bluuebunny/crossref_metadata_2025 huggingface dataset:
Interleukin 2 (IL-2)-induced tyrosine phosphorylation of IL-2 receptor p75.
Authors: Asao H , Takeshita T , Nakamura M , Nagata K , Sugamura K
Published: June 2004

We have recently established a mAb named TU11 mAb specific for the p75 subunit of human IL-2 receptor (IL-2R). The present study using TU11 mAb demonstrates the IL-2-induced phosphorylation of IL-2Rp75 on tyrosine residues in IL-2-dependent T cells. The tyrosine phosphorylation is mediated by the high affinity IL-2R, correlates with the IL-2-induced cell growth, and rapidly increases during the first 5 min of IL-2 stimulation. Phosphorylation of serine and threonine residues of IL-2Rp75 is also detected, but its IL-2 dependency is not significant during at least the first 5 min. These results suggest some roles of a tyrosine kinase associated with IL-2Rp75 in the IL-2-induced signal-transducing pathway.
Presence of clonal T cell populations in chronic B lymphocytic leukemia and smoldering myeloma.
Authors: Wen T , Mellstedt H , Jondal M
Published: June 2004

Clonality in the non-neoplastic T cell population was investigated in 21 patients with B cell chronic leukemic (B-CLL) or multiple myeloma (MM) by probing for TCR beta chain gene rearrangements using Southern blot analysis. In three patients with a benign form of B-CLL (stage 0), and in one patient with smoldering MM, evidence was found for predominant T cell clones. As cellular immunity against the malignant cells may be important in leukemia, the results are discussed in view of the potential role of T cell immunity in B-CLL and MM.
A large fraction of human peripheral blood gamma/delta + T cells is activated by Mycobacterium tuberculosis but not by its 65-kD heat shock protein.
Authors: Kabelitz D , Bender A , Schondelmaier S , Schoel B , Kaufmann S H
Published: June 2004

We report that M. tuberculosis organisms, but neither PHA nor allogeneic stimulator cells, preferentially activate gamma/delta+ cells within E rosette-purified peripheral blood T cells. gamma/delta+ T cells from purified protein derivative (PPD)-nonimmune healthy donors were enriched by depletion of CD4+ and CD8+ cells; double-negative (DN) cells contained 65-92% gamma/delta+ T cells. Limiting dilution (LD) analyses revealed that 1 of 2-19 purified DN cells proliferated in response to mycobacteria, while frequencies of DN cells proliferating in response to a recombinant 65-kD heat shock protein (hsp 65) of M. tuberculosis/M. bovis were 10-20-fold lower. Established clones of mycobacteria-reactive gamma/delta+ T cells specifically recognized mycobacteria, but neither PPD nor hsp 65. Restimulation of these clones required the presence of PBMC feeder cells; EBV-transformed lymphoblastoid cell lines could not substitute for PBMC. Mycobacteria-reactive gamma/delta+ clones proliferated equally well in the presence of autologous or allogeneic (HLA-DR-different) PBMC feeder cells and thus were not MHC class II restricted. Taken together, these results demonstrate that mycobacteria-reactive gamma/delta+ T cells are present in high frequency in the peripheral blood of healthy individuals, and suggest that hsp 65 of mycobacteria is not a major antigen for gamma/delta+ T cells of normal PPD-nonimmune blood donors.
Incorporation, distribution, and turnover of arachidonic acid within membrane phospholipids of B220+ T cells from autoimmune-prone MRL-lpr/lpr mice.
Authors: Tomita-Yamaguchi M , Babich J F , Baker R C , Santoro T J
Published: June 2004

