Modulation of Alveolar Macrophages by Postimmunobiotics: Impact on TLR3-Mediated Antiviral Respiratory Immunity.

Beneficial microbes with immunomodulatory capacities (immunobiotics) and their non-viable forms (postimmunobiotics) could be effectively utilized in formulations towards the prevention of respiratory viral infections. In this study, novel immunobiotic strains with the ability to increase antiviral immunity in porcine alveolar macrophages were selected from a library of Lactobacillus gasseri. Postimmunobiotics derived from the most remarkable strains were also evaluated in their capacity to modulate the immune response triggered by Toll-like receptor 3 (TLR3) in alveolar macrophages and to differentially regulate TLR3-mediated antiviral respiratory immunity in infant mice. We provide evidence that porcine alveolar macrophages (3D4/31 cells) are a useful in vitro tool for the screening of new antiviral immunobiotics and postimmunobiotics by assessing their ability to modulate the expression IFN-ß, IFN-λ1, RNAseL, Mx2, and IL-6, which can be used as prospective biomarkers. We also demonstrate that the postimmunobiotics derived from the Lactobacillus gasseri TMT36, TMT39 and TMT40 (HK36, HK39 or HK40) strains modulate the innate antiviral immune response of alveolar macrophages and reduce lung inflammatory damage triggered by TLR3 activation in vivo. Although our findings should be deepened and expanded, the results of the present work provide a scientific rationale for the use of nasally administered HK36, HK39 or HK40 to beneficially modulate TLR3-triggerd respiratory innate immune response.

The Side Effects and Adverse Clinical Cases Reported after COVID-19 Immunization.

COVID-19 remains a deadly disease that poses a serious threat to humanity. COVID-19 vaccines protect the public and limit viral spread. However, public acceptance is significantly dependent on the efficacy and side effects (SEs) of the vaccinations being produced. Four important mechanisms have been examined for COVID-19 vaccines: DNA-based, mRNA-based, protein-based, and inactivated viruses. Vaccination safety research was formerly limited to manufacturer-sponsored studies, but numerous additional cross-sectional survey-based studies conducted globally have contributed to the generation of vaccine-related safety data reports. Twenty-seven studies and twenty-four case reports published-up till 2021 were overviewed for the presentation of SEs and their severity. Injection site pain remained the most dominant localized SE, while headache and fatigue were the most prevalent systemic SEs. Most studies reported that all vaccinations were safe, with very little or no adverse effects, but the nature of SEs was reported to be more persistent in DNA- and mRNA-based vaccines, while inactivated viral vaccines were associated with longer-duration SEs. Overall, SEs were found to be more dominant in women and youngsters. Case reports of adverse reactions have also been documented, but there is still a need to find out their pathological linkage with the COVID-19 vaccination.