Induced synthesis of immunoglobulin messenger RNA accompanies induction of immunoglobulin production in cultured mouse spleen cells.

Immunoglobulin kappa type light chain mRNA (Lkappa mRNA) accumulated in parallel with secretion of immunoglobulin M in cultured mouse spleen cells activated by lipopolysaccharide. Actinomycin D suppressed the accumulation of kappa chain mRNA completely without affecting the degradation rate of kappa chain mRNA. The half life of kappa chain mRNA was about 9 h. Available evidence indicates that lipopolysaccharide stimulates de novo synthesis of kappa chain mRNA. The accumulation of kappa chain mRNA was markedly suppressed by inhibitors of DNA or protein synthesis such as hydroxyurea, cytosine arabinoside and cycloheximide.     

Chaperone and foldase coexpression in the baculovirus-insect cell expression system

Conclusions The BEVS has become widely utilized for production of recombinant proteins. However, protein aggregation and inefficient processing often limit yields, especially for secreted and membrane proteins. Since many proteins of pharmaceutical interest require similar posttranslational processing steps, engineering the folding, assembly, and secretion pathway may enhance the production of a wide variety of valuable complex proteins. Efforts should be undertaken to coexpress the relevant chaperones or foldases at low levels in concert with the final product to ensure the ideal folding and assembly environment. In the future, expression of oligosaccharide modifying enzymes and secretion factors may further improve secretion rates of assembled proteins and provide heterologous proteins with altered glycoforms. Also significant is the use of BEVS as an in vivo eucaryotic laboratory to study the fundamental roles of differnt chaperones, foldases, and secretion factors. The coexpression of chaperones and foldases will complement other approaches such as the development of alternative insect cell lines, promoters, and signal peptides to optimize the baculovirus-insect cell expression system for generating high yields of valuable proteins.Abbreviations BEVS Baculovirus expression vector system - BiP immunoglobulin heavy chain binding protein - ELISA Enzyme-linked immunosorbent assay - ER Endoplasmic reticulum - GRP Glucose regulated protein - Hsp Heat shock protein - IgG Immunoglobulin G - PDI Protein Disulfide Isomerase - PPI Peptidyl-prolyl cis-trans isomerase - Sf-9 Spodoptera frugeperda     

髓系细胞触发受体-1研究进展

髓系细胞表达的触发受体1（triggering receptor expressed on myeloid cells-1,TREM-1）是主要表达于巨噬细胞、中性细胞等的表面受体蛋白,它属于免疫球蛋白超家族的成员,主要由赖氨酸残基的跨膜结构域、V型Ig样胞外结构域和缺乏信号基序的胞浆结构域等三个部分组成。TREM-1分子在感染性疾病中发挥重要作用,通过其和细胞外受体蛋白DAP-12结合,引起下游信号通路活化,导致多种炎症介质的分泌,具有预激和诱导炎症反应的作用,对感染性疾病的诊断起到重要作用。但最近研究显示TREM-1不仅在感染性组织中表达增高,在非感染性炎症、结缔组织及肿瘤组织中也有增高表现,本文就TREM-1最新研究进展做一综述。     

Oral intake of Lactobacillus pentosus strain b240 accelerates salivary immunoglobulin A secretion in the elderly: A randomized, placebo-controlled, double-blind trial

Background

Immunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections. The effect of oral intake of lactic acid bacteria on salivary secretory IgA (SIgA) in the elderly has not been reported. The objective of this study was to demonstrate the acceleration of salivary SIgA secretion by oral intake of Lactobacillus pentosus strain b240 (b240) in the elderly.

Results

A total of 80 healthy elderly individuals were randomly allocated to either an intervention (i.e., b240) or a control (i.e., placebo) group. The elderly individuals in the b240 group were given a sterile water beverage (125 mL) containing heat-killed b240 (4 × 10⁹ cells), while those in the placebo group were given only a sterile water beverage (125 mL); both groups received their respective beverages once daily for 12 weeks. Saliva was collected before initiation of the study and every 2 weeks thereafter. Saliva flow rate and SIgA concentration were determined, and the SIgA secretion rate was calculated. The mean salivary SIgA secretion rate in the b240 group steadily increased until week 4 (exhibiting a 20% elevation relative to that at week 0), and then remained stable until week 12. Changes in SIgA secretion rate over the intervention period were significantly greater in the b240 group than in the placebo group. The treatment groups exhibited no significant differences in adverse events.