The metabolism of AA-containing phosphoglycerides within T cell membranes leads to the generation of second messengers that appear to play a crucial role in transmembrane signal transduction. To test the hypothesis that aberrations in the movement of arachidonoyl-phospholipids are associated with and may potentially contribute to abnormal T cell function, the incorporation, distribution, and turnover of AA within the membrane glycerolipids of cells that are known to exhibit immunoregulatory disturbances was examined. Thy-1+, Ly-1+, L3T4-, Lyt-2-, B220+ T cells from autoimmune MRL-lpr/lpr mice were used as the cellular model. In contrast to control lymph node T cells, which preferentially incorporate labeled AA into phosphatidylcholine (PC), B220+ T cells displayed a predilection for distributing [3H]arachidonate into phosphatidylinositol (PI). The arachidonoyl-phospholipid pools were normal in B220+ T cells. The constitutive turnover of [3H]arachidonoyl-PI was significantly enhanced and that of [3H]arachidonate-PC substantially reduced in B220+ T cell compared with control cells. Using membrane homogenates B220+ T cells demonstrated a functional increase in the levels of lyso-PI. Intact B220+ T cells prelabeled with [3H]myoinositol and cultured in the absence of stimulation with exogenous antigens or mitogens, exhibited increased production of lyso-PI. The data indicate that the preferential formation of [3H]arachidonoyl-PI in B220+ T cells is the result of greatly increased, constitutive PI turnover that appears to be due to a membrane phospholipase A2 activity. It remains possible that disturbances in the movement of arachidonate within phospholipids of B220+ T cells play a role in the expression of aberrant immunological activity.
Biased expression of JH-proximal VH genes occurs in the newly generated repertoire of neonatal and adult mice.
Authors: Malynn B A , Yancopoulos G D , Barth J E , Bona C A , Alt F W
Published: June 2004

We have previously demonstrated a dramatic preference for utilization of the most JH-proximal VH gene segments in the newborn liver versus adult spleen. We now examine in detail the relative expression of different VH gene families throughout ontogeny and in immunodeficient mice to gain insight into factors that cause the shift in VH usage. We find that the relative expression of VH gene families remains constant and biased throughout fetal and neonatal liver development. In addition, the primary VH repertoire expressed in neonatal spleen displays a similarly biased, position-dependent VH repertoire. The pattern of VH gene expression begins to change at 5-7 d postnatally and reaches the adult randomized pattern at approximately 2 wk of age. We also find biased expression of JH-proximal VH gene families in adult bone marrow and in spleens of adult leaky scid mice, suggesting that the spontaneously generated repertoire of adult mice is similar to that observed in neonates. Together, these data suggest that a position-dependent repertoire is generated in differentiating pre-B cells at all stages of ontogeny, at least in part, as a result of preferential rearrangement of proximal VH gene segments. Therefore, mechanisms subsequent to V gene rearrangement, such as regulatory interactions and antigen selection, must play a major role in normalizing the repertoire.
Anchor sequence-dependent endogenous processing of human immunodeficiency virus 1 envelope glycoprotein gp160 for CD4+ T cell recognition.
Authors: Polydefkis M , Koenig S , Flexner C , Obah E , Gebo K , Chakrabarti S , Earl P L , Moss B , Siliciano R F
Published: June 2004

Human CD4+ T cell clones and cell lines were shown to lyse recombinant vaccinia virus-infected cells that synthesize the HIV-1 envelope glycoprotein gp160. The processing of endogenously synthesized gp160 for recognition by CD4+ T cells required that the protein, after synthesis on the rough endoplasmic reticulum and during subsequent cellular transport, remain attached to the luminal/extracellular membrane face by a hydrophobic anchor sequence.
Clonal deletion and clonal anergy in the thymus induced by cellular elements with different radiation sensitivities.
Authors: Roberts J L , Sharrow S O , Singer A
Published: June 2004

The present study demonstrates that immune tolerance can be achieved in the thymus both by clonal deletion and by clonal inactivation, but that the two tolerant states are induced by cellular elements with different radiation sensitivities. TCR engagement of self antigens on bone marrow-derived, radiation-sensitive (presumably dendritic) cells induces clonal deletion of developing thymocytes, whereas TCR engagement of self antigens on radiation-resistant cellular elements, such as thymic epithelium, induces clonal anergy. The nondeleted, anergic thymocytes can express IL-2-Rs but are unable to proliferate in response to either specific antigen or anti-TCR antibodies, and do develop into phenotypically mature cells that emigrate out of the thymus and into the periphery.
A novel addition to the T cell repertory. Cell surface expression of tumor necrosis factor/cachectin by activated normal human T cells.
Authors: Kinkhabwala M , Sehajpal P , Skolnik E , Smith D , Sharma V K , Vlassara H , Cerami A , Suthanthiran M
Published: June 2004

