Presence of immunoglobulin E-expressing antibody-secreting cells in the dermis close to bullous pemphigoid lesions.

Antibody-secreting cells (ASCs) produce immunoglobulin (Ig) G and IgE autoantibodies in secondary lymphoid organs. Evidence also suggests their existence in the skin in various chronic inflammatory conditions, and in association with CXCL12 and CXCL13, they regulate the recruitment/survival of ASCs and germinal center formation to generate ASCs, respectively. However, the presence of IgG and IgE in bullous pemphigoid (BP) lesions needs to be addressed. Here, we aimed to analyse BP skin for the presence of IgG and IgE and the factors contributing to their generation, recruitment, and persistence. Skin samples from 30 patients with BP were stained to identify ASCs and the immunoglobulin type they expressed. The presence of tertiary lymphoid organ (TLO) elements, which generate ASCs in non-lymphoid tissues, and the chemokines CXCL12 and CXCL13, which regulate the migration/persistence of ASCs in lymphoid tissues and formation of TLOs, respectively, were evaluated in BP skin. BP skin harboured ASCs expressing the two types of antibodies IgG and IgE. ASCs were found in high-grade cellular aggregates containing TLO elements: T cells, B cells, CXCL12+ cells, CXCL13+ cells and high endothelial venules. IgG+ ASCs were detected among these aggregates, whereas IgE+ ASCs were dispersed throughout the dermis. CXCL12+ fibroblast-like cells were located close to ASCs. The inflammatory microenvironment of BP lesions may contribute to the antibody load characteristic of the skin of patients with BP by providing a site for the presence of ASCs. CXCL13 and CXCL12 expression may contribute to the generation and recruitment/survival of ASCs, respectively.

The challenge of avidity determination in SARS-CoV-2 serology.

The serological responses towards severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein, receptor-binding domain (RBD), and spike protein S1 are characterized by incomplete avidity maturation. Analysis with varying concentrations of urea allows to determine distinct differences in avidity maturation, though the total process remains at an unusually low level. Despite incomplete avidity maturation, this approach allows to define early and late stages of infection. It therefore can compensate for the recently described irregular kinetic patterns of immunoglobulin M and immunoglobulin G (IgG) directed towards SARS-CoV-2 antigens. The serological responses towards seasonal coronaviruses neither have a negative nor positive impact on SARS-CoV-2 serology in general. Avidity determination in combination with measurement of antibody titers and complexity of the immune response allows to clearly differentiate between IgG responses towards seasonal coronaviruses and SARS-CoV-2. Cross-reactions seem to occur with very low probability. They can be recognized by their pattern of response and through differential treatment with urea. As high avidity has been shown to be essential in several virus systems for the protective effect of neutralizing antibodies, it should be clarified whether high avidity of IgG directed towards RBD indicates protective immunity. If this is the case, monitoring of avidity should be part of the optimization of vaccination programs.

IgG Fc N-Glycosylation Translates MHCII Haplotype into Autoimmune Skin Disease.

The major histocompatibility complex haplotype represents the most prevalent genetic risk factor for the development of autoimmune diseases. However, the mechanisms by which major histocompatibility complex-associated genetic susceptibility translates into autoimmune disease are not fully understood. Epidermolysis bullosa acquisita is an autoimmune skin-blistering disease driven by autoantibodies to type VII collagen. Here, we investigated autoantigen-specific plasma cells, CD4+ T cells, and IgG fraction crystallizable glycosylation in murine epidermolysis bullosa acquisita in congenic mouse strains with the disease-permitting H2s or disease-nonpermitting H2b major histocompatibility complex II haplotypes. Mice with an H2s haplotype showed increased numbers of autoreactive CD4+ T cells and elevated IL-21 and IFN-γ production, associated with a higher frequency of IgG autoantibodies with an agalactosylated, proinflammatory N-glycan moiety. Mechanistically, we show that the altered antibody glycosylation leads to increased ROS release from neutrophils, the main drivers of autoimmune inflammation in this model. These results indicate that major histocompatibility complex II-associated susceptibility to autoimmune diseases acuminates in a proinflammatory IgG fraction crystallizable N-glycosylation pattern and provide a mechanistic link to increased ROS release by neutrophils.

