Characterization of Early and Late Damage in a Mouse Model of Pelvic Radiation Disease.

Pelvic radiation disease (PRD), a frequent side effect in patients with abdominal/pelvic cancers treated with radiotherapy, remains an unmet medical need. Currently available preclinical models have limited applications for the investigation of PRD pathogenesis and possible therapeutic strategies. In order to select the most effective irradiation protocol for PRD induction in mice, we evaluated the efficacy of three different locally and fractionated X-ray exposures. Using the selected protocol (10 Gy/day × 4 days), we assessed PRD through tissue (number and length of colon crypts) and molecular (expression of genes involved in oxidative stress, cell damage, inflammation, and stem cell markers) analyses at short (3 h or 3 days after X-ray) and long (38 days after X-rays) post-irradiation times. The results show that a primary damage response in term of apoptosis, inflammation, and surrogate markers of oxidative stress was found, thus determining a consequent impairment of cell crypts differentiation and proliferation as well as a local inflammation and a bacterial translocation to mesenteric lymph nodes after several weeks post-irradiation. Changes were also found in microbiota composition, particularly in the relative abundance of dominant phyla, related families, and in alpha diversity indices, as an indication of dysbiotic conditions induced by irradiation. Fecal markers of intestinal inflammation, measured during the experimental timeline, identified lactoferrin, along with elastase, as useful non-invasive tools to monitor disease progression. Thus, our preclinical model may be useful to develop new therapeutic strategies for PRD treatment.

PARP1 Activation Induces HMGB1 Secretion Promoting Intestinal Inflammation in Mice and Human Intestinal Organoids.

Extracellular High-mobility group box 1 (HMGB1) contributes to the pathogenesis of inflammatory disorders, including inflammatory bowel diseases (IBD). Poly (ADP-ribose) polymerase 1 (PARP1) has been recently reported to promote HMGB1 acetylation and its secretion outside cells. In this study, the relationship between HMGB1 and PARP1 in controlling intestinal inflammation was explored. C57BL6/J wild type (WT) and PARP1-/- mice were treated with DSS to induce acute colitis, or with the DSS and PARP1 inhibitor, PJ34. Human intestinal organoids, which are originated from ulcerative colitis (UC) patients, were exposed to pro-inflammatory cytokines (INFγ + TNFα) to induce intestinal inflammation, or coexposed to cytokines and PJ34. Results show that PARP1-/- mice develop less severe colitis than WT mice, evidenced by a significant decrease in fecal and serum HMGB1, and, similarly, treating WT mice with PJ34 reduces the secreted HMGB1. The exposure of intestinal organoids to pro-inflammatory cytokines results in PARP1 activation and HMGB1 secretion; nevertheless, the co-exposure to PJ34, significantly reduces the release of HMGB1, improving inflammation and oxidative stress. Finally, HMGB1 release during inflammation is associated with its PARP1-induced PARylation in RAW264.7 cells. These findings offer novel evidence that PARP1 favors HMGB1 secretion in intestinal inflammation and suggest that impairing PARP1 might be a novel approach to manage IBD.

Radiotherapy, PARP Inhibition, and Immune-Checkpoint Blockade: A Triad to Overcome the Double-Edged Effects of Each Single Player.

Radiotherapy and, more recently, PARP inhibitors (PARPis) and immune-checkpoint inhibitors represent effective tools in cancer therapy. Radiotherapy exerts its effects not only by damaging DNA and inducing tumor cell death, but also stimulating anti-tumor immune responses. PARPis are known to exert their therapeutic effects by inhibiting DNA repair, and they may be used in combination with radiotherapy. Both radiotherapy and PARPis modulate inflammatory signals and stimulate type I IFN (IFN-I)-dependent immune activation. However, they can also support the development of an immunosuppressive tumor environment and upregulate PD-L1 expression on tumor cells. When provided as monotherapy, immune-checkpoint inhibitors (mainly antibodies to CTLA-4 and the PD-1/PD-L1 axis) result particularly effective only in immunogenic tumors. Combinations of immunotherapy with therapies that favor priming of the immune response to tumor-associated antigens are, therefore, suitable strategies. The widely explored association of radiotherapy and immunotherapy has confirmed this benefit for several cancers. Association with PARPis has also been investigated in clinical trials. Immunotherapy counteracts the immunosuppressive effects of radiotherapy and/or PARPis and synergies with their immunological effects, promoting and unleashing immune responses toward primary and metastatic lesions (abscopal effect). Here, we discuss the beneficial and counterproductive effects of each therapy and how they can synergize to overcome single-therapy limitations.

