Orientia tsutsugamushi, a causative pathogen of Scrub typhus, is a gram-negative intracellular bacterium. Outer membrane vesicles (OMVs) are produced from the membrane of bacteria and play many roles related to the survival of the pathogen. However, there have been no reports confirming whether O. tsutsugamushi indeed produce OMVs. O. tsutsugamushi boryong was cultured in ECV-304 cells for the purification of OMVs. Western blot analysis and immunoenrichment using anti-O. tsutsugamushi monoclonal antibody and electron microscopy were employed for identification and characterization of OMVs. We confirm the presence of OMVs derived from O. tsutsugamushi, and also found that those OMVs contain a major surface antigen of 56-kDa protein and variant immunogenic antigens.
Antibodies, Monoclonal/*immunology ; Antigens, Bacterial/*immunology ; Antigens, Surface/*immunology ; Cell Line ; Cell Membrane/immunology ; Humans ; Microscopy, Electron ; Orientia tsutsugamushi/*immunology/metabolism ; Scrub Typhus/diagnosis/microbiology ; Secretory Vesicles/*immunology

We investigated the co-stimulatory role of a cell-surface protein, CD99. Co-ligation of CD99 and suboptimal CD3 induced T-cell activation to a level comparable to that obtained with optimal CD3 or CD3+CD28. We also noted concomitant enhancement of the earliest T-cell receptor (TCR) signaling events. In addition, co-ligation of CD99 and CD3 led to translocation of TCR complexes into the lipid raft, without concomitant migration of CD99 to the raft, and consequent enhancement of TCR zeta-mediated signal 1. These data demonstrate the unique properties of CD99 co-stimulation that distinguish this molecule from CD28 and other raft-resident co-stimulatory factors.
Antigens, CD/*immunology ; Antigens, CD3/immunology ; Cell Adhesion Molecules/*immunology ; Down-Regulation ; Humans ; Jurkat Cells ; Lymphocyte Activation/*immunology ; Membrane Microdomains/*immunology ; Membrane Proteins/*immunology ; Phosphorylation ; Phosphotyrosine/*metabolism ; Protein Transport ; Receptors, Antigen, T-Cell/*immunology ; T-Lymphocytes/*immunology

Ion channels are a widespread class of membrane proteins that help establish and control cell membrane potential by allowing the passive diffusion of inorganic ions with high specificity through cell membrane. They are widely distributed in various cells and tissues, and their normal structure and function are of fundamental importance for all living organisms. The rapid advances in molecular cloning, protein structure analysis, patch clamp recordings and other technologies have greatly promoted the research on the biophysical and molecular properties of ion channels, and made significant progress in the study of the relationship between ion channels and pathophysiology as well. The immune system is made up of immune cells and organs that work together to protect the body and respond to infection and disease. Remarkably, recent basic and clinical research has revealed that ion channels are frequently and abundantly expressed in immune cells and have crucial roles in immune cell development and immune response. This review summarized recent progress in the roles of ion channels in immune cells, including the expression and regulation of ion channels in immune cells, the effects of ion flux mediated by ion channels on lymphocyte development, and functional roles of ion channels in both innate and adaptive immune responses. We also discussed some unresolved and insufficiently addressed issues in the current research, so as to provide an informative reference for better understanding the functional roles of ion channels in the immune system and further elucidation of their function from a physiological and pathological point of view.
Cell Membrane ; Immunity ; physiology ; Ion Channels ; immunology ; Membrane Proteins ; Research ; trends

OBJECTIVETo explore the pathogenesis of rheumatoid arthritis (RA) by studying the expression of T cell receptors (TCRs).

METHODST cell receptor Vbeta (TCR Vbeta) gene usage and expression were analyzed from synovial membrane and peripheral blood of 8 RA patients, 2 osteoarthritis patients and 2 accident amputees. The complementary determining region 3 (CDR3) of 25 TCR Vbeta subfamily genes in unselected T cell populations were amplified semi-quantitatively by reverse transcription-polymerase chain reaction (RT-PCR). The products were further studied by genescan for frequency of Vbeta usage.

RESULTSThe numbers of Vbeta subfamilies expressed by T cells from RA peripheral blood and synovial membrane were not significantly restricted. More importantly, biased Vbeta gene expression in RA synovium was observed and Vbeta6, Vbeta17, and Vbeta22 genes were the predominant subfamilies. It was noteworthy that the expression of Vbeta17 in RA synovium was significantly increased.

CONCLUSIONOur data were consistent with the hypothesis that several antigen or superantigen-driven processes may be involved in the pathogenesis of RA.

Arthritis, Rheumatoid ; genetics ; immunology ; Genes, T-Cell Receptor beta ; Humans ; Synovial Membrane ; metabolism ; T-Lymphocytes ; immunology

In protection against microbes, an organism recognizes the pathogen associated molecular pattern (PAMP) on microbes by pattern recognition receptor (PRR). Toll-like receptor is called innate immunity. A family of cell membrane receptor was found in recent years that can mediate innate immune responses through the activation of a series of immune-related genes. In phylogenesis, it is highly conservative. However, its functions are getting more diversified with the complication of the immune functions of organisms.
Animals ; Humans ; Immunity ; Membrane Glycoproteins ; immunology ; Phylogeny ; Receptors, Cell Surface ; immunology ; Toll-Like Receptors

