High Immunoglobulin Research Articles

Intravascular CNS Lymphoma: An elusive diagnosis (P2-5.016)

<h3>Objective:</h3> To report a rare case of intravascular CNS lymphoma presenting with subacute neuropsychiatric symptoms and multifocal cerebral infarcts and hemorrhages. <h3>Background:</h3> Intravascular lymphoma is a rare and aggressive subtype of extra-nodal non-Hodgkin lymphoma. It is characterized by proliferation of neoplastic B-lymphocytes within the lumen of small blood vessels, especially capillaries and post-capillary venules. Presentation is variable and depends on the organ dysfunction due to small vessel occlusion. Most common organs involved are CNS, skin and lungs. Given the rarity of the disease, variable presentation and absence of an extravascular tumor mass or peripheral blood abnormalities, the diagnosis can be extremely challenging and is often delayed. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 62-year old healthy woman presented with transient left hemiplegia and left facial numbness and was diagnosed with transient ischemic attack. In one month, she developed dysarthria and left hemibody clonic seizures without any systemic complaints. Over the next four months, she had a step-wise decline and developed severe apathy, decreased verbal fluency, diffuse hypertonia and worsening encephalopathy. Serial brain MRIs over four months showed acute-subacute infarcts and intracerebral hemorrhages involving both anterior and posterior circulation bilaterally with scattered micro-hemorrhages. Extensive work up, including CT-angiogram and PET-CT were unrevealing. CSF was notable for high protein level without pleocytosis and negative infectious and autoimmune workup. DSA was unrevealing. She did not respond to high dose steroids, intravenous immunoglobulin and cyclophosphamide. Brain biopsy revealed CNS intravascular large B-cell lymphoma. Patient was started on chemotherapy with HyperCVAD-R protocol with no improvement. <h3>Conclusions:</h3> Intravascular CNS lymphoma is a challenging diagnosis. It presents as subacute-chronic CNS vasculopathy with multifocal infarcts and hemorrhages and can mimic other CNS vasculopathies, including primary CNS angiitis and amyloid-related angiopathy. Tissue biopsy is the diagnostic gold standard and should be considered early if poor response to immunotherapy is noted. Despite high-dose chemotherapy, prognosis is poor. <b>Disclosure:</b> Dr. Ticku has nothing to disclose. Dr. Serra has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Biogen Idec. Dr. Serra has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Bristol Myers Squibb.

Effect of house dust mite allergen on sleep parameters and sleep quality.

The role of nasal problems such as allergic rhinitis in the development of obstructive sleep apnea (OSA) is controversial. The purpose of this study was to analyze the effects of house dust mite (HDM) allergen on sleep-related problems. In a retrospective study patients were classified according to the house dust mite (HDM)-related specific immunoglobulin E (IgE) level into a low HDM-IgE group (group A) and a high HDM-IgE group (group B). Polysomnographic indices, OSA severity, and self-administered questionnaire results were compared between groups. Correlational analysis was used to identify associations between specific IgE values and sleep parameters related to respiratory events. A total of 327 patients were enrolled.N1 stage ratio, apnea index, and apnea-hypopnea index were significantly higher in group B (P = 0.010, 0.003, and 0.002 respectively) than in group A. N2 stage ratio, and lowest and mean oxygen saturation were significantly lower in group B (P = 0.001, 0.001, and < 0.001 respectively). After propensity score matching, the apnea index and lowest and mean oxygen saturation remained significantly different (P = 0.005, 0.005, and 0.001 respectively). Patients in group B were more likely to have severe OSA and worse subjective sleep quality. In correlational analysis, lowest and mean oxygen saturation were significantly negatively correlated with specific IgE values. A high HDM-specific IgE level was associated with the occurrence of respiratory events and oxygen desaturation during sleep, and with the presence of severe OSA, as well as poorer subjective sleep quality.

OA35 Early identification of large vessel vasculitis: a specific benefit of a non-specific symptom pathway?