Expression of the pluripotent molecule TNF in a focused and antigen-restricted fashion might provide an advantage to the host organism. Given the central role of T cells in antigen-specific immunity, we examined whether activated T cells express TNF on their cell surface. FACS analysis of highly purified normal human T cells labeled with an anti-TNF mAb revealed that T cells express cell surface TNF when signaled with the synergistic combination of a calcium ionophore, ionomycin, and a protein kinase C activator, 12-o-tetradecanoyl phorbol acetate. Cell surface radioiodination studies of stimulated T cells demonstrated the presence of 26-kD transmembrane protein, a size predicted by TNF cDNA and different from that of the 17-kD secreted TNF molecule. The induced cell surface expression of TNF could be blocked with cyclosporine and/or methylprednisolone, and Northern analysis for TNF-specific transcripts revealed that this inhibitory effect occurs pretranslationally. Our demonstration for the first time that stimulated normal human T cells display cell surface TNF provides a mechanistic basis for the realization of effects of TNF in an antigen-specific fashion.
The sequence of the mu transmembrane segment determines the tissue specificity of the transport of immunoglobulin M to the cell surface.
Authors: Williams G T , Venkitaraman A R , Gilmore D J , Neuberger M S
Published: June 2004

Membrane IgM is expressed on the surface of B lymphocytes. It is not transported to the surface of transfected plasmacytoma or COS cells. Here, we show that mutation of four hydrophilic amino acids in the microm transmembrane is sufficient to overcome the intracellular retention of membrane IgM in non-B cells. This suggests that the B cell-specific IgM-associated proteins that have been postulated to assist the transport of membrane IgM to the cell surface (3) act either by forming a hydrophobic sheath that surrounds the microm transmembrane segment or by displacing an interaction with this segment that would otherwise cause retention. Experiments with a CD8/mu hybrid H chain indicate that the proteins that assist the transport of membrane IgM to the B cell surface at most need the mu CH4 and transmembrane/cytoplasmic portion for interaction.
DNA rearrangement and constitutive expression of the interleukin 6 gene in a mouse plasmacytoma.
Authors: Blankenstein T , Qin Z H , Li W Q , Diamantstein T
Published: June 2004

To study the potential involvement of IL-6 in the development of plasmacytomas, a number of plasmacytoma lines were analyzed for alterations in the IL-6 locus. A DNA rearrangement due to the insertion of an intracisternal A particle retrotransposon 18 bp 5' of the transcriptional start site was detected in the cell line MPC11. The IL-6 gene is constitutively expressed in MPC11, suggesting the involvement of IL-6 in the development of certain myeloma/plasmacytomas according to the "autocrine growth hypothesis".
Transgenic mice demonstrate that epithelial homing of gamma/delta T cells is determined by cell lineages independent of T cell receptor specificity.
Authors: Bonneville M , Itohara S , Krecko E G , Mombaerts P , Ishida I , Katsuki M , Berns A , Farr A G , Janeway C A , Tonegawa S
Published: June 2004

gamma/delta T cells with different TCR repertoires are compartmentalized in different epithelia. This raises the possibility that the TCR-gamma/delta directs homing of T cells to these epithelia. Alternatively, the signals that induce TCR-gamma/delta expression in developing T cells may also induce homing properties in such cells, presumably in the form of cell surface receptors. We have examined this issue by studying the homing of gamma/delta T cells in transgenic mice constructed with specific pairs of rearranged gamma and delta genes. In such mice, most gamma/delta T cells express the transgene-encoded TCR. We find that homing to both skin and gut epithelia is a property of T cells and is not determined by the type of gamma and delta genes used to encode their TCR. We also studied the effect of TCR replacement on the expression of Thy-1 and CD8 proteins on the gamma/delta T cells associated with gut epithelia. Our results show that the expression of the appropriate type of TCR-gamma/delta is not required for the Thy-1 expression by these T cells, suggesting that Thy-1 is not an activation marker. In contrast, CD8 expression by gut gamma/delta T cells seems to depend on the expression of the appropriate type of TCR.
Loss of epidermal integrity by T cell-mediated attack induces long-term local resistance to subsequent attack. I. Induction of resistance correlates with increases in Thy-1+ epidermal cell numbers.
Authors: Shiohara T , Moriya N , Gotoh C , Hayakawa J , Nagashima M , Saizawa K , Ishikawa H
Published: June 2004

