Soluble Antigen Research Articles

Enfermedad del legionario en Argentina: evolución de la estrategia diagnóstica en el laboratorio

Legionnaires’ disease (LD) is severe acute pneumonia that occurs in sporadic or epidemic form, and generally requires hospitalization. The objective of this work was to describe the experience in the LD laboratory diagnostic approach in Argentina during the period 2016–2021. The laboratory analyzed 168 clinical specimens from 93 cases of suspected LD pneumonia. Laboratory tests included the detection of the soluble antigen of Legionella pneumophila serogroup 1 in urine sample, detection of DNA of Legionella spp. in lower respiratory secretions by conventional and commercial molecular methods and isolation in selective medium. LD was confirmed in 12 patients. The urinary antigen allowed the diagnosis for 8 patients. L. pneumophila was isolated from the respiratory material of 6 patients suffering from health care-associated pneumonia, who had been previously diagnosed using the commercial molecular method. Fifty percent of these cases did not show detectable urinary antigen. A single patient did not shows neither detectable antigenuria nor isolation of Legionella from the respiratory sample and was diagnosed as a confirmed case of LD by the detection of DNA of Legionella spp. by PCR directly from the respiratory secretion and the epidemiological link with another case of confirmed LD by culture. Urinary antigen detection is the first-line diagnostic test. However, the incorporation of complementary molecular methods has proved to avoid false negatives and contributed to a better understanding of the true incidence of the disease.

A review of serological tests available in Brazil for intestinal schistosomiasis diagnosis.

The World Health Organization (WHO) roadmap and recommendations for elimination of schistosomiasis were recently updated. With significant reductions in the prevalence and intensity of schistosomiasis infections worldwide, there is a need for more sensitive diagnostic methods. There are a few remaining transmission hotspots in Brazil, although low endemicity settings comprise most of the endemic localities. For the latter, serology may represent a tool for population screening which could help eliminate transmission of schistosomiasis. Here, we review serology tests currently available in Brazil from both public health and private laboratories: immunofluorescent antibody tests (IFATs) on adult worm sections and enzyme-linked immunosorbent assays (ELISAs) with soluble egg and adult worm antigens. Both in-house and commercially available tests have received less than adequate performance evaluations. Our review of immediate basic and operational research goals may help identify local adjustments that can be made to improve control interventions aimed at elimination of schistosomiasis as a public health problem.

ПСЕВДОТУБЕРКУЛЁЗНЫЕ СЫВОРОТКИ В ДОТ-ИММУНОАНАЛИЗЕ С ЗОЛОТЫМИ НАНОЧАСТИЦАМИ

For the experiment, we obtained two antigens: disintegrated membranes (DM) of Yersinia pseudotuberculosis and lipopolysaccharide (LPS) of Y. pseudotuberculosis. DM represented bacterial cell walls destroyed by ultrasound and sodium dodecyl sulfate. LPS was obtained by the phenolic method and did not contain protein impurities. To obtain hyperimmune blood sera, five-fold immunization of rabbits with these antigens was carried out. During immunization, the ratio of adjuvant to antigen solution was 1:1. DM was injected into the rabbit in an amount of 2 mg, LPS – in an amount of 0.25 mg. A 1% solution of polyazolidinammonium modified with hydrate ions of iodine was used as an adjuvant. The obtained serums were tested in dot immunoassay (DIA) with soluble and corpuscular antigens. Bacterial suspensions with a concentration of 109 cells/ml were used as corpuscular antigens. The indicator system in DIA was a conjugate of protein A with gold nanoparticles of 15.2 nm in size. Serum obtained by LPS Y. pseudotuberculosis, had insufficient antibodies to use it in DIA, unlike serum to DM Y. pseudotuberculosis. The last serum had high antibody titers in DIA and had a pronounced species specificity. Her antibody titers in DIA with Y. pseudotuberculosis strains O:1, O:3, O:4, O:5 serovariants were 1:1600-1:3200. No serum interactions were observed with Y. enterocolitica O:3, O:9 serovariants, Enterobacter aerogenes, Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Klebsiella pneumoniae cells. Commercial pseudotuberculous and intestinal yersiniosis O:3 sera (from diagnostic kits for RNG diagnosis) were less active in DIA than the experimental serum obtained for DM Y. pseudotuberculosis. Thus, the serum obtained by immunization of rabbits with DM Y. pseudotuberculosis can be used in the future to create a pseudotuberculous dot-immunotest system

Assays to Detect Cross-Dressing by Dendritic Cells In Vivo and In Vitro.

