The immune system is comprised of several CD4⁺ T regulatory (Treg) cell types, of which two, the Foxp3⁺ Treg and T regulatory type 1 (Tr1) cells, have frequently been associated with transplant tolerance. However, whether and how these two Treg‐cell types synergize to promote allograft tolerance remains unknown. We previously developed a mouse model of allogeneic transplantation in which a specific immunomodulatory treatment leads to transplant tolerance through both Foxp3⁺ Treg and Tr1 cells. Here, we show that Foxp3⁺ Treg cells exert their regulatory function within the allograft and initiate engraftment locally and in a non‐antigen (Ag) specific manner. Whereas CD4⁺CD25⁻ T cells, which contain Tr1 cells, act from the spleen and are key to the maintenance of long‐term tolerance. Importantly, the role of Foxp3⁺ Treg and Tr1 cells is not redundant once they are simultaneously expanded/induced in the same host. Moreover, our data show that long‐term tolerance induced by Foxp3⁺ Treg‐cell transfer is sustained by splenic Tr1 cells and functionally moves from the allograft to the spleen.

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Infectious diseases in older people are associated with higher mortality rates and probiotics have been hypothesised to reduce the occurrence of infection. to assess the effectiveness and safety of probiotics in the occurrence of infections in older adults in comparison to placebo. a systematic review and meta-analysis of randomised placebo-controlled trials were conducted on 30 December 2016 using Medline, Embase, CENTRAL, Web of Science and LILACS databases. Efficacy outcomes were: occurrence of infection, quality of life, mortality and mean duration of infection per episode. Safety outcomes were adverse events. Data were analysed using relative risk ratios with 95% confidence intervals. Relative risk ratios were pooled where more than three estimates were available. fifteen articles were included, with a total of 5,916 participants with a mean age of 75.21 years. The effect of probiotics was not significantly different from that reported for placebo on the occurrence of infection, adverse events, mortality or mean duration of infection episodes (relative risk (RR) 0.90, 95% confidence interval (CI) 0.76 to 1.08; RR 1.01, 95% CI 0.91 to 1.12; RR 1.09, 95% CI 0.70 to 1.72; MD −0.35, 95% CI −1.57 to 0.87, respectively). the current low-quality evidence does not support the use of probiotics for the reduction in the occurrence of infection in older adults, however, the safety outcomes were similar between probiotics and placebo. Further research is required to confirm these findings. PROSPERO: CRD42014013707

Since the first case of COVID-19 in the world, there has been an evolution in the understanding of how the virus spreads and what must be done to contain the viral transmission at high-risk settings. Long-term care facilities (LTCFs) are considered at higher risk for virus outbreaks with poorer outcomes of residents, which can be particularly devastating in low- and middle-income countries³,⁴. In March 2020, the Brazilian Society of Geriatrics and Gerontology and the World Health Organization recommended the suspension of external visits to residents in LTCFs⁵. Therefore, the assessment of SARS CoV-2 seroprevalence is important in the definition of heath care policies in LTCFs.