Deep phenotypic characterization of immunization-induced antibacterial IgG repertoires in mice using a single-antibody bioassay.

Antibodies with antibacterial activity need to bind to the bacterial surface with affinity, specificity, and sufficient density to induce efficient elimination. To characterize the anti-bacterial antibody repertoire, we developed an in-droplet bioassay with single-antibody resolution. The assay not only allowed us to identify whether the secreted antibodies recognized a bacterial surface antigen, but also to estimate the apparent dissociation constant (KD app) of the interaction and the density of the recognized epitope on the bacteria. Herein, we found substantial differences within the KD app/epitope density profiles in mice immunized with various species of heat-killed bacteria. The experiments further revealed a high cross-reactivity of the secreted IgG repertoires, binding to even unrelated bacteria with high affinity. This application confirmed the ability to quantify the anti-bacterial antibody repertoire and the utility of the developed bioassay to study the interplay between bacteria and the humoral response.

Pre-existing Helicobacter pylori serum IgG enhances the vibriocidal antibody response to CVD 103-HgR live oral cholera vaccine in Malian adults.

Accumulating evidence indicates that persistent Helicobacter pylori gastric infection influences immune responses to oral enteric vaccines. We studied the association between pre-existing H. pylori serum IgG and serum pepsinogens levels (PGs) as markers of gastric inflammation and the immune response to single-dose live oral cholera vaccine CVD 103-HgR in Malian adults. Baseline sera obtained during a phase 2 safety/immunogenicity clinical trial of cholera vaccine CVD 103-HgR among 93 healthy Malian adults were tested for H. pylori IgG antibodies and PGI and PGII levels using enzyme linked immunosorbent assays. Overall 74/93 (80%) vaccine recipients were H. pylori IgG seropositive at baseline. Vibriocidal antibody seroconversion (≥ fourfold increase 14 days following administration of CVD 103-HgR compared to baseline) among vaccine recipients was 56%. However, vibriocidal antibody seroconversion was markedly higher among H. pylori seropositives than seronegatives 64% vs. 26% (p = 0.004); adjusted relative risk: 2.20 (95% confidence intervals 1.00-4.80; p = 0.049). Among H. pylori seropositive vaccine recipients, there were no significant associations between PGI, PGII and PGI:PGII levels and vibriocidal seroconversion. The enhanced seroconversion to oral cholera vaccine CVD 103-HgR among H. pylori seropositive African adults provides further evidence of the immunomodulating impact of H. pylori on oral vaccine immunogenicity.

Importance of colostrum IgG antibodies level for prevention of infection with Cryptosporidium parvum in neonatal dairy calves.

Cryptosporidiosis is one of the most common zoonosis worldwide, causing intestinal infection to both humans and livestock. The purpose of this study was to assess whether the level of anti-C. parvum IgG antibodies transferred through colostrum from dams to newborn calves impacts the susceptibility to cryptosporidiosis. A number of 50 dams and their healthy newborns were included in the study. Colostrum samples were collected within 12 h after birth and anti-C. parvum IgG antibody levels were determined by single radial immunodiffusion. The health condition of the newborns was daily monitored, and fecal samples were collected at first diarrheic episode of a calf. In all dams, the anti-C. parvum IgG antibody concentration in colostrum varied between 570 and 4070 mg/dl; in dams who gave birth to calves with diarrhea and were C. parvum-positive, the antibody concentration in colostrum varied between 680 and 3680 mg/dl (Table 1). The point-biserial correlation showed a negative correlation between the levels of anti-C. parvum antibodies and manifestation of clinical cryptosporidiosis (r=-0.425). Our findings highlight the importance of IgG levels in colostrum received by neonatal calves during their first day of life for prevention of C. parvum infection.

IgG plasma cells initiate changes in the protein C system in mouse ulcerative colitis through CD14+CD64+ macrophage activation.