Abstract Background/Aims Since December 2020 in Cornwall there has been a Non-Specific Symptom Pathway (NSSP): a 2-week-wait pathway by which GPs can access a CT thorax, abdomen &amp; pelvis (CT-TAP) to assess non-specific symptoms where there is a suspicion of malignancy, but conventional 2-week-wait referral criteria are not met. An unexpected consequence of this pathway was the finding of cases of suspected large vessel vasculitis (LVV) being referred to rheumatology outpatients. Methods Cases with a new diagnosis of LVV or cancer were identified using the NSSP database over the period of December 2021- May 2022. Clinical and laboratory features were analysed and compared. During this time period a Logiq E10 US machine was acquired by the department, enabling axillary US to be performed for some of the suspected LVV cases that were referred to rheumatology. Results Of the 241 accepted referrals, 14 patients (5.81%) had a subsequent definite cancer diagnosis, 6 (2.49%) had LVV diagnosed as a direct consequence of the NSSP. 5 (83%) cases of LVV had CRP &amp;gt;60 versus 4 (33%) of the cancer patients where measured. Mean CRP was 38.9 in cancer patients and 82.3 in LVV (normal 0-5mg/L). Mean platelet count was 401 in cancer patients, 510 in LVV patients (normal 150-400x109). 3 LVV patients had immunoglobulins and serum protein electrophoresis tested, of which 2 had significantly raised IgG and 1 was confirmed as polyclonal. In one case, significant thoracic aneurysmal dilatation was identified; a 59-year-old previously healthy woman presented to primary care with fatigue, night sweats and arm pain. Investigations showed anaemia, thrombocytosis, polyclonal high immunoglobulins, CRP 74. CT-TAP via NSSP revealed thoracic aorta wall thickening with aneurysmal dilatation, diameter being 4.5cm at the aortic arch. Subsequently the patient was referred to vascular surgeons and rheumatology. Rheumatology clinic review noted no symptoms of cranial giant cell arteritis or polymyalgia rheumatica. Examination revealed significant blood pressure discrepancy between right and left arms (diastolic difference of 62mmHg) and bilateral axillary bruits. Bilateral axillary artery ultrasound revealed significant intima-media thickening: right distal 1.19mm, left distal 1.37mm (normal less than 0.9mm) consistent with LVV. 10mg Prednisolone and subsequently leflunomide 10mg were initiated with resolution of inflammatory markers and symptoms. Surgical intervention was not felt to be required but regular surveillance continues. Conclusion Polyclonal raised IgG, unexplained raised CRP and thrombocytosis, arm blood pressure discrepancy and axillary bruits may be useful indicator tests for referral to the NSSP. LVV diagnosis normally requires extensive inpatient investigations in patients with pyrexia-of-unknown-origin and can be challenging in the absence of PMR or cranial GCA symptoms. As well as early identification of cancer, NSSP has the additional benefit of detecting cases of LVV that may have otherwise gone unnoticed, including the cases with secondary aneurysmal change. Disclosure R. Machin: None. M. Hughes: None.

Recreation of an antigen-driven germinal center in vitro by providing B cells with phagocytic antigen

Successful vaccines rely on activating a functional humoral immune response through the generation of class-switched high affinity immunoglobulins (Igs). The germinal center (GC) reaction is crucial for this process, in which B cells are selected in their search for antigen and T cell help. A major hurdle to understand the mechanisms of B cell:T cell cooperation has been the lack of an antigen-specific in vitro GC system. Here we report the generation of antigen-specific, high-affinity, class-switched Igs in simple 2-cell type cultures of naive B and T cells. B cell antigen uptake by phagocytosis is key to generate these Igs. We have used the method to interrogate if T cells confer directional help to cognate B cells that present antigen and to bystander B cells. We find that bystander B cells do not generate class-switched antibodies due to a defective formation of T-B conjugates and an early conversion into memory B cells.

Dissolving Microneedles Loaded with Nanoparticle Formulation of Respiratory Syncytial Virus Fusion Protein Virus-like Particles (F-VLPs) Elicits Cellular and Humoral Immune Responses.

