Effects of a nonapeptide thymic hormone on intestinal intraepithelial lymphocytes in mice following administration of 5-fluorouracil

The Relationship between Annual Airborne Pollen Levels and Occurrence of All Cancers, and Lung, Stomach, Colorectal, Pancreatic and Breast Cancers: A Retrospective Study from the National Registry Database of Cancer Incidence in Japan, 1975-2015

Suppression of risk factors including smoking, overdrinking and infections by human papilloma and hepatitis B and C viruses has been recommended for cancer prevention; however, identification of other environmental risk factors has not been enough. Besides the 2003 report that Kawasaki disease may be triggered by pollen exposure, 40 Japanese specific intractable diseases have recently been reported as "pollen diseases," also potentially triggered by pollen exposure．Various human organs are affected by pollen exposure, leading to systemic vasculitis; autoimmune connective tissue diseases, inflammatory bowel diseases and intractable neuromuscular and bone diseases, suggesting the common effects of pollen exposure on fundamental functions of vital metabolism. In this context, cancer and malignant tumors may be another group of intractable diseases triggered by epigenetic pollen exposure. Thus, this study compared the number of newly registered patients with 24 types of cancer and airborne pollen levels measured from 1975 to 2015. We searched for statistical correlations with Bonferroni correction between the annual number of newly registered patients for all cancers or for each of lung, stomach, colorectal, pancreatic and breast cancers in the patient-registry year "x", and annual airborne pollen levels measured in the same year as "x", or 1-7 years prior to the year "x". The number of newly registered patients for lung, and pancreatic cancers in the patient-registry year "x" was highly correlated with airborne pollen levels measured 2 years prior to "x". That for breast cancer was correlated with pollen levels measured 2 and 5 years prior to "x". To our knowledge, this is the first rapid communication of the association between pollen levels and cancer incidence.

Structural and dynamic properties of thymopoietin mimetics

We propose a hypothesis that the T-cell receptor is a possible target of thymic hormones. We modelled the conformational dynamics of thymopentin and its structural variants in solution, as well as the interactions of these short peptides with the proposed molecular target. Thymopentin is a five-amino-acid fragment of the thymic hormone thymopoietin (residues 32 to 36) that reproduces the immunomodulatory activity of the complete hormone. Using molecular dynamics and flexible docking methods, we demonstrated high-affinity binding of thymopentin and its prospective mimetics with the T-cell receptor. The calculated biological activity spectra of thymopentin and its two promising modifications can be used in immunomodulatory activity screenings with live systems.

Immunomodulation of Homeopathic Thymulin 5CH in a BCG-Induced Granuloma Model

The present study analyzed the immune modulation mechanisms of thymulin 5CH in a granuloma experimental model. Male adult Balb/c mice were inoculated with BCG into the footpad to induce granuloma, which was quantitatively evaluated. The phenotypic characterization of phagocyte, T- and B-lymphocyte populations in the peritoneum, and local lymph node was done by flow cytometry. During all experimental periods, thymulin 5CH and vehicle (control) were given ad libitum to mice, diluted into the drinking water (1.6 × 10⁻¹⁷ M). After 7 days from inoculation, thymulin-treated mice presented reduction in the number of epithelioid cytokeratine-positive cells (P = 0.0001) in the lesion, in relation to young phagocytes. After 21 days, the differentiation of B1 peritoneal stem cells into phagocytes reached the peak, being higher in thymulin-treated mice (P = 0.0001). Simultaneously, the score of infected phagocytes in the lesion decreased (P = 0.001), and the number of B1-derived phagocytes, CD4+ and CD8+ T lymphocytes in the local lymph node increased in relation to control (P = 0.0001). No difference was seen on the CD25+ Treg cells. The results show that thymulin 5CH treatment is able to improve the granuloma inflammatory process and the infection remission, by modulating local and systemic phagocyte differentiation.

Thymus peptides regulate activity of RAW 264.7 macrophage cells: inhibitory analysis and a role of signal cascades

OBJECTIVES

The aim of this study was to reveal T-lymphocyte-independent mechanisms of thymic peptide-mediated immunomodulation.