BACKGROUND: Inhibition of the protein C system (PCS) might be one of the mechanisms of ulcerative colitis (UC). OBJECTIVES: The aim of the study was to explore the role of IgG plasma cells in changes in the PCS in UC. MATERIAL AND METHODS: Dextran sulfate sodium (DSS) was chosen to induce mouse UC. Inflammation was assessed using hematoxylin & eosin (H&E) staining and immunofluorescence. The profiling of colonic plasma cells and macrophages from colitis mice was analyzed with flow cytometry. After stimulation of macrophages with IgG type immune complex (IgG-IC), western blot was used to determine tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) protein levels. After co-incubation of colonic mucosa microvascular endothelial cells (MVECs) with TNF-α or IL-6, mitogen-activated protein kinase (MAPK) expression was detected. RESULTS: The DSS-colitis mice showed higher inflammatory indexes (p < 0.05 or p < 0.01), accompanied by greater infiltration of CD38+IgG+ plasma cells (p < 0.01), CD14+CD64+ macrophages (p < 0.01) and IgG-IC than healthy mice. Enhancement of TNF-α and IL-6 protein expression was demonstrated in this subset of macrophages when stimulated by IgG-IC (p < 0.01). After MVECs were incubated with TNF-α or IL-6, the expression of ß-arrestin1, pP38 MAPK and pJNK MAPK exhibited an increase (p < 0.05 or p < 0.01), but downregulation of endothelial protein C receptor (EPCR) expression was observed (p < 0.05 or p < 0.01); this inhibition of EPCR expression was reversed by SB203580, SP600125 or U0126 (p < 0.05 or p < 0.01). In addition, changes in activated protein C (APC) presented results similar to those for EPCR expression (p < 0.05 or p < 0.01). CONCLUSIONS: These results reveal that the PCS is inhibited during UC processing. There is a possibility that the interaction between IgG plasma cells and CD14+CD64+ macrophages, as well as further secretion of cytokines from CD14+CD64+ macrophages by the formation and stimulation of IgG-IC, subsequently influence MVECs through the ß-arrestin-MAPK pathway. Enhancement of PCS activity may represent a novel approach for treating UC.

Disease heterogeneity in IgG4-related hypophysitis: report of two histopathologically proven cases and review of the literature.

IgG4-related hypophysitis (IgG4-RH) is a rare disease, which can occur singularly or as manifestation of a systemic IgG4-related disease (IgG4-RD). Less than one hundred cases have been reported in the literature, very few of which were histopathologically documented. We analyzed the clinical, radiological, and histopathological features of two cases of IgG4-RH, the former observed in a 66-year-old man in the context of an IgG4-RD, and the latter affecting a 21-year-old woman, as an isolated lesion. In addition, we performed a comprehensive review of the previously published histopathologically documented cases of IgG4-RH. Pituitary samples from both patients showed dense lymphoplasmacytic infiltration, interstitial and storiform fibrosis, and high numbers of IgG4-positive plasma cells, consistent with IgG4-RH. From the literature review, we retrieved 18 papers reporting a total of 22 cases of histopathologically documented IgG4-RH. The revision of these cases, also including the two reported herein, showed an equal distribution of IgG4-RH in the two sexes, albeit significant clinico-pathological variation was found between cases arisen in female and male patients, respectively. In detail, IgG4-RH females were affected in their second-third decade of life, with a solitary pituitary lesion, low IgG4 serum level, and frequent association with autoimmune disorders. By contrast, IgG4-RH in men was a disease of the elderly, often in the context of a systemic IgG4-RD, with high IgG4 serum levels. Our study shows that IgG4-RH, as currently defined, is a clinically heterogenous disease, with different features in the two sexes. Indeed, cases diagnosed in young women, as our case 2, mostly do not present other evidence of IgG4-RD and might be better classified as lymphocytic hypophysitis with abundant IgG4+ plasma cells. For this reason, the histopathological examination of the pituitary lesion, particularly in female patients, may still be useful for a correct differential diagnosis with other variants of primary hypophysitis.

Antibody responses to Plasmodium vivax Duffy binding and Erythrocyte binding proteins predict risk of infection and are associated with protection from clinical Malaria.

