It has been suggested that the human C1qRp is a receptor for the complement component C1q; however, there is no direct evidence for an interaction between C1q and C1qRp. In this study, we demonstrate that C1q does not show enhanced binding to C1qRp-transfected cells compared with control cells. Furthermore, a soluble recombinant C1qRp-Fc chimera failed to interact with immobilized C1q. The proposed role of C1qRp in the phagocytic response in vivo is also unsupported in that we demonstrate that this molecule is not expressed by macrophages in a variety of human tissues and the predominant site of expression is on endothelial cells. Studies on the rodent homolog of C1qRp, known as AA4, have suggested that this molecule may function as an intercellular adhesion molecule. Here we show that C1qRp is the Ag recognized by several previously described mAbs, mNI-11 and two anti-CD93 Abs (clones X2 and VIMD2b). Interestingly, mNI-11 (Fab′) has been shown to promote monocyte-monocyte and monocyte-endothelial cell adhesive interactions. We produced a recombinant C1qRp-Fc chimera containing the C-type lectin-like domain of C1qRp and found specific binding to vascular endothelial cells in sections of inflamed human tonsil, indicating the presence of a C1qRp ligand at this site. This interaction was Ca2+ independent and was not blocked by our anti-C1qRp mAb BIIG-4, but was blocked by the proadhesive mAb mNI-11. Collectively, these data indicate that C1qRp is not a receptor for C1q, and they support the emerging role of C1qRp (here renamed CD93) in functions relevant to intercellular adhesion.

-4). In these blocking experiments using the mAbs, the main differences in the results between PBMCs and U937 cells were that the mAbs against TLR-2 and TLR-4 did not block the Sophy ␤-glucan-induced production of IL-8 in the U937 cells. Furthermore, a mAb to the ␤-glucan receptor, Dectin-1, significantly (P<0.05) blocked the Sophy ␤-glucaninduced DNA synthesis in the PBMCs, and Sophy ␤-glucan-induced production of IL-8 in the U937 cells. The Sophy ␤-glucan-induced production of IL-8 in the U937 cells was significantly (P<0.01) blocked by the conventional protein kinase C (PKC) inhibitor Go6976, the novel PKC inhibitor Rottlerin, the protein kinase A (PKA) inhibitor H-89, and the protein tyrosine kinase (PTK) inhibitor herbimycin A. Among these, the blocking effect of the novel PKC (PKC delta isoenzyme) inhibitor Rottlerin was the most pronounced. Studies employing reverse transcriptase-polymerase chain reaction (RT-PCR) showed that Sophy ␤-glucan stimulated the expression of IL-8 mRNA in the U937 cells, and that this induction was inhibited by Rottlerin. Sophy ␤-glucan also blocked the stimulator cell induction of DNA synthesis and IFN-␥ production in the responder cells in a one-way mixed lymphocyte reaction (MLR) using allogenic PBMCs. Interestingly, immunoglobulin G (IgG), but not IgM to Sophy ␤-glucan was detected in the sera derived from normal adult donors and from the umbilical cord blood of neonates. Taken together, these findings strongly suggest that the Sophy ␤-glucan may have unique immune regulatory or enhancing properties that could be exploited by the health food, medical and pharmaceutical industries.

Rao et al. Immune Enhancement to Combat COVID-19 consuming nutritional supplements that enhance the immune system. We recommend clinical studies to validate AFO-202 beta glucan in COVID-19 patients to prove its efficacy in overcoming a hyper-inflammation status, thus reducing the mortality, until a definite vaccine is made available.

BackgroundNon-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are highly prevalent conditions characterized by inflammation and fibrosis of the liver which can progress to cirrhosis and hepatocellular carcinoma if left untreated. Lifestyle disorders such as obesity, diabetes and dyslipidaemia predispose to and are associated with the disease progression. Conventional modalities are mainly symptomatic, with no definite solution. Beta glucan-based biological response modifiers are a potential strategy in lieu of their beneficial metabolic effects. Aureobasidium pullulans strains AFO-202 and N-163 beta glucans were evaluated for anti-fibrotic and anti-inflammatory hepatoprotective potentials in a NASH animal model in this study.MethodsIn the STAM™ murine model of NASH, five groups were studied for eight weeks— (1) vehicle (RO water), (2) AFO-202 beta glucan; (3) N-163 beta glucan, (4) AFO-202+N-163 beta glucan, and (5) telmisartan (standard pharmacological intervention). Evaluation of biochemical parameters in plasma and hepatic histology including Sirius red staining and F4/80 immunostaining were performed.ResultsAFO-202 beta glucan significantly decreased inflammation-associated hepatic cell ballooning and steatosis. N-163 beta glucan decreased fibrosis and inflammation significantly (p value<0.05). The combination of AFO-202 with N-163 significantly decreased the NAFLD Activity Score (NAS) compared with other groups.ConclusionThis preclinical study supports the potential of N-163 and AFO-202 beta glucans alone or in combination as potential preventive and therapeutic agent(s), for NASH.Graphical abstract