METHODS

The effects of two thymic peptides- thymulin and thymopentin were studied in cultured RAW 264.7 macrophages (lipopolysaccharide-stimulated or unstimulated) by measuring cytokine production and signal protein levels.

RESULTS

Both peptides increased proinflammatory cytokine secretion by unstimulated RAW 264.7 macrophages and these effects were blocked by the NF-κB cascade inhibitor, stress-activated protein kinase (SAPK)/JNK cascade inhibitor and, to a lesser extent, Toll-like 4 receptor activity inhibitor. In macrophages stimulated by bacterial lipopolysaccharide, peptides alone did not affect cytokine secretion, but significantly enhanced effects of each of the inhibitors. Thymopentin increased activation of both NF-κB and SAPK/JNK cascades in unstimulated macrophages, while thymulin significantly decreased activation of the SAPK/JNK but not NF-κB cascade in LPS-stimulated macrophages. Thymulin and thymopentin increased production of the heat shock protein HSP72 both in LPS-stimulated and unstimulated cells.

CONCLUSIONS

Thymulin and thymopentin are effective anti-inflammatory modulators with direct actions on innate immune cells; the effects involve multiple signal cascades, including NF-κB and SAPK/JNK pathways. Since signaling cascades are now considered to be targets for new therapies, thymic peptides may be prospective modulators of signaling cascades, acting alone or in combination with other agents.

Thymus hormones as prospective anti-inflammatory agents

IMPORTANCE OF THE FIELD

Inflammatory diseases are characterized by severe immune imbalances, leading to excessive or inappropriate release of mediators, which, in turn, result in massive damage to organs and systems. Effective means to control inappropriate immune reactions are often life-critical needs. Available data on the role of thymus-derived hormones in inflammation show their great potential.

AREAS COVERED IN THIS REVIEW

The review aims to systematize information for the last two decades on immune system regulation by thymic peptide hormones, with a primary focus on the role of these hormones in the systemic inflammatory response and inflammatory diseases. Anti-inflammatory potential of three thymic hormones - thymulin, thymosin-alpha, and thymopoietin - is discussed, reviewing recently published clinical and experimental studies.

WHAT THE READER WILL GAIN

Our analysis revealed the regulation of inflammatory processes via thymic hormones that could be prospective for therapeutic application. This regulation may be mediated through thymic hormone effects on peripheral immune cell activities and bidirectional coupling between thymic hormones and the hypothalamic-pituitary-adrenal axis.

TAKE-HOME MESSAGE

In view of the role of thymic hormones in immune and neuroendocrine systems, they could be suitable as therapeutic agents for inflammation.

Thymulin, a thymic peptide, prevents the overproduction of pro-inflammatory cytokines and heat shock protein Hsp70 in inflammation-bearing mice

The effects of synthetic analogue of peptide hormone thymulin, which is normally produced by thymic epithelial cells, on immune cells activity and blood cytokine profile had been studied in male NMRI mice with acute inflammation induced by injection of lipopolysaccharide from gram-negative bacteria (LPS, 250 microg/100 g of body weight). Inflammation induced by LPS resulted in accumulation of several plasma pro-inflammatory cytokines, IL-1 beta, IL-2, IL-6, TNF-alpha, interferon-gamma, and also IL-10, anti-inflammatory cytokine. Thymulin previously injected in dose of 15 microg/100 g body weight, prevented the accumulation of proinflammatory cytokines in plasma. Thymulin also prevented LPS-induced up-regulation of production of several cytokines by spleen lymphocytes and peritoneal macrophages. Added in vitro, thymulin decreased the peak of TNF-alpha production in macrophages cultivated with LPS. In addition, thymulin lowered the peak of Hsp70 production induced by LPS treatment. The results indicate that thymulin having significant anti-inflammatory effect may be promising in clinical application.