BACKGROUND: The Plasmodium vivax Duffy Binding Protein (PvDBP) is a key target of naturally acquired immunity. However, region II of PvDBP, which contains the receptor-binding site, is highly polymorphic. The natural acquisition of antibodies to different variants of PvDBP region II (PvDBPII), including the AH, O, P and Sal1 alleles, the central region III-V (PvDBPIII-V), and P. vivax Erythrocyte Binding Protein region II (PvEBPII) and their associations with risk of clinical P. vivax malaria are not well understood. METHODOLOGY: Total IgG and IgG subclasses 1, 2, and 3 that recognize four alleles of PvDBPII (AH, O, P, and Sal1), PvDBPIII-V and PvEBPII were measured in samples collected from a cohort of 1 to 3 year old Papua New Guinean (PNG) children living in a highly endemic area of PNG. The levels of binding inhibitory antibodies (BIAbs) to PvDBPII (AH, O, and Sal1) were also tested in a subset of children. The association of presence of IgG with age, cumulative exposure (measured as the product of age and malaria infections during follow-up) and prospective risk of clinical malaria were evaluated. RESULTS: The increase in antigen-specific total IgG, IgG1, and IgG3 with age and cumulative exposure was only observed for PvDBPII AH and PvEBPII. High levels of total IgG and predominant subclass IgG3 specific for PvDBPII AH were associated with decreased incidence of clinical P. vivax episodes (aIRR = 0.56-0.68, P≤0.001-0.021). High levels of total IgG and IgG1 to PvEBPII correlated strongly with protection against clinical vivax malaria compared with IgGs against all PvDBPII variants (aIRR = 0.38, P<0.001). Antibodies to PvDBPII AH and PvEBPII showed evidence of an additive effect, with a joint protective association of 70%. CONCLUSION: Antibodies to the key parasite invasion ligands PvDBPII and PvEBPII are good correlates of protection against P. vivax malaria in PNG. This further strengthens the rationale for inclusion of PvDBPII in a recombinant subunit vaccine for P. vivax malaria and highlights the need for further functional studies to determine the potential of PvEBPII as a component of a subunit vaccine for P. vivax malaria.

Anti-N and anti-Doa immunoglobulin G alloantibody-mediated delayed hemolytic transfusion reaction with hyperhemolysis in sickle cell disease treated with eculizumab and HBOC-201: case report and review of the literature.

BACKGROUND: Delayed hemolytic transfusion reaction (DHTR) with hyperhemolysis is a potentially fatal complication resulting from alloimmunization that can cause severe hemolysis of both transfused and intrinsic red blood cells (RBCs). Patients with sickle cell disease often receive multiple RBC units during their lifetime and thus are likely to develop alloantibodies that increase the risk for DHTR. Treatment to decrease hemolysis includes intravenous immunoglobulin (IVIG), steroids, eculizumab, rituximab, and plasmapheresis in addition to erythropoietin (EPO), intravenous (IV) iron, vitamin B12, and folate to support erythropoiesis. RBC transfusion is preferably avoided in DHTR due to an increased risk of exacerbating the hemolysis. CASE REPORT: We report a rare case of anti-N and anti-Doa immunoglobulin (Ig)G alloantibody-mediated life-threatening DHTR with hyperhemolysis in a patient with hemoglobin SS after RBC transfusion for acute chest syndrome who was successfully treated with eculizumab and HBOC-201 (Hemopure) in addition to steroids, IVIG, EPO, IV iron, and vitamin B12. HBOC-201 (Hemopure) was successfully used as a RBC alternative in this patient. CONCLUSION: Anti-N and anti-Doa IgG alloantibodies can rarely cause severe life-threatening DHTR with hyperhemolysis. HBOC-201 (Hemopure) can be a lifesaving alternative in this scenario. Our report also supports the use of eculizumab in DHTR; however, prospective studies are needed to determine the appropriate dose and sequence of eculizumab administration.

New insights into immune cells cross-talk during IgG4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) is a newly acknowledged entity, characterized by an immune-mediated fibro-inflammatory process affecting virtually all organs, with infiltration of IgG4+ bearing plasma cells. Until today the pathogenesis of IgG4-RD remains unknown. Treatment with anti-CD20 monoclonal antibodies efficiently induced remission and attenuated the secretory phenotype of myofibroblasts responsible of uncontrolled collagen deposition. This supports the pathogenic role of the adaptive immunity, particularly B cell compartment and B cell/T cell interaction. Latest studies have also highlighted the importance of innate immune system that has been underestimated before and the key role of a specific T cell subset, T follicular helper cells that are involved in IgG4-class-switching and plasmablast differentiation. In this review, we aim to review the most recent knowledge of innate immunity, T and B cells involvement in IgG4-RD, and introduce tertiary lymphoid organs (TLO) as a potential marker of relapse in this condition.