The cutaneous graft-versus-host disease (GVHD) lesions induced by intradermal injection of cloned autoreactive T cells have been shown to subside rapidly and the epidermis returns to normal 2 wk after injection. Those mice that had spontaneously recovered from the cutaneous GVHD became resistant to subsequent attempts to induce the cutaneous GVHD by the T cells while maintaining their activity to mount delayed-type hypersensitivity (DTH) responses and to induce the enlargement of the popliteal lymph nodes (PLN). The resistance appeared to be restricted to the epidermal structures of the injection sites, suggesting the involvement of locally acting suppression mechanisms. This local resistance was not specific for the clonotype used for the induction of the resistance. A loss of the epidermal integrity by an attack of T cells capable of producing cutaneous GVHD was a prerequisite for the induction of the resistance. By up to at least 8 mo after injection of the T cells, no mice became susceptible to the cutaneous GVHD again, provided that the T cells were injected into the same footpad sites that had initially received the T cells. This resistance correlated well with the great increase (20-30-fold) in Thy-1+ EC number. The great increase in the number of Thy-1+ EC following destruction of epidermal structures may be important in protecting the epidermal integrity from an additional attack by T cells.
Infection of monocytes by human immunodeficiency virus type 1 blocked by inhibitors of CD4-gp120 binding, even in the presence of enhancing antibodies.
Authors: Perno C F , Baseler M W , Broder S , Yarchoan R
Published: June 2004

Infection of monocyte/macrophages (M/M) by a variety of viruses (including HIV-1) has been shown to be enhanced in the presence of low concentrations of antiviral antibodies. This process has been hypothesized as occurring through binding of the virus-antibody complex to Fc or complement receptors followed by endocytosis. In the current study, we explored whether such a mechanism might provide a CD4-independent route of infection by HIV-1 for any of several populations of M/M. In the absence of anti-HIV antibodies, replication of HIV-1 in M/M was blocked by viral binding inhibitors such as soluble CD4 or OKT4A mAb. Furthermore, while infection of the M/M populations by a low multiplicity of infection of HIV-1 was found to be somewhat enhanced by the presence of very low concentrations of anti-HIV antibodies, this process was also consistently inhibited by recombinant soluble CD4 and by OKT4A antibody. These results suggest that under the variety of conditions studied, CD4 binding was an essential step in the infection of M/M by HIV. Moreover, they are consistent with the notion that "enhancing" antibodies may serve to concentrate HIV onto CD4 receptors or, alternately, may act at other steps in the process of viral entry and replication.
Lipopolysaccharide-stimulated human monocytes secrete, apart from neutrophil-activating peptide 1/interleukin 8, a second neutrophil-activating protein. NH2-terminal amino acid sequence identity with melanoma growth stimulatory activity.
Authors: Schröder J M , Persoon N L , Christophers E
Published: June 2004

Purification of monocyte-derived NAP-1/IL-8 by preparative reversed-phase (RP)-HPLC led to the detection of a second peak with polymorphonuclear leukocyte (PMNL)-activating (degranulation, chemotaxis) properties. The monokine responsible for this biological activity, which we tentatively termed NAP-3, could be purified to homogeneity by three different RP-HPLC steps. Tricine-SDS-PAGE analysis gave a single line at Mr 5.3 kD (NAP-1/IL-8 = 5.8 kD). NH2-terminal amino acid sequence analysis read as a major sequence (ASVATELRXCXLQT. .), which shows greater than 40% homology to that of NAP-1/IL-8. The sequence is identical to that found for the 13-kD moiety of melanoma growth stimulating activity (MGSA) and the product of the oncogene gro. Determination of neutrophil chemotactic activity of NAP-3 revealed a typical bell-shaped dose-response curve (ED50 = 2 ng/ml) with no significant neutrophil chemotactic activity at doses greater than 200 ng/ml. Also, in cytochalasin B-pretreated PMNL, NAP-3 elicited release of myeloperoxidase and beta-glucuronidase. Crossdesensitization studies in PMNL enzyme release revealed crossreactivities with the NAP-1/IL-8-R on PMNL. NAP-3 (MGSA/gro) appears to represent the first member of the novel supergene family of beta-thromboglobulin-like host defense cytokines, which expresses both mitogenic as well as proinflammatory properties at the nanogram level.
Biased accumulation of T lymphocytes with "memory"-type CD45 leukocyte common antigen gene expression on the epithelial surface of the human lung.
Authors: Saltini C , Kirby M , Trapnell B C , Tamura N , Crystal R G
Published: June 2004

