Which experimental models and explorations to use in regenerative endodontics? A comprehensive review on standard practices.

Since the discovery of dental pulp stem cells, a lot of teams have expressed an interest in dental pulp regeneration. Many approaches, experimental models and biological explorations have been developed, each including the use of stem cells and scaffolds with the final goal being clinical application in humans. In this review, the authors' objective was to compare the experimental models and strategies used for the development of biomaterials for tissue engineering of dental pulp with stem cells. Electronic queries were conducted on PubMed using the following terms: pulp regeneration, scaffold, stem cells, tissue engineering and biomaterial. The extracted data included the following information: the strategy envisaged, the type of stem cells, the experimental models, the exploration or analysis methods, the cytotoxicity or viability or proliferation cellular tests, the tests of scaffold antibacterial properties and take into account the vascularization of the regenerated dental pulp. From the 71 selected articles, 59% focused on the "cell-transplantation" strategy, 82% used in vitro experimentation, 58% in vivo animal models and only one described an in vivo in situ human clinical study. 87% used dental pulp stem cells. A majority of the studies reported histology (75%) and immunohistochemistry explorations (66%). 73% mentioned the use of cytotoxicity, proliferation or viability tests. 48% took vascularization into account but only 6% studied the antibacterial properties of the scaffolds. This article gives an overview of the methods used to regenerate dental pulp from stem cells and should help researchers create the best development strategies for research in this field.

The presence of senescent peripheral T-cells is negatively correlated to COVID-19 vaccine-induced immunity in cancer patients under 70 years of age.

Purpose: Cancer patients are at risk of severe COVID-19 infection, and vaccination is recommended. Nevertheless, we observe a failure of COVID-19 vaccines in this vulnerable population. We hypothesize that senescent peripheral T-cells alter COVID-19 vaccine-induced immunity. Methods: We performed a monocentric prospective study and enrolled cancer patients and healthy donors before the COVID-19 vaccination. The primary objective was to assess the association of peripheral senescent T-cells (CD28-CD57+KLRG1+) with COVID-19 vaccine-induced immunity. Results: Eighty cancer patients have been included, with serological and specific T-cell responses evaluated before and at 3 months post-vaccination. Age ≥ 70 years was the principal clinical factor negatively influencing the serological (p=0.035) and specific SARS-CoV-2 T-cell responses (p=0.047). The presence of senescent T-cells was correlated to lower serological (p=0.049) and specific T-cell responses (p=0.009). Our results sustained the definition of a specific cut-off for senescence immune phenotype (SIP) (≥ 5% of CD4 and ≥ 39.5% of CD8 T-cells), which was correlated to a lower serological response induced by COVID-19 vaccination for CD4 and CD8 SIPhigh (p=0.039 and p=0.049 respectively). While CD4 SIP level had no impact on COVID-19 vaccine efficacy in elderly patients, our results unraveled a possible predictive role for CD4 SIPhigh T-cell levels in younger cancer patients. Conclusions: Elderly cancer patients have a poor serological response to vaccination; specific strategies are needed in this population. Also, the presence of a CD4 SIPhigh affects the serological response in younger patients and seems to be a potential biomarker of no vaccinal response.

Influenza vaccination coverage at community pharmacies: Positioning, needs, expectations and involvement of community pharmacists in the Franche-Comté region.

INTRODUCTION: Influenza vaccination coverage currently remains below the 75% recommended threshold by the World Health Organization. To correct this situation, experiments have been successively carried out in France to enable community pharmacists to vaccinate at-risk populations. In this context, a study was conducted with pharmacists from the French Franche-Comté region to evaluate their positioning, needs and expectations regarding influenza vaccination at community pharmacies. MATERIALS AND METHODS: A survey was created and sent to licensed pharmacists in March of 2018. This consisted of 4 parts: characteristics of the community pharmacy; positioning of the pharmacist regarding vaccinations carried out at the pharmacy; training needs and expectations; and willingness to implement vaccinations. RESULTS: The participation rate in this survey was 32% (137/427). More than 90% of the pharmacists agreed that community pharmacies' assets were adequate for the implementation of these vaccinations (accessibility and availability), although 52% considered this complicated. Their main fears were reluctance from patients and conflicts of interest with other health professionals authorized to vaccinate (58%). The needs and expectations regarding pharmacy student training were essential for 94% of them as well as continuous training of practicing pharmacists (96%). The willingness of pharmacists to vaccinate stemmed from the fact that influenza vaccination coverage would increase for at-risk subjects (36%). CONCLUSION: This survey allowed us to assess the favorable positioning and the real interest of pharmacists from Franche-Comté regarding the influenza vaccination done at community pharmacies, given the proviso that they were given relevant training and allocated adequate resources.

[New immunotherapeutic approaches in oncology and hematology]. / Nouvelles approches d'immunothérapie en onco-hématologie.

Scientific advances in the last decade have demonstrated the critical role of host immune system in the elimination and suppression of cancer cells. Better knowledge of signaling pathways has enabled the development of new cancer immunotherapy. The discovery of negative feedback mechanisms following the lymphocyte activation has promoted the development of new antibodies targeting molecule inhibitors such as PD1, PDL1 or CTLA-4. Dramatic results were obtained with melanoma. Checkpoint inhibitors (pembrolizumab and ipilimumab) have many advantages in terms of rate of objective response and overall survival. Recent studies in translational research aimed to understand and analyze mechanisms of action of anti-PD1/anti-PDL1. Expression of PDL1 in the tumor is associated with a significantly greater objective response rate (immunohistochemistry). Nevertheless, limits with tumor immunohistochemical analysis encourage new biomarkers research. Other immunotherapy approaches, such as cell and gene therapies using engineered T cells call for further advancements to broaden their applicability. However, these therapies are very expensive and their manufacturing process very restrictive, which could lately limit their use in case of inefficiency of checkpoint inhibitors or when lymphocytic infiltration in tumor is absent. In this case, the objective would be to engineer ex vivo the patient's immune system by restoring the ability of T cells to identify and suppress tumor cells. Currently, two gene-reprogramming tools are under development: chimeric antigen receptor and TCR modified T cells.

Heat shock protein 100 and the amastigote stage-specific A2 proteins of Leishmania donovani.

HSP100 protein in Leishmania spp. plays an important role for the survival and integrity of intracellular amastigotes. The A2 proteins of L. donovani are functionally linked to HSP100. There is evidence for an interdependence between these two proteins, which are both expressed predominantly in the amastigote stage of Leishmania donovani. Mutant strains lacking either of these proteins display very similar phenotypes, i.e. loss of virulence both in vivo and in vitro. Also, both proteins colocalise specifically to small foci within the cytoplasm of amastigotes.