Tyk2-signaling plays an important role in host defense against Escherichia coli through IL-23-induced IL-17 production by gammadelta T cells

Tyrosine kinase 2 (Tyk2), a member of the JAK-signal transducer family, is involved in intracellular signaling triggered by various cytokines, including IL-23. We have recently reported that resident gammadelta T cells in the peritoneal cavity of naive mice produced IL-17 in response to IL-23. In this study, we examined importance of Tyk2-mediated signaling in the IL-17 production by gammadelta T cells using Tyk2 deficient (-/-) mice. Gammadelta T cells in the peritoneal cavity of Tyk2(-/-) mice displayed effecter/memory phenotypes and TCR V repertoire similar to those in Tyk2(+/+) mice and produced comparable level of IL-17 to those in Tyk2(+/+) mice in response to PMA and ionomycin, indicating normal differentiation to IL-17-producing effectors in the absence of Tyk2-signaling. However, gammadelta T cells in Tyk2(-/-) mice produced less amount of IL-17 in response to IL-23 in vitro than those in Tyk2(+/+) mice. Similarly, gammadelta T cells in the peritoneal cavity of Tyk2(-/-) mice showed severely impaired IL-17 production after an i.p. infection with E. coli despite comparable level of IL-23 production to Tyk2(+/+) mice. As a consequence, Tyk2(-/-) mice showed a reduced infiltration of neutrophils and severely impaired bacterial clearance after Escherichia coli infection. These results indicate that Tyk2-signaling is critical for IL-23-induced IL-17 production by gammadelta T cells, which is involved in the first line of host defense by controlling neutrophil-mediated immune responses.

Intestinal toxicity induced by 5-fluorouracil in pigs: a new preclinical model

BACKGROUND

The goal of this study was to develop an animal model of intestinal injury induced by 5-fluorouracil (5-FU) in pigs.

METHODS

Six domestic pigs were used as control (healthy group) and another 6 malnourished pigs orally received 5-FU (treated group). After 4 weeks of treatment, pigs were sacrificed and jejunum, ileum and colon were isolated for histological, immunological and biochemical analyses.

RESULTS

5-FU caused a decrease in the intestinal mass. Disaccharidase, and phosphate alkaline activities, and glutathione redox cycle were disrupted by 5-FU. Histopathological alterations in the crypts and villous were greater in the small intestine than in the colon. 5-FU decreased the number of peripheral and intestinal leukocytes, promoting an increase in T-cytotoxic cells and a decrease in T-helper and B cells.

CONCLUSION

This pig model of intestinal dysfunction closely mimics the common side effects of cancer chemotherapy in humans, and provides a useful tool for evaluating novel antimucotoxic agents.

In vivo treatment with a nonapeptide thymic hormone, facteur thymique serique (FTS), ameliorates chronic colitis induced by dextran sulphate sodium in mice

Facteur thymique serique (FTS), a thymic hormone with nonapeptide is involved in T cell differentiation in intestine. Here we investigated the effect of FTS on dextran sulphate sodium (DSS)-induced colitis. BALB/c mice were subcutaneously treated with 1 mug/mouse/day of FTS daily. FTS did not affect the course of acute colitis induced by DSS as assessed by survival rate, clinical activity of diseases, extent of tissue damage of colons. On the other hand, FTS significantly ameliorated chronic colitis induced by multiple cycles of DSS as reflected by lower lethality, weight loss, clinical scores and histological scores. The levels of interferon (IFN)-gamma, interleukin 1(IL-1)-beta, and IL-12p40 in the culture supernatants of lamina propria (LP) cells of colon without any stimulation and IFN-gamma by T cells in the LP T cells under T cell receptor (TCR) triggering were reduced in FTS-treated mice, whereas the levels of IL-10 by LP cells and LPT cells were higher in FTS-treated mice. Thus, FTS may serve to suppress inflammation in DSS-induced chronic colitis accompanied by increased IL-10 production.

Enforced Expression of Bcl-2 Partially Restores Cell Numbers but Not Functions of TCRγδ Intestinal Intraepithelial T Lymphocytes in IL-15-Deficient Mice