Increased biting rate and decreased Wolbachia density in irradiated Aedes mosquitoes.

BACKGROUND: Releasing considerable numbers of radiation-sterilized males is a promising strategy to suppress mosquito vectors. However, releases may also include small percentages of biting females, which translate to non-negligible numbers when releases are large. Currently, the effects of irradiation on host-seeking and host-biting behaviors have not been exhaustively investigated. Information is also lacking regarding the effects of sterilizing treatment on the endosymbiotic bacterium Wolbachia, which is known to affect the vector competence of infected mosquitos. METHODS: To ascertain the effects of irradiation on females, the pupae of two Aedes albopictus strains, differing in their natural or artificial Wolbachia infection type, and Aedes aegypti-which is not infected by Wolbachia-were treated with various doses of X-rays and monitored for key fitness parameters and biting behavior over a period of 2 weeks. The effect of radiation on Wolbachia was investigated by quantitative polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FISH) analysis. RESULTS: Partial Aedes albopictus female sterility was achieved at 28 Gy, but the number of weekly bites more than doubled compared to that of the controls. Radiation doses of 35 and 45 Gy completely inhibited progeny production but did not significantly affect the survival or flight ability of Ae. albopictus females and caused a tripling of the number of bites per female per week (compared to untreated controls). These results were also confirmed in Ae. aegypti after treatment at 50 Gy. Wolbachia density decreased significantly in 45-Gy-irradiated females, with the greatest decreases in the early irradiation group (26 ± 2-h-old pupae). Wolbachia density also decreased as adults aged. This trend was confirmed in ovaries but not in extra-ovarian tissues. FISH analysis showed a strongly reduced Wolbachia-specific fluorescence in the ovaries of 13 ± 1-day-old females. CONCLUSIONS: These results suggest that, under sterile insect technique (SIT) programs, the vector capacity of a target population could increase with the frequency of the irradiated females co-released with the sterile males due to an increased biting rate. In the context of successful suppression, the related safety issues are expected to be generally negligible, but they should be conservatively evaluated when large-scale programs relying on imperfect sexing and high overflooding release ratios are run for long periods in areas endemic for arboviral diseases. Also, the effects of irradiation on the vector competence deserve further investigation.

Severe Acute Respiratory Syndrome Coronavirus-2 Infection and Autoimmunity 1 Year Later: The Era of Vaccines.

Impressive efforts have been made by researchers worldwide in the development of target vaccines against the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and in improving the management of immunomodulating agents. Currently, different vaccine formulations, such as viral vector, mRNA, and protein-based, almost all directed toward the spike protein that includes the domain for receptor binding, have been approved. Although data are not conclusive, patients affected by autoimmune rheumatic diseases (ARDs) seem to have a slightly higher disease prevalence, risk of hospitalization, and death from coronavirus disease-2019 (COVID-19) than the general population. Therefore, ARD patients, under immunosuppressive agents, have been included among the priority target groups for vaccine administration. However, specific cautions are needed to optimize vaccine safety and effectiveness in these patients, such as modification in some of the ongoing immunosuppressive therapies and the preferential use of mRNA other than vector-based vaccines. Immunomodulating agents can be a therapeutic opportunity for the management of COVID-19 patients; however, their clinical impact depends on how they are handled. To place in therapy immunomodulating agents in the correct window of opportunity throughout the identification of surrogate markers of disease progression and host immune response is mandatory to optimize patient's outcome.