The presentation of peptides derived from exogenous antigens on major histocompatibility complex (MHC) class I molecules of antigen-presenting cells (APCs), termed cross-presentation, is crucial for the activation of cytotoxic T-lymphocytes during cell-mediated immune response. Typically, the APCs acquire exogenous antigens by (i) endocytosis of soluble antigens present in their external milieu, or (ii) through phagocytosis of dying/dead cancer cells or infected cells, followed by intracellular processing, before presentation by MHC I on the surface, or (iii) uptake of heat shock protein-peptide complexes generated in the antigen donor cells (3). In a fourth new mechanism, preformed peptide-MHC complexes can be directly transferred from the surface of antigen donor cells (i.e., cancer cells or infected cells) to that of APCs, without the need of further processing, in a process referred to as cross-dressing. Recently, the importance of cross-dressing in dendritic cell-mediated antitumor immunity and antiviral immunity has been demonstrated. Here, we describe a protocol to study cross-dressing of dendritic cells with tumor antigens.

Characterization of Regulatory T Cells in Patients Infected by Leishmania Infantum.

High IL-10 levels are pivotal to parasite survival in visceral leishmaniasis (VL). Antigenic stimuli induce IL-10 expression and release of adenosine by CD39/CD73. Due their intrinsic ability to express IL-10 and produce adenosine from extracellular ATP, we evaluated the IL-10, CD39, and CD73 expression by Regulatory T cells (Treg) correlated with VL pathology. Using flow cytometry, Treg cells was analyzed in peripheral blood samples from VL patients (in the presence and absence of Leishmania infantum soluble antigen (SLA)) and healthy individuals (negative endemic control-NEC group), without any treatment. Additionally, IL-10 levels in leukocytes culture supernatant were measured in all groups by ELISA assay. VL patients presented more Treg frequency than NEC group, independently of stimulation. ELISA results demonstrated that SLA induced higher IL-10 expression in the VL group. However, the NEC group had a higher Treg IL-10+ compared to the VL group without stimulation and SLA restored the IL-10 in Treg. Additionally, an increase in Treg CD73+ in the VL group independently of stimuli compared to that in the NEC group was observed. We suggest that Treg are not the main source of IL-10, while the CD73 pathway may be an attempt to modulate the exacerbation of immune response in VL disease.

Assembly of Immunogenic Protein Particles toward Advanced Synthetic Vaccines.

Immunogenic carrier proteins such as the non-toxic diphtheria toxin variant, cross-reacting material 197 (CRM197), are widely used in subunit vaccine formulations to boost immunogenicity of chemically conjugated antigens. Conjugate vaccines are inherently expensive due to laborious manufacturing steps. Here, this work develops a particulate vaccine platform based on using engineered Escherichia coli to assemble CRM197-antigen fusion proteins into discrete submicron-sized particles. This approach enables precise loading of diverse antigens and epitopes enhancing their immunogenicity. A cost-effective, high-yield, and scalable biomanufacturing process is developed. Purified particulate CRM197-antigen vaccines are ambient-temperature stable. CRM197 particles incorporating pathogen-specific antigens or epitopes from SARS-CoV-2, Streptococcus pyogenes (group A), and Mycobacterium tuberculosis induced cell-mediated and humoral immune responses mediating protective immunity in respective animal models of infection. The CRM197 particle vaccine platform is versatile, enabling co-delivery of selected antigens/epitopes together with immunogenic CRM197 as discrete stable particles avoiding laborious manufacture of soluble CRM197 and antigen followed by chemical conjugation.

Urgency and necessity of Epstein-Barr virus prophylactic vaccines.

