Splenic NK Cell Activity Research Articles

Condensed Fuzheng extract increases immune function in mice with cyclophosphamide-induced immunosuppression.

Our general purpose was to examine the effect of condensed Fuzheng extract (CFE) on the alleviation of immunosuppression. A mouse model of immunosuppression was established by intraperitoneal injection of CTX. A healthy control group received no CTX and no CFE; different intragastric doses of CFE were administered to three groups of mice for 28 days (4500, 2250, or 1125 mg/kg/day); a negative control received CTX alone, and a positive control received CTX and levamisole hydrochloride. We evaluated the effects of CFE on the immune system organs, cells, and molecules by comparing the different groups. CFE significantly improved immune system organs (spleen and thymus indices and histology), stimulated immune cell activities (number of white blood cells and lymphocytes, phagocytosis of mononuclear phagocytes, proliferation of splenic lymphocytes, antibody formation, and NK cell activity), and increased the levels of immunoglobulins (IgA, IgG, and IgM) and cytokines (IL-2 and IFN-γ). Thus CFE effectively alleviated CTX-mediated immunosuppression and oxidative stress and enhanced the immunological functions of mice.

The immune-enhancing effects of a mixture of Astragalus membranaceus (Fisch.) Bunge, Angelica gigas Nakai, and Trichosanthes Kirilowii (Maxim.) or its active constituent nodakenin

Ethnopharmacological relevanceA mixture (SH003) of Astragalus membranaceus (Fisch.) Bunge, Angelica gigas Nakai, and Trichosanthes Kirilowii (Maxim.) has beneficial effects against several carcinomas. There have been few reports on an immune-enhancing activity of SH003 and its active constituent nodakenin. Aim of the studyThis study aimed at identifying the immune-enhancing effect of SH003 and nodakenin. Materials and methodsThe immune-enhancing effect was evaluated using RAW264.7 macrophages, mouse primary splenocytes, and a cyclophosphamide (CP)-induced immunosuppression murine model. ResultsThe results show that SH003 or nodakenin stimulated the production levels of granulocyte colony-stimulating factor, IL-12, IL-2, IL-6, TNF-α, and nitric oxide (NO) and the expression levels of iNOS in RAW264.7 macrophages. SH003 or nodakenin also enhanced NF-κB p65 activation in RAW264.7 macrophages. SH003 or nodakenin stimulated the production levels of IFN-γ, IL-12, IL-2, TNF-α, and NO and the expression levels of iNOS in splenocytes. SH003 or nodakenin increased the splenic lymphocyte proliferation and splenic NK cell activity. In addition, SH003 or nodakenin increased the levels of IFN-γ, IL-12, IL-2, IL-6, and TNF-α in the serum and spleen of CP-treated mice, alleviating CP-induced immunosuppression. ConclusionTaken together, the results of this study show that SH003 improved immunosuppression through the activation of macrophages, splenocytes, and NK cells. These findings suggest that SH003 could be applied as a potential immunostimulatory agent for a variety of diseases caused or exacerbated by immunodeficiency.

Silk peptide treatment potentiates natural killer cell activity in vitro and induces natural killer cell maturation and activation in mouse splenocytes

Context: Silk peptide from cocoons of silkworm (Bombyx mori L., Bombycidae) has been employed as a biomedical material and exhibits various bioactivities, including immune-modulating activity.Objective: We analyzed whether silk peptide exerts direct modulating effects on NK cells using an NK cell line in vitro and ex vivo splenocytes. We also attempted to delineate the mechanism underlying the modulation.Material and methods: In vitro activity of silk peptide on NK cells was determined by measurement of cytolytic activity against K562 cells at an effector-to-target ratio of 5:1 after incubation of NK-92MI cells with silk peptide (0–2000 μg/mL) for 48 and 72 h. Ex vivo activity of silk peptide on mouse splenic NK cells was determined similarly by using YAC-1 cells.Results: Treatment of NK-92MI NK cells with silk peptide (500–2000 μg/mL) significantly increased cytolytic activity on target cells by 2- to 4-fold. The same concentrations (500–2000 μg/mL) of silk peptide treatment also significantly enhanced the cytolytic activity of splenic NK cells against YAC-1 cells. Silk peptide treatment of IL-2-stimulated splenocytes induced enhanced expression of Th1, 2 and 17 cytokines including TNF-α, IFN-γ, IL-6, IL-4 and IL-17. Finally, ex vivo treatment with silk peptide on mouse splenocytes significantly enhanced the degree of NK cell maturation in a dose-dependent manner from 3.49 to 23.79%.Discussion and conclusions: These findings suggest that silk peptide stimulates NK cells, thereby influencing systemic immune functions and improving natural immunity. Thus, silk peptide could be useful as a complementary therapy in cancer patients.