A series of sperm membrane antigens, the important molecular markers associated with the program of spermatogenesis and maturation of sperm, which also are for attachment of the physiological mechanism of the sperm-egg interaction and fusion and the pathological changes in the infertility, were reviewed. Some traditional crucial sperm membrane proteins, such as FA-1, PH-20, fertilin, have been cloned and sequenced, and some novel gene which encode new proteins associated with the sperm membrane also have been screened out successively. All of these provided a basement for lucubration of these proteins and the research of the contraception vaccine.
Animals ; Antigens, Surface ; genetics ; immunology ; Cell Membrane ; immunology ; Cloning, Molecular ; Humans ; Male ; Mice ; Spermatozoa ; immunology ; Vaccines, Contraceptive

Burns ; immunology ; Chemokine CCL2 ; immunology ; Humans ; Infection ; immunology ; Macrophages ; immunology ; Membrane Glycoproteins ; immunology ; NF-kappa B ; immunology ; Receptors, Cell Surface ; immunology ; T-Lymphocytes ; immunology ; Toll-Like Receptors ; Transcription Factor AP-1 ; immunology

OBJECTIVETo investigate the mechanism of immune escape in renal cell carcinoma(RCC).

METHODSFas and FasL expressions were examined by immunohistochemical technique in 44 RCC patients, with the Ki67 expression and apoptosis of tumor infiltrating lymphocytes(TIL) monitored simultaneously. Cytokines including IL2 and IFN alpha were used to induce the expression of the renal carcinoma cell lines 786-0 cells. Combination treatment of 786-0 with cytokines and Anti-Fas monoclonal antibody (FasAb) was used to induce apoptosis. FasL function was assessed by in vitro co-culture assays using renal cancer cells 786-0 and Fas-sensitive Jurkat T-cells.

RESULTS(1) Fas expression rate in RCC(22.8%) was lower than that in the controlled normal kidney tissues(53.8%, P < 0.01). FasL expression rate in RCC (46.5%) was higher than that in the controlled normal kidney tissues (23.2%, P < 0.01). That of Ki67 was 32.8%, with the expressions of Fas and Ki67 showing a negative correlation (r = -0.62, P < 0.05). In contrast, the expressions of FasL and Ki67 showed a positive correlation. (r = 0.93, P < 0.01). The Fas expression of stage I was significantly higher than that of stages III and IV. The expression rate of FasL in RCC was significantly increased with RCC stage (P < 0.01). (2) The apoptotic rate of TIL in RCC (33.9%) was significantly higher than that of the normal kidney tissues (3.5%, P < 0.01). The expression of FasL and the apoptotic rate of TIL in RCC gave a positive correlation (r = 0.96, P < 0.01). (3) Fas expression rate in 786-0 cells was 13.7%. The apoptotic rate mediated by FAsAb was 9.6%. IFN alpha was able to up-regulate the Fas expression and subsequently augment the FasAb-mediated apoptosis in 786-0 cells. But IL2 did not show similar effects. (4) The FasL expression rate of 786-0 was 18.6%. FasL expressed by 786-0 cells was able to induce apoptosis of Jurkat T-cells in co-culture assays and the apoptosis of Jurkat T-cells was significantly lowered after blocking the effect of FasL with Fas-neutralizing antibody NOK-2, giving the apoptotic rates of 14.9% and 2.0%, respectively, the difference therein is statistically significant (P < 0.01).

CONCLUSIONDown-regulation of Fas expression and up-regulation of FasL-expression are the mechanisms through which the RCC cells escape from immune attack.

Adult ; Aged ; Carcinoma, Renal Cell ; immunology ; Fas Ligand Protein ; Female ; Humans ; Ki-67 Antigen ; immunology ; Kidney Neoplasms ; immunology ; Male ; Membrane Glycoproteins ; immunology ; Middle Aged ; fas Receptor ; immunology

OBJECTIVEScreening monoclonal antibodies selectively distribute on hepatocellular membrane by hybridoma technology and exploring their relationship with liver diseases.

METHODSPlasma membrane vesicles of rat hepatocytes were prepared using density gradient centrifugation and BALB/c mice were immunized with the membrane vesicles. Monoclonal antibodies were made with hybridoma technology. The immunizing valences and monoclonal antibodies were detected and screened by ELISA. Mh7 antigen was identified by immunoprecipitation method. Liver tissues of carbon tetrachloride injured rat models and diabetic rat models were used to detect the pathology value of mh7-antigen.

RESULTSHepatocellular membrane vesicles were obtained successfully. Several monoclonal antibodies were yielded by hybridoma technology. Immunofluorescence and pre-embedding immunogold-silver cytochemistry confirmed that mh7-antigen was a membrane molecule and with a 200KD molecular weight. Immunohistochemistry results indicated mh7 selectively distributed on hepatocellular membrane. Results with rat models demonstrated that mh7-antigen was dramatically reduced in fatty degenerated hepatocyte of carbon tetrachloride injured rat models and distributed as straps in diabetic rat models.

CONCLUSIONSMh7 is a new hepatocellular membrane monoclonal antibody and may closely related with liver diseases.

Animals ; Antibodies, Monoclonal ; immunology ; isolation & purification ; Antibody Specificity ; immunology ; Cell Membrane ; immunology ; Hepatocytes ; immunology ; Mice ; Mice, Inbred BALB C ; Rats ; Rats, Sprague-Dawley

The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212-215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either "negligible" or "lack of" immunogenicity in iPSC derivatives (Nature 494:100-104, 2013; Cell Stem Cell 12:407-412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics.
Animals ; Cell Cycle Proteins ; metabolism ; Cell Transplantation ; methods ; Graft Rejection ; immunology ; Induced Pluripotent Stem Cells ; immunology ; transplantation ; Membrane Proteins ; metabolism ; Mice, Knockout ; Teratoma ; immunology ; metabolism