Respiratory syncytial virus (RSV) is one of the leading causes of bronchiolitis and pneumonia in children ages five years and below. Recent outbreaks of the virus have proven that RSV remains a severe burden on healthcare services. Thus, a vaccine for RSV is a need of the hour. Research on novel vaccine delivery systems for infectious diseases such as RSV can pave the road to more vaccine candidates. Among many novel vaccine delivery systems, a combined system with polymeric nanoparticles loaded in dissolving microneedles holds a lot of potential. In this study, the virus-like particles of the RSV fusion protein (F-VLP) were encapsulated in poly (D, L-lactide-co-glycolide) (PLGA) nanoparticles (NPs). These NPs were then loaded into dissolving microneedles (MNs) composed of hyaluronic acid and trehalose. To test the in vivo immunogenicity of the nanoparticle-loaded microneedles, Swiss Webster mice were immunized with the F-VLP NPs, both with and without adjuvant monophosphoryl lipid A (MPL) NPs loaded in the MN. The mice immunized with the F-VLP NP + MPL NP MN showed high immunoglobulin (IgG and IgG2a) levels both in the serum and lung homogenates. A subsequent analysis of lung homogenates post-RSV challenge revealed high IgA, indicating the generation of a mucosal immune response upon intradermal immunization. A flowcytometry analysis showed high CD8+ and CD4+ expression in the lymph nodes and spleens of the F-VLP NP + MPL NP MN-immunized mice. Thus, our vaccine elicited a robust humoral and cellular immune response in vivo. Therefore, PLGA nanoparticles loaded in dissolving microneedles could be a suitable novel delivery system for RSV vaccines.

The relationship between blood–brain barrier dysfunction and neurocognitive impairments in first-episode psychosis: findings from a retrospective chart analysis

Even before the onset of psychotic symptoms, individuals with schizophrenia display cognitive impairments. Simultaneously, increasing amounts of individuals exhibit dysfunction of the blood-brain barrier (BBB). However, the impact of BBB dysfunction on neurocognitive impairment in people with first-episode psychosis has not yet been investigated. To advance understanding of said relationship, we considered one of the largest first-episode psychosis cohorts with cerebrospinal fluid parameters available, and investigated whether BBB dysfunction is related to working memory, working speed and attention. We conducted a retrospective chart review of 121 in-patients diagnosed with a first episode of a schizophrenia spectrum disorder. Patients underwent neurocognitive testing and a lumbar puncture within routine clinical care. To define BBB dysfunction, albumin cerebrospinal fluid/serum quotients, immunoglobulin G ratios and oligoclonal band types were evaluated, and gender-specific differences investigated. Neurocognitive functioning was assessed by the Wechsler Adult Intelligence Scale, Test of Attentional Performance and Repeatable Battery for the Assessment of Neuropsychological Status. We performed simple and multiple linear regression analyses to interpret associations of interest. Of those tested, 16% showed an alteration in albumin quotients and 12% had an oligoclonal band type indicating BBB dysfunction. Notably, male patients were more likely to have an increased albumin quotient and a higher immunoglobulin G ratio than female patients. We found no significant association between BBB dysfunction and neurocognitive assessments. The hypothesised relationship between BBB and neurocognitive impairments was not detectable in our retrospective cohort. Further cerebrospinal fluid-based studies with a longitudinal assessment of cognitive functioning and disease trajectory are urgently needed.

Association between poly-sensitisation and sensitisation to staphylococcal enterotoxin A and B affecting allergic severity in children.

Accumulating evidence suggests that Staphylococcus aureus plays a significant role as a disease modifier in upper and lower airway diseases. We aimed to assess the association between staphylococcal enterotoxins (SEs) with allergic diseases and the degree of allergen sensitisation in children, which remains unclear. We retrospectively reviewed the medical records of 455 patients aged 3-18years between March 2018 and March 2022. Clinical history and demographic data were obtained. The baseline study included paranasal sinus X-ray scan, multiple allergen simultaneous test, and ImmunoCAP® for measuring serum total and specific immunoglobulin E (IgE) levels to allergens and staphylococcal enterotoxin A and B (SEA and SEB). The mean age was 9.77 ± 4.3years. 133 patients (29.2%) were sensitised to one inhalant allergen, and 188 patients (41.3%) showed polysensitisation. Patients sensitised to SEs showed higher total and specific IgE levels and total eosinophil counts compared to non-SE-sensitised patients. Sensitisation to SEs is closely associated with polysensitisation to inhalant allergens and allergic multimorbidity. When the SE-IgE value was 0.35 or higher, the odds ratio for allergen polysensitisation was significantly higher than when the SE-IgE value was lower than 0.35. Association between polysensitisation and sensitisation to SEs in children shows the higher the specific IgE levels for SEs, the higher the likelihood of polysensitisation. Considering the relationship between polysensitisation, high IgE levels, and the severity of allergic morbidity, sensitisation to SEs is thought to be related to allergy severity.