Effects of the Acupoint Catgut Embedding on Nerve-Endocrine-Immune Network in Dysmenorrhea Rats

To explore the underlying mechanism of acupoint catgut embedding in improving primary dysme-norrhea (PD) in rats based on functional activities of the neuro-endocrine-immune (NEI) network. Forty female rats were equally randomized into blank control, PD model, medication, and acupoint catgut embedding groups. The PD model was established by subcutaneous injection of estradiol benzoate (0.5 mg/rat on the 1st and 10th d, and 0.2 mg/rat from 2nd to 9th d) and oxytocin (2 U/rat, i．p.). Rats of the medication group were treated by intragastric perfusion of fenbid (0.8 mL/rat, 125 mg/100 mL), once daily for 10 days. The catgut embedding was applied to bilateral "Ciliao" (BL 32), "Sanyinjiao" (SP 6) and "Guanyuan" (CV 4) before modeling. The body writhing times in 30 minutes were recorded, plasma β-endorphin(β-EP) content, and prostaglandin E 2 (PGE2) and prostaglandin F 2 α (PGF2α) contents in the uterus tissue were assayed using ELISA, and the activity of natural killer cell (NK cell) in the spleen tissue was detected using 3-(4，5-dimethyl-2-thiazolyl)-2，5-diphenyl-2-H-tetrazolium bromide (MTT) method after isolation and co-culture with K 562 cells. The body writhing times were no-tably more in the model group than in the control group (P<0.01), and obviously fewer in both medication and catgut embedding groups than in the model group (P<0.01). After modeling, the plasma β-EP and uterus PGE2 contents and splenic NK cell activity were significantly decreased (P<0.01), while the uterus PGF2α content was evidently increased in the model group relevant to the control group (P<0.01). Following the treatment, plasma β-EP and uterus PGE2 contents and splenic NK cell activity were considerably up-regulated (P<0.01), and uterus PGF2α content was markedly down-regulated in both medication and acupoint catgut embedding groups (P<0.01), suggesting an involvement of the NEI network in catgut embedding-induced improvement of PD. The therapeutic effect of catgut embedment was markedly superior to that of medication in up-regulating splenic NK cell activity (P<0.01). No significant differences were found between the medication and catgut embedding groups in the body writhing times within 30 min, and in the levels of plasma β-EP and uterus PGE2 and PGF2α (P>0.05). The acupoint catgut embedding has a significant efficacy in relieving PD in rats, which may be related to its effect in up-regulating plasma β-EP, uterus PGE2 contents and splenic NK cell activity and in down-regulating uterus PGF2α level.

Alleviation of cyclophosphamide-induced immunosuppression in mice by naturally acetylated hemicellulose from bamboo shavings

ABSTRACTBamboo-shavings hemicellulose (BSH) is a water-extractable hemicellulose isolated from steamed-exploded bamboo shavings. The present study investigated the protective potential of BSH against cyclophosphamide (CPA)-induced immunosuppression in mice. Mice were orally administered BSH once daily at the dose of 50, 100 or 200 mg/kg body weight (BW) for 14 days, coupled with a hypodermic injection of CPA (70 mg/kg BW/day) on days 4, 8 and 12. The results showed that 14 days of oral administration of BSH at a dose of 100 or 200 mg/kg BW/day significantly accelerated the recoveries of serum hemolysin formation, phagocytic function of the reticuloendothelial system, splenocyte proliferation, splenic NK cell activity, secretion of splenic Th1/Th2 cytokines (IL-2, IL-12, TNF-α, INF-γ/IL-4) together with mRNA expression of Th1/Th2 transcription factors (T-bet/GATA-3) in CPA-induced immunosuppressive mice. Our results demonstrated that BSH could ameliorate CPA-induced immunosuppression in mice and may potentially serve as a supportive therapy in conventional chemotherapy.