Expression of alternatively spliced products of the CD45 leukocyte common antigen gene identifies two populations of blood T cells: "naive" T cells (containing CD45R-IV mRNA transcripts, CD45 220, 205 kD surface proteins detected with antibody 2H4) that respond poorly to recall antigens, and "memory" T cells (containing CD45R-0 mRNA transcripts, expressing CD45 180 kD protein, detected with antibody UCHL1) that respond promptly to recall antigens. While blood contains approximately equal numbers of "naive" and "memory" T cells, it is known that UCHL1+ "memory" T cells accumulate at sites of chronic inflammation. To test the concept that "memory" T cells are a feature of the T lymphocyte populations present in tissues chronically exposed to antigens in normals as well as in individuals with chronic inflammation, we evaluated T lymphocytes obtained from blood and the epithelial surface of the lower respiratory tract of normal individuals for the expression of specific CD45 surface protein isoforms and corresponding mRNA transcripts. Flow cytometric analysis of CD45 220, 205, and 180 kD surface proteins demonstrated that lung T cells of normals are dominated by UCHL1+ "memory" cells (86 +/- 2%) while autologous blood T cells have equal proportions of "memory" UCHL1+ and "naive" 2H4+ T cells. In addition, polymerase chain reaction analysis of CD45 mRNA transcripts revealed that the lung cells expressed CD45R-0 mRNA transcripts but 17-fold fewer CD45R-IV mRNA transcripts than autologous blood T cells (p less than 0.01). The pattern of lung T cells being dominated by CD45R-0 mRNA+, UCHL1+ "memory" T cells was also observed in individuals with chronic beryllium disease, an example of a chronic inflammatory disease in which antigen-specific T cells accumulate on the pulmonary epithelial surface. Like the normals, the lung T cells of the beryllium disease patients were dominated by CD45R-0 mRNA transcript+, UCHL1+, T cells. However, on a quantitative basis, the beryllium patients contained far greater numbers of T cells, i.e., the T cell populations on the surface of the normal and inflamed lung are similar in character ("memory" T cells) but differ in numbers (there are far more in the chronic inflammatory state). Thus, T cell populations on the epithelial surface of the normal lung likely reflect the chronic exposure to a diverse set of antigens, with a pattern that is qualitatively similar to that observed among T cells accumulating in response to a single antigen.
Human neutrophil adherence to laminin in vitro. Evidence for a distinct neutrophil integrin receptor for laminin.
Authors: Bohnsack J F , Akiyama S K , Damsky C H , Knape W A , Zimmerman G A
Published: June 2004

We used mAbs against polymorphonuclear leukocyte (PMN) surface proteins to investigate the mechanisms by which stimulated human neutrophils (PMNs) adhere in vitro to laminin, the major glycoprotein of mammalian basement membrane. mAb IB4, which is directed against the common beta 2 chain of the CD11/CD18, only partially inhibited the adherence of PMA-stimulated PMNs to both laminin and to subendothelial matrices. In contrast, IB4 completely inhibited PMA-stimulated PMN adherence to gelatin, fibronectin, collagen IV, and endothelial cell monolayers. PMA-stimulated PMNs from a patient with severe congenital CD11/CD18 deficiency also adhered to laminin, but not to gelatin or endothelial cell monolayers. Therefore, PMA-stimulated PMNs adhere to laminin by both CD11/CD18-dependent and CD11/CD18-independent mechanisms. Expression of CD11/CD18-independent adherence to laminin was agonist dependent, occurring after stimulation with the calcium ionophore A23187 and recombinant TNF-alpha, but not with the chemotactic factors FMLP, platelet activating factor, or recombinant human C5a. Expression of CD11/CD18-independent adherence was also divalent cation dependent, occurring in the presence of Mg2+ but not Ca2+ as the sole added divalent cation. The mAbs AIIB2 and 13, which are directed against the beta 1 subunit of the VLA integrins, significantly inhibited the CD11/CD18-independent adherence of normal PMNs to laminin, and completely abolished the adherence of CD11/CD18-deficient PMNs to laminin. Both anti-beta 1 mAbs bound to PMNs, as demonstrated by flow cytometry, and immunoprecipitated a membrane molecule of Mr 130,000 daltons from 125I-labeled, detergent-solubilized PMNs. These data suggest that human PMNs possess beta 1 and beta 2 classes of integrins, and that both mediate PMN adherence.
Amyloidosis and female protein in the Syrian hamster. Concurrent regulation by sex hormones.
Authors: Coe J E , Ross M J
Published: June 2004

