Background: The silkworm, Bombyx mori, is an important insect in the textile industry and its pupa are used in Chinese cuisine and traditional Chinese medicine. The silk, urine and dander of silkworms is often the cause of allergies in sericulture workers and the pupa has been found to be a food allergen in China. Recent studies have focused on reporting cases of silkworm allergies, but only a few studies have addressed the specific allergens present in the B. mori silkworm. Methods: We collected sera from 10 patients with a positive skin prick test to silkworm crude extract (SCE) and analyzed these samples by Western blot and ELISA. The cDNA of arginine kinase from the B. mori silkworm was also cloned and expressed in high yield in Escherichia coli. Allergenicity and cross-allergenicity of the recombinant B. mori arginine kinase (rBmAK) were investigated by ELISA inhibition assay. Results: Collected sera all reacted to a 42-kDa protein in a Western blot with SCE as the antigen. Preincubation of sera with rBmAK eliminated the reactivity of the patients’ sera to this 42-kDa band. All patient sera also exhibited positive reactivity to SCE in an ELISA assay. BmAK also demonstrated cross-reactivity with a recombinant AK from cockroach. Conclusion: Arginine kinase from the B. mori silkworm is a major allergen and crossreacts with cockroach AK.
Oxidative stress plays a significant role in exacerbation of asthma. The role of vitamin D in oxidative stress and asthma exacerbation remains unclear. We aimed to determine the relationship between vitamin D status and oxidative stress in asthma exacerbation. Severe asthma exacerbation patients with 25-hydroxyvitamin D3-deficiency (V-D deficiency) or 25-hydroxyvitamin D-sufficiency (V-D sufficiency) were enrolled. Severe asthma exacerbation with V-D-deficiency showed lower forced expiratory volume in one second (FEV1) compared to that with V-D-sufficiency. V-D-deficiency intensified ROS release and DNA damage and increased TNF-α, OGG1 and NFκB expression and NFκB phosphorylation in severe asthma exacerbation. Supplemental vitamin D3 significantly increased the rates of FEV1 change and decreased ROS and DNA damage in V-D-deficiency. Vitamin D3 inhibited LPS-induced ROS and DNA damage and were associated with a decline in TNF-α and NFκB in epithelial cells. H2O2 reduces nuclear translocation of glucocorticoid receptors in airway epithelial cell lines. V-D pretreatment enhanced the dexamethasone-induced nuclear translocation of glucocorticoid receptors in airway epithelial cell lines and monocytes from 25-hydroxyvitamin D3-deficiency asthma patients. These findings indicate that V-D deficiency aggravates oxidative stress and DNA damage, suggesting a possible mechanism for corticosteroid resistance in severe asthma exacerbation.
The most important indoor allergens for humans are house dust mites (HDM). Fourteen Dermatophagoides farinae allergens (Der f 1–3, 6, 7, 10, 11, 13–18, and 22) are reported although more than 30 allergens have been estimated in D. farinae. Seventeen allergens belonging to 12 different groups were identified by a procedure of proteomics combined with two-dimensional immunoblotting from D. farina extracts. Their sequences were determined by Edman degradation, mass spectrometry analysis, and cDNA cloning. Their allergenicities were assayed by enzyme-linked immunosorbent assay inhibition tests, immunoblots, basophil activation test, and skin prick tests. Eight of them are the first report as D. farinae allergens. The procedure of using a proteomic approach combined with a purely discovery approach using sera of patients with broad IgE reactivity profiles to mite allergens was an effective method to investigate a more complete repertoire of D. farinae allergens. The identification of eight new D. farinae allergens will be helpful for HDM allergy diagnosis and therapy, especially for patients without response for HDM major allergens. In addition, the current work significantly extendedthe repertoire of D. farinae allergens.
Specific immunotherapy (SIT) is the only specific remedy for the treatment of allergic diseases currently. B cells are important immune cells in the immunity. The role of B cells in immune regulatory activities has not been fully understood yet. This study aims to elucidate the role of the thrombospondin (TSP)1-producing B cells in the immune regulatory role of SIT. The results showed that after SIT, the frequency of CD35+ B cells was increased in the intestine of mice with food allergy. The CD35+ B cells expressed TSP1 after exposure to specific antigens. Co-culture with the TSP1-producing CD35+ B cells decreased the levels of CD80/CD86 in dendritic cells; the cells convert naïve CD4+ T cells to regulatory T cells to inhibit allergic inflammation in the intestine.
The pathogenesis of some chronic inflammation such as inflammatory bowel disease is unclear. Insulin-like growth factor-1 (IGF1) has active immune regulatory capability. This study aims to investigate into the mechanism by which IGF1 modulates the monocyte (Mo) properties to inhibit immune inflammation in the intestine. In this study, the production of IGF1 by intestinal epithelial cells was evaluated by real time RT-PCR and Western blotting. Mos were analyzed by flow cytometry. A mouse colitis model was created with trinitrobenzene sulfonic acid. The results showed that mouse IECs produced IGF1, which could be up regulated by exposure to CpG-ODN (CpG-oligodeoxynueleotides) in the culture. Culture the CpG-ODN-primed IEC cells and Mos or exposure of Mos to IGF1 in the culture induced the Mos to express IL-10. The IGF1-primed Mos showed the immune suppressive effect on inhibiting the immune inflammation in the mouse colon. In conclusion, the IGF1-primed Mos are capable of suppressing immune inflammation in the intestine.
We previously observed enhanced immunoglobulin A (IgA) responses in severe COVID‐19, which might confer damaging effects. Given the important role of IgA in immune and inflammatory responses, the aim of this study was to investigate the dynamic response of the IgA isotype switch factor TGF‐β1 in COVID‐19 patients. We observed, in a total of 153 COVID‐19 patients, that the serum levels of TGF‐β1 were increased significantly at the early and middle stages of COVID‐19, and correlated with the levels of SARS‐CoV‐2‐specific IgA, as well as with the APACHE II score in patients with severe disease. In view of the genetic association of the TGF‐β1 activator THBS3 with severe COVID‐19 identified by the COVID‐19 Host Genetics Initiative, this study suggests TGF‐β1 may play a key role in COVID‐19.