Prospects of developing a prophylactic vaccine against human lymphatic filariasis - evaluation of protection in non-human primates.

Lymphatic filariasis (LF) affects 120 million people around the world and another 856 million people are at risk of acquiring the infection. Mass Drug Administration (MDA) spearheaded by the World Health Organization is the only current strategy to control this infection. Recent reports suggest that despite several rounds of MDA, elimination has not been achieved and there is a need for more stringent control strategies for control of LF. An effective prophylactic vaccine combined with MDA has significant potential. Initial trials using a prophylactic trivalent recombinant Brugia malayi heat shock protein 12.6, abundant larval transcript -2 and tetraspanin large extra-cellular loop (rBmHAT) vaccine developed in our laboratory conferred only 35% protection in macaques. Therefore, the focus of the present study was to improve the current vaccine formulation to obtain better protection in non-human primates. We made two modifications to the current formulation: (i) the addition of another antigen, thioredoxin peroxidase-2 (TPX-2) to make it a tetravalent vaccine (rBmHAXT) and (ii) the inclusion of an adjuvant; AL019 (alum plus glucopyranosyl lipid adjuvant-stable emulsion) that is known to promote a balanced Th1/Th2 response. A double-blinded vaccination trial was performed with 40 macaques that were divided into three treatment groups and one control group (n = 10/group). Vaccinated animals received 4 immunisations at 1 month intervals with 150 µg/ml of rBmHAT plus alum, rBmHAT plus AL019 or rBmHAXT plus AL019. Control animals received AL019 only. All vaccinated macaques developed significant (P ≤ 0.003) titers of antigen-specific IgG antibodies (1:20,000) compared with the controls. One month after the last dose, all macaques were challenged s.c. with 130-180 B. malayi L3s. Our results showed that seven out of 10 (70%) of macaques given the improved rBmHAXT vaccine did not develop the infection compared with AL019 controls, of which seven out of 10 macaques developed the infection. Titers of antigen-specific IgG1 and IgG2 antibodies were significantly (P ≤ 0.01) higher in vaccinated animals and there was an increase in the percentage of IL-4 and IFN-γ secreting antigen-responding memory T cells. These studies demonstrated that the improved formulation (rBmHAXT plus AL019) is a promising vaccine candidate against human lymphatic filariasis.

Structural and visual functional deficits in a rat model of neuromyelitis optica spectrum disorders related optic neuritis.

Neuromyelitis optica spectrum disorders (NMOSD) are a group of autoimmune astrocytopathies in the central nervous system, which are mainly caused by immunoglobulin G (IgG) against astrocyte water channel aquaporin-4 (AQP4). In this study, we aimed to establish a model of NMOSD-related optic neuritis (NMOSD-ON) and to evaluate the progressive changes of the optic nerve and visual function. AQP4 IgG-positive serum from NMOSD patients was injected into the subarachnoid space of the rat optic nerve to induce the NMOSD-ON model (AQP4 + group), and healthy serum was injected as the control. The visual evoked potential, pupillary light reflex and optical coherence tomography were monitored every week for 3 weeks after induction. Compared with the control group, the amplitude of the N1-P1 peak and pupillary light reflex in the AQP4+ group were reduced within the first week and then remained low thereafter. Consistent with the functional deficits, the thickness of the peripapillary retinal nerve fiber layer in the AQP4 + group was also greatly reduced. At the end of 3 weeks, there was a loss of retinal ganglion cells and the optic nerves showed characteristic NMOSD-like pathologic changes, including deposition of AQP4 IgG, local astrocyte damage, demyelination, microglia activation, macrophage infiltration and axonal injury. Thus, we have established an NMOSD-ON rat model with deficits in the optic nerve and visual function that may be a valuable tool for exploring the mechanism of NMOSD-ON and evaluating its potential therapeutic treatment.

Protective efficacy of a plasmid DNA vaccine against transgene-specific tumors by Th1 cellular immune responses after intradermal injection.

