Adjuvant Effect of Killed Propionibacterium acnes on Mouse Peritoneal B-1 Lymphocytes and Their Early Phagocyte Differentiation

B-1 lymphocytes are the predominant cells in mouse peritoneal cavity. They express macrophage and lymphocyte markers and are divided into B-1a, B-1b and B-1c subtypes. The role of B-1 cells is not completely clear, but they are responsible for natural IgM production and seem to play a regulatory role. An enriched B-1b cell population can be obtained from non-adherent peritoneal cell cultures, and we have previously demonstrated that these cells undergo differentiation to acquire a mononuclear phagocyte phenotype upon attachment to the substrate in vitro. Nevertheless, the B-1 cell response to antigens or adjuvants has been poorly investigated. Because killed Propionibacterium acnes exhibits immunomodulatory effects on both macrophages and B-2 lymphocytes, we analyzed whether a killed bacterial suspension or its soluble polysaccharide (PS) could modulate the absolute number of peritoneal B-1 cells in BALB/c mice, the activation status of these cells and their ability to differentiate into phagocytes in vitro. In vivo, P. acnes treatment elevated the absolute number of all B-1 subsets, whereas PS only increased B-1c. Moreover, the bacterium increased the number of B-1b cells that were positive for MHC II, TLR2, TLR4, TLR9, IL-4, IL-5 and IL-12, in addition to up-regulating TLR9, CD80 and CD86 expression. PS increased B-1b cell expression of TLR4, TLR9, CD40 and CD86, as well as IL-10 and IL-12 synthesis. Both of the treatments decreased the absolute number of B-1b cells in vitro, suggesting their early differentiation into B-1 cell-derived phagocytes (B-1CDP). We also observed a higher phagocytic activity from the phagocytes that were derived from B-1b cells after P. acnes and PS treatment. The adjuvant effect that P. acnes has on B-1 cells, mainly the B-1b subtype, reinforces the importance of B-1 cells in the innate and adaptive immune responses

Anatomical Basis of the Myofascial Trigger Points of the Gluteus Maximus Muscle

Myofascial pain syndrome is characterized by pain and limited range of motion in joints and caused by muscular contracture related to dysfunctional motor end plates and myofascial trigger points (MTrPs). We aimed to observe the anatomical correlation between the clinically described MTrPs and the entry point of the branches of the inferior gluteal nerve into the gluteus maximus muscle. We dissected twenty gluteus maximus muscles from 10 human adult cadavers (5 males and 5 females). We measured the muscles and compiled the distribution of the nerve branches into each of the quadrants of the muscle. Statistical analysis was performed by using Student’s t-test and Kruskal-Wallis tests. Although no difference was observed either for muscle measurements or for distribution of nerve branching among the subjects, the topography of MTrPs matched the anatomical location of the entry points into the muscle. Thus, anatomical substract of the MTrPs may be useful for a better understanding of the physiopathology of these disorders and provide basis for their surgical and clinical treatment

Differentiation of B-1b cells into B-1 cell-derived phagocytes (B-1CDP).

<p>The peritoneal cells from mice treated with <i>P. acnes</i>, PS or saline (control group) were cultured for 5 days. The non-adherent cells were re-cultured on cover glasses for 1 to 120 hours for phagocyte differentiation. The cells that adhered to the cover glasses were then fixed, stained with Giemsa and analyzed using optical microscopy. Magnification 500×.</p

Analysis of the activation status of B-1b lymphocytes <i>in vitro</i>.

<p>The non-adherent cell population that was obtained after 5 days in a B-1b enriched culture obtained from <i>P. acnes</i>-, PS-, or saline- (control group) treated mice was analyzed to determine TLR, co-stimulatory molecule, MHC II and cytokine expression in B-1b lymphocytes. The cells were stained with mAbs to identify the absolute numbers (A to C) of B-1b lymphocytes that expressed each molecule and the mean fluorescence intensity (MFI) of each marker (D to F). The absolute cell number and MFI are the means of two independent experiments with similar results. * <i>p</i><0.05 between the control and treated groups. ^#<i>p</i><0.05 between the <i>P. acnes</i> and PS treated groups.</p

Determination of the absolute number of B-1 cell subsets <i>in vivo</i> and <i>in vitro</i>.

<p>Peritoneal cells from <i>P. acnes</i>-, PS- or saline-treated mice were analyzed 24 h after treatment (<i>in vivo</i>). The non-adherent population of 5-day-old B-1b enriched cultures was also analyzed (<i>in vitro</i>). The cells were stained with mAbs to identify the B-1 cell subsets. (A to C) The small (R1) and large granular (R2) cells from the SSC-H×FSC-H dot plots are shown, followed by the CD23×CD19 analysis from R1 and R2 and the CD5×CD11b analysis from R3 and R4. (D and E) The absolute numbers of B-1b, B-1a and B-1c lymphocytes from mice treated with saline (control group), <i>P. acnes</i> and PS. The absolute numbers of the B-1a and B-1b lymphocytes are the sum of R1 and R2, and the B-1c values are derived from R1. The absolute cell number is the mean of two independent experiments with similar results. * <i>p</i><0.05 compared to the control group. ^#<i>p</i><0.05 between the <i>P. acnes</i> and PS treated groups.</p