IL-15 knockout (KO) mice have severely reduced numbers of TCRgammadelta intestinal intraepithelial T lymphocytes (i-IEL), suggesting requirements of IL-15 signaling in the development or maintenance of i-IEL. To determine an involvement of survival signals via Bcl-2 in IL-15-mediated homeostasis of TCRgammadelta i-IEL, we introduced a bcl-2 transgene into IL-15 KO mice. In situ apoptosis of TCRgammadelta i-IEL was decreased in Bcl-2 transgenic (Tg) x IL-15 KO mice compared with IL-15 KO mice. The enforced expression of Bcl-2 partially restored the numbers of TCRgammadelta i-IEL in IL-15 KO mice. However, effector functions of TCRgammadelta i-IEL, including cytokine production and cytotoxic activity, were not recovered in Bcl-2 Tg x IL-15 KO mice. Importantly, TCRgammadelta i-IEL in Bcl-2 Tg x IL-15 KO mice expressed a reduced level of eomesodermin, a transcription factor critical for effector functions of NK cells and CD8(+) T cells. Similar to the case of TCRgammadelta i-IEL, enforced expression of Bcl-2 restored the numbers but not the functions of NK cells in IL-15 KO mice. These results suggest that Bcl-2-mediated survival signal is involved in the IL-15-mediated homeostasis of TCRgammadelta i-IEL and NK cells, but other signals from IL-15 are critical for inducing transcription factors, such as eomesodermin for their effector functions.

The Effect of Granulocyte Macrophage-Colony Stimulating Factor on Bacterial Translocation after Administration of 5-Fluorouracil in Rats

BACKGROUND

After surgical resection for colorectal carcinoma there is a high recurrence rate and, therefore, adjuvant chemotherapy may be useful in some patients. 5-Fluorouracil (5-FU) is the most commonly used chemotherapeutic agent in the management of patients with colorectal cancer. However, gastrointestinal injury induced by chemotherapeutic agents may result in bacterial translocation from the gut into the systemic circulation. Granulocyte macrophage-colony stimulating factor (GM-CSF) may be used to prevent this side effect by means of macrophage activity stimulation.

MATERIALS AND METHODS

A total of 45 rats were divided into three groups. Control group received intraperitoneal saline solution, 5-FU and GM-CSF groups received 50 mg/kg/day 5-FU intravenous infusion and GM-CSF group also received 200 ng/day GM-CSF subcutaneously for 6 days. Intestinal tissue was also sampled for pathological examination at day 7. Plasma levels of tumor necrosis factor-alpha and interleukin-6 were determined, bacterial translocation was quantified by lymph node, liver and spleen culture, and plasma endotoxin content was measured.

RESULTS

White blood cell counts of the 5-FU rats were significantly lower than in the control and GM-CSF groups (P < 0.01). The plasma endotoxin, tumor necrosis factor-alpha and interleukin-6 levels in the 5-FU and GM-CSF groups were significantly increased at day 7 compared with the control groups (P < 0.01), but these levels were significantly lower in the GM-CSF group compared to the 5-FU group (P < 0.01). 5-FU intervention caused significant increase in the frequencies of bacterial translocation at liver, spleen, mesenteric lymph node, and portal blood. Compared with 5-FU group, GM-CSF decreased the bacterial translocation (P < 0.01).

CONCLUSIONS

This study observed that the administration of 5-FU resulted in bacterial translocation. Activation of inflammatory response with GM-CSF is highly effective in prevention of bacterial translocation in 5-FU interventions.

Individuals exhibiting conspicuous nevi (lentigo simplex) are resistant to allergic rhinitis/conjunctivitis (pollinosis), but those who do not show increased susceptibility to pollinosis

We investigated 115 individuals in Tokyo from two groups of persons with conspicuous nevi on the head, neck, and arms, etc. (nevus-positive group) and persons who do not exhibit such nevi (nevi-negative group) interviewing them to determine whether they suffered from allergic rhinitis/conjunctivitis (pollinosis) and examining them for the presence and extent of nevi. There was a distinct correlation: only 5 persons among 85 individuals of the nevus-positive group suffered from pollinosis, and all 30 people in the nevus-negative group had pollinosis. Thus, individuals exhibiting conspicuous nevi are resistant to pollinosis, but those who do not show increased susceptibility to pollinosis.

