The detection of iselt autoantibodies provides a powerful tool for the prediction of type 1 diabetes. Combining initial genetic screening with later autoantibody testing may be the most efficacious approach to identifying beta-cell autoimmunity. Once safe and effective interventional methods are available, widespread public health service projects should be undertaken to prevent type 1 diabetes. Table 10 summarizes the use of autoantibody markers in the prediction of type 1 diabetes.
Shortly after birth, the human thymus begins a life long process of involution, whereby the net size of the thymus is not altered but the organ is replaced by adipose tissue. As a result, it has long been believed that thymic involution is indicative of a nonfunctional organ. Recently, however, with the use of computed tomography analysis and innovative molecular approaches that measure T-cell receptor circles, indicative of recent thymic emigrants, doubt has been placed on that dogma. The thymus appears to be active in thymopoiesis throughout the adult life, albeit inversely correlated with age. Being faced with diseases that deplete T-cells such as the acquired immunodeficiency syndrome (AIDS), this recent finding has the potential to exploit novel approaches that enhance thymic output as a mechanism to reconstitute the immune system. In this review, we will revisit the role of T-cells in immunity, the relationship between thymic function and age, and closely examine the impact of HIV-mediated thymic dysregulation on thymopoiesis.
Human fetus is a natural allograft which survives much longer than any other allograft in an immunologically competent recipient. Namely, semiallogenic trophoblast cells of foetal origin are in intimate contact with mother's decidual mucosa that is abundantly infiltrated by immunocompetent cells. Macrophages are important cytokine producing cells and their number does not change during pregnancy. T lymphocytes are scattered throughout human decidua representing approximately 10-15% of decidual lymphocytes (DL). Decidual large granulated lymphocytes (dLGL) account for about 80% of the total leukocyte population and cause an increase in CD56/CD3 cell ratio to more than 5. Decidual LGL distinct from peripheral blood NK cells. They are CD3-CD16-CD56bright+ with high content of cytolytic mediator-perforin in their granules. The percentage of P+ cells in the suspension of DL is twice higher peripheral blood lymphocytes (PBL) from the same women (55% vs. 27%). However, NK activity of DL is much much lower than NK activity of PBL in spite of the fact that they are full of perforin. The question could be raised as to when and how these cells can be activated? NK cell activity is regulated via signals that are transmitted through killer inhibitory receptor (KIR) and killer activity receptors (KAR). Expression of KIR and absence of CD16 molecules on dLGL are potential mechanism for preventing lysis of trophoblast during normal pregnancy.
To our knowledge SpermCheck I represents the first immunodiagnostic device that has been developed to rapidly measure sperm in a platform suitable for both physician office and over-the-counter testing. At the time of this writing, the prototype device is poised to undergo clinical testing to gain the necessary performance data for the FDA approval process. The successful development of the working prototype establishes the proof of concept that immunodiagnostic devices of sufficient sensitivity can be developed to create products useful for male infertility as well as contraception and post-asectomy cases.
During untreated HIV-1 infection, a chronic state of immune activation and inflammation develops at the lymphoid tissue sites of viral replication. The early effect of potent combination drug therapy is a reduction in peripheral viral burden and a reduction in the production of inflammatory and type 1 cytokines. Further along in treatment there are trends toward normalization in the frequencies of CD88 T-cells, CD4+ CD45RA+ cells, as well as CD4+ CD45R0+ cells. Finally, the CD1a+ dendritic cell network is re-established and germinal centers are reformed. Although this restoration of the lymphoid dynamic form is coupled to a reconstitution of peripheral blood T-cell function in vitro and by skin testing, sterilizing immunity to HIV-1 does not develop. Furthermore there is no heightened development of cytotoxic CD8+ T-cell function at the site of HIV-1 latency. This is evidenced by a massive recrudescence of HIV-1 viral replication within lymphoid tissue when therapy is stopped. The development of supplemental therapies, which reconstitute anti-HIV-1 immunity, will be required. Specific defects in anti-HIV-1 activity which occur in lymphoid tissue during infection include a downregulation of perform expression by cytotoxic T-cells, the down regulation of the TCR signal transducing chain CD3ζ, and inadequate CD4+ T-cell help within the tissue compartment of immune regeneration.
miRNAs are short RNA molecules regulating multiple cellular processes through post-transcriptional gene silencing. Over the past decade, miRNAs have been found in the extracellular space and have been consistently shown to mediate functional communication between cells. While it remains widely accepted that miRNA transfer between cells occurs via extracellular vesicles (EVs), multiple other carriers of cell-free miRNA have been described. In addition, some studies have demonstrated that both miRNAs and their binding partners, Argonaute proteins, remain hardly detectable in common isolates of EVs. In this Opinion article, we summarize the state-of-the-art mechanisms of miRNA sorting and secretion, discuss methodological challenges associated with extracellular miRNA research, and suggest experimental steps to resolve current inconsistencies in the field of miRNA-mediated cell–cell communication.
Autoantibodies to ribosomal P protein (anti-P) are a specific hallmark of systemic lupus erythematous (SLE). Several authors found significant associations of anti-P antibodies with neuropsychiatric, hepatic, and renal disease. We now report the isolation by phage display of human anti-idiotype (Id) monoclonal antibody fragments as single-chain Fv fragment (scFv) against anti-P antibodies. The V gene repertoires were derived from the RNA obtained from the B cells of a SLE patient. Affinity-purified anti-P antibodies were used for the selection of bacterial clones producing anti-P-specific scFv antibody fragments and little reactivity with normal IgG and other IgG antibodies. The anti-Id antibody recognizes a public idiotope broadly cross-reactive with polyclonal anti-P antibodies and inhibited binding of anti-P to ribosomal P antigen in immunoassays and on Jurkat cells. The anti-Id scFv antibody fragment may have therapeutic implications in SLE. They may also be used as probes in the study of the structure of the idiotype.
The tumor microenvironment is the key regulator of carcinogenesis that controls the sequence of tumor development and progression, as well as the tumor response to different types of treatment. The initiation, development, and progression of tumors are highly dependent on interactions between the cancerous and nonmalignant cells in the tumor microenvironment. Among the immune cells, dendritic cells (DCs) play a key role in the induction and maintenance of antitumor responses owing to their abilities for antigen presentation and activation of lymphocytes that target neoplasic cells. Tumor-infiltrating DCs have been found to be clinically significant in many human malignancies such as colon, hepatic, stomach, lung, breast carcinoma, melanoma, and other tumors. However, the tumor microenvironment can polarize DCs, transforming them into immunosuppressive regulatory DCs, which directly and indirectly limit functional activity of effector T cells and support tumor progression. Thus the balance between immunogenic and tolerogenic DC subpopulations, as well as between resident DCs and administered DC vaccines, is an important player controlling tumor regression and progression. A better understanding of how the tumor microenvironment affects the differentiation, function, survival, and polarization of DC subsets in different cancers will expedite development of more effective DC-based cancer vaccines and other immunotherapeutic approaches.
The purpose of this review is to give a brief summary of the techniques of single point mutation detection by gene array analysis in a manner which will illustrate the current state-of-the-art, as well as the strengths and limitations, of the technology. This provides a framework for future development of the technology by focusing our efforts on the areas in which clinical gain is most substantial and direct.
