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Objective: Recent studies have reported dysregulated expression of matrix metalloproteinases (MMPs), especially MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, TIMP-2), and extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in activated macrophages of patients with inflammatory diseases. Therefore, MMP-2, MMP-9, and their regulators may represent a new target for treatment of inflammatory diseases. Probiotics, which are comprised of lactic acid bacteria, have the potential to modulate inflammatory responses. In this experimental study, we investigated the anti-inflammatory effects of cell-free supernatants (CFS) from Lactobacillus acidophilus (L. acidophilus) and L. rhamnosus GG (LGG) in phorbol myristate acetate (PMA)-differentiated THP-1 cells. Materials and Methods: In this experimental study, PMA-differentiated THP-1 cells were treated with CFS from L. acidophilus, LGG and uninoculated bacterial growth media (as a control). The expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNAs were determined using real-time quantitative reverse transcription polymerase chain reaction (RTPCR). The levels of cellular surface expression of CD147 were assessed by flow cytometry, and the gelatinolytic activity of MMP-2 and MMP-9 were determined by zymography. Results: Our results showed that CFS from both L. acidophilus and LGG significantly inhibited the gene expression of MMP-9 (P=0.0011 and P=0.0005, respectively), increased the expression of TIMP-1 (P<0.0001), decreased the cell surface expression of CD147 (P=0.0307 and P=0.0054, respectively), and inhibited the gelatinolytic activity of MMP-9 (P=0.0003 and P<0.0001, respectively) in PMA-differentiated THP-1 cells. Although, MMP-2 expression and activity and TIMP-2 expression remained unchanged. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of M2000, a novel non-steroidal anti-inflammatory drug (NSAID) with immunosuppressive property and without gastro-nephrotoxicitic effects on matrix metalloproteinases (MMP)-2 and (MMP)-9 in phorbol myristate acetate (PMA)-differentiated THP-1 cells. Gene expression and activity of MMP-2 and MMP-9 are inhibited respectively by the tissue inhibitor of matrix metalloproteinase (TIMP)-2 and (TIMP)-1 and are induced by extracellular matrix metalloproteinase inducer (CD147/EMMPRIN). In this study, real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to determine gene expression of MMP-2, MMP-9, TIMP-1, and TIMP-2. Flow cytometry and zymography were applied to determine cellular surface expression of CD147 and activity of MMP-2 and MMP-9, respectively. Our results showed that treatment of THP-1 cells with high concentration (25 µg/mL) of M2000 significantly decreased the cellular surface expression of CD147 (p<0.05) and the gene expression of MMP-2, MMP-9 and TIMP-1 (p<0.05), and inhibited the gelatinolytic activity of MMP-2 and MMP-9 (p<0.05). According to our results, M2000 can reduce inflammation through inhibition of the cellular surface expression of CD147 and decrease the gene expression and gelatinolytic activity of MMP-2 and MMP-9 in PMA-differentiated THP-1 cells. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effects of M2000, a novel non-steroidal anti-inflammatory drug (NSAID) with immunosuppressive property and without gastronephrotoxicitic effects on matrix metalloproteinases (MMP)-2 and (MMP)-9 in phorbol myristate acetate (PMA)-differentiated THP-1 cells. Gene expression and activity of MMP-2 and MMP-9 are inhibited respectively by the tissue inhibitor of matrix metalloproteinase (TIMP)-2 and (TIMP)-1 and are induced by extracellular matrix metalloproteinase inducer (CD147/EMMPRIN). In this study, real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to determine gene expression of MMP-2, MMP-9, TIMP-1, and TIMP- 2. Flow cytometry and zymography were applied to determine cellular surface expression of CD147 and activity of MMP-2 and MMP-9, respectively. Our results showed that treatment of THP-1 cells with high concentration (25 μg/mL) of M2000 significantly decreased the cellular surface expression of CD147 (p<0.05) and the gene expression of MMP-2, MMP-9 and TIMP-1 (p<0.05), and inhibited the gelatinolytic activity of MMP-2 and MMP-9 (p<0.05). According to our results, M2000 can reduce inflammation through inhibition of the cellular surface expression of CD147 and decrease the gene expression and gelatinolytic activity of MMP-2 and MMP-9 in PMA-differentiated THP-1 cells. [ABSTRACT FROM AUTHOR]