CD8 alpha-deficient mice are highly susceptible to 5-fluorouracil-induced lethality

Intestinal intraepithelial lymphocytes (i-IEL) expressing CD8 alpha are located in the intestine and may confer protection against invasion of intestinal microflora. We found that mice rendered deficient in CD8 alpha molecules by homologous recombination were susceptible to 5-fluorouracil (5-FU)-induced lethality accompanied by translocation of members of the enterobacteria. The number of i-IEL was greatly reduced on day 6 after 5-FU administration in both CD8 alpha(+/-) mice and CD8 alpha(-/-) mice, whereas the recovery of the level of i-IEL thereafter was significantly impaired in CD8 alpha(-/-) mice compared with that in CD8 alpha(+/-) mice. The ability of i-IEL to produce gamma interferon in response to immobilized T-cell receptor (TCR) alpha beta or TCR gamma delta monoclonal antibodies was significantly lower in CD8 alpha(-/-) mice than in CD8 alpha(+/-) mice. Transfer of CD8(+) i-IEL conferred significant protection against 5-FU-induced lethality in CD8 alpha(-/-) mice. The results suggest that CD8(+) i-IEL play an important role in protection against 5-FU-induced lethality with translocation of Enterobacteriaceae.

Effect of the deletion of US2 and US3 from herpes simplex virus type 2 on immune responses in the murine vagina following intravaginal infection

We investigated the effects of US2 and US3 deficiencies of herpes simplex virus type 2 (HSV-2) on host immunity in a murine model of genital herpes infection. Viral clearance from the vaginal mucosa was more rapid in mice infected with a US3-deficient mutant L1BR1 as compared with a wild-type 186 or YY2 (US2-deficient mutant) infection, although there was no significant difference among them in initial growth in the early stage of infection. Flow cytometric studies revealed that the number of vaginal mononuclear cells in L1BR1-infected mice was significantly greater than that in 186- or YY2-infected mice. Dendritic cells, macrophages and T cells were induced more rapidly and in greater numbers within the vaginas of L1BR1-infected mice. Moreover, the levels of IL-12 and IFN-gamma increased in L1BR1-infected mice over levels in 186-infected mice. These results indicate that a US3 deficiency alters the induction of the host immune response; therefore, the inactivation of US3 may be a promising strategy in the development of novel vaccines for genital herpes.

Neuroendocrine control of thymus physiology

The thymus gland is a central lymphoid organ in which bone marrow-derived T cell precursors undergo differentiation, eventually leading to migration of positively selected thymocytes to the peripheral lymphoid organs. This differentiation occurs along with cell migration in the context of the thymic microenvironment, formed of epithelial cells, macrophages, dendritic cells, fibroblasts, and extracellular matrix components. Various interactions occurring between microenvironmental cells and differentiating thymocytes are under neuroendocrine control. In this review, we summarize data showing that thymus physiology is pleiotropically influenced by hormones and neuropeptides. These molecules modulate the expression of major histocompatibility complex gene products by microenvironmental cells and the extracellular matrix-mediated interactions, leading to enhanced thymocyte adhesion to thymic epithelial cells. Cytokine production and thymic endocrine function (herein exemplified by thymulin production) are also hormonally controlled, and, interestingly in this latter case, a bidirectional circuitry seems to exist since thymic-derived peptides also modulate hormonal production. In addition to their role in thymic cell proliferation and apoptosis, hormones and neuropeptides also modulate intrathymic T cell differentiation, influencing the generation of the T cell repertoire. Finally, neuroendocrine control of the thymus appears extremely complex, with possible influence of biological circuitry involving the intrathymic production of a variety of hormones and neuropeptides and the expression of their respective receptors by thymic cells.

The role of cytokines and prostaglandin-E(2) in thymulin induced hyperalgesia

We have recently reported that intraperitoneal (i.p.) injection of thymulin at low doses (50 ng) resulted in thermal and mechanical hyperalgesia and upregulation of the level of interleukin-1beta in the liver. In this study, we demonstrate that such injections of thymulin result in a significant elevation in the levels of TNF-alpha (P<0.01), NGF (P<0.01) and PGE(2) (P<0.01) in the liver of the treated rats, in addition to the increase in the levels of IL-1beta. Pretreatment with specific antagonists to each of these factors (polyclonal anti-TNF-alpha, anti-NGF antiserum and IL-1 receptor antagonist) did not result in the abolition of the hyperalgesia as assessed by the paw pressure, hot plate, paw immersion and tail flick tests. However, pretreatment with a combination of the above antagonist and antisera almost completely prevented thymulin-induced hyperalgesia. The cyclooxygenase inhibitor, meloxicam, reversed in a dose dependent manner (0.2, 0.4 and 2 mg/kg) thymulin effects as assessed by the different pain tests. It also abolished the thymulin-induced increase in the level of cytokines and NGF in the liver. Our results indicate that PGE(2) could be the key mediator of the hyperalgesic action of thymulin and the observed upregulation of proinflammatory cytokines and NGF.