왕느릅나무 추출물에 의한 비장세포 생존률 및 NK cell 세포독성 증가

Ulmi cortex is the elm bark or root bark of Ulmus macrocarpa Hance and has been used as an ingredient of traditional medicine for anti-inflammatory, analgesic, anti-cancer and wound healing on both the East and the West. This study investigated whether the Ulmus macrocarpa Hance Water extract (UMWE) has the in vivo and in vitro immune activating effect. Animals were orally administrated for 14 days as follows: no treat group with distilled water, cyclophosphamide (CY) group with 120 mg/kg of CY, UMWE 100+CY group with 100 mg/kg of UMWE and 120 mg/kg of CY, UMWE 200+CY group with 200 mg/kg of UMWE and 120 mg/kg of CY, UMWE 100 group with 100 mg/kg of UMWE and UMWE 200 group with 200 mg/kg of UMWE. The immunosuppressive drug CY was intraperitoneally injected to induce immune suppression. Spleen indices showed small changes in CY injected groups but splenocyte indices showed greater decrease in the same groups. However, UMWE appeared to relieve CY’s immunosuppression. UMWE also delayed in vitro splenocyte death increasing its longevity. These data obtained by MTT assay and 7-amino-actinomycin D which stains preferentially dead than live cells. UMWE alone did not show cytotoxicity based on its apoptototic effect on splenocytes in vitro and in vivo. Splenic NK cell activity was maintained by UMWE under the presence of CY in vitro. The data indicated that UMWE protects splenocytes from the immunosuppressive drug CY under in vitro and in vivo conditions.

The thyroid status reprograms T cell lymphoma growth and modulates immune cell frequencies.

In spite of considerable evidence on the regulation of immunity by thyroid hormones, the impact of the thyroid status in tumor immunity is poorly understood. Here, we evaluated the antitumor immune responses evoked in mice with different thyroid status (euthyroid, hyperthyroid, and hypothyroid) that developed solid tumors or metastases after inoculation of syngeneic T lymphoma cells. Hyperthyroid mice showed increased tumor growth along with increased expression of cell cycle regulators compared to hypothyroid and control tumor-bearing mice. However, hypothyroid mice showed a higher frequency of metastases than the other groups. Hyperthyroid mice bearing tumors displayed a lower number of tumor-infiltrating T lymphocytes, lower percentage of functional IFN-γ-producing CD8(+) T cells, and higher percentage of CD19(+) B cells than euthyroid tumor-bearing mice. However, no differences were found in the distribution of lymphocyte subpopulations in tumor-draining lymph nodes (TDLNs) or spleens among different experimental groups. Interestingly, hypothyroid TDLN showed an increased percentage of regulatory T (Treg) cells, while hyperthyroid mice displayed increased number and activity of splenic NK cells, which frequency declined in spleens from hypothyroid mice. Moreover, a decreased number of splenic myeloid-derived suppressor cells (MDSCs) were found in tumor-bearing hyperthyroid mice as compared to hypothyroid or euthyroid mice. Additionally, hyperthyroid mice showed increased cytotoxic activity, which declined in hypothyroid mice. Thus, low levels of intratumoral cytotoxic activity would favor tumor local growth in hyperthyroid mice, while regional and systemic antitumor response may contribute to tumor dissemination in hypothyroid animals. Our results highlight the importance of monitoring the thyroid status in patients with T cell lymphomas. T cell lymphoma phenotype is paradoxically influenced by thyroid status. Hyperthyroidism favors tumor growth and hypothyroidism rises tumor dissemination. Thyroid status affects the distribution of immune cell types in the tumor milieu. Thyroid status also modifies the nature of local and systemic immune responses.