Validation of a biomarker tool capable of measuring the absorbed dose soon after exposure to ionizing radiation.

A radiological or nuclear attack could involve such a large number of subjects as to overwhelm the emergency facilities in charge. Resources should therefore be focused on those subjects needing immediate medical attention and care. In such a scenario, for the triage management by first responders, it is necessary to count on efficient biological dosimetry tools capable of early detection of the absorbed dose. At present the validated assays for measuring the absorbed dose are dicentric chromosomes and micronuclei counts, which require more than 2-3 days to obtain results. To overcome this limitation the NATO SPS Programme funded an Italian-Egyptian collaborative project aimed at validating a fast, accurate and feasible tool for assessing the absorbed dose early after radiation exposure. Biomarkers as complete blood cell counts, DNA breaks and radio-inducible proteins were investigated on blood samples collected before and 3 h after the first fraction of radiotherapy in patients treated in specific target areas with doses/fraction of about: 2, 3.5 or > 5 Gy and compared with the reference micronuclei count. Based on univariate and multivariate multiple linear regression correlation, our results identify five early biomarkers potentially useful for detecting the extent of the absorbed dose 3 h after the exposure.

ADP-ribosylation in evasion, promotion and exacerbation of immune responses.

ADP-ribosylation is the addition of one or more (up to some hundreds) ADP-ribose moieties to acceptor proteins. This evolutionary ancient post-translational modification (PTM) is involved in fundamental processes including DNA repair, inflammation, cell death, differentiation and proliferation, among others. ADP-ribosylation is catalysed by two major families of enzymes: the cholera toxin-like ADP-ribosyltransferases (ARTCs) and the diphtheria toxin-like ADP-ribosyltransferases (ARTDs, also known as PARPs). ARTCs sense and use extracellular NAD, which may represent a danger signal, whereas ARTDs are present in the cell nucleus and/or cytoplasm. ARTCs mono-ADP-ribosylate their substrates, whereas ARTDs, according to the specific family member, are able to mono- or poly-ADP-ribosylate target proteins or are devoid of enzymatic activity. Both mono- and poly-ADP-ribosylation are dynamic processes, as specific hydrolases are able to remove single or polymeric ADP moieties. This dynamic equilibrium between addition and degradation provides plasticity for fast adaptation, a feature being particularly relevant to immune cell functions. ADP-ribosylation regulates differentiation and functions of myeloid, T and B cells. It also regulates the expression of cytokines and chemokines, production of antibodies, isotype switch and the expression of several immune mediators. Alterations in these processes involve ADP-ribosylation in virtually any acute and chronic inflammatory/immune-mediated disease. Besides, pathogens developed mechanisms to contrast the action of ADP-ribosylating enzymes by using their own hydrolases and/or to exploit this PTM to sustain their virulence. In the present review, we summarize and discuss recent findings on the role of ADP-ribosylation in immunobiology, immune evasion/subversion by pathogens and immune-mediated diseases.

Cytokine Release Syndrome in COVID-19 Patients, A New Scenario for an Old Concern: The Fragile Balance between Infections and Autoimmunity.

On 7 January 2020, researchers isolated and sequenced in China from patients with severe pneumonitis a novel coronavirus, then called SARS-CoV-2, which rapidly spread worldwide, becoming a global health emergency. Typical manifestations consist of flu-like symptoms such as fever, cough, fatigue, and dyspnea. However, in about 20% of patients, the infection progresses to severe interstitial pneumonia and can induce an uncontrolled host-immune response, leading to a life-threatening condition called cytokine release syndrome (CRS). CRS represents an emergency scenario of a frequent challenge, which is the complex and interwoven link between infections and autoimmunity. Indeed, treatment of CRS involves the use of both antivirals to control the underlying infection and immunosuppressive agents to dampen the aberrant pro-inflammatory response of the host. Several trials, evaluating the safety and effectiveness of immunosuppressants commonly used in rheumatic diseases, are ongoing in patients with COVID-19 and CRS, some of which are achieving promising results. However, such a use should follow a multidisciplinary approach, be accompanied by close monitoring, be tailored to patient's clinical and serological features, and be initiated at the right time to reach the best results. Autoimmune patients receiving immunosuppressants could be prone to SARS-CoV-2 infections; however, suspension of the ongoing therapy is contraindicated to avoid disease flares and a consequent increase in the infection risk.