Epstein-Barr virus (EBV), a γ-herpesvirus, is the first identified oncogenic virus, which establishes permanent infection in humans. EBV causes infectious mononucleosis and is also tightly linked to many malignant diseases. Various vaccine formulations underwent testing in different animals or in humans. However, none of them was able to prevent EBV infection and no vaccine has been approved to date. Current efforts focus on antigen selection, combination, and design to improve the efficacy of vaccines. EBV glycoproteins such as gH/gL, gp42, and gB show excellent immunogenicity in preclinical studies compared to the previously favored gp350 antigen. Combinations of multiple EBV proteins in various vaccine designs become more attractive approaches considering the complex life cycle and complicated infection mechanisms of EBV. Besides, rationally designed vaccines such as virus-like particles (VLPs) and protein scaffold-based vaccines elicited more potent immune responses than soluble antigens. In addition, humanized mice, rabbits, as well as nonhuman primates that can be infected by EBV significantly aid vaccine development. Innovative vaccine design approaches, including polymer-based nanoparticles, the development of effective adjuvants, and antibody-guided vaccine design, will further enhance the immunogenicity of vaccine candidates. In this review, we will summarize (i) the disease burden caused by EBV and the necessity of developing an EBV vaccine; (ii) previous EBV vaccine studies and available animal models; (iii) future trends of EBV vaccines, including activation of cellular immune responses, novel immunogen design, heterologous prime-boost approach, induction of mucosal immunity, application of nanoparticle delivery system, and modern adjuvant development.

SjHSP90 recombinant protein and its possible application in the diagnosis of schistosomiasis and treatment efficacy monitoring

PurposeThe fraction antigen of Schistosoma japonicum (107-121 kDa) eggs can be used for treatment efficacy monitoring, but the methods are laborious. This study analyzed the antigen and its feasibility for infection screening and treatment efficacy monitoring, which is the key to schistosomiasis control. MethodsThe fraction antigens have been analyzed by shotgun mass spectrometry. The recombinant proteins of candidates from the fraction antigens have been prokaryotic expression and purification in large amounts with high purity. The sera have been collected from rabbits and mice models of schistosomiasis infection and treatment. ELISA evaluated the diagnostic value of the candidate proteins. ResultsSJCHGC00820 and SJCHGC06900, with higher credibility, were identified through Shotgun mass spectrometry. ELISA results showed that rSj00820 has a diagnostic value for schistosomiasis (positive OD/negative OD P/N=3.6), while rSj06900 showed negative (P/N)<2. In rabbits, the specific serum antibodies for SjHSP90(rSj00820) in the infected animals peaked 6 weeks after infection and gradually decreased after treatment, reaching negative levels at 11 weeks. SjHSP90-ELISA was used to test serum samples from infected mice. The sensitivity and specificity reached >90%, similar to the diagnostic value obtained with soluble egg antigen (SEA) (SEA-ELISA). After treatment, the negative conversion rate reached >80%, significantly superior to SEA-ELISA. ConclusionsThe SjHSP90-ELISA can be used for the immunological diagnosis and treatment efficacy monitoring of schistosomiasis. The study lays a foundation for further developing screening and diagnostic kits.

Longitudinal changes in cell-mediated immunity after varicella-zoster virus skin test in the general population; Shozu Herpes Zoster Study: SHEZ study.

Varicella-zoster virus-specific cell-mediated immunity has been associated with the onset and severity of herpes zoster (HZ), and the administration of the HZ vaccine enhanced the immunity. However, limited data is available on the duration of cell-mediated immunity enhancement by soluble antigen of varicella-zoster virus (VZV) skin test. A prospective, community-based cohort study was conducted in Shozu County, Kagawa Prefecture, Japan. Repeated VZV skin tests containing inactivated VZV antigen and blood tests were performed on 365 subjects aged 60 years and older at baseline, 1, 2, and 3 years later. The differential immunity indices of VZV over time for cell-mediated and humoral immunity were evaluated.VZV skin test reaction and ELISpot counts increased significantly at 1, 2, and 3 years later compared to the baseline. However, humoral immunity indices did not change materially over time. Soluble antigen by VZV skin test enhanced VZV-specific cell-mediated immunity, and it persisted for at least 1 year. In addition, the inoculation with inactivated antigens every year by VZV skin test continued to enhance VZV-specific cell-mediated immunity after 2 and 3 years.

Corroboration of cross-reactivity between Mycobacterium leprae and hosts' salivary and cutaneous proteins: A hope for prognostic biomarkers for the pathogenesis of reactions in leprosy.