Conclusions

Oral intake of L. pentosus strain b240 for 12 weeks significantly accelerated salivary SIgA secretion, thereby indicating its potential utility in the improvement of mucosal immunity and resistance against infection in the elderly.     

Immunoglobin M biosynthesis. Intracellular accumulation of 7s subunits

Immunoglobulin M biosynthesis was studied with mouse plasma cell tumour MOPC 104E as a model system. Cell suspensions prepared from solid tumours were incubated in vitro with tritiated leucine; the radioactivity incorporated into intracellular and secreted proteins was analysed by polyacrylamide-gel electrophoresis, sucrose-density-gradient centrifugation and precipitation with rabbit antiserum specific for the macroglobulin. The tumour was found to secrete immunoglobulin M and light chains in a 1:2 weight ratio, with lag periods of 20–30min. Within the cells there was a 7s component precipitable with specific antiserum to the macroglobulin that was shown to consist of heavy and light chains. This 7s subunit of the macroglobulin appeared to accumulate in the intracellular environment, so that even after long periods of incubation (3hr.) no more than trace amounts of fully assembled 19s molecules could be detected in cell lysates. Polymerization of the subunits into the pentamer therefore appears to take place shortly before, or simultaneously with, secretion of the molecules.     

Cyclic AMP-mediated modulation of immunoglobulin production in B cells by prostaglandin E1.

We had previously demonstrated in a transformed human B cell line, LA350, the existence of an inverse relationship between cyclic adenosine monophosphate (cAMP) content and immunoglobulin secretion using the cAMP-elevating agents such as cholera toxin and forskolin. In this paper we report that cAMP acting as a second messenger for prostaglandin exerts a similar effect on the antibody response of B lymphocytes. Incubation of the cells with PGE1 in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX) produced a concentration- and time-dependent elevation of intracellular cAMP. Significant increases of cAMP production were observed at physiologically relevant levels of PGE1 (10(-7) and 10(-8) M). Immunoglobulin production, whether measured as the total number of immunoglobulin-secreting cells by a reverse hemolytic plaque assay or as specific immunoglobulin production (IgM) by an enzyme-linked immunoadsorbent assay, was suppressed in a dose-dependent fashion by the presence of IBMX. This suppression of immunoglobulin production was significantly enhanced by the presence of PGE1. Phorbol myristate acetate-induced IgM production was also inhibited by the presence of PGE1. These results imply that prostaglandins regulate B cell activation and immunoglobulin production by signal transduction mechanisms involving cyclic nucleotides.     

EFFECT OF EXERCISE ON THE LEVEL OF IMMUNOGLOBULIN A IN SALIVA

The aim of this paper is to describe the structure, production and function of secretory immunoglobulin A (sIgA) as well as changes of its concentration caused by exercise of various intensity and duration. Immunoglobulin A is the main class of antibodies present in the body secreted fluids such as saliva, tears or mucus from the intestines. It is generally recognized that IgA, due to its dominance in the immune system of mucous membranes, is the first line of defence against harmful environmental factors. The secretion and composition of saliva depends on the activity of the sympathetic and parasympathetic nervous systems. Physical activity, stimulating the autonomous nervous system, may reduce the amount of saliva and/or inhibit its secretion. The relationship between physical activity and the suppression of the immune system is not fully understood, but it is known that moderate intensity exercise can improve immune defences, while extreme effort can reduce them by creating an increased risk of upper respiratory tract inflammation (URTI). In athletes, the lowest risk of upper tract infection was connected with the case of moderate intensity exercise. It is now believed that the relationship between exercise volume and the risk of URTI has the shape of the letter “J”. This means that both too little and too much physical activity may increase the risk of upper respiratory tract infection. Training optimization and correct balance between exercise and rest periods may reduce the risk of adverse changes in the immune system and decrease the frequency of URTI.     