Multifaceted Role of PARP-1 in DNA Repair and Inflammation: Pathological and Therapeutic Implications in Cancer and Non-Cancer Diseases.

PARP-1 (poly(ADP-ribose)-polymerase 1), mainly known for its protective role in DNA repair, also regulates inflammatory processes. Notably, defects in DNA repair and chronic inflammation may both predispose to cancer development. On the other hand, inhibition of DNA repair and inflammatory responses can be beneficial in cancer therapy and PARP inhibitors are currently used for their lethal effects on tumor cells. Furthermore, excess of PARP-1 activity has been associated with many tumors and inflammation-related clinical conditions, including asthma, sepsis, arthritis, atherosclerosis, and neurodegenerative diseases, to name a few. Activation and inhibition of PARP represent, therefore, a double-edged sword that can be exploited for therapeutic purposes. In our review, we will discuss recent findings highlighting the composite multifaceted role of PARP-1 in cancer and inflammation-related diseases.

Effects of Simulated Space Radiations on the Tomato Root Proteome.

Plant cultivation on spacecraft or planetary outposts is a promising and actual perspective both for food and bioactive molecules production. To this aim, plant response to ionizing radiations, as an important component of space radiation, must be assessed through on-ground experiments due to the potentially fatal effects on living systems. Hereby, we investigated the effects of X-rays and γ-rays exposure on tomato "hairy root" cultures (HRCs), which represent a solid platform for the production of pharmaceutically relevant molecules, including metabolites and recombinant proteins. In a space application perspective, we used an HRC system previously fortified through the accumulation of anthocyanins, which are known for their anti-oxidant properties. Roots were independently exposed to different photon radiations, namely X-rays (250 kV) and γ-rays (Co60, 1.25 MeV), both at the absorbed dose levels of 0.5, 5, and 10 Gy. Molecular changes induced in the proteome of HRCs were investigated by a comparative approach based on two-dimensional difference in-gel electrophoresis (2D-DIGE) technology, which allowed to highlight dynamic processes activated by these environmental stresses. Results revealed a comparable response to both photon treatments. In particular, the presence of differentially represented proteins were observed only when roots were exposed to 5 or 10 Gy of X-rays or γ-rays, while no variations were appreciated at 0.5 Gy of both radiations, when compared with unexposed control. Differentially represented proteins were identified by mass spectrometry procedures and their functional interactions were analyzed, revealing variations in the activation of stress response integrated mechanisms as well as in carbon/energy and protein metabolism. Specific results from above-mentioned procedures were validated by immunoblotting. Finally, a morphometric analysis verified the absence of significant alterations in the development of HRCs, allowing to ascribe the observed variations of protein expression to processes of acclimation to ionizing radiations. Overall results contribute to a meaningful risk evaluation for biological systems exposed to extra-terrestrial environments, in the perspective of manned interplanetary missions planned for the near future.

Enhancing the Secretion of a Glyco-Engineered Anti-CD20 scFv-Fc Antibody in Hairy Root Cultures.

