Partial depletion of regulatory T cells does not influence the inflammation caused by high dose hemi-body irradiation

Compartment specific responses to contractility in the small intestinal epithelium

Tissues are subject to multiple mechanical inputs at the cellular level that influence their overall shape and function. In the small intestine, actomyosin contractility can be induced by many physiological and pathological inputs. However, we have little understanding of how contractility impacts the intestinal epithelium on a cellular and tissue level. In this study, we probed the cell and tissue-level effects of contractility by using mouse models to genetically increase the level of myosin activity in the two distinct morphologic compartments of the intestinal epithelium, the crypts and villi. We found that increased contractility in the villar compartment caused shape changes in the cells that expressed the transgene and their immediate neighbors. While there were no discernable effects on villar architecture or cell polarity, even low levels of transgene induction in the villi caused non-cell autonomous hyperproliferation of the transit amplifying cells in the crypt, driving increased cell flux through the crypt-villar axis. In contrast, induction of increased contractility in the proliferating cells of the crypts resulted in nuclear deformations, DNA damage, and apoptosis. This study reveals the complex and diverse responses of different intestinal epithelial cells to contractility and provides important insight into mechanical regulation of intestinal physiology.

Compartment specific responses to contractility in the small intestinal epithelium

Tissues are subject to multiple mechanical inputs at the cellular level that influence their overall shape and function. In the small intestine, actomyosin contractility can be induced by many physiological and pathological inputs. However, we have little understanding of how contractility impacts the intestinal epithelium on a cellular and tissue level. In this study, we probed the cell and tissue-level effects of contractility by using mouse models to genetically increase the level of myosin activity in the two distinct morphologic compartments of the intestinal epithelium, the crypts and villi. We found that increased contractility in the villar compartment caused shape changes in the cells that expressed the transgene and their immediate neighbors. While there were no discernable effects on villar architecture, even low levels of transgene induction in the villi caused non-cell autonomous hyperproliferation of the transit amplifying cells in the crypt, driving increased cell flux through the crypt-villar axis. In contrast, induction of increased contractility in the proliferating cells of the crypts resulted in nuclear deformations, DNA damage, and apoptosis. This study reveals the complex and diverse responses of different intestinal epithelial cells to contractility and provides important insight into mechanical regulation of intestinal physiology.

The analysis of Treg lymphocyte blood percentage changes in patients with head and neck cancer during combined oncological treatment: a preliminary report

Introduction

In patients with cancer, Treg lymphocytes seem to play an important role in promoting tumour growth. The number of circulating Treg cells has been associated with poor survival among patients suffering from various types of cancers. The aim of the present study was to evaluate the changes in the percentage levels of Treg lymphocytes in the blood samples of patients with head and neck cancer during combined treatment with respect to the stage of the disease and the intensity of the radiation reaction as monitored using the Dische scale.

Material and methods

Peripheral blood samples were collected from 20 head and neck cancer patients prior to the combined oncological treatment, during, and then one week after the completion of the therapy.

Results

A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected in patients during radiotherapy (RTH), chemotherapy (CTH), and chemoradiotherapy (CRT) than before the treatment began (p < 0.0001). A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected after RTH/CRT than before treatment, with respect to the radiation reaction as evaluated using the Dische scale (p = 0.0150).

Conclusions

The increase in the percentage of Treg cells correlated with an increase in the intensity of the radiation reaction measured using the Dische scale which indicates the advance of the oral mucositis reaction to RTH. In conclusion, because the role of Treg lymphocytes in cancer patients is complex, it is necessary to monitor the percentages of these cells in patients during combined oncological therapies.

A novel Hemi-Body Irradiation technique using electron beams (HBIe-)

PURPOSE

Certain radiation responsive skin diseases may develop symptoms on the upper or the lower half of the body. The concept of a novel Hemi-Body Electron Irradiation (HBIe^-) technique, described in this work, provides a low cost, LINAC based, intermediate treatment option in between extremely localized and Total Skin irradiation techniques.

MATERIALS AND METHODS

The HBIe^- technique, developed in our department, incorporates a custom crafted treatment chamber equipped with adjustable Pb shielding and a single electron beam in extended Source-Skin Distance (SSD) setup. The patient is positioned in 'Stanford' technique positions. The geometrical setup provides both optimal dose homogeneity and dose deposition up to a depth of 2 cm. To confirm this, the following characteristics were measured and evaluated: a) percentage depth dose (PDD) on the treatment plane produced by a single electron beam at perpendicular incidence for six fields at 'Stanford' angles, b) 2D profile of the entrance dose on the treatment plane produced by a single field and c) the total surface dose on an anthropomorphic phantom delivered by all 6 fields.