Ligelizumab: A novel molecule in the management of chronic spontaneous urticaria

The next-generation high affinity monoclonal immunoglobulin E (IgE) inhibitor Ligelizumab is being tested in clinical studies to treat chronic spontaneous urticaria (CSU). In 2020, the US Food and Drug Administration (FDA) designated Ligelizumab (QGE031) as a breakthrough therapy for patients with chronic idiopathic urticaria; however, FDA clearance has not yet been granted, despite the phase 3 trial’s completion. Recent clinical investigations have shown that it has a considerable affinity for the high-affinity IgE receptor (FcRI) on the surface of immune cells, which is quite beneficial in the management of the distressing symptoms of CSU. Studies have been done comparing Ligelizumab to Omalizumab, the current standard of care for treating CSU that is refractory. While omalizumab is more effective than Ligelizumab at inhibiting IgE: CD23 interactions, Ligelizumab exhibits stronger inhibition of IgE binding to FcRI, basophil activation, IgE synthesis by B cells, and passive systemic anaphylaxis. To learn about this molecule’s extended characteristics, long-term efficacy and safety, and potential uses in other dermatological disorders, more clinical data is needed.

Conjugated surfactant micelles: A non‐denaturing purification platform for concentrated human immunoglobulin G

AbstractAs downstream purification and separation technologies progress towards raising the concentration of therapeutic‐grade monoclonal antibodies (mAbs) in cell culture, downstream processing has begun to face increased difficulty in efficiently coping with such high immunoglobulin G (IgG) titers (≤25 mg mL−1). In the current study, we demonstrate the ability of a non‐chromatographic, ligand‐free procedure to recover almost quantitatively (84–99% yield, by densitometry) polyclonal, human IgG present at high concentrations (15–25 mg mL−1) in E. coli lysate. Instead of chromatographic media and columns, we use conjugated, mixed‐micelles comprising non‐ionic detergents, tyrosine monomers, and the amphiphilic [(bathophenanthroline)3:Fe2+] complex. Capture and extraction processes are performed at pH 6.5–7, thereby avoiding antibody exposure to acidic, potentially denaturing conditions. Recovered IgG is monomeric as determined by dynamic light scattering (DLS). Process upscaling from 0.1 to 5 mL requires only proportional increase in all reagents and does not affect overall yield or antibody purity.

Treatment of patients with atopic dermatitis and extremely high immunoglobulin E: world experience and own clinical observation

Atopic dermatitis is a chronic inflammatory skin disease characterized by a recurrent course, difficulty in individual selection of therapy, especially in patients with severe course. When examining and treating such patients, one of the routine diagnostic methods is to determine the level of total immunoglobulin E in the blood serum. The article is devoted to the analysis of available world practice data on published clinical cases of the use of biological therapy with dupilumab in real clinical practice in patients with severe atopic dermatitis, in whom high and very high levels of immunoglobulin E. The appointment of biological therapy for this cohort of patients often raises significant concerns. However, the use of a monoclonal antibody against IL-4/IL-13 proved effective, did not lead to serious adverse reactions in such patients and was accompanied by a decrease in the level of immunoglobulin E during treatment. It was noted that immunosuppressive treatment prior to biological therapy led to the development of adverse events in these patients. A separate group of patients with genetically determined hyper-IgE syndrome and severe atopic dermatitis is described, in which the positive experience of using dupilumab is also noted. The author presents his own clinical case of a patient with severe atopic dermatitis and a high level of immunoglobulin E receiving successful targeted therapy after a preliminary thorough examination except for lymphoproliferative and autoimmune diseases. Against the background of dupilumab therapy, there was a pronounced clinical regression of skin symptoms, a decrease in the level of immunoglobulin E, an increase in the patient’s quality of life, and the absence of side effects.