Hairy root (HR) cultures represent an attractive platform for the production of heterologous proteins, due to the possibility of secreting the molecule of interest in the culture medium. The main limitation is the low accumulation yields of heterologous proteins. The aim of this study is to enhance the accumulation of a tumor-targeting antibody with a human-compatible glycosylation profile in HR culture medium. To this aim, the authors produce Nicotiana benthamiana HR cultures expressing the red fluorescent protein (RFP) to easily screen for different auxins able to induce heterologous protein secretion in the medium. The hormone 2,4-dichlorophenoxyacetic acid (2,4-D) is found to induce high accumulation levels (334 mg L-1 ) of RFP in the culture medium. The same protocol is used to improve the secretion of the tumor-targeting, CD20-specific 2B8-FcΔXF recombinant antibody from glyco-engineered ΔXTFT N. benthamiana HR cultures. The addition of 2,4-D determine a 28-fold increase of the accumulation of fully functional 2B8-FcΔXF in the culture medium, at levels of ≈16 mg L-1 . Antibody N-glycosylation profiling reveal the prominent occurrence of GnGn structures and low levels of xylose- and fucose-containing counterparts. This result is the first example of the expression of an engineered anti-CD20 antibody with a scFv-Fc format at high levels in HR.

Immune-Modulating Perspectives for Low Frequency Electromagnetic Fields in Innate Immunity.

In recent years, the effects of electromagnetic fields (EMFs) on the immune system have received a considerable interest, not only to investigate possible negative health impact but also to explore the possibility to favorably modulate immune responses. To generate beneficial responses, the immune system should eradicate pathogens while "respecting" the organism and tolerating irrelevant antigens. According to the current view, damage-associated molecules released by infected or injured cells, or secreted by innate immune cells generate danger signals activating an immune response. These signals are also relevant to the subsequent activation of homeostatic mechanisms that control the immune response in pro- or anti-inflammatory reactions, a feature that allows modulation by therapeutic treatments. In the present review, we describe and discuss the effects of extremely low frequency (ELF)-EMF and pulsed EMF on cell signals and factors relevant to the activation of danger signals and innate immunity cells. By discussing the EMF modulating effects on cell functions, we envisage the use of EMF as a therapeutic agent to regulate immune responses associated with wound healing.

N-glycan engineering of a plant-produced anti-CD20-hIL-2 immunocytokine significantly enhances its effector functions.

Anti-CD20 recombinant antibodies are among the most promising therapeutics for the treatment of B-cell malignancies such as non-Hodgkin lymphomas. We recently demonstrated that an immunocytokine (2B8-Fc-hIL2), obtained by fusing an anti-CD20 scFv-Fc antibody derived from C2B8 mAb (rituximab) to the human interleukin 2 (hIL-2), can be efficiently produced in Nicotiana benthamiana plants. The purified immunocytokine (IC) bearing a typical plant protein N-glycosylation profile showed a CD20 binding activity comparable to that of rituximab and was efficient in eliciting antibody-dependent cell-mediated cytotoxicity (ADCC) of human PBMC against Daudi cells, indicating its fuctional integrity. In this work, the immunocytokine devoid of the typical xylose/fucose N-glycosylation plant signature (IC-ΔXF) and the corresponding scFv-Fc-ΔXF antibody not fused to the cytokine, were obtained in a glyco-engineered ΔXylT/FucT N. benthamiana line. Purification yields from agroinfiltrated plants amounted to 20-35 mg/kg of leaf fresh weight. When assayed for interaction with FcγRI and FcγRIIIa, IC-ΔXF exhibited significantly enhanced binding affinities if compared to the counterpart bearing the typical plant protein N-glycosylation profile (IC) and to rituximab. The glyco-engineered recombinant molecules also exhibited a strongly improved ADCC and complement-dependent cytotoxicity (CDC). Notably, our results demonstrate a reduced C1q binding of xylose/fucose carrying IC and scFv-Fc compared to versions that lack these sugar moieties. These results demonstrate that specific N-glycosylation alterations in recombinant products can dramatically affect the effector functions of the immunocytokine, resulting in an overall improvement of the biological functions and consequently of the therapeutic potential.

Production of an active anti-CD20-hIL-2 immunocytokine in Nicotiana benthamiana.