Conventional vaccines to combat COVID-19 through different approaches are at various stages of development. The complexity of COVID-19 such as the potential mutations of the virus leading to antigenic drift and the uncertainty on the duration of the immunity induced by the vaccine have hampered the efforts to control the COVID-19 pandemic. Thus, we suggest an alternative interim treatment strategy based on biological response modifier glucans such as the Aureobasidium pullulans AFO-202-derived β-glucan, which has been reported to induce trained immunity, akin to that induced by the Bacille Calmette-Guérin vaccine, by epigenetic modifications at the central level in the bone marrow. These β-glucans act as pathogen-associated molecular patterns, activating mucosal immunity by binding with specific pathogen recognition receptors such as dectin-1 and inducing both the adaptive and innate immunity by reaching distant lymphoid organs. β-Glucans have also been used as immune adjuvants for vaccines such as the influenza vaccine. Therefore, until a conventional vaccine is widely available, an orally consumable vaccine adjuvant that acts like biosimilars, termed as the wide-spectrum immune-balancing food-supplement-based enteric (β-WIFE) vaccine adjuvant approach, with well-reported safety is worth in-depth investigation and can be considered for a clinical trial.

The transcription factor GATA-3 has been shown to play an important role for the in vitro induction of T(h)2 cells. To clarify how the in vivo immune response is governed under GATA-3 function, we generated double-transgenic mice by crossing GATA-3 transgenic mice with ovalbumin (OVA)-specific TCR transgenic mice. After immunization with OVA, the double-transgenic mice showed increased expression of GATA-3 in antigen-reactive fresh CD4(+) T cells, and higher production of IL-5 and IL-13 in cultured spleen cells in the presence of cognate antigen without any polarizing conditions for T(h)2 cells. Moreover, the immunized double-transgenic mice showed a higher increase of in vivo secretion of IL-5 and IL-13 in bronchoalveolar lavage fluid after OVA aerosol challenging. The serum levels of OVA-specific IgG1, IgE and IgA antibodies were much higher in the immunized double-transgenic mice than TCR transgenic mice. These findings provide direct evidence that antigen-stimulated CD4(+) T cells in the immunized mice have already been committed into T(h)2 cells producing IL-5 and IL-13 selectively through enhanced GATA-3 expression in vivo, thereby inducing higher production of antigen-specific antibody for three isotypes other than IgM.

Objective In this pilot clinical study, we report the beneficial effects of beta glucans derived from two strains AFO-202 and N-163 of a black yeast Aureobasidium pullulans on the biomarkers for cytokine storm and coagulopathy in COVID-19 patients. Methods A total of 24 RT-PCR positive COVID-19 patients were recruited and randomly divided into three groups (Gr): Gr. 1 control (n=8) – Standard treatment; Gr. 2: Standard treatment + AFO-202 beta glucan (n=8); and Gr. 3, Standard treatment + combination of AFO-202 and N-163 beta glucans (n=8) for 30 days. Results There was no mortality or requirement of ventilation of the subjects in any of the groups. There was a decrease in D-Dimer values (751 ng/ml to 143.89 ng/ml) and IL-6 values (7.395 pg/ml to 3.16 pg/ml) in Gr. 1 in 15 days but the levels increased to abnormal levels on day 30 (D-Dimer: 202.5 ng/ml; IL-6 55.37 pg/ml); which steadily decreased up to day 30 in groups 2 (D-dimer: 560.99 ng/dl to 79.615; IL-6: 26.18 pg/ml to 3.41 pg/ml) and 3 (D-dimer: 1614 ng/dl to 164.25 ng/dl; IL-6: 6.25 pg/ml to 0.5 pg/ml). The same trend was observed with ESR. LCR and LeCR increased while NLR decreased significantly in Gr. 3. CD4+ and CD8+ T cell count showed relatively higher increase in Gr.3. There was no difference in CRP within the groups. Conclusion As these beta glucans are well known food supplements with a track record for safety, larger multi-centric clinical studies are recommended to validate their use as an adjunct in the management of COVID-19 and the ensuing long COVID-19 syndrome.

Direct endothelial injury by viruses and dysregulation of clotting mechanisms due to cytokine storm are the major precipitating factors of mortality in COVID-19; both are attributed to a fundamental dysregulation of the immune system. While immune dysregulation can be attributed to several factors, the risk of associated thrombogenic disruption varies across individuals. This variation depends on several factors, such as comorbidities, including diabetes, hypertension, and cardiovascular diseases. When considering ethnic variations, the vulnerability of Caucasians, African Americans and Hispanics needs to be addressed before arriving at strategies to handle thromboembolic complications, which have been identified in recent reports as the leading causes of mortality in COVID-19. Although evaluation of D-dimer and prothrombin during admission is considered to predict prognosis and mortality, there are no preventive or prophylactic strategies before hospital admission. Herein, we present our perspectives on the effect of regular supplementation with the biological response modifier beta glucan based on its relevance to immune modulation. This effect is of paramount importance in decreasing the development of severe COVID-19 and reducing mortality against the background of coagulopathy, especially in vulnerable populations.