A comprehensive analysis of the allergenicity and IgE epitopes of myosinogen allergens in Scylla paramamosain.

BACKGROUND: Scylla paramamosain is one of the most common and serious food allergens in Asia. Therefore, research on its prevalence, accurate diagnosis, and IgE-binding pattern of the allergens is crucial. OBJECTIVE: To identify the IgE epitopes of the myosinogen allergens in S. paramamosain using phage peptide library. METHODS: The prevalence of allergy to crabs (AC) and of sensitization was analysed using a questionnaire and a serological assay. BAT was performed by flow cytometry, and its diagnostic performance was evaluated in relation to allergens purified from crab myosinogen. IgE-binding epitopes were identified by phage display using the IgE from patients with AC. Sequence- and structure-based bioinformatics analyses were performed to identify allergenic epitopes. RESULTS: Crab was the most common cause of food allergies in this study. Subjects with AC (n = 30) with clear clinical symptoms were identified by immunoblotting and BAT. All of the myosinogen allergens triggered basophil activation; surface expression of CD63 and CD203c was higher in patients allergic to AK and FLN c than in patients allergic to SCP and TIM. In addition to six conformational epitopes of SCP, six linear epitopes and eight conformational epitopes of AK were identified. Five linear epitopes and three conformational epitopes of TIM, nine linear and ten conformational epitopes of FLN c were also identified, and the sequence VH(I/T) L was appeared in epitopes of both TIM and FLN c. The number of epitopes showed consistency with the value of BAT. CONCLUSIONS AND CLINICAL RELEVANCE: BAT can be used for accurate diagnosis of AC. Identification of particular allergenic motifs could be a valuable tool for prevention, diagnosis, and treatment of food allergies.

Nucleus-translocated matrix metalloprotease 1 regulates innate immune response in Pacific abalone (Haliotis discus hannai).

As an important economical shellfish in coastal area of China, abalone is susceptible to bacterial infection, especially Vibiro parahemolyticus (V. parahemolyticus). Matrix metalloproteinases (MMPs) have been extensively investigated in the immune response of mammals. However, little is known about the involvement of MMP in abalone innate immune system against pathogen infection. In this study, the role of MMP-1 in the immune response of Pacific abalone (Haliotis discus hannai) was explored. The results showed that V. parahemolyticus infection induced significantly elevated expression of MMP-1 as well as immune related genes including allograft inflammatory factor 1 (AIF-1), macrophage expressed gene 1 (MPEG-1) and TPA-inducible sequence 11 family protein (Tis11FP). Notably, silencing of MMP-1 reduced the expression of these genes, suggesting that MMP-1 was an upstream regulatory factor in V. parahemolyticus infection. Further analysis showed that MMP-1 was engaged in the regulation of cellular (phagocytosis, apoptosis) and humoral [superoxide dismutase (SOD), alkaline phosphatase (ALP), acid phosphatase (ACP)] immunity. Interestingly, the extracellularly distributed MMP-1 could be translocated to the nuclei of hemocytes, thereby functioning as a transcriptional regulator or by selectively activating or inactivating other components through proteolysis. Hence, our study established an important role of MMP-1 in abalone innate immunity against V. parahemolyticus infection and it represented the first report on the investigation of MMP in abalone.

Involvement of clip-domain serine protease in the anti-Vibrio immune response of abalone (Haliotis discus hannai)-Molecular cloning, characterization and functional analysis.

Vibrio parahemolyticus (V. parahemolyticus) is a major pathogen for abalone, an important economical shellfish in coastal area of China. There is little known about the abalone innate immune system against pathogen infection. Clip-domain serine proteases (cSPs) are increasingly recognized to play important roles in host immune defense in invertebrates. In this study, we cloned a cSP (Hdh-cSP) from abalone (Haliotis discus hannai). We found out that Hdh-cSP was widely expressed in multiple tissues of abalone, with highest level in the immune-like organ, hepatopancreas. V. parahemolyticus infection induced significantly elevated expression of Hdh-cSP in addition to better-characterized innate immune component genes including Rel/NF-κB, allograft inflammatory factor (ALInFa), macrophage expressed protein (MEP) and caspase-8. Importantly, the silencing of Hdh-cSP reduced the expression of these genes, suggesting that Hdh-cSP was an upstream regulatory factor in V. parahemolyticus infection. Further analysis showed that apoptosis of hemocytes was inhibited when the transcription of Hdh-cSP was knocked down, suggesting that Hdh-cSP participated in cell apoptosis by regulation of caspase 8 expression in V. parahemolyticus infection. Therefore, our study established an important role of cSP in the innate immunity against V. parahemolyticus infection in abalone.