Anti-CD20 murine or chimeric antibodies (Abs) have been used to treat non-Hodgkin lymphomas (NHLs) and other diseases characterized by overactive or dysfunctional B cells. Anti-CD20 Abs demonstrated to be effective in inducing regression of B-cell lymphomas, although in many cases patients relapse following treatment. A promising approach to improve the outcome of mAb therapy is the use of anti-CD20 antibodies to deliver cytokines to the tumour microenvironment. In particular, IL-2-based immunocytokines have shown enhanced antitumour activity in several preclinical studies. Here, we report on the engineering of an anti-CD20-human interleukin-2 (hIL-2) immunocytokine (2B8-Fc-hIL2) based on the C2B8 mAb (Rituximab) and the resulting ectopic expression in Nicotiana benthamiana. The scFv-Fc-engineered immunocytokine is fully assembled in plants with minor degradation products as assessed by SDS-PAGE and gel filtration. Purification yields using protein-A affinity chromatography were in the range of 15-20 mg/kg of fresh leaf weight (FW). Glycopeptide analysis confirmed the presence of a highly homogeneous plant-type glycosylation. 2B8-Fc-hIL2 and the cognate 2B8-Fc antibody, devoid of hIL-2, were assayed by flow cytometry on Daudi cells revealing a CD20 binding activity comparable to that of Rituximab and were effective in eliciting antibody-dependent cell-mediated cytotoxicity of human PBMC versus Daudi cells, demonstrating their functional integrity. In 2B8-Fc-hIL2, IL-2 accessibility and biological activity were verified by flow cytometry and cell proliferation assay. To our knowledge, this is the first example of a recombinant immunocytokine based on the therapeutic Rituximab antibody scaffold, whose expression in plants may be a valuable tool for NHLs treatment.

Effects of GSM-modulated 900 MHz radiofrequency electromagnetic fields on the hematopoietic potential of mouse bone marrow cells.

Studies describing the influence of radiofrequency electromagnetic fields on bone marrow cells (BMC) often lack functional data. We examined the effects of in vivo exposure to a Global System for Mobile Communications (GSM) modulated 900 MHz RF fields on BMC using two transplantation models. X-irradiated syngeneic mice were injected with BMC from either RF-field-exposed, sham-exposed or cage control mice. Twelve weeks after transplantation, no differences in thymocyte number, frequency of subpopulations and cell proliferation were found in mice receiving BMC from either group. Also, in the spleen cell number, percentages of B/T cells, B/T-cell proliferation, and interferon γ (IFN-γ) production were similar in all groups. In parallel, a mixture of BMC from congenic sham- and RF-exposed mice were co-transplanted into lymphopenic Rag2 deficient mice. BMC from RF-exposed and sham-exposed mice displayed no advantage or disadvantage when competing for the replenishment of lymphatic organs with mature lymphocytes in Rag2 deficient mice. This model revealed that BMC from sham-exposed and RF-exposed mice were less efficient than BMC from cage control mice in repopulating the thymus, an effect likely due to restraint stress. In conclusion, our results showed no effects of in vivo exposure to GSM-modulated RF-fields on the ability of bone marrow (BM) precursors to long-term reconstitute peripheral T and B cell compartments.

Beyond DNA repair, the immunological role of PARP-1 and its siblings.

ADP-ribosylation is the addition of one or more (up to some hundreds) ADP-ribose moieties to acceptor proteins. There are two major families of enzymes that catalyse this reaction: extracellular ADP-ribosyl-transferases (ARTs), which are bound to the cell membrane by a glycosylphosphatidylinositol anchor or are secreted, and poly(ADP-ribose)-polymerases (PARPs), which are present in the cell nucleus and/or cytoplasm. Recent findings revealed a wide immunological role for ADP-ribosylating enzymes. ARTs, by sensing extracellular NAD concentration, can act as danger detectors. PARP-1, the prototypical representative of the PARP family, known to protect cells from genomic instability, is involved in the development of inflammatory responses and several forms of cell death. PARP-1 also plays a role in adaptive immunity by modulating the ability of dendritic cells to stimulate T cells or by directly affecting the differentiation and functions of T and B cells. Both PARP-1 and PARP-14 (CoaSt6) knockout mice were described to display reduced T helper type 2 cell differentiation and allergic responses. Our recent findings showed that PARP-1 is involved in the differentiation of Foxp3+ regulatory T (Treg) cells, suggesting a role for PARP-1 in tolerance induction. Also ARTs regulate Treg cell homeostasis by promoting Treg cell apoptosis during inflammatory responses. PARP inhibitors ameliorate immune-mediated diseases in several experimental models, including rheumatoid arthritis, colitis, experimental autoimmune encephalomyelitis and allergy. Together these findings show that ADP-ribosylating enzymes, in particular PARP-1, play a pivotal role in the regulation of immune responses and may represent a good target for new therapeutic approaches in immune-mediated diseases.