With DNA vaccines, it is important to monitor the movement of transfectants and to overcome immune deviations. We used a pCMV-LacZ plasmid (expressing ß-galactosidase) and a pcDNA-hNIS plasmid (expressing the human sodium/iodide symporter [hNIS] gene) as non-secreted visual-imaging markers. Transfectants carrying the hNIS or LacZ gene migrated to peripheral lymphoid tissues. hNIS-expressing cells were observed specifically in the LNs and spleen. Anti-ß-galactosidase was detected in LacZ DNA immunized mice after boosting twice, suggestive of Th2 humoral immune responses. Antibody isotyping defined the humoral immune response. A dominant IgG2a type occurred in hNIS-immunized mice in ELISAs. IgG2a/IgG1 ratios increased after hNIS DNA vaccination. High levels of INF-γ-secreting cells were identified in ELISpot and increased IFN-γ levels were found in cytokine ELISAs. Tumor growth decreased in hNIS DNA-immunized mice. In conclusion, humoral immune responses switched to the Th1 cellular immune response, even though we administered plasmid DNA by intra dermal injection.

Mannose-Binding Lectin2 Gene Polymorphism and IgG4 in Membranous Nephropathy.

BACKGROUND: Idiopathic membranous nephropathy (IMN) has been linked to the lectin pathway, IgG4 and genetic susceptibility. We investigated the frequency of mannose-binding lectin2 (MBL2) gene polymorphisms and the serum ratio of IgG4 in patients with membranous nephropathy (MN). METHODS: Polymorphisms in the exon 1 of the MBL2 gene (codons 52, 54, and 57) and single base polymorphisms at positions -550 (HL) and -221 (XY) in the promoter region were evaluated in 60 patients compared to a control group (CG) of 101 blood donors. It established the frequency of polymorphisms and the serum ratio of IgG4 comparing 2 etiologies of MN: idiopathic (35 patients) and secondary to systemic lupus erythematosus (25 patients). RESULTS: Patients with MN had a 2.54-fold higher probability (95% CI 1.51-4.31) of carrying the O alelle, exon 1 variant, and 11.16-fold higher probability (95% CI 4.77-28.41) of having A/O genotype when compared to CG. The frequency of polymorphisms in the promoter region was similar between the groups. Combined genotypes generally related to the defective production of MBL (YA/O, XA/O and O/O) were more frequent in patients with MN (OR 7.11; 95% CI 2.69-21.27), when compared to controls. The median of serum ratio IgG4 was 5% for idiopathic MN and 3% for lupus MN patients (p = 0.016). CONCLUSIONS: Our data suggests that MBL2 polymorphisms may be associated with the activation of the lectin pathway by IgG4 subclass antibodies in MN.

Bullosis Diabeticorum: A Rare Presentation with Immunoglobulin G (IgG) Deposition Related Vasculopathy. Case Report and Focused Review.

BACKGROUND Bullosis diabeticorum (BD) is a condition characterized by recurrent, spontaneous, and non-inflammatory blistering in patients with poorly controlled diabetes mellitus. While etiopathogenesis remains unclear, roles of neuropathy, vasculopathy and UV light are hypothesized. Most literature reports negative direct and indirect immunofluorescence findings in diabetics with bullous eruptions. Porphyria cutanea tarda, bullous pemphigoid, epidermolysis bullosa, and pseudoporphyria are other differential diagnoses of bullous lesions, and they must be excluded. CASE REPORT We present a 42-year-old African American male with long standing poorly controlled insulin dependent diabetes mellitus with blisters on his left hand and feet. The blisters were noticed three weeks prior to presentation and, thereafter, rapidly increased in size and spontaneously ruptured. Physical examination revealed a multitude of both roofed and unroofed bullous painless skin lesions. Hematoxylin and eosin (H&E) staining dramatized the dermal-epidermal blistering and re-epithelization process. Direct Immunofluorescence (DIF) was positive for 2 + IgG deposition in the already thickened basement membrane of the capillaries of the superficial vascular plexus. After debridement, his wounds greatly improved with over three months of aggressive wound care. CONCLUSIONS Primary immunologic abnormality likely plays no role in the onset of BD. To date, only one article has reported nonspecific capillary-associated immunoglobulin M and C3. This is the first case of BD with IgG deposition in the superficial capillary basement membrane. Positive findings on DIF suggest vasculopathy. Dermal microangiopathy, secondary to immunologic abnormality, is a possible underlying pathogenesis to bullae formation. Punch biopsy with DIF can be an additional diagnostic modality in the management of such cases.