Clinicopathological characteristics of immunoglobulin G4-related sialadenitis

IntroductionImmunoglobulin G4-related disease (IgG4-RD) is a newly recognized fibro-inflammatory condition. Forty-two cases with immunoglobulin G4-related sialadenitis (IgG4-RS) confirmed by histopathological and immunohistochemical assessment were studied to clarify the clinicopathologic characteristics of the salivary glands involved in IgG4-RS, especially the relationship between the histopathologic features and function of salivary glands or serum levels of IgG4.MethodsClinical, serologic, imaging and histopathological data of these cases were analyzed. CT volumes of submandibular, parotid, and lacrimal glands were calculated. The saliva flow rate was measured. Scintigraphy with 99mTc-pertechnetate was undertaken in 31 cases, and the concentration index (CI) and secretion index (SI) was calculated. Relationships between fibrosis severity and salivary gland function or serum IgG4 levels were analyzed.ResultsThe first symptom was swelling of bilateral submandibular or lacrimal glands. Physical examination showed multiple bilateral major salivary glands (including sublingual and accessory parotid glands) and lacrimal glands were enlarged in IgG4 RS. Multiple enlarged cervical lymph nodes were noted in 30 patients. Saliva flow at rest was lower than normal in 34 cases; stimulated saliva flow was lower than normal in 15 cases. Secretory function was reduced more severely in the submandibular glands than in the parotid glands. Serum levels of IgG4 were elevated in 95.2% of cases and 78.6% patients had increased IgE levels. Serum IgG4 level was higher and saliva secretion lower as glandular fibrosis increased.ConclusionsProminent changes in the morphology, histology, immunohistochemistry and secretion of the major salivary glands of IgG4-RS patients were accompanied by involvement of the lacrimal glands and cervical lymph nodes. Elevated IgE, allergic history, eosinophil infiltration suggest allergic reactions as a potential pathogenesis of IgG4-RS. Severity of glandular fibrosis correlated with salivary function and serum levels of IgG4.     

Regulating the retention of T-cell receptor alpha chain variants within the endoplasmic reticulum: Ca(2+)-dependent association with BiP.

Immunoglobulin heavy chain binding protein (BiP, GRP 78) coprecipitates with soluble and membrane-associated variants of the T-cell antigen receptor alpha chain (TCR-alpha) which are stably retained within the ER. Chelation of Ca2+ during solubilization of cells leads to the dissociation of BiP from the TCR-alpha variants, which is dependent upon the availability of Mg2+ and hydrolyzable ATP; this suggests that Ca2+ levels can serve to modulate the association/dissociation of these proteins with BiP. In vivo treatment of cells expressing either the soluble or membrane-anchored TCR-alpha variants with the Ca2+ ionophore, A23187, or an inhibitor of an ER Ca(2+)-ATPase, thapsigargin, or the membrane-permeant Ca2+ chelator BAPTA-AM, results in the redistribution of these proteins out of the ER and their subsequent secretion or cell surface expression. Under the same assay conditions, no movement of BiP out of the ER is observed. Taken together, these observations indicate that decreased Ca2+ levels result in the dissociation of a protein bound to BiP, leading to its release from ER retention. These data suggest that the intracellular fate of newly synthesized proteins stably associated with BiP can be regulated by Ca2+ levels in the ER.     

Increased rat alveolar macrophage expression of functional iNOS induced by a Dirofilaria immitis immunoglobulin superfamily protein.

Dirofilaria immitis is a worldwide filarial nematode causing heartworm disease in dogs and cats. Several mosquito species, which are able to feed both on humans and animals, can transmit this parasite. Inflammatory progression of host tissues induced by parasites are mediated by several molecules, including nitric oxide (NO), which usually exerts deleterious effects on parasites and occasionally on the host. We analyze the in vitro effect of total D. immitis adult worm somatic antigens on na?ve rat alveolar macrophage NO production and further separation of parasite proteins to define specific D. immitis somatic molecules influencing host cell NO secretion. Additionally, we address the possible influence of Wolbachia spp. on the in vitro production of NO by macrophages. Our results demonstrate that D. immitis adult worm soluble antigens are able to specifically induce NO production from host macrophages. Furthermore, we demonstrated that this effect is due to nematode antigens rather than to defined components (LPS and metabolic molecules) derived from its endosymbiont, Wolbachia spp. In addition, we were able to isolate and identify one of the parasite specific components from the DiSo extract, denominated DiID35.3 and putatively belonging to the Immunoglobulin Superfamily Protein (ISP) group, triggering NO release from macrophages in a dose-dependent and specific manner.     