Previous results have shown that when compared to male Syrian hamsters, female Syrian hamsters have a distinct predisposition to acquire amyloidosis either normally with aging or experimentally with sodium caseinate or diethylstilbestrol (DES) treatments. In the present study, we tested the influence of testosterone on expression of amyloid to determine if this hormone was solely responsible for the sex-limited amyloidosis of the Syrian hamster. Males deprived of testosterone by castration acquired amyloid at an unusually young age, an age of onset similar to that in female hamsters. Also, the amyloidogenic effect of DES in male Syrian hamsters was inhibited by concomitant injections of testosterone, indicating that estrogens induce amyloid in male hamsters by inhibiting testosterone synthesis. When administered to female hamsters, testosterone inhibited expression of amyloid in aging female Syrian hamsters and extended the life span of this gender. Of the two components of amyloid, the major component Amyloid A-derived fibril or the minor constituent, Amyloid P component, only the P component is under sex hormone control in the Syrian hamster; testosterone inhibits the hepatic synthesis of the P component homologue (called female protein), which is normally expressed 100-200-fold greater in female vs. male Syrian hamster. In general, the serum level of female protein under various experimental conditions correlated with the presence of amyloid and indicated that in the Syrian hamster the P component homologue is of primary importance in the deposition of amyloid.
Clustering of cytokine genes on mouse chromosome 11.
Authors: Wilson S D , Billings P R , D'Eustachio P , Fournier R E , Geissler E , Lalley P A , Burd P R , Housman D E , Taylor B A , Dorf M E
Published: June 2004

The presence of positionally conserved amino acid residues suggests that the mouse proteins TCA3, P500, MIP1-alpha, MIP1-beta, and JE are members of a single gene family. These proteins are activation specific and can be expressed by both myeloid and lymphoid cells. MIP1-alpha/MIP1-beta and MCAF (the putative human homologue of JE) act as chemotactic and activating agents for neutrophils and macrophages, respectively. The functions of TCA3 and P500 are unknown. We have used interspecies somatic cell hybrids and recombinant inbred mouse strains to show that the genes encoding TCA3, MIP1-alpha, MIP1-beta, and JE (provisionally termed Tca3, Mip-1a, Mip-1b, and Sigje, respectively) map as a cluster on the distal portion of mouse chromosome 11 near the Hox-2 gene complex. DNA sequence analysis indicates that the P500 and TCA3 proteins are encoded by alternative splicing products of one genomic gene. Additionally, the genes encoding TCA3 and JE are found to be strikingly similar with respect to the positions of intron-exon boundaries. Together, these data support the model that the cytokines TCA3, P500, MIP1-alpha, MIP1-beta, and JE are encoded by a single cluster of related genes. The gene encoding IL-5 (Il-5), which acts as a T cell-replacing factor, a B cell growth factor, and an eosinophil differentiation factor, is also mapped to mouse chromosome 11.Il-5 maps approximately 25 cM proximal to the Tca-3 gene and appears tightly linked to a previously described gene cluster that includes Il-3, Il-4, and Csfgm. We discuss the potential relevance of the two cytokine gene clusters described here with particular attention to specific human hematologic malignancies associated with chromosomal aberrations at corresponding locations on human chromosomes 5 and 17.
Purification of macrophage deactivating factor.
Authors: Srimal S , Nathan C
Published: June 2004

Macrophage deactivation factor (MDF) in P815 tumor cell-conditioned medium was assayed by its suppression of the ability of activated mouse peritoneal macrophages to release hydrogen peroxide. MDF displayed properties of a soluble protein(s) associated with both low (8-25,000) and high (greater than 450,000) Mr fractions. MDF was purified 6,140-fold by a seven-step procedure: extraction with acid-ethanol; precipitation with ether; and fractionation on gel filtration, anion-exchange, diphenyl reversed-phase and C4 reversed-phase HPLC columns, the last column twice. The final preparation contained two species: (a) a approximately 13,000 Mr band on reducing or nonreducing SDS-PAGE and on autoradiograms after radioiodination with chloramine T, and (b) a 66,000 Mr species ranging from approximately 5% to approximately 50% of the protein detectable by silver strain. The 66,000 Mr species was identified as albumin from its NH2-terminal amino acid sequence. However, no amino acid sequence could be obtained for the approximately 13,000 Mr species, either in fluid phase or after electroelution of the corresponding SDS-PAGE band. Thus, approximately 13,000 Mr MDF associates tightly with albumin through a variety of separation techniques, and may have a blocked NH2 terminus. Purified MDF afforded 50% inhibition of activated macrophage H2O2 releasing capacity at a concentration of 1-10 nM. Separation of MDF from most higher Mr moieties was associated with disproportionately small increases in specific activity, suggesting MDF might be partially inactivated by purification. As purified, MDF was approximately 1,000-fold less potent at deactivating macrophages than TGF-beta. Antibodies that neutralized the macrophage-deactivating effect of TGF-beta did not inhibit deactivation by MDF.
Release of heparan sulfate from endothelial cells. Implications for pathogenesis of hyperacute rejection.
Authors: Platt J L , Vercellotti G M , Lindman B J , Oegema T R , Bach F H , Dalmasso A P
Published: June 2004