Sonic Hedgehog Is a Remotely Produced Cue that Controls Axon Guidance Trans-axonally at a Midline Choice Point.

At the optic chiasm choice point, ipsilateral retinal ganglion cells (RGCs) are repelled away from the midline by guidance cues, including Ephrin-B2 and Sonic Hedgehog (Shh). Although guidance cues are normally produced by cells residing at the choice point, the mRNA for Shh is not found at the optic chiasm. Here we show that Shh protein is instead produced by contralateral RGCs at the retina, transported anterogradely along the axon, and accumulates at the optic chiasm to repel ipsilateral RGCs. In vitro, contralateral RGC axons, which secrete Shh, repel ipsilateral RGCs in a Boc- and Smo-dependent manner. Finally, knockdown of Shh in the contralateral retina causes a decrease in the proportion of ipsilateral RGCs in a non-cell-autonomous manner. These findings reveal a role for axon-axon interactions in ipsilateral RGC guidance, and they establish that remotely produced cues can act at axon guidance midline choice points.

[Tumor derived IgG suppress the proliferation of T cells in cord blood].

OBJECTIVE: To explore the function of tumor derived IgG (tIgG) and whether the tIgG can inhibit T cells activity. METHODS: The tIgG was purified from ovarian cancer tissue. The cord blood monocyte cells (CBMC) and cord blood lymphocyte (CBL) were isolate from human umbilical cord blood. The CBMC and CBL were stimulated with phytohaemagg lutinin (PHA) in order to let the CBMC and CBL in the state of proliferation. Carboxyfluorescein succinimidyl amino ester (CFSE) was cultured with CBMC and CBL. CFSE had no cell toxicity, which could penetrate through the cell membrane and combine the intracellular protein. The fluorescence intensity decreased with the proliferation of cells step by step, so the proliferation of these cells could be detected in flow ctytometry. The tIgG which was purified from ovarian cancer tissue was divided into three groups, 1 mg/L group, 10 mg/L group, and 100 mg/L group, and the intravenous immunoglobulin (IVIG) was also divided into three groups too. The CBMC and CBL were treated by tIgG with 1 mg/L, 10 mg/L, and 100 mg/L in order to observe the proliferation of T cells. The cells were treated with IVIG as a positive control group, and the cells were treated with phosphate buffer saline (PBS) as a negative control. The proliferation of CD4+ or CD8+ T cells were detected in CBMC and CBL. The proliferation of the T cells in CBMC and CBL after 64 h and 86 h were detected. RESULTS: In the system of CBMC, the tIgG could suppress the proliferation of CD4+ or CD8+ T cells. The results could also be found in the system of CBL. The CD4+ or CD8+ T cells in the group which were treated with PBS were more active than those in the group which were treated with tIgG and IVIG. The suppression in the group which were treated with tIgG, was stronger than that in the group treated with IVIG. In addition, the suppression of T cells in the group which were stimulated with tIgG as 100 mg/L was more effective than that in the group which were stimulated with tIgG as 10 mg/L. This could prove that tIgG had the function of immunomodulation. CONCLUSION: The tIgG can be involved in immune escape of cancer.

Eosinophilic esophagitis: unclear roles of IgE and eosinophils.

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the oesophagus. Recognized as a distinct entity only two decades ago, the emergence of the disease along with the availability of new technologies has rapidly opened new research avenues and outlined the main features of the pathogenesis of EoE. Yet, each advance in our understanding of the disease has raised new questions about the previous consensus. Currently, new subsets of the disease challenge our diagnostic criteria. For instance, it was believed that EoE did not respond to proton pump inhibitor (PPI) therapy; however, it has now been shown that a substantial proportion of EoE patients indeed respond to PPIs. In addition, a new subset of patients not even presenting eosinophil infiltrates in the oesophagus has also been described. Moreover, approaches for better understanding the heritability of the disease bring into question the dogma of predominant genetic involvement. Furthermore, the specificity and sensitivity of allergy testing for targeted food avoidance is highly controversial, and the production of specific antibodies in EoE now includes IgG4 in addition to IgE. In conclusion, EoE is perceived as 'a moving target' and the aim of this review was to summarize the current understanding of EoE pathogenesis.