In vivo augmentation of NK cell activity by methanol extract of cultured cambial meristematic cells of mountain wild ginseng (P4393)

Abstract Although mountain wild ginseng (MWG, Panax ginseng C.A.Meyer) has been regarded to be more effective than cultivated ginseng, very few data have been accumulated until now because of its limited availability and expensiveness. Some of us established a technique of isolation and culture of innately undifferentiated cambial meristematic cells from MWG as an attractive alternative. Using methanol extract of cultured MWG cambium-derived cells (MEGC), we here investigated in vivo immunomodulatory effect in a mouse model. Mice were intraperitoneally given MEGC (200 mg/Kg) and adaptive immunity was unaffected by MEGC treatment. Without Ag immunization, splenic NK cell activity in MEGC-treated mice was significantly higher when compared to controls. However, number of NK1.1+ cells and surface expression of activation/ inhibitory receptors and activation markers were unaltered by MEGC. Instead, RT-PCR data clearly demonstrated that MEGC treatment increases constitutive expression of Granzyme B and perforin in fresh spleen cells. When spleen cells were cocultured with Yac-1 in the presence of IL-2, Granzyme B and IFNγ levels were also higher in MEGC-treated group. However, these effects were achieved solely at early phase of culture (&amp;lt; day 1) and lower concentration of IL-2. Collectively, MEGC augments in vivo NK cell activity through up-regulated constitutive expression of cytolytic mediators and data suggest that ginseng may act at early phase of NK cell response.

β-1,4-Mannobiose Stimulates Innate Immune Responses and Induces TLR4-Dependent Activation of Mouse Macrophages but Reduces Severity of Inflammation during Endotoxemia in Mice

β-1,4-Mannobiose (MNB) has been shown to exert prebiotic activity and modulate mucosal gene expression. In this study, the immune-modulating effect of MNB in healthy and endotoxemic mice and its role in Toll-like receptor (TLR) 2/4–mediated macrophage activation were investigated. Mice were supplemented daily with MNB (0, 5, 10, or 25 mg/kg) for 14 d. To examine the effect of MNB during endotoxemia, mice were supplemented with or without MNB (25 mg/kg) for 14 d, followed by challenge with intraperitoneal LPS or saline. MNB induced expression of both T helper (Th) 1– and Th2-type cytokines in the ileum (P < 0.05) and increased fecal IgA production and splenic NK cell activity (P < 0.05) in healthy mice. In endotoxemic mice, MNB reduced the expression of Tnfa, Il-6, iNos (P < 0.05), and Il-10 (P < 0.05), and reduced LPS-induced weight loss but increased Ifng, Il-12p40, Il-5, and Ifna expression (P < 0.05) and NK cell activity relative to positive control (LPS) mice. Treatment of RAW 264.7 macrophages with MNB induced TNF-α and IL-6 secretion (P < 0.05), and this effect was abrogated by inhibiting TLR4, but not TLR2, signaling. Pretreatment of RAW 264.7 cells with MNB induced tolerance to TLR2 and TLR4 agonists, reducing TNF-α production (P < 0.05) upon secondary stimulation with LPS or lipoteichoic acid. These results indicate that MNB can modulate intestinal and systemic immune responses in healthy and endotoxemic mice and prevent LPS-induced immune suppression, as well as directly stimulating innate immune mechanisms in vitro as a TLR4 agonist.