Scientific basis for the Soviet and Russian radiofrequency standards for the general public.

The former Soviet Union (USSR) and the USA were the first countries to introduce standards limiting exposure to radiofrequency (RF) fields. However, the exposure limits in the USSR standards were always much lower than those in the USA and other countries. The objective of this article is to provide a history of the development of the Soviet and Russian RF standards. In addition, we summarize the scientific evidence used to develop the original USSR RF and subsequent Russian public health standards, as well as the mobile telecommunications standard published in 2003, but we do not critique them. We also describe the protective approaches used by the Soviet and Russian scientists for setting their limits. A translation of the papers of the key studies used to develop their standards is available in the online version of this publication.

Prenatal exposure to radiofrequencies: effects of WiFi signals on thymocyte development and peripheral T cell compartment in an animal model.

Wireless local area networks are an increasing alternative to wired data networks in workplaces, homes, and public areas. Concerns about possible health effects of this type of signal, especially when exposure occurs early in life, have been raised. We examined the effects of prenatal (in utero) exposure to wireless fidelity (WiFi) signal-associated electromagnetic fields (2450 MHz center-frequency band) on T cell development and function. Pregnant mice were exposed whole body to a specific absorption rate of 4 W/kg, 2 h per day, starting 5 days after mating and ending 1 day before the expected delivery. Sham-exposed and cage control groups were used as controls. No effects on cell count, phenotype, and proliferation of thymocytes were observed. Also, spleen cell count, CD4/CD8 cell frequencies, T cell proliferation, and cytokine production were not affected by the exposure. These findings were consistently observed in the male and female offspring at early (5 weeks of age) and late (26 weeks of age) time points. Nevertheless, the expected differences associated with aging and/or gender were confirmed. In conclusion, our results do not support the hypothesis that the exposure to WiFi signals during prenatal life results in detrimental effects on the immune T cell compartment.

Early life exposure to 2.45GHz WiFi-like signals: effects on development and maturation of the immune system.

The development of the immune system begins during embryogenesis, continues throughout fetal life, and completes its maturation during infancy. Exposure to immune-toxic compounds at levels producing limited/transient effects in adults, results in long-lasting or permanent immune deficits when it occurs during perinatal life. Potentially harmful radiofrequency (RF) exposure has been investigated mainly in adult animals or with cells from adult subjects, with most of the studies showing no effects. Is the developing immune system more susceptible to the effects of RF exposure? To address this question, newborn mice were exposed to WiFi signals at constant specific absorption rates (SAR) of 0.08 or 4 W/kg, 2h/day, 5 days/week, for 5 consecutive weeks, starting the day after birth. The experiments were performed with a blind procedure using sham-exposed groups as controls. No differences in body weight and development among the groups were found in mice of both sexes. For the immunological analyses, results on female and male newborn mice exposed during early post-natal life did not show any effects on all the investigated parameters with one exception: a reduced IFN-γ production in spleen cells from microwaves (MW)-exposed (SAR 4 W/kg) male (not in female) mice compared with sham-exposed mice. Altogether our findings do not support the hypothesis that early post-natal life exposure to WiFi signals induces detrimental effects on the developing immune system.