Heparan sulfate proteoglycan associated with endothelial cells in normal blood vessels inhibits intravascular coagulation and egress of blood cells and plasma proteins, key features of hyperacute rejection. It was shown herein that exposure of cultured porcine endothelium to human serum as a source of natural antibodies and complement caused cleavage and release of 5% of endothelial cell proteoglycans within 4 min and greater than 50% within 1 h. Proteoglycan release depended on activation of the classical complement pathway and preceded irreversible cell injury. These findings suggest that loss of endothelial cell proteoglycan may be a critical step in the pathogenesis of hyperacute rejection and in diseases involving humoral injury to endothelial cells.
Regulation of murine lymphokine production in vivo. III. The lymphoid tissue microenvironment exerts regulatory influences over T helper cell function.
Authors: Daynes R A , Araneo B A , Dowell T A , Huang K , Dudley D
Published: June 2004

We investigated the capacity of murine T lymphocytes, isolated from various lymphoid organs of normal or antigen-primed donors, to produce IL-2 or IL-4 after activation with anti-CD3 or specific antigen. Our results established that T cells resident within lymphoid organs being drained by nonmucosal tissue sites (e.g., axillary, inguinal, brachial lymph nodes, or spleen) produced IL-2 as the predominant T cell growth factor (TCGF) after activation. Conversely, activated T cells from lymphoid organs being drained by mucosal tissues (Peyer's patches, and cervical, periaortic, and parathymic lymph nodes) produced IL-4 as the major species of TCGF. Analysis of the lymphoid tissues obtained from adoptive recipients of antigen-primed lymphocytes provided by syngeneic donors provided evidence that direct influences were being exerted on T cells during their residence within defined lymphoid compartments. These lymphoid tissue influences appeared to be responsible for altering the potential of resident T cells to produce distinct species of TCGF. Steroid hormones, known transcriptional enhancers and repressors of specific cellular genes, were implicated in the controlling mechanisms over TCGF production. Glucocorticoids (GCs) were found to exert a systemic effect on all recirculating T cells, evidenced by a marked dominance in IL-4 production by T cells obtained from all lymphoid organs of GC-treated mice, or after a direct exposure of normal lymphoid cells to GCs in vitro before cellular activation with T cell mitogens. Further, the androgen steroid DHEA appeared to be responsible for providing an epigenetic influence to T cells trafficking through peripheral lymphoid organs. This steroid influence resulted in an enhanced potential for IL-2 secretion after activation. Anatomic compartmentalization of the DHEA-facilitated influence appears to be mediated by differential levels of DHEA-sulfatase in lymphoid tissues. DHEA-sulfatase is an enzyme capable of converting DHEA-sulfate (inactive) to the active hormone DHEA. We find very high activities of this enzyme isolated in murine macrophages. The implications of our findings to immunobiology are very great, and indicate that T cells, while clonally restricted for antigen peptide recognition, also appear to exhibit an extreme flexibility with regards to the species of lymphokines they produce after activation. Regulation of this highly conservative mechanism appears to be partially, if not exclusively, controlled by cellular influences being exerted by distinct species of steroid hormones, supplied in an endocrine or a paracrine manner where they mediate either systemic or tissue-localized influences, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
MHC class II-derived peptides can bind to class II molecules, including self molecules, and prevent antigen presentation.
Authors: Rosloniec E F , Vitez L J , Buus S , Freed J H
Published: June 2004