Antibody responses following the surge of SARS-CoV-2 Omicron infection among patients with systemic autoimmune rheumatic diseases.

Objectives: The surge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant Omicron infections has affected most Chinese residents at the end of 2022, including a number of patients with systemic autoimmune rheumatic diseases (SARDs). Methods: To investigate the antibody level of the Omicron variant in SARD patients after SARS-CoV-2 Omicron infection, we tested BA.5.2 and BF.7 Omicron variant IgG antibody levels using ELISA on blood samples collected from 102 SARD patients and 19 healthy controls (HCs). The type of SARD, demographics, concurrent treatment, doses of SARS-CoV-2 vaccines and outcomes were also recorded. Results: A total of 102 SARD patients (mean age: 40.3 years; 89.2% female), including 60 SLE, 32 RA and 10 other SARDs, were identified. Of these, 87 (85.3%) were infected with SARS-CoV-2. We found that the BA.5.2 and BF.7 antibody levels of infected SARD patients were lower than those of HCs (P < 0.05). Sixty-five (63.7%) patients had at least one dose of a SARS-CoV-2 vaccine. SARD patients with at least two doses of SARS-CoV-2 vaccine had a higher level of BA.5.2 and BF.7 antibodies than the unvaccinated group (P < 0.05). There was no evidence for a significant inhibitory effect of glucocorticoids (GCs) on the BA.5.2 and BF.7 Omicron variant antibody levels in SARD patients. SLE patients using biologic DMARDs had a lower BA.5.2 Omicron variant antibody level than patients using GCs and/or HCQ. Conclusion: These data suggest that patients with SARDs had a lower antibody response than HCs after Omicron infection.

[Induction and mechanism study of anti-melanoma immune response by M. tuberculosis Ag85B].

AIM: To study the anti-melanoma immunity efficacy of Ag85B antigen gene therapy in vivo. METHODS: C57BL/6 mice were inoculated s.c. with B16 cells, and 8 days later the mice were inoculated s.c. again with B16 cells (control group 1), B16/pcDNA3 cells (control group 2) or B16/pcDNA3-Ag85B cells (experimental group), respectively. Tumor volume, survival time, serum IFN-gamma level and IL-4 level of 3 groups mice were observed. Antitumor activity of Ag85B was studied. RESULTS: From 12 to 23 day, the mean tumor volume of mice increased from 1.1058 cm(3) and 0.9123 cm(3) to 7.5983 cm(3) and 5.8746 cm(3) in the control group 1 and 2, respectively. But it increased from 0.5158 cm(3) to 1.5080 cm(3) in the experimental group. The mean survival time of mice was 24.1 days and 24.7 days in the control group 1 and 2, respectively. That was 27.8 days in the experimental group. Within 13 days after the last inoculation, the serum IFN-gamma level of all groups experienced increased (That increased to 26.3 ng/L, 23.0 ng/L and 25.2 ng/L in the control group 1, 2 and the experimental group, respectively). Subsequently, the serum IFN-gamma level in the two control groups decreased (That decreased to 19.3 ng/L and 18.3 ng/L in the control group 1 and 2) while it still augmented in the experimental group (That increased to 46.5 ng/L). IL-4 level was slightly but not significantly enhanced and then declined in all mice. CONCLUSION: Ag85B induced the increase of serum IFN-gamma level in the animals experiments, inhibited the tumor growth and prolonged the survival of the tumor-bearing mice.