Humoral immune response to SARS-CoV-2 in pregnant and nonpregnant women following infection

Immune changes that occur during pregnancy may place pregnant women at an increased risk for severe disease following viral infections like SARS-CoV-2. Whether these immunologic changes modify the immune response to SARS-CoV-2 infection during pregnancy is not well understood. This study aimed to compare the humoral immune response to SARS-CoV-2 infection in pregnant and nonpregnant women. The immune response following vaccination for SARS-CoV-2 was also explored. In this cohort study, 24 serum samples from 20 patients infected with SARS-CoV-2 during pregnancy were matched by number of days after a positive test with 46 samples from 40 nonpregnant women of reproductive age. Samples from 9 patients who were vaccinated during pregnancy were also examined. Immunoglobulin G and immunoglobulin M levels were measured. Trends in the log antibody levels over time and mean antibody levels were assessed using generalized estimating equations. The median number of days from first positive test to sampling was 6.5 in the pregnant group (range, 3-97) and 6.0 among nonpregnant participants (range, 2-97). No significant differences in demographic or sampling characteristics were noted between the groups. No differences in immunoglobulin G or immunoglobulin M levels over time or mean antibody levels were noted among pregnant and nonpregnant participants following SARS-CoV-2 infection for any of the SARS-CoV-2 antigen targets examined (spike, spike receptor-binding domain, spike N-terminal domain, and nucleocapsid). Participants who were vaccinated during pregnancy had higher immunoglobulin G levels than pregnant patients who tested positive for all SARS-CoV-2 targets except nucleocapsid antibodies (all P<.001) and had lower immunoglobulin M spike (P<.05) and receptor-binding domain (P<.01) antibody levels. This study suggests that the humoral response following SARS-CoV-2 infection does not seem to differ between pregnant women and their nonpregnant counterparts. These findings should reassure patients and healthcare providers that pregnant patients seem to mount a nondifferential immune response to SARS-CoV-2.

Effects of different protectants on the IgY content and physico-chemical properties of spray-dried egg yolk powder.

Egg yolk powder (EYP) with high immunoglobulin of yolk (IgY) content and good solubility is in great demand in the market of functional foods. In this article, the properties of spray-dried EYP with the addition of five protectants (maltodextrin, trehalose, mannitol, maltitol and sucrose) were investigated. All the protectants increased IgY activity and solubility of EYP. Among them, EYP with maltodextrin displayed the highest activity of IgY (27.11 mg/g), the highest solubility (66.39%) and the lowest surface hydrophobicity. Moreover, the average particle size of EYP with maltodextrin was the smallest (9.78 μm). The egg yolk particles obtained by adding the protectants are more uniformly distributed and have smaller particle size. Fourier-transform infrared spectroscopy confirmed the structural integrity of the proteins, indicating that the protectants addition enhanced the hydrogen bonding forces between the EYP protein molecules. The addition of protectants can significantly improve the IgY content, solubility and structural stability of EYP. © 2023 Society of Chemical Industry.

Adaptive immune receptor features related to breast cancer tissue in Kenyan patients: high immunoglobulin gene expression and high levels of gamma-delta T-cells.

Characterization of the breast cancer (BC) immune response may provide information for a point of intervention, such as application of immunotherapeutic treatments. In this study, we sought to recover and characterize the adaptive immune receptor (IR) recombination reads from genomics files representing Kenyan patients, to better understand the immune response specifically related to those patients. We used a previously applied algorithm and software to obtain productive IR recombination reads from cancer and adjacent normal tissue samples representing 22 Kenyan BC patients. From both the RNAseq and exome files, there were significantly more T-cell receptor (TCR) recombination reads recovered from tumor samples compared to marginal tissue samples. Also, the immunoglobulin (IG) genes were expressed at a much higher level than the TCR genes (p-value = 0.0183) in the tumor samples. And, the tumor IG CDR3s consistently represented more positively charged amino acid R-groups, in comparison to the marginal tissue, IG CDR3s. For Kenyan patients, a high level of IG expression, representing specific CDR3 chemistries, was associated with BC. These results lay the foundation for studies that could support specific immunotherapeutic interventions for Kenyan BC patients.