Lipoteichoic acid of Bifidobacterium in combination with 5-fluorouracil inhibit tumor growth and relieve the immunosuppression

To investigate the therapeutic efficacy of lipoteichoic acid of Bifidobacterium (BLTA) in combination with 5-fluorouracil (5-FU) treatment on the mice bearing inoculated hepatoma-22 (H22) cells and the effects of BLTA on immunological regulation of organism, and explore its mechanisms. MethodsTumor-bearing mice were treated with 5-FU alone, BLTA alone or BLTA in combination with 5-FU. The tumor size were observed and measured regularly. The growth inhibiting rate (IR) of tumor was detected. MTT assay was used to evaluate the proliferation of T lymphocytes and splenic NK cell and CTL activity. Enzyme linked immunosorbent assay (ELISA) was used to detect the change of IFN-Γ. FCM was used to detect T subgroup ratio of spleen cells of tumor-bearing mice. Expression change of mRNA and proteins of Foxp3 and TIM-3 were detected by Real-Time-PCR and Western blot in tumor-bearing mice tumor tissue. ResultsBoth 5-FU and BLTA had inhibition effect on tumor-growth. While in the 5-FU+BLTA group, the inhibition of tumor growth was more significant, with increased T lymphocyte proliferation and IFN-Γproduction of spleen cells. Spleen cells of tumor-bearing mice had high CD4+CD25+regulatory T cell (CD4+CD25+Treg) ratio and high mRNA and proteins expression of Foxp3 and TIM-3, but in the BLTA and 5-FU group, CD4+CD25+Treg ratio degraded, with down regulation mRNA and proteins expression of Foxp3 and TIM-3. But CD4+ T cells also decreased in spleen cells of tumor-bearing mice by alone 5-FU treated, splenic NK cell and CTL activity also degraded, while CD4+ T cells and splenic NK cell and CTL activity significantly increased by BLTA treated. BLTA in combination with 5-FU could also enhance the ratio of CD4+ T cells and splenic NK cell and CTL activity. ConclusionThe present study suggested that BLTA in combination with 5-FU could enhance antitumor effect, with inhibiting TIM-3/TIM-3L pathway, cutting down immunosuppressive activity of CD4+CD25+ Treg and enhancing cell-mediated immunity.

Morphofunctional Characteristic of the Immune System in BALB/c and C57Bl/6 Mice

Inbred animals serve as an adequate model to study the role of genetic factors in adaptive, disadaptive, and pathological processes. Morphofunctional study of the immune system was performed on intact BALB/c and C57Bl/6 mice. The structural and functional parameters of the immune system in BALB/c and C57Bl/6 mice differ under physiological conditions. In BALB/c mice, volume density of T zone in the spleen and production of IL-2, IL-3, IL-4, IL-10, and TNF-α were much higher than in C57Bl/6 mice. However, IL-12 production in BALB/c mice was lower than in C57Bl/6 mice. C57Bl/6 mice were characterized by higher cytostatic activity of splenic NK cells. The observed interstrain differences are genetically determined and contribute to the type of adaptive processes and different sensitivity of these mice to pathogenic agents.

Deletion of galectin-3 in the host attenuates metastasis of murine melanoma by modulating tumor adhesion and NK cell activity

Galectin-3, a β galactoside-binding lectin, plays an important role in the processes relevant to tumorigenesis such as malignant cell transformation, invasion and metastasis. We have investigated whether deletion of Galectin-3 in the host affects the metastasis of B16F1 malignant melanoma. Galectin-3-deficient (Gal-3(-/-)) mice are more resistant to metastatic malignant melanoma as evaluated by number and size of metastatic colonies in the lung. In vitro assays showed lower number of attached malignant cells in the tissue section derived from Gal-3(-/-) mice. Furthermore, lack of Galectin-3 correlates with higher serum levels of IFN-γ and IL-17 in tumor bearing hosts. Interestingly, spleens of Gal-3(-/-) mice have lower number of Foxp3(+) T cells after injection of B16F1 melanoma cells. Finally, we found that while CD8(+) T cell and adherent cell cytotoxicity were similar, there was greater cytotoxic activity of splenic NK cells of Gal-3(-/-) mice compared with "wild-type" (Gal-3( +/+ )) mice. Despite the reduction in total number of CD3ε(-)NK1.1(+), Gal-3(-/-) mice constitutively have a significantly higher percentage of effective cytotoxic CD27(high)CD11b(high) NK cells as well as the percentage of immature CD27(high)CD11b(low) NK cells. In contrast, CD27(low)CD11b(high) less functionally exhausted NK cells and NK cells bearing inhibitory KLRG1 receptor were more numerous in Gal-3( +/+ ) mice. It appears that lack of Galectin-3 affects tumor metastasis by at least two independent mechanisms: by a decrease in binding of melanoma cells onto target tissue and by enhanced NK-mediated anti-tumor response suggesting that Galectin-3 may be considered as therapeutic target.