Effects of SNPs using differentially expressed serum proteins at growth stages on average daily gain in pig

This study was aimed to search SNPs, which have been generated from differentially expressed proteins at growth stages, to use as molecular or biological markers accounting for variation of average daily gain (ADG). A total of 40 purebred Yorkshire pigs in half-sib pedigree were used to detect differentially expressed blood serum proteins at growth stages (12, 18, 24, and 30 weeks of age) using two-dimensional electrophoresis (2-DE). Differentially expressed spots between growth stages have been identified by MS/MS analysis resulting in nine genes (Immunoglobulin Kappa, Lambda, and Gamma, Retinol-Binding Protein, Albumin, Fibrinogen Alpha and Gamma, Antithrombin, and Alpha-1-Antitrypsin). Expression patterns by growth stages have been defined to four types depending on expression levels. PCR analysis showed 12 successful amplified products, and the sequence alignment for 270 individuals revealed 49 SNPs for the segments of SSP7107, SSP4410, SSP5112F, SSP5112R, and SSP4004. A total of 27 SNPs revealed substitutions of amino acids by SNPs in four genes (Gamma fibrinogen, Immunoglobulin G, Retinol-Binding Protein, and Immunoglobulin K), and the newly identified sequences have been submitted to GenBank with accession numbers. The genotypes from SNPs (positions at 306 of SSP4410; 280 of SSP5211F; 411 of SSP7107) were significantly associated with ADG showing additive and dominance allele effects. The identified SNPs may be helpful to understand different expression profiles of proteins at various growth stages as well as to explain genetic variations associated with ADG in pig industry.     

Inhibitory effects of superoxide dismutase 3 on IgE production in B cells

Immunoglobulin E (IgE) functions as a first-line defense against parasitic infections. However, aberrant production of IgE is known to be associated with various life-threatening allergic diseases. Superoxide dismutase 3 (SOD3) has been found to suppress IgE in various allergic diseases such as allergic conjunctivitis, ovalbumin-induced allergic asthma, and dust mite-induced atopic dermatitis-like skin inflammation. However, the role of SOD3 in the regulation of IgE production in B cells remains elusive. In this study, we investigated the effect of SOD3 on LPS/IL-4 and anti-CD40/IL-4-mediated secretion of IgE in murine B cells. Our data showed that SOD3 can suppress both LPS/IL-4 and antiCD40/IL-7-induced IgE secretion in B cells isolated from both wild-type (SOD3^+/+) and SOD3 knock-out (SOD3^?/?) mice. Interestingly, B cells isolated from SOD3^?/? mice showed higher secretion of IgE, whereas, the use of DETCA, a known inhibitor of SOD3 activity, reversed the inhibitory effect of SOD3 on IgE production. Similarly, SOD3 was found to reduce the proliferation, IgE isotype switch, ROS level, and CCL17 and CCL22 productions in B cells. Furthermore, SOD3 was found to suppress both LPS/IL-4 and anti-CD40/IL-4-mediated activation of downstream signaling such as JAK1/JAK3, STAT6, NF-κB, p38, and JNK in B cells. Taken together, our data showed that SOD3 can be used as an alternative therapy to restrict IgE-mediated allergic diseases.     

Inhibition of N-glycosylation induces tyrosine sulphation of hybridoma immunoglobulin G.

Immunoglobulin G2a (IgG2a) secreted by the hybridoma line M 31 was found to contain covalently linked sulphate. The sulphate was bound to the heavy chain which existed in several isoelectric variants. All variants were sulphated, the more acidic ones being more highly sulphated. Within the heavy chain the sulphate was not linked to tyrosine, threonine or serine residues, but appeared to be bound to N-linked oligosaccharides located in the Fab-portion. In contrast, the N-linked oligosaccharides in the Fc-portion were unsulphated. Surprisingly, the unglycosylated IgG secreted in the presence of tunicamycin, an inhibitor of N-glycosylation, was not unsulphated, but contained four times as much sulphate on the heavy chain as control IgG. All isoelectric variants of the non-glycosylated heavy chain contained sulphate. This sulphate was localized in the Fc-portion and was largely bound to tyrosine residues. These results show that, upon inhibition of N-glycosylation, the IgG is not simply secreted in non-glycosylated form, but has undergone a different post-translational modification, tyrosine sulphation. We discuss the possibility that tyrosine sulphate residues functionally compensate for the absence of N-linked (sulphated) oligosaccharides in IgG. One common function for these two protein modifications could be to serve as signals for the secretion of IgG.     