RESULTS

The resulting homogeneity of the surface dose in the treatment plane for an average patient was 5-6%, while surface dose homogeneity on the anthropomorphic phantom was 7% for both the upper and the lower HBIe^- variants. The total PDD exhibits an almost linear decrease to a practical range of 2 g/cm².

CONCLUSION

In conclusion, HBIe^- was proven effective in delivering the prescribed dose to the target area, while protecting the healthy skin.

Radiotherapy in the age of cancer immunology: Current concepts and future developments

Major advances in the knowledge of cancer biology and its interactions with tumor immune environment led to the emergence, in the last five years of new immunotherapy-based treatment strategies in cancer patients. At the same time, improvement in radiation technique and progress in radiobiology allowed in the last decade to expand the applications of radiotherapy in a growing number of settings. At present, there are strong theoretical basis to propose immune-enhanced radiation therapy that may represent in the future a new paradigm of treatment, combining the intrinsic power of radiotherapy to elicit a specific, systemic, tumor-directed immune response with modern highly conformal and precise dose delivery, in order to maximize response at the major site of disease and obtain durable disease control. The aim of this review is to describe the principal mechanisms of immune modulation of response to radiation and investigational strategies to harness the potential of radiation-inducible immune response: radiation therapy is expected to be not just a local treatment but the cornerstone of a multimodal strategy that might achieve long-lasting tumor remission at the primary site and systemic efficacy metastatic lesions.

IL-17A Is an Important Effector of the Immune Response of the Mammary Gland to Escherichia coli Infection

The cytokine IL-17A has been shown to play critical roles in host defense against bacterial and fungal infections at different epithelial sites, but its role in the defense of the mammary gland (MG) has seldom been investigated, although infections of the MG constitute the main pathology afflicting dairy cows. In this study, we showed that IL-17A contributes to the defense of the MG against Escherichia coli infection by using a mouse mastitis model. After inoculation of the MG with a mastitis-causing E. coli strain, the bacterial load increased rapidly, triggering an intense influx of leukocytes into mammary tissue and increased concentrations of IL-6, IL-22, TNF-α, and IL-10. Neutrophils were the first cells that migrated intensely to the mammary tissue, in line with an early production of CXCL2. Depletion of neutrophils induced an increased mammary bacterial load. There was a significant increase of IL-17-containing CD4(+) αβ T lymphocyte numbers in infected glands. Depletion of IL-17A correlated with an increased bacterial colonization and IL-10 production. Intramammary infusion of IL-17A at the onset of infection was associated with markedly decreased bacterial numbers, decreased IL-10 production, and increased neutrophil recruitment. Depletion of CD25(+) regulatory T cells correlated with a decreased production of IL-10 and a reduced bacterial load. These results indicate that IL-17A is an important effector of MG immunity to E. coli and suggest that an early increased local production of IL-17A would improve the outcome of infection. These findings point to a new lead to the development of vaccines against mastitis.

The extent of irradiation-induced long-term visceral organ damage depends on cranial/brain exposure

In case of high-dose radiation exposure, mechanisms controlling late visceral organ damage are still not completely understood and may involve the central nervous system. To investigate the influence of cranial/brain irradiation on late visceral organ damage in case of high-dose exposure, Wistar rats were irradiated at 12 Gy, with either the head and fore limbs or the two hind limbs protected behind a lead wall (head- and hind limbs-protected respectively), which allows long-term survival thanks to bone marrow protection. Although hind limbs- and head-protected irradiated rats exhibited similar hematopoietic and spleen reconstitution, a late body weight loss was observed in hind limbs-protected rats only. Histological analysis performed at this time revealed that late damages to liver, kidney and ileum were attenuated in rats with head exposed when compared to animals whose head was protected. Plasma measurements of inflammation biomarkers (haptoglobin and the chemokine CXCL1) suggest that the attenuated organ damage in hind limbs-protected rats may be in part related to reduced acute and chronic inflammation. Altogether our results demonstrate the influence of cranial/brain exposure in the onset of organ damage.