Immunological reactions are frequent complications that may occur either before, during, or after treatment and affect 30-50% of leprosy patients. The presence of autoantibodies like rheumatoid factor, antinuclear factor, and antibodies to host collagen, keratin, actin, myosin, endothelial cells, and myelin basic protein (MBP) has been earlier reported in leprosy patients. The purpose of this study was to identify cross-reactive proteins in clinical samples such as saliva and slit skin scrapings (SSS) of leprosy patients which could be utilised as prognostic biomarkers for Type 1 Reaction (T1R) in leprosy. A total of 10 leprosy patients in T1R and 5 healthy volunteers were recruited. The protein was extracted from their SSS and saliva samples, thereafter, isoelectric focusing (IEF) and two-dimensional PAGE were performed to analyse the proteins. Furthermore, the cross-reactivity was identified by western blotting host proteins in gel against purified IgG from Mycobacterium leprae soluble antigen (MLSA)- hyperimmunized rabbit sera, thereafter, cross-reactive proteins were identified by MS/MS. The cross-reactive host proteins were analysed for homologous bacterial proteins and B cell epitopes (BCEs) were predicted by using bioinformatic tools. A total of five spots of salivary proteins namely S100-A9, 35.3 kDa, and 41.5 kDa proteins, Serpin peptidase inhibitor (clade A), Cystatin SA-III, and four spots of SSS namely 41.4 kDa protein, Alpha-1 antitrypsin, vimentin, and keratin 1, were identified as cross-reactive. Further, a total of 22 BCEs of cross-reactive host proteins were predicted and visualised. This data provides strong evidence of cross-reactivity/molecular mimicry between host and pathogen in leprosy patients with reaction. These BCEs of cross-reactive proteins could be further studied to predict reactions and may be utilised as an early diagnostic biomarker for T1R in leprosy.

Immunological evaluation of the prophylactic impact of soluble egg antigen (SEA) combined with schistosomula lung antigen preparation (SLAP) on murine model of schistosomiasis mansoni

Immunological evaluation of the prophylactic impact of soluble egg antigen (SEA) combined with schistosomula lung antigen preparation (SLAP) on murine model of schistosomiasis mansoni

Deficiency in TLR4 impairs regulatory B cells production induced by Schistosome soluble egg antigen

Regulatory B cells (Bregs) producing IL-10 have negative regulatory function. Several studies have shown the important roles for Toll-like receptor 2 (TLR2), TLR4, and TLR9 ligation in the development of Bregs. We have reported that Schistosome soluble egg antigen (SEA) induced the production of Bregs. However, it remains unclear whether such activation is via the TLR pathway. The present study showed that IL-10 and TLR4 mRNA expression in spleen B cells of significantly increased in C57BL/10 J mice spleen B cells following SEA stimulation. The level of secreted IL-10 and IL-10+ B cell proportion decreased in spleen B cells derived from TLR4-deficient C57BL/10ScNJ (TLR4-/-) mice following SEA or LPS stimulation compared with C57BL/10 J mice. The CD1dhiCD5+ B cells proportion decreased in spleen B cells of TLR4-/- mice following SEA stimulation compared with control mice. NF-κB, ERK, p38MAPK and JNK signal transduction inhibitors significantly suppressed IL-10 secretion in CD1dhiCD5+ B cells induced by SEA or LPS. The phosphorylation levels of IκBα, p65, ERK, JNK and p38 were increased in CD1dhiCD5+ B cell of C57BL/10 J mice treated with LPS or SEA. In conclusion, this study suggests that TLR4 plays a critical role in Bregs activation induced by SEA. And the TLR4-triggered NF-κB and MAPK pathways activation in CD1dhiCD5+ B cells stimulated with SEA. The findings elucidated the mechanism of SEA induction of CD1dhiCD5+ B cells and helped us to understand the immune regulation during Schistosoma japonicum infection.