Upregulation of PD-1 Expression and High sPD-L1 Levels Associated with COVID-19 Severity

COVID-19 has several mechanisms that can lead to lymphocyte depletion/exhaustion. The checkpoint inhibitor molecule programmed death protein 1 (PD-1) and its programmed death-ligand 1 (PDL-1) play an important role in inhibiting cellular activity as well as the depletion of these cells. In this study, we evaluated PD-1 expression in TCD4+, TCD8+, and CD19+ lymphocytes from SARS-CoV-2-infected patients. A decreased frequency of total lymphocytes and an increased PD-1 expression in TCD4+ and CD19+ lymphocytes were verified in severe/critical COVID-19 patients. In addition, we found a decreased frequency of total monocytes with an increased PD-1 expression on CD14+ monocytes in severe/critical patients in association with the time of infection. Moreover, we observed an increase in sPD-L1 circulant levels associated with the severity of the disease. Overall, these data indicate an important role of the PD-1/PDL-1 axis in COVID-19 and may provide a severity-associated biomarker and therapeutic target during SARS-CoV-2 infection

Modulation of the type I hypersensitivity late phase reaction to OVA by Propionibacterium acnes-soluble polysaccharide

Late phase reaction (LPR) of immediate hypersensitivity is a Th2 response characterized by eosinophil recruitment and related to allergic asthma pathogenesis. Several strategies were developed trying to control the tissue damage observed in this reaction. Recently, we verified that killed Propionibacterium acnes (P. acnes), a Gram-positive bacillus, immunomodulated LPR in a murine model, potentiating or suppressing it depending on the treatment protocol used. However, the bacterium compounds responsible for this effect are not known, leading us to investigate if P acnes purified Soluble polysaccharide (PS) could be a major component involved on the modulation induced by the bacterium. Recently. we demonstrated that PS, like P. acnes, induces adjuvant effect on DNA vaccine, increases bone marrow dendritic cell precursors in vivo and its maturation in vitro, and modulates in vitro macrophage tumoricidal activity. Herein, we determined the chemical PS composition, which is mainly constituted by galactopyranose, ribopyranose, arabinopyranose, glucopyranose, ribofuranose and mannopyranose, and analyzed its capacity to modulate the immediate hypersensitivity in mice. Animals were subcutaneously implanted with coagulated hen's egg white (HEW) and 14 days later challenged with ovalbumin (OVA) in the footpad, developing a typical LPR after 24 h. Similarly to the whole bacterium, Th2 response to OVA was potentiated when PS was administered concomitantly to HEW implantation, by increase in footpad eosinophilia and IL4-producing spleen cells, and decrease in anti-OVA IgG2a titers and IL-12- or IFN-gamma-producing cells. On the other hand, the reaction was abrogated when HEW implantation was performed 1 week after PS-treatment, by decrease in footpad swelling, eosinophilia and anti-OVA IgG1 levels, and increase in IgG2a titers and IL-12-producing cells, These data suggest that PS seems to be the major P. acnes compound responsible for its effects on the modulation of immediate hypersensitivity reaction in mice. (C) 2008 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, Disciplina Imunol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, Disciplina Imunol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04023900 São Paulo, BrazilWeb of ScienceFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Impact of Inflammatory Immune Dysfunction in Psoriasis Patients at Risk for COVID-19

Psoriasis is an immune-mediated dermatosis usually associated with comorbidities. Treatment varies from topicals to systemic drugs and data on susceptibility to viral infections in psoriatic patients are scarce. The objectives of this study were to analyze psoriatic patients on different therapies who were at risk for COVID-19 for seroprevalence of SARS-COV-2, pro-inflammatory cytokine profile, comorbidities and outcomes in order to unveil the immunological mechanisms involved in the anti-viral response in patients with psoriasis. Seventy-five patients with psoriasis were divided according to treatment: immunobiologics, methotrexate, topicals and acitretin. Twenty healthy controls were included. Plasma samples were collected for: IgG SARS-COV-2 (ELISA); IL-27, IL-29 and IL-18 (ELISA); and IL-1β, IL-17A, IL-6 and TNF (cytometric array). Seropositivity for SARS-COV-2 was detected in 24 out of 75 psoriasis patients and did not relate to COVID-19 symptoms and/or hospitalization, despite associated comorbidities. Psoriasis patients who were asymptomatic for SARS-COV-2 exhibited immune imbalance with high levels of IL-18, IL-17A and IL-6, and low levels of IL-27 compared to healthy controls. Psoriasis groups showed significant increased cytokine levels only in the group with immunobiologics. Despite immune deviations and lower IL-27, which has a potential antiviral impact, psoriatic patients did not exhibit complications related to COVID-19. An understanding of this kind of proinflammatory profile of psoriatic patients and of the lack of severe outcomes for COVID-19 is essential to establish novel therapeutic approaches and preventive measures, including with regard to the concomitance of viral infections