Supplementation with bovine colostrum enhances natural killer cell activity in influenza‐infected mice

Bovine colostrum (BC), from the first milking following partuition, is available as a human nutraceutical for immune support, although data are limited. Oral administration of BC in mice has been demonstrated to affect local intestinal immunity, including an increase in the percentage of NK cells; however, resistance to infection has not been studied. Therefore, we proposed to investigate the effects of BC (W150, La Belle, Inc.) on the innate immune response to influenza infection in 4 month‐old female C57BL/6 mice supplemented with 1g of BC/kg of body weight by pipette for 7 days prior to and following a non‐lethal infection with mouse‐adapted influenza A virus (H1N1, PR8). Animals were observed through 3 days of infection and assessed for weight loss and recovery, lung virus titers, splenic NK cell activity and serum IgA. BC‐supplemented mice demonstrated less reduction in body weight and decreased lung virus burden following infection compared to controls, indicating a less severe infection. BC‐supplemented mice also demonstrated a significant increase in influenza‐enhanced NK cell cytotoxicity compared to controls at 3 days post‐infection (P&lt;0.05). There were no differences in IgA levels between groups. BC supplementation enhanced NK cell cytotoxicity and improved the immune response to influenza virus infection in mice, with no effect on serum IgA. (Sponsored by La Belle, Inc., Bellingham, WA)

Processed Aconite Root Prevents Cold-Stress-Induced Hypothermia and Immuno-Suppression in Mice

Processed aconite root (PA) is a crude drug used in traditional Chinese or Japanese medicine to generate heat in interior body and dispel cold. We evaluated the effects of PA on hypothermia and reduction in the activity of natural killer (NK) cells in mice exposed to chronic cold stress. Male mice were reared at 4 degrees C, and powdered PA was administered for 10 d as a food additive. Core body temperature of mice significantly decreased by approximately 1 degrees C after rearing in a cold environment, and PA administration significantly restored the reduction in core body temperature in a dose-dependent manner. After 10 d, splenic NK-cell activity of cold-stressed mice was significantly reduced, and the reduction was dose-dependently recovered by PA administration. An aconitine-type alkaloid fraction prepared from PA was ineffective when administered to cold-stressed mice, and the thermogenic effect on hypothermic mice was present in the fraction containing low-molecular-weight compounds without alkaloids. In cold-stressed mice, the weight of brown adipose tissue (BAT) and uncoupling protein (UCP)-1 level in BAT increased, whereas the weight of white adipose tissue decreased. The increase in UCP-1 level in BAT of cold-stressed mice was further augmented by PA treatment. These results indicate that PA exhibited a thermogenic effect on hypothermia induced by cold stress in mice by additional upregulation of UCP-1 level in BAT, which was already enhanced by hypothermia, and that the active ingredients present in PA are non-alkaloidal low-molecular-weight compounds.

Immunostimulation-Mediated Antitumor Activity by Preconditioning with Rice-Shochu Distillation Residue Against Implanted Tumor in Mice

We investigated the ability of rice-shochu postdistillation residue (RSDR) to stimulate the activity of macrophages. RSDR significantly stimulated mouse macrophage activity and induced significant IL-12 production in vitro. In syngeneic C38 solid tumor model in mice, a diet containing 1.0% RSDR caused a significant suppression of tumor growth and prolonged the life span of the tumor-bearing mice. Further, using this model, mice fed for 21 days with RSDR showed significantly increased levels of serum IL-12 and IFN-γ compared with controls. Moreover, the splenic NK cell activity of mice fed with RSDR was significantly elevated compared with that of mice on a normal diet and thereby suppressed C38 tumor growth. We also investigated the tumor growth suppressing effect of RSDR using a tumor model of B16-F10 melanoma cells. Dietary preconditioning with RSDR significantly suppressed B16-F10 tumor growth. Moreover, RSDR significantly increased the production of IL-12 either before or after B16-F10 tumor implantation. These results suggest that dietary RSDR suppresses tumor growth by stimulating the immune system of the host.