Combined targeting of soluble latent TGF-ß and a solid tumor-associated antigen with adapter CAR T cells

ABSTRACT Solid tumors consist of malignant and nonmalignant cells that together create the local tumor microenvironment (TME). Additionally, the TME is characterized by the expression of numerous soluble factors such as TGF-β. TGF-β plays an important role in the TME by suppressing T cell effector function and promoting tumor invasiveness. Up to now CAR T cells exclusively target tumor-associated antigens (TAA) located on the cell membrane. Thus, strategies to exploit soluble antigens as CAR targets within the TME are needed. This study demonstrates a novel approach using Adapter CAR (AdCAR) T cells for the detection of soluble latent TGF-β within the TME of a pancreatic tumor model. We show that AdCARs in combination with the respective adapter can be used to sense soluble tumor-derived latent TGF-β, both in vitro and in vivo. Sensing of the soluble antigen induced cellular activation and effector cytokine production in AdCAR T cells. Moreover, we evaluated AdCAR T cells for the combined targeting of soluble latent TGF-β and tumor cell killing by targeting CD66c as TAA in vivo. In sum, our study broadens the spectrum of targetable moieties for AdCAR T cells by soluble latent TGF-β.

Pathology and molecular mechanisms of Schistosoma japonicum-associated liver fibrosis.

Schistosomiasis has been widely disseminated around the world, and poses a significant threat to human health. Schistosoma eggs and soluble egg antigen (SEA) mediated inflammatory responses promote the formation of egg granulomas and liver fibrosis. With continuous liver injuries and inflammatory stimulation, liver fibrosis can develop into liver cirrhosis and liver cancer. Therefore, anti-fibrotic therapy is crucial to increase the survival rate of patients. However, current research on antifibrotic treatments for schistosomiasis requires further exploration. In the complicated microenvironment of schistosome infections, it is important to understand the mechanism and pathology of schistosomiasis-associated liver fibrosis(SSLF). In this review, we discuss the role of SEA in inhibiting liver fibrosis, describe its mechanism, and comprehensively explore the role of host-derived and schistosome-derived microRNAs (miRNAs) in SSLF. Inflammasomes and cytokines are significant factors in promoting SSLF, and we discuss the mechanisms of some critical inflammatory signals and pro-fibrotic cytokines. Natural killer(NK) cells and Natural killer T(NKT) cells can inhibit SSLF but are rarely described, therefore, we highlight their significance. This summarizes and provides insights into the mechanisms of key molecules involved in SSLF development.

TLR7 controls myeloid-derived suppressor cells expansion and function in the lung of C57BL6 mice infected with Schistosoma japonicum.

Toll-like receptors (TLRs) play an important role in the induction of innate and adaptive immune responses against Schistosoma japonicum (S. japonicum) infection. However, the role of Toll-like receptor 7 (TLR7) in the mouse lung during S. japonicum infection and the myeloid-derived suppressor cells (MDSCs) affected by the absence of TLR7 are not clearly understood. In this study, the results indicated that the MDSCs were accumulated and the proportion and activation of CD4+ and CD8+ T cells were decreased in the lung of mice at 6-7 weeks after S. japonicum infection. Then, the expression of TLR7 was detected in isolated pulmonary MDSCs and the results showed that the expression of TLR7 in MDSCs was increased after infection. Furthermore, TLR7 agonist R848 could down-regulate the induction effect of the soluble egg antigen (SEA) on pulmonary MDSCs in vitro. Meanwhile, TLR7 deficiency could promote the pulmonary MDSCs expansion and function by up-regulating the expression of PD-L1/2 and secreting of IL-10 in the mice infected with S. japonicum. Mechanistic studies revealed that S. japonicum infection and the antigen effects are mediated by NF-κB signaling. Moreover, TLR7 deficiency aggravates S. japonicum infection-induced damage in the lung, with more inflammatory cells infiltration, interstitial dilatation and granuloma in the tissue. In summary, this study indicated that TLR7 signaling inhibits the accumulation and function of MDSCs in S. japonicum infected mouse lung by down-regulating the expression of PD-L1/2 and secreting of IL-10, via NF-κB signaling.

Use of Antigen Combinations to Address Complex Leishmania-Seropositivity Patterns in Dogs Living in Canine Leishmaniosis Endemic Regions of Portugal.