Interleukin-15 production at the early stage after oral infection with Listeria monocytogenes in mice

We previously reported that exogenous interleukin-15 (IL-15) induces proliferation and activation of intestinal intraepithelial lymphocytes (i-IEL) in naive mice. To investigate the ability of endogenous IL-15 to stimulate i-IEL in vivo, we monitored i-IEL and intestinal epithelial cells (i-EC) in mice after an oral infection with Listeria monocytogenes. Although the populations of alphabeta and gammadelta i-IEL were not significantly changed after the oral infection, the expression level of interferon-gamma (IFN-gamma) was increased both at transcriptional and protein levels, and a conversely marked decrease in interleukin-4 (IL-4) was detected in the i-IEL on day 1 after infection as compared with before infection. The T helper 1 (Th1)-biased response of i-IEL coincided with a peak response of IL-15 production in the i-EC after oral infection. These results suggested that IL-15 produced from i-EC may be at least partly involved in the stimulation of i-IEL to produce IFN-gamma after oral infection with L. monocytogenes.

A thymic hormone protects mice from enteropathy during acute graft-versus-host disease

We have previously reported that a nonapeptide thymic hormone, facteur thymique serique (FTS), is involved in the differentiation and activation of intestinal intraepithelial lymphocytes (i-IEL) in mice. In this study, we examined the effect of FTS treatment on enteropathy in a murine model for acute graft-vs.-host disease (GVHD) induced by injection of parental C57BL/6 splenocytes into unirradiated (C57BL/6 x DBA/2) F1 hybrids. FTS treatment significantly protected mice from developing acute GVHD as assessed by mortality rate, splenomegaly and enteropathy. The infiltration of donor-derived TCR alpha beta i-IEL bearing CD8 alpha beta was significantly inhibited in the small intestine of FTS-treated mice, and the frequencies of apoptosis of crypt cells in the intestinal mucosa were decreased in these mice during acute GVHD. These results suggest that FTS treatment contributes to protection against enteropathy of acute GVHD. Thus, FTS may provide a useful approach to control acute GVHD after blood transfusion or bone marrow transplantation.

Murine model of IgE production with a predominant Th2-response by feeding protein antigen without adjuvants

Stimulation of systemic antigen-specific IgE production plays an important role in the mediation of food allergy; however, the mechanism of IgE production against food antigens is not fully understood. The development of relevant animal models may help to elucidate the pathogenesis of food allergy. We here show that DBA/2 mice receiving a casein diet without any adjuvant produced high levels of IgE specific for casein, accompanied by predominant Th2-like responses in liver lymphocytes, mesenteric lymph node cells and spleen cells. This model of IgE production produced by feeding protein antigen as a constituent of the diet can be applied to investigate the mechanism of IgE production and to develop reagents for controlling food allergy.

Interleukin-15 preferentially promotes the growth of intestinal intraepithelial lymphocytes bearing gamma delta T cell receptor in mice

Several cytokines including stem cell factor (SCF) and interleukin (IL)-7 are known to be required for development of gamma delta T cell receptor (TCR) intestinal intraepithelial lymphocytes (i-IEL) in mice. We show here the effects of IL-15 on the proliferation and maintenance of murine gamma delta i-IEL in vitro. gamma delta i-IEL constitutively expressed a high level of IL-15 receptor alpha mRNA and proliferated in response to IL-15 more vigorously than alpha beta i-IEL. V gamma/delta repertoire analysis revealed that IL-15, like IL-2, induced polyclonal expansion of gamma delta i-IEL, whereas gamma delta i-IEL responding to IL-7 showed a V gamma/delta repertoire skewed towards V gamma 1/V delta 4, V delta 5. IL-15 efficiently prevented gamma delta i-IEL from apoptosis induced by growth factor deprivation. This rescue was accompanied by up-regulation of Bcl-2 expression. These results suggest that IL-15 plays important roles in proliferation and maintenance of gamma delta i-IEL.