The effect of BCG vaccination on infection and antibody levels against SARS-CoV-2—The results of ProBCG: a multicenter randomized clinical trial in Brazil

Evatuate if Bacillus Calmette-Guérin (BCG) vaccine could be used as a tool against SARS-CoV-2 based on the concept of trained immunity. A multicenter, double-blinded, randomized clinical trial recruited health care workers (HCWs) in Brazil. The incidence rates of COVID-19, clinical manifestations, absenteeism, and adverse events among HCWs receiving BCG vaccine (Moreau or Moscow strains) or placebo were compared. BCG vaccine-mediated immune response before and after implementing specific vaccines for COVID-19 (CoronaVac or COVISHIELD) was analyzed. Cox proportional hazard and linear mixed effect modeling were used. A total of 264 volunteers were included for analysis (BCG=134 and placebo=130). The placebo group presented a COVID-19 cumulative incidence of 0.75% vs 0.52% of BCG. The Moreau strain also presented a higher incidence rate (1.60%×0.22%). BCG did not show a protective hazard ratio against COVID-19. In addition, the log (immunoglobulin G) level against SARS-CoV-2 presented a higher increase in the BCG group, whether or not participants had COVID-19, but also without statistical significance. Our results suggest that BCG has a tendency of protection against SARS-CoV-2 and higher immunoglobulin G levels than placebo. The clinical trial was registered at https://clinicaltrials.gov/ (NCT04659941).

Aglycosylated extracellular loop of inwardly rectifying potassium channel 4.1 (KCNJ10) provides a target for autoimmune neuroinflammation.

Multiple sclerosis is an autoimmune disease of the central nervous system. Yet, the autoimmune targets are still undefined. The extracellular e1 sequence of KCNJ10, the inwardly rectifying potassium channel 4.1, has been subject to fierce debate for its role as a candidate autoantigen in multiple sclerosis. Inwardly rectifying potassium channel 4.1 is expressed in the central nervous system but also in peripheral tissues, raising concerns about the central nervous system-specificity of such autoreactivity. Immunization of C57Bl6/J female mice with the e1 peptide (amino acids 83-120 of Kir4.1) induced anti-e1 immunoglobulin G- and T-cell responses and promoted demyelinating encephalomyelitis with B cell central nervous system enrichment in leptomeninges and T cells/macrophages in central nervous system parenchyma from forebrain to spinal cord, mostly in the white matter. Within our cohort of multiple sclerosis patients (n = 252), 6% exhibited high anti-e1 immunoglobulin G levels in serum as compared to 0.7% in the control cohort (n = 127; P = 0.015). Immunolabelling of inwardly rectifying potassium channel 4.1-expressing white matter glia with the anti-e1 serum from immunized mice increased during murine autoimmune neuroinflammation and in multiple sclerosis white matter as compared with controls. Strikingly, the mouse and human anti-e1 sera labelled astrocytoma cells when N-glycosylation was blocked with tunicamycin. Western blot confirmed that neuroinflammation induces Kir4.1 expression, including its shorter aglycosylated form in murine experimental autoencephalomyelitis and multiple sclerosis. In addition, recognition of inwardly rectifying potassium channel 4.1 using mouse anti-e1 serum in Western blot experiments under unreduced conditions or in cells transfected with the N-glycosylation defective N104Q mutant as compared to the wild type further suggests that autoantibodies target an e1 conformational epitope in its aglycosylated form. These data highlight the e1 sequence of inwardly rectifying potassium channel 4.1 as a valid central nervous system autoantigen with a disease/tissue-specific post-translational antigen modification as potential contributor to autoimmunity in some multiple sclerosis patients.