Introduction. Neutralizing antibodies have been widely used for the prophylaxis and treatment of COVID-19. Hypothesis. The major target for these neutralizing antibodies is the receptor-binding domain (RBD) of the viral spike protein. Aim. In the present study, we developed and characterized three neutralizing chimeric mouse-human mAbs for potential therapeutic purposes. Methodology. Light and heavy chain variable region genes of three mouse mAbs (m4E8, m3B6, and m1D1) were amplified and ligated to human Cγ1 and Cκ constant region genes by PCR. After cloning into a dual promoter mammalian expression vector, the final constructs were transiently expressed in DG-44 cells and the purified chimeric antibodies were characterized by ELISA and Western blotting. The neutralizing potency of the chimeric mAbs was determined by three different virus neutralization tests including sVNT, pVNT, and cVNT. Results. All three recombinant chimeric mAbs display human constant regions and are able to specifically bind to the RBD of SARS-CoV-2 with affinities comparable to the parental mAbs. Western blot analysis showed similar epitope specificity profiles for both the chimeric and the parental mouse mAbs. The results of virus neutralization tests (sVNT, pVNT, and cVNT) indicate that c4E8 had the most potent neutralizing activity with IC50 values of 1.772, 0.009, and 0.01 µg ml -1 , respectively. All chimeric and mouse mAbs displayed a similar pattern of reactivity with the spike protein of the SARS-CoV-2 variants of concern (VOC) tested, including alpha, delta, and wild-type. Conclusion. The chimeric mAbs displayed neutralizing potency similar to the parental mouse mAbs and are potentially valuable tools for disease control.

Background: Incidence and severity of SARS-CoV2 infection are significantly lower in children and teenagers proposing that certain vaccines, routinely administered to neonates and children may provide cross-protection against this emerging infection., Objective: To assess the cross-protection induced by prior measles, mumps and rubella (MMR) vaccinations against COVID-19., Methods: The antibody responses to MMR and tetanus vaccines were determined in 53 patients affected with SARS-CoV2 infection and 52 age-matched healthy subjects. Serum levels of antibodies specific for NP and RBD of SARS-CoV2 were also determined in both groups of subjects with ELISA., Results: Our results revealed significant differences in anti-NP (P<0.0001) and anti-RBD (P<0.0001) IgG levels between patients and healthy controls. While the levels of rubella- and mumps specific IgG were not different in the two groups of subjects, measles-specific IgG was significantly higher in patients (P<0.01). The serum titer of anti-tetanus antibody, however, was significantly lower in patients compared to healthy individuals (P<0.01)., Conclusion: Our findings suggest that measles vaccination triggers those B cells cross-reactive with SARS-CoV2 antigens leading to the production of increased levels of measles-specific antibody.

Background: Mesenchymal stem cells (MSCs) are important candidates for MSC-based cellular therapy. Current paradigm states that MSCs support local progenitor cells in damaged tissue through paracrine signaling. Therefore, study of paracrine effects and secretome of MSCs could lead to the appreciation of mechanisms and molecules associated with the therapeutic effects of these cells. This study analyzed anti-inflammatory and immune-modulatory effects of MSC secretomes derived from embryonic stem cells (ESCs) and bone marrow cells after hypoxia and normoxia preconditioning., Methods: ESCs differentiated into MSCs and characterized by flow cytometry and differentiation into adipocytes and osteoblasts. The experimental groups consisted of individual groups of ESC-MSCs and BM-MSCs (bone marrow-derived mesenchymal stromal cells), which were preconditioned with either hypoxia or normoxia for 24, 48 and 72 h. After collecting the cell-free medium from each treatment, secretomes were concentrated by centrifugal filters. Using a peripheral blood mononuclear cell (PBMC) assay and ELISA, IL-10 concentration in PBMCs was evaluated after their incubation with different secretomes from preconditioned and non-preconditioned MSCs., Results: A significant difference was observed between ESC-MSC normoxia and ESC-MSC hypoxia in IL-10 concentration, and normoxia secretomes increased IL-10 secretion from PBMCs. Moreover, the strongest IL-10 secretion from PBMCs could be detected after the stimulation by ESC-MSC conditioned secretomes, but not BM-MSC conditioned medium., Conclusions: Human hypoxia preconditioned ESC-MSC secretome indicated stronger immune-modulatory effects compared to BM-MSC conditioned medium. It could be suggested that induced MSCs confer less immune-modulatory effects but produce more inflammatory molecules such as tumor necrosis factor α, which needs further investigation., Competing Interests: CONFLICT OF INTEREST. None declared.