Canine leishmaniosis (CanL) is a vector-borne disease caused by Leishmania infantum. Infection in dogs can result in a disease with non-specific clinical signs or in a subclinical condition. Infection diagnosis is crucial to guide public health measures considering the zoonotic potential of L. infantum. Serological approaches to detect infection with a reduced antigen panel potentially limit the quality of the information obtained. To evaluate the impact of using distinct antigens in a serological survey, a cohort with 390 dogs from endemic regions in Portugal was subjected to a serological evaluation using ELISA and DAT. Using ELISA, six Leishmania-specific antigens in conjunction with a non-related antigen, Escherichia coli soluble antigens, were evaluated. The global seroprevalence was 10.5% for DAT and 15.4 to 23.1% for ELISA, depending on the antigen for the latter. Still, only 8.2% of the animals were seropositive to all Leishmania-specific antigens. Importantly, a further 31.0% presented antigen-dependent seropositivity. Considering this observation, a serological score system was proposed and validated to address the complex serology results. With this system, the overall dog seropositivity was 26.9%. This work highlights the limitations of single-antigen serological surveys and presents an approach that might contribute to the establishment of CanL-specific serological profiles.

Inflammasome Activation Dampens Type I IFN Signaling to Strengthen Anti-Toxoplasma Immunity.

Innate immunity acts as the first line of defense against pathogen invasion. During Toxoplasma gondii infection, multiple innate immune sensors are activated by invading microbes or pathogen-associated molecular patterns (PAMPs). However, how inflammasome is activated and its regulatory mechanisms during T. gondii infection remain elusive. Here, we showed that the infection of PRU, a lethal type II T. gondii strain, activates inflammasome at the early stage of infection. PRU tachyzoites, RNA and soluble tachyzoite antigen (STAg) mainly triggered the NLRP3 inflammasome, while PRU genomic DNA (gDNA) specially activated the AIM2 inflammasome. Furthermore, mice deficient in AIM2, NLRP3, or caspase-1/11 were more susceptible to T. gondii PRU infection, and the ablation of inflammasome signaling impaired antitoxoplasmosis immune responses by enhancing type I interferon (IFN-I) production. Blockage of IFN-I receptor fulfilled inflammasome-deficient mice competent immune responses as WT mice. Moreover, we have identified that the suppressor of cytokine signaling 1 (SOCS1) is a key negative regulator induced by inflammasome-activated IL-1β signaling and inhibits IFN-I production by targeting interferon regulatory factor 3 (IRF3). In general, our study defines a novel protective role of inflammasome activation during toxoplasmosis and identifies a critical regulatory mechanism of the cross talk between inflammasome and IFN-I signaling for understanding infectious diseases. IMPORTANCE As a key component of innate immunity, inflammasome is critical for host antitoxoplasmosis immunity, but the underlying mechanisms are still elusive. In this study, we found that inflammasome signaling was activated by PAMPs of T. gondii, which generated a protective immunity against T. gondii invasion by suppressing type I interferon (IFN-I) production. Mechanically, inflammasome-coupled IL-1β signaling triggered the expression of negative regulator SOCS1, which bound to IRF3 to inhibit IFN-I production. The role of IFN-I in anti-T. gondii immunity is little studied and controversial, and here we also found IFN-I is harmful to host antitoxoplasmosis immunity by using knockout mice and recombinant proteins. In general, our study identifies a protective role of inflammasomes to the host during T. gondii infection and a novel mechanism by which inflammasome suppresses IFN-I signaling in antitoxoplasmosis immunity, which will likely provide new insights into therapeutic targets for toxoplasmosis and highlight the cross talk between innate immune signaling in infectious diseases prevention.