FcγRI FG-loop functions as a pH sensitive switch for IgG binding and release.

Understanding the molecular mechanism underlying the hierarchic binding between FcγRs and IgG antibodies is critical for therapeutic antibody engineering and FcγR functions. The recent determination of crystal structures of FcγRI-Fc complexes, however, resulted in two controversial mechanisms for the high affinity receptor binding to IgG. Here, we describe high resolution structures of a bovine FG-loop variant of FcγRI in complex with the Fc fragment of IgG1 crystallized in three different conditions at neutral pH, confirming the characteristic FG loop-Fc interaction is critical to the high affinity immunoglobulin binding. We showed that the FcγRI D2-domain FG-loop functioned as a pH-sensing switch for IgG binding. Further live cell imaging of FcγRI-mediated internalization of immune complexes showed a pH sensitive temporal-spatial antibody-antigen uptake and release. Taken together, we demonstrate that the structures of FcγRI-Fc crystallized at neutral and acidic pH, respectively, represent the high and low affinity binding states of the receptor for IgG uptake and release. These results support a role for FcγRI in antigen delivery, highlight the importance of Fc glycan in antibody binding to the high affinity receptor and provide new insights to future antibody engineering.

Laser-assisted intradermal delivery of a microparticle vaccine for respiratory syncytial virus induces a robust immune response.

Respiratory syncytial virus (RSV) is an infectious disease that poses a significant public health risk in young children. Vaccine studies conducted in the 1960s using an intramuscular injection of formalin-inactivated respiratory syncytial virus (Fi-RSV) resulted in an enhanced respiratory disease and led to the failure of the vaccine. Thus, the virus-like particles (VLP) of the RSV fusion (F) protein was used as the vaccine antigen in this study. The F-VLP was encapsulated in a microparticle (MP) matrix composed of cross-linked bovine serum albumin (BSA) to enhance the antigen presentation and uptake. Moreover, a painless vaccination method would be desirable for an infectious disease that mainly affects young children. Thus, an ablative laser device, Precise Laser Epidermal System (P.L.E.A.S.E), was utilized to create micropores on the skin for vaccine delivery. We observed enhanced antigen presentation of the vaccine microparticles (F-VLP MP) with and without the adjuvant monophosphoryl lipid A (MPL-A) MP in dendritic cells. Consequently, Swiss Webster mice were immunized with the adjuvanted vaccine microparticles using the P.L.E.A.S.E laser to study the in vivo immunogenicity. The immunized mice had high serum immunoglobulin (IgG, IgG2a) levels, indicating a Th1 response. Subsequent analysis of lung homogenates post- RSV challenge revealed high IgA, indicating generation of a mucosal immune response upon intradermal immunization. Flowcytometry analysis showed high CD8+, and CD4+ expression in the lymph node and spleen of the adjuvanted vaccine microparticle immunized mice. Increased expression of interferon gamma (IFN-γ) in the spleen cells further proved Th1 polarized immune response. Finally, an immune plaque assay indicated significantly low lung viral titer in the mice immunized with intradermal adjuvanted vaccine microparticles. Thus, ablative laser-assisted immunization with the F-VLP based adjuvanted vaccine microparticles could be a promising vaccine candidate for RSV.

Salivary IgA as a Surrogate Biomarker for Microbial Infections in Postoperative Patients Receiving Chemo-Radio-Therapy for Head and Neck Cancer.

