying mechanisms of interaction between the central nervous system (CNS) and the immune system (IS) and vice versa. Here, we demonstrate the potential role played by the arcuate nucleus of the hypothalamus in the acquisition of association memory between the CS and the US. Chemical destruction of the arcuate nucleus with monosodium glutamate (MSG) was used for this purpose. Mice with arcuate nucleus lesion prior to the association protocol did not demonstrate a conditioned increase in NK cell activity. However, the lesion has no effect if produced prior to exposure to the CS at recall. These studies demonstrate the significant role played by the hypothalamus (arcuate nucleus) in a conditioned response.

Octreotide does not alter endotoxin lethality in mice or endotoxin-induced suppression of human leukocyte migration

Octreotide, a somatostatin analog, was evaluated for its effects on long-term survival in a mouse model of endotoxemia and for its effects on endotoxin-induced suppression of human leukocyte migration. Swiss Webster mice were simultaneously rendered endotoxemic with a single intraperitoneal injection of 800 micrograms E. coli Lipopolysaccharide (LPS) and treated with one of four doses of subcutaneous (s.c.) octreotide (1.0 mg/kg in 0.4 ml saline, 0.1 mg/kg in 0.4 ml saline, 0.1 mg/kg in 0.04 ml saline, or 0.001 mg/kg in 0.04 ml saline) or saline alone (fluid-resuscitated control group: 0.4 ml saline s.c.; or non-fluid-resuscitated control group: 0.04 ml saline s.c.). Octreotide was continued with or without supplemental s.c. fluid resuscitation (0.4 ml saline) at eight hour intervals for either twenty-four or forty hours. There was no statistical significance to differences in long-term survival between comparable groups of octreotide treated vs saline treated animals during the entire fourteen day period of observation. Fluid resuscitation during the first forty hours following endotoxemia induction delayed death, but did not significantly improve long-term survival. In vitro work was conducted to determine the effect of octreotide on endotoxin-induced suppression of human leukocyte migration. Octreotide at concentrations ranging from 3.05 x 10(-5) Molar to 3.05 x 10(-11) Molar had no significant effect on leukocyte migration. In this study octreotide treatment failed to improve long-term survival in mice with endotoxemia and did not alter endotoxin-induced suppression of leukocyte migration.