In vivoboosting of lung natural killer and lymphokine-activated killer cell activity by interleukin-2: comparison of systemic, intrapleural and inhalation routes

Natural killer (NK) cells are thought to play a role in host defence against malignancy and infection, in immunoregulation and as precursor cells in a generation of lymphokine-activated killer (LAK) cells which can lyse NK-resistant tumour cells. As the lung is a major site for malignancy and infection and as there are large numbers of lymphoid cells including NK cells in the interstitial compartment of the lung, we evaluated the capacity of interleukin-2 (IL-2), a lymphokine capable of augmenting NK activity in vitro, to augment lung NK cell activity in vivo, using different routes of IL-2 administration. We compared both systemic (i.v. and i.p.) and local (intrapleural and inhalation) routes of IL-2 administration (50,000 U/daily for 5 days) using CBA mice, assessing NK and LAK cell activity in the spleen (systemic) and in the lung. The target cells used for these studies were the YAC-1 (NK-sensitive) and P815, NO36 and HA56 (NK-resistant, LAK-sensitive) cell lines. Splenic NK activity was increased by 1.4-1.9-fold for i.v./i.p., respectively, compared with controls with both systemic routes of administration, and lung NK activity was increased 3.2-fold and 3.8-fold (i.v./i.p, respectively, P less than 0.05), to levels which were comparable to systemic (splenic) NK activity following the same therapy. Intrapleural IL-2 administration similarly enhanced lung NK activity (3.3-fold) and splenic NK activity (1.3-fold; P less than 0.05 versus controls for both). Surprisingly, inhaled IL-2 suppressed both splenic and lung NK cell activity (84 +/- 8% and 78 +/- 10% suppression, respectively, P less than 0.05). LAK cell activity was also enhanced in the lung by 1.8-8-fold in response to i.v., i.p. and intrapleural IL-2, whereas inhaled IL-2 was ineffective in generating LAK cell activity. These results suggest that the systemic and intrapleural administration of IL-2 effectively boost pulmonary NK and LAK activity whereas inhalation of IL-2 does not. Thus, in clinical situations where boosting of local lung NK or LAK cell activity is desired, these routes of IL-2 administration may be effective.

Alterations in NK Cell Cytotoxicity Induced by Peripheral Nerve Injury in Mice

Chronic pain is often associated with changes in the immune responses, which highlights the need for the aggressive pain control to obtain a better prognosis. This study examined splenic NK cell cytotoxicity in an attempt to assess the possible changes in the immune function under chronic neuropathic pain after a partial transsection of the sciatic nerve. Methods: After confirming tactile allodynia in response to the von Frey filament, a modified lactate dehydrogenase (LDH) release assay was used to determine the cytotoxic activity of splenic NK cells on the YAC-1 cell line in C3H/HeN (H-2k) mice (n = 6). NK cells as effector cells were mixed with YAC-1 cells as target cells (1 × 104/100μl), resulting in an effector-target ratio of 1：25, 1：50, 1：100 in the culture medium. Results: At 1 and 2 weeks after the nerve injury, all the subjects showed significant mechanical sensitivity compared with those observed before surgery. The percentage of NK cell cytotoxicity of the neuropathic mice increased significantly 1 week after the nerve injury but decreased within 2 weeks compared with the normal mice. Conclusions: In terms of the altered NK cell cytotoxicity, neuropathic pain can cause changes in the normal performance of the immune function.

