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Cadmium is one of the most toxic heavy metal contaminants in soils and water bodies and poses a serious threat to ecosystems and humans. However, cadmium is also an important resource widely used in many industries. The recovery of cadmium in the form of high-value products is considered as an ideal disposal strategy for Cd-contaminated environments. In this work, Pistia stratiotes was used to recycle cadmium from wastewaters through phytoaccumulation and then transformed into carbon-supported cadmium sulfide photocatalyst (CdS@C) through carbonization and hydrothermal reaction. The CdS@C photocatalyst contained a mixture of cubic and hexagonal CdS with lower band gap energy (2.14 eV) and high electron-hole separation efficiency, suggesting an excellent photoresponse ability and photocatalytic efficiency. The impressive stability and photocatalytic performance of CdS@C were demonstrated in efficient photodegradation of organic pollutants. •OH and O2•- were confirmed as the major active species for organic pollutants degradation during CdS@C photocatalysis. This work provides new insights into addressing Cd contaminated water bodies and upcycling in the form of photocatalyst.

Parametric modeling of transition tubes were implemented based on constant cross section area assumption along the main central routes on CATIA software. The key objective of modeling these similar structures is to provide more geometric configuration options and modifications of micro channels for multi phase flow systems. The modeling processes were parameterized and analyzed by CATIA “Generative Shape Design” module with the help of “Parameters” and “Relations” functions. The surface models are all designed in circular cross sections that are constrained in two ways: one is perpendicular to the main central routes of the tube for planar transitional junction, and another is, perpendicular to the sub-branch central routes for oblique transitional junction three dimensionally. Next work is emphasized on numerical simulation and experimental investigation with these geometric structures in a multi phase flow system.

Objective T cells are implicated in the production of anti-La/SSB and anti-Ro/SSA autoantibodies commonly associated with the DR3/DQ2 haplotype in systemic lupus erythematosus and Sjogren's syndrome. This study was undertaken to investigate the DR3/DQ2-restricted T cell response to wild-type human La (hLa) and a truncated form of mutant La. Methods Humanized transgenic mice expressing HLA–DRB1*0301/DQB1*0201 (DR3/DQ2) were immunized with recombinant antigen and examined for development of autoantibodies and T cell proliferation against overlapping peptides spanning the La autoantigen. HLA restriction and peptide binding of identified T cell epitopes to DR3 or DQ2 were determined using blocking monoclonal antibodies and a direct binding assay. Results DR3/DQ2-transgenic mice generated an unusually rapid class-switched humoral response to hLa with characteristic spreading to Ro 52 and Ro 60 proteins following hLa protein immunization. Seven T cell determinants in hLa were restricted to the HLA–DR3/DQ2 haplotype. Six epitopes tested were restricted to HLA–DR and bound DR3 with semiconserved DR3 binding motifs. No DQ restriction of these epitopes was demonstrable despite efficient DQ binding activity in some cases. No neo–T cell epitopes were identified in mutant La; however, T cells primed with mutant La exhibited a striking increase in proliferation to the epitope hLa151–168 compared with T cells primed with hLa. Conclusion Multiple DR3-restricted epitopes of hLa have been identified. These findings suggest that truncation of La produced by somatic mutation or possibly granzyme B–mediated cleavage alters the immunodominance hierarchy of T cell responsiveness to hLa and may be a factor in the initiation or maintenance of anti-La autoimmunity.

A human La/Sjögren’s syndrome-B (hLa)–specific TCR/hLa neo–self-Ag double-transgenic (Tg) mouse model was developed and used to investigate cellular tolerance and autoimmunity to the ubiquitous RNA-binding La Ag often targeted in systemic lupus erythematosus and Sjögren’s syndrome. Extensive thymic clonal deletion of CD4+ T cells occurred in H-2k/k double-Tg mice presenting high levels of the I-Ek–restricted hLa T cell epitope. In contrast, deletion was less extensive in H-2k/b double-Tg mice presenting lower levels of the epitope, and some surviving thymocytes were positively selected as thymic regulatory T cells (tTreg). These mice remained serologically tolerant to hLa and healthy. H-2k/b double-Tg mice deficient of all endogenous Tcra genes, a deficiency known to impair Treg development and function, produced IgG anti-hLa autoantibodies and displayed defective tTreg development. These autoimmune mice had interstitial lung disease characterized by lymphocytic aggregates containing Tg T cells with an activated, effector memory phenotype. Salivary gland infiltrates were notably absent. Thus, expression of nuclear hLa Ag induces thymic clonal deletion and tTreg selection, and lymphocytic infiltration of the lung is a consequence of La-specific CD4+ T cell autoimmunity.