S2935 Autoimmune Hepatitis After COVID-19 Vaccine: An Unusual Complication

Introduction: Vaccination against SARS-Cov2 has represented a major milestone in our ability to ameliorate the COVID-19 pandemic. The vaccines are generally safe and effective, but some adverse events have been reported, including recent reports of autoimmune-like hepatitis. This case report presents a rare diagnosis of autoimmune hepatitis after administration of an mRNA COVID-19 vaccine. Case Description/Methods: An 18-year-old man with no medical history presented after receiving the Pfizer COVID-19 vaccine in April 2021, and second dose in May 20221. In June of 2021, about two weeks after the second dose, the patient was found with AST 120 u/L, ALT 181 u/L, Platelets 90. See Table 1 for further lab values. Per family, prior liver chemistries were normal. Initial serological workup was completed, including viral hepatitis (Hepatitis A, B, C, E), CMV IgG and IgM, EBV IgG and IgM, ceruloplasmin, alpha-1-antitrypsin, iron studies, all of which were unremarkable. Patient was also found to have ANA titer 1:640, positive anti-smooth-muscle antibody of 1:640, IgG level of 1,845, and positive antibody to soluble liver antigen of 2.321. Abdominal MRI was completed with findings of splenomegaly 20 cm, radiographic evidence of advanced hepatic fibrosis Patient underwent a liver biopsy with foci of interface and lobular hepatitis, areas of bridging necrosis, and scarring and focal nodularity concerning for transition to cirrhosis. Given these findings and it's timing close to administration of COVID-19 vaccine, the patient was diagnosed with autoimmune hepatitis associated with the vaccine. Patient was started on steroids in November 2021, and later, azathioprine, with improvement of liver enzymes. Discussion: Autoimmune hepatitis is a rare complication of COVID-19 vaccines, reported in few case reports in the literature. The pathophysiology remains unclear but is hypothesized to be related to molecular mimicry. The mRNA vaccines developed against COVID-19 leads to the production of the spike protein, and its antibodies. Antibodies to the spike protein have high affinity toward other human tissue proteins, which can lead to autoimmune tissue injury. In most reports, patients improved after treatment with steroids, though two have been reported to have passed away of liver failure. No liver transplants have yet been reported. Given the serious implications of this disease and the number of vaccines against COVID-19 given world-wide, further research is needed to better understand this entity and its pathophysiology. Table 1. - Lab Values 6/6/2021 11/15/2021 12/2/2021 1/12/2022 2/11/2022 4/18/2022 5/30/2022 AST U/L 120 323 31 35 48 37 50 ALT U/L 181 519 87 58 74 44 48 ALK P U/L 265 292 165 101 109 116 124 PLATELET COUNT 90 86 93 82 96 111 98

Bronchus-associated macrophages efficiently capture and present soluble inhaled antigens and are capable of local Th2 cell activation.

In allergic asthma, allergen inhalation leads to local Th2 cell activation and peribronchial inflammation. However, the mechanisms for local antigen capture and presentation remain unclear. By two-photon microscopy of the mouse lung, we established that soluble antigens in the bronchial airway lumen were efficiently captured and presented by a population of CD11c+ interstitial macrophages with high CX3CR1-GFP and MHC class II expression. We refer to these cells as Bronchus-Associated Macrophages (BAMs) based on their localization underneath the bronchial epithelium. BAMs were enriched in collagen-rich regions near some airway branchpoints, where inhaled antigens are likely to deposit. BAMs engaged in extended interactions with effector Th2 cells and promoted Th2 cytokine production. BAMs were also often in contact with dendritic cells (DCs). After exposure to inflammatory stimuli, DCs migrated to draining lymph nodes, whereas BAMs remained lung resident. We propose that BAMs act as local antigen presenting cells in the lung and also transfer antigen to DCs.

Lab-scale production of anti-Schistosoma monoclonal antibodies by hybridoma culturing in serum free medium: Enhancement of growth, cryopreservation survival rate, and diagnostic accuracy

This study was performed to evaluate the effect of two commercially available serum-free culture media; serum free medium (SFM) and chemically defined medium (CDM), on the growth rate, antibody productivity and post adaptation cryopreservation and revival reactivity of hybridoma cells compared to the conventional serum based medium (SBM). In addition, the diagnostic efficacy of MAbs secreted in each culture medium was evaluated by testing their performance in sandwich ELISA for antigen detection. Anti- Schistosoma mansoni soluble egg antigen hybridoma cell line (7A/8F) secreting previously characterized IgG Kappa mAbs, were retrieved and propagated in each of the three aforementioned media. Growth rate and viability were assessed post culturing in each media. The data collected from this study indicated that MAbs secreted from hybridoma cells cultured in SFM were the most abundant, easiest to purify, and the most effective in antigen detection by sandwich ELISA, in comparison to those produced in the other two media. Moreover, combination of fresh and conditioned medium with DMSO 7.5% was the most promising formulation for the cryopreservation of hybridoma cells cultivated in serum independent media (SFM or CDM).