Alterations of immune functions induced by 12C6+ ion irradiation in mice

Purpose: To estimate the biological risks to the immune system of the type of space radiation, 12C6+, encountered by cosmonauts during long-term travel in space.Materials and methods: The Kun-Ming strain mice were whole-body irradiated by 12C6+ ion with 0, 0.01, 0.05, 0.075, 0.2, 0.3, 0.5, 0.75, 1 or 2 Gy, at a dose rate of 1 Gy/min. At 35 days after irradiation, the thymus and spleen weights were measured, the natural killer (NK) cells activity of spleen was determined by 3-(4, 5-dimethylthiazol-2-yl)- 2, 5-diphenyl tetrazolium bromide (MTT), and the interferon-γ (IFN-γ) levels in serum and thymus were detected with enzyme-linked immunosorbent assays (ELISA).Results: The results showed that the thymus weight, IFN-γ levels in serum and the activity of splenic NK-cells had significantly increased at a dose of 0.05 Gy. With further dose increase, the weight of spleen continued to increase but the weight of thymus, IFN-γ level and NK-cells activity declined.Conclusions: These results suggest that the dose of 0.05 Gy irradiation has a stimulatory effect on mouse immunity; this effect declined with increasing dose.

Bovine immune colostrum against 17 strains of diarrhea bacteria and in vitro and in vivo effects of its specific IgG

Bovine colostral antibodies of cows immunized with a multivalent vaccine consisting of whole cells of 17 strains of pathogenic diarrhea bacteria were generated, and the specific IgG with high activities and titres directed against these pathogens was purified using an ammonium sulfate precipitation and verified by SDS-PAGE. We demonstrate that specific IgG has a strong activity of inhibiting in vitro growth and colonization in pathogens by agglutinating with bacteria and destroying cell walls. Normal IgG purified from non-immunized bovine colostrum is incapable of eliciting the same consequences as specific IgG. Specific IgG prevents enteroinvasive Escherichia coli/ Salmonella typhi-induced diarrhea and may exert an effective protection by enhancing splenic NK cell activity, elevating IL-2 level and inhibiting excessive release of TNF-α in mice. Thus, the specific IgG from colostral antibodies of immunized bovine can provide effective protection or therapy for multibacteria-induced diarrhea.

Modulation of immune response following dietary genistein exposure in F0 and F1 generations of C57BL/6 mice: Evidence of thymic regulation

To further determine whether genistein (GEN) modulation of the immune responses was related to its endocrine-disrupting properties and time of exposure, pregnant C57BL/6 mice were exposed to GEN at 0–1250 ppm in feed starting on day 14 of gestation. The C57BL/6 offspring were exposed to GEN in utero and lactationally, and through feed after weaning until postnatal day 42. In dams, exposure to GEN increased the terminal body weight (250 and 1250 ppm), the number of splenic T cells and NK cells (250 ppm), and the activity of NK cells (250 ppm). In F 1 males, GEN increased the terminal body and spleen weights (25 and 250 ppm), the number of CD4 +CD8 + and CD4 −CD8 + thymocytes (25 ppm), and the number of splenic T cell subsets and NK cells (25 and 250 ppm). Moreover, splenic NK cell activity and anti-CD3-mediated splenocyte proliferation were increased in all treatment groups. In F 1 females, the percentages of CD4 −CD8 + and CD4 −CD8 − thymocytes (25 and 250 ppm), and CD4 +CD8 − and CD4 +CD8 + splenocytes (25 and 250 ppm) were increased. In contrast, the percentage and number of CD4 +CD8 + thymocytes were decreased (250 ppm). Exposure to GEN decreased the percentages of splenic NK cells in all treatment groups, and decreased the activity of splenic NK cells at the 25 ppm concentration. Additionally, evaluation of CD25 + and CD44 + expression by thymocytes indicated that the decrease in the percentage of CD44 +CD25 + thymocytes was at least partially responsible for the decrease in the percentage of CD4 −CD8 − thymocytes in F 1 male mice. Overall, the results demonstrate that GEN can modulate the immune system in both adult and developing C57BL/6 mice in a dose-specific manner. The gender-specific effects of GEN on the immune responses in F 1 mice suggest that GEN may modulate the immune system by functioning as either an estrogen agonist or antagonist. The differential effects of GEN on thymocytes in F 1 male and female mice indicate that GEN immunomodulation might be related to its effect on thymus.