Systemic autoimmune diseases are characterized by the development of anti-nuclear autoantibodies. In order to understand the immunologic events leading to the development of such antibodies, knowledge of mechanisms of immune tolerance to nuclear antigens is required. By utilizing adoptive T cell transfer strategies with transgenic mouse models expressing nuclear neo-self antigens, T cell tolerance to the lupus-related nuclear antigens human La and nRNP A has been demonstrated. These findings also indicate the existence in normal animals of autoreactive B cells continuously presenting nuclear antigen, suggesting that nuclear antigens are not sequestered from the immune system. Investigations of CD4+ T cell tolerance to non-nuclear antigens have revealed a number of mechanisms that protect the host from autoreactivity, including autoreactive T cell deletion, regulatory T cell development and anergy induction. Recent studies using T cell receptor and neo-self nuclear antigen transgenic mice are revealing the importance of such mechanisms in maintaining tolerance to nuclear antigens. Mechanisms of tolerogenic antigen presentation, identification of tolerogenic antigen source(s), and the pathways leading to loss of tolerance to nuclear antigens in systemic autoimmune disease states are currently being sought.

Overt anti-ribosomal P (anti-P) autoantibodies are restricted to a subset of systemic lupus erythematosus (SLE) patients, and are potentially pathogenic. Covert anti-P are detected in all other individuals. An idiotype (Id) network is nonoperational in those with overt anti-P, whereas it is functional in all others. The aim of this study was to produce a murine monoclonal (mAb) anti-Id to characterize the anti-P Id network in SLE. BALB/c mice were immunized with F(ab')(2) fragments of IgG anti-P from a patient with a broadly cross-reactive Id. One mAb was chosen (mAb41) that reacted preferentially to the immunogen. This IgG1 mAb bound comparably in ELISAs to affinity-purified anti-P from 11 SLE patients with overt anti-P. This binding was partially inhibited with ribosomal P antigen. In contrast, it did not bind to affinity-purified control autoantibodies, nor to normal human IgG. mAb41 inhibited anti-P binding to ribosomal P antigen in immunoassays and on Jurkat cells. No change was detected in patients' anti-P antibodies over time when mAb41 was used in Id-specific ELISAs. We conclude that mAb41 is an anti-Id that recognizes a public idiotope within the antigen-combining site of anti-P antibodies. Thus, it is analogous to its human counterparts, and potentially, would modulate the pathogenicity of anti-P autoantibodies in vivo.

Summary Mechanisms responsible for the induction of anti-nuclear autoantibodies (ANA) following exposure of the immune system to an excess of apoptotic cells are incompletely understood. In this study, the immunogenicity of late apoptotic cells expressing heterologous or syngeneic forms of La/SS-B was investigated following subcutaneous administration to A/J mice, a non-autoimmune strain in which the La antigenic system is well understood. Immunization of A/J mice with late apoptotic thymocytes taken from mice transgenic (Tg) for the human La (hLa) nuclear antigen resulted in the production of IgG ANA specific for human and mouse forms of La in the absence of foreign adjuvants. Preparations of phenotypically healthy cells expressing heterologous hLa were also immunogenic. However, hLa Tg late apoptotic cells accelerated and enhanced the apparent heterologous healthy cell-induced anti-La humoral response, while non-Tg late apoptotic cells did not. Subcutaneous administration of late apoptotic cells was insufficient to break existing tolerance to the hLa antigen in hLa Tg mice or to the endogenous mouse La (mLa) antigen in A/J mice immunized with syngeneic thymocytes, indicating a requirement for the presence of heterologous epitopes for anti-La ANA production. Lymph node dendritic cells (DC) but not B cells isolated from non-Tg mice injected with hLa Tg late apoptotic cells presented immunodominant T helper cell epitopes of hLa. These studies support a model in which the generation of neo-T cell epitopes is required for loss of tolerance to nuclear proteins after exposure of the healthy immune system to an excess of cells in late stages of apoptosis.

Autoantibodies to ribosomal P proteins (anti-P) are detected almost exclusively in the serum samples from patients with systemic lupus erythematosus when conventional enzyme-linked immunosorbent assay and immunoblotting techniques are used. Anti-P are not detected in serum samples from healthy adults by these techniques. By treating serum from healthy adults with ribosome-coated beads, we unexpectedly unmasked anti-P in virtually all individuals. This unmasking of anti-P occurs by the displacement of an antibody inhibitor from anti-P. We wanted to determine whether anti-P from healthy adults could also be unmasked by treatment of their serum or plasma with isolated ribosomal P proteins. Recombinant human ribosomal P2 protein was produced in bacteria as a TrpE fusion protein, resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, blotted onto nitrocellulose membranes, and isolated as strips of membranes corresponding to the size of the P2 fusion protein. Serum or plasma from six healthy adults and three patients with systemic lupus erythematosus were incubated with these strips overnight rather than for 2 hours, as is done in conventional immunoblots. Acid eluates were obtained from the strips and analyzed for antibody activity by immunoblot. Eluates from healthy adults and patients contained antibodies reactive with recombinant ribosomal P2 protein. They also reacted with the three ribosomal P proteins in purified rabbit ribosomes. Their anti-P activity was completely inhibited by a peptide corresponding to the immunodominant linear epitope of the ribosomal P proteins. The antibodies in the eluate were immunoglobulin G. We conclude that anti-P autoantibodies from healthy adults can be unmasked by affinity purification on denatured, recombinant ribosomal P proteins and that antigen excess is sufficient for inhibitor displacement.