免疫球蛋白基因的转录调控

免疫球蛋白(Ig)的表达是B细胞特异性和发育阶段特异性的事件.Oct2、NF-kB和HLH蛋白与Ig基因细胞特异转录有关.Oct2含有POU结构域,属POU转录调控因子家族;NF-kB有rel-like结构域,属rel-like转录调控因子家族;HLH蛋白特征性结构为螺旋-环-螺旋(helix-loop-helix,HLH)结构域,已报道的HLH蛋白都与转录调节有关.     

Preparation of a low-density species of endocytic vesicle containing immunoglobulin A.

Immunoglobulin A is transported across hepatocytes in specialized vesicles. A population of endocytic vesicles of approx. 140 nm diameter, containing immunoglobulin A, has now been separated from all other major cytoplasmic organelles, including plasma membrane and lysosomes, by sequential centrifugation on Ficoll/sucrose and Metrizamide gradients.     

Cloning of mouse myeloma cells and detection of rare variants

Cultured mouse myeloma cells have been cloned in soft agar using a modification of the method established by Pluznik and Sachs ('65, '66) and by Bradley and Metcalf ('66). A linear relationship existed between the number of cells plated and the number of colonies produced. Conditions for obtaining optimum cloning efficiency and colony size were determined for the MPC-11 cell line. Feeder cells of mouse, human and rabbit origin and conditioned growth medium obtained from mouse cultures and had an enhancing effect on colony formation. Immunoglobulin production by cloned cells was detected by overlaying the clones with anti-immunoglobulin antiserum. The antiserum had no adverse effect on cloning efficiency or colony size. A reconstruction experiment was performed to show that the plate assay could reliably detect rare variants of immunoglobulin producing cells. The plate assay was validated by studying immunoglobulin production following recovery of clones from dishes and their growth to mass suspension culture. Immunoglobulin formation in these cultures was assessed by a Ouchterlony immunodiffusion of the supernatant medium, and by incubating the cells with radioactive amino acids and analyzing the intracellular and secreted immunoglobulin on polyacrylamide gels.     

Design of a peptide for immunodetection of IgA antigliadin antibody for the purpose of screening of celiac disease

Celiac disease (CD) is gluten induced enteropathy which requires jejunal biopsy for diagnosis. To select the patients for endoscopoic procedure some serologic tests are popular in clinical practice for screening of CD. Although gliadin is one of the key immuno activator of the disease; serological screening by immuno-detection of gliadin is not recommended. In this context we have designed a peptide using tools of computational biology keeping molecular pathogenesis of the disease into consideration such that antigliadin antibody detection based sensitive and specific cost effective tool for screening of celiac disease can be developed. The designed peptide QPFPEP interacts in a stable manner with dimeric immunoglobin A1 molecule and its parent peptide QPFPQP are sequentially present in maximum number of gliadin epitopes. This hexapeptide is predicted to interact with dimeric IgA1, which increases in the biofluids of the CD patients. ABBREVIATIONS: CD - Celiac disease, TT - Tissue transglutamase, IgA - Immunoglobulin A, AGA - antigliadin antibody, Immunoglobulin G - IgG.     

Immunoglobulin A monoclonal antibodies protect against Sendai virus.

Immunoglobulin A anti-Sendai virus HN protein monoclonal antibodies, generated via a mucosal immunization protocol, were shown to neutralize virus in vitro and, when passively administered to the mouse respiratory tract, to protect against Sendai virus in vivo. Thus, immunoglobulin A antibodies by themselves can protect against respiratory virus infection.     

Bovine fetal cerebral absidiomycosis.

Only 1 case of fetal cerebral mycosis was found in 4015 aborted bovine fetuses. Absidia corymbifera was associated with vasculitis, thrombosis, abscessation and cavitation of the brain. Antibodies against A. corymbifera and other fungal antigens were not detected in fetal serum by immunodiffusion techniques. Immunoglobulin G (IgG) in excess of the normal was detected in the fetal serum by radial-immunodiffusion assay.     

Sequence and N-glycan diversity analysis of immunoglobulin G from buffalo milk using RP-UHPLC MS/MS

Amino Acids - Immunoglobulin G is the abundant antibody present in the colostrum and milk of major dairy animals. In the present study, buffalo milk IgG was characterized for its amino acid...