Objective Radiotherapy (RT) and chemotherapy (CT) are important treatment options in patients with head and neck cancers. A common complication of this is microbial colonization or infection of mucosal surfaces. These infections may commonly be due to bacteria or yeasts. Salivary proteins with their buffering activity and immunoglobulin, especially immunoglobulin A (IgA), protect oral tissue, mucosal surfaces, and teeth from various microorganisms. This study characterizes the common microorganisms encountered and evaluates the role of salivary IgA in predicting microbial infections in this group of patients with mucositis. Methods A total of 150 adult head and neck cancer patients on CTRT were evaluated at baseline and at the end of 3 and 6 weeks, respectively. Oral swabs collected from buccal mucosa were processed in the microbiology laboratory for the presence of microorganisms. Saliva was processed for IgA level estimation on Siemens Dimension Automated biochemistry analyzer. Results Pseudomonas aeruginosa and Klebsiella pneumonia e were the most common organisms found in our patients, followed by Escherichia coli and group A beta-hemolytic Streptococci . A significant increase ( p = 0.0203) in the incidence of bacterial infection was observed in post-CTRT patients (61%) compared to pre-CTRT patients (49.33%). There was significant increase in levels of salivary IgA ( p = 0.003) in patients with bacterial and fungal infection ( n = 135/267) when compared to those in samples showing no growth ( n = 66/183). Conclusion A significant increase in the incidence of bacterial infection in post-CTRT patients was observed in this study. This study also indicated that postoperative head and neck cancer patients with oral mucositis that developed an infection were associated with high salivary IgA levels, and it may serve as a surrogate biomarker of infection in these patients.

Follow-up of patients with a 5-year survival after paraquat poisoning using computed tomography images and spirometry.

The study aimed to examine long-term survival of patients with acute paraquat poisoning using computed tomography (CT) images and spirometry. A total of 36 patients with long-term survival after paraquat poisoning were followed-up and divided into mild (11 patients), moderate (17 patients), and severe (8 patients) paraquat poisoning groups. Differences among the groups were compared using clinical indicators, such as peripheral capillary oxygen saturation, arterial partial pressure of oxygen and 6-min walk test (6-MWT), chest CT, spirometry, and serum immunoglobulin E (IgE). The 6-MWT distance was significantly shorter in the severe paraquat poisoning group than that in the mild and moderate paraquat poisoning groups. In the mild paraquat poisoning group, CT revealed no obvious lung injury, and spirometry showed normal lung function in most patients. In moderate or severe paraquat poisoning group, CT images showed fibrotic lesions as cord-like high-density shadows, reticulations, and honeycombs. In addition, other pulmonary changes, including bronchiectasis, increased lung transparency, and pulmonary bullae, were discovered. In moderate or severe paraquat poisoning group, obvious obstructive ventilation dysfunction with slight restrictive and diffuse impairment were observed in some patients, with positive bronchial relaxation test and high serum IgE level. In the long-term follow-up, patients with severe paraquat poisoning showed the lowest exercise endurance. In moderate or severe paraquat poisoning group, CT images revealed diversified changes, not only dynamic evolution of pulmonary fibrosis process, but also signs of bronchiectasis, and chronic obstructive pulmonary disease. Some patients with moderate or severe paraquat poisoning developed obstructive ventilatory dysfunction with airway hyperresponsiveness.

Huwe1 supports B-cell development, B-cell-dependent immunity, somatic hypermutation and class switch recombination by regulating proliferation.

The development and differentiation of B cells is intimately linked to cell proliferation and the generation of diverse immunoglobulin gene (Ig) repertoires. The ubiquitin E3 ligase HUWE1 controls proliferation, DNA damage responses, and DNA repair, including the base excision repair (BER) pathway. These processes are of crucial importance for B-cell development in the bone marrow, and the germinal center (GC) response, which results in the clonal expansion and differentiation of B cells expressing high affinity immunoglobulins. Here, we re-examined the role of HUWE1 in B-cell proliferation and Ig gene diversification, focusing on its involvement in somatic hypermutation (SHM) and class switch recombination (CSR). B-cell-specific deletion of Huwe1 resulted in impaired development, differentiation and maturation of B cells in the bone marrow and peripheral lymphoid organs. HUWE1 deficiency diminished SHM and CSR by impairing B-cell proliferation and AID expression upon activation in vitro and in vivo, and was unrelated to the HUWE1-dependent regulation of the BER pathway. Interestingly, we found that HUWE1-deficient B cells showed increased mRNA expression of Myc target genes upon in vitro activation despite diminished proliferation. Our results confirm that the E3 ligase HUWE1 is an important contributor in coordinating the rapid transition of antigen naïve, resting B cells into antigen-activated B cells and regulates mutagenic processes in B cells by controlling AID expression and the post-transcriptional output of Myc target genes.