Seven synthetic peptides corresponding to the polymorphic regions of the alpha and beta chains of the I-Ak molecule were examined for their ability to inhibit the presentation of foreign antigens to antigen-specific, I-A-restricted T cell hybridomas. Two of the peptides, representing the sequences found in the first and third polymorphic regions (PMR) of the A alpha k chain (alpha k-1 and alpha k-3) were capable of inhibiting the presentation of three different HEL-derived peptide antigens to their appropriate T cells. In addition, the alpha k-1 peptide inhibited the presentation of the OVA(323-339) immunodominant peptide to the I-Ad-restricted T cell hybridomas specific for it. Prepulsing experiments demonstrated that the PMR peptides were interacting with the APC and not with the T cell hybridomas. These observations were confirmed and extended by the demonstration that the alpha k-1 and alpha k-3 peptides blocked the direct binding of HEL(46-61) to purified I-Ak and that the alpha k-1 peptide blocked the binding of OVA(323-339) to I-Ad. The binding competition experiments suggest that the alpha k-1 peptide binds to the I-Ak molecule from which it was derived with a Kd approximately 10(-5) M, while the alpha k-3 peptide binds slightly less well. These combined data, suggesting that class II-derived peptides can bind to MHC class II molecules, including the autologous molecule from which they are derived, have important implications for the molecular basis of alloreactivity and autoreactivity. Further, they suggest a possible mechanism by which selecting elements, involving only MHC molecules, may be generated in the thymus.
Autoimmune mice make anti-Fc gamma receptor antibodies.
Authors: Boros P , Chen J M , Bona C , Unkeless J C
Published: June 2004

We demonstrate, using a recombinant truncated Fc gamma RII molecule as a probe, the presence of anti-Fc gamma R antibodies in several strains of autoimmune mice. Affinity chromatography on a truncated Fc gamma R column of pooled sera from aged NZB females resulted in isolation of 16 micrograms of IgM per ml of serum, approximately 2% of the total IgM; no anti-Fc gamma R IgM was found in sera from C58/J mice. Mice with high titers of anti-Fc gamma R IgM also had anti-Fc gamma R IgG. Affinity-purified anti-Fc gamma R IgG bound to Fc gamma R-bearing cells. A good correlation was found between the presence of anti-Fc gamma R Ig and impaired phagocytosis of immune complexes in autoimmune strains such as NZB or NZB/NZW F1. Sera with high titers of anti-Fc gamma R Ig from NZB and motheaten mice inhibited the binding of soluble immune complexes. Furthermore, BXSB, a lupus-prone mouse strain that does not produce anti-Fc gamma R Ig, shows normal macrophage binding and phagocytosis of immune complexes. A set of four IgM mAbs that bind to Fc gamma R was identified. These antibodies were polyspecific; some were directed against DNA, and others recognized a wide variety of antigens including histones, thyroglobulin, and transferrin, but all anti-Fc gamma R IgM antibodies effectively inhibited the binding of IgG1 anti-DNP/DNP20BSA complexes to J774 macrophages. The role of anti-Fc gamma R Ig in autoimmunity remains to be established. It may act to crosslink and activate Fc gamma Rs on neutrophils, macrophages, NK, and mesangial cells, or it may desensitize Fc gamma R function of Fc gamma R-bearing cells.
Absence of interleukin 2 production in a severe combined immunodeficiency disease syndrome with T cells.
Authors: DiSanto J P , Keever C A , Small T N , Nicols G L , O'Reilly R J , Flomenberg N
Published: June 2004

We have characterized a child with a severe combined immunodeficiency disease syndrome with increased numbers, but a normal distribution, of CD3+ T cells. This patient's immunological defect appears to be attributable to a selective deficiency in T cell production of IL-2, which may reflect a subtle abnormality in the IL-2 gene locus or a defect in a regulatory factor necessary for IL-2 transcription. The increased numbers of phenotypically normal T cells in this patient suggest that alternative pathways of T cell development exist in man or that IL-2 production intra- and extrathymically is controlled via distinct regulatory mechanisms.
The distinct leukocyte integrins of mouse spleen dendritic cells as identified with new hamster monoclonal antibodies.
Authors: Metlay J P , Witmer-Pack M D , Agger R , Crowley M T , Lawless D , Steinman R M
Published: June 2004

Hybridoma fusions with hamster hosts were undertaken to generate mAbs to mouse spleen dendritic cells. Two mAb were obtained and used to uncover the distinct integrins of these APC. One, 2E6, bound a determinant common to all members of the CD11/CD18 family, most likely the shared 90 kD CD18 beta chain. 2E6 immunoprecipitated the characteristic beta 2 integrin heterodimers from lymphocytes (p180, 90; CD11a) and macrophages (p170,90; CD11b), but from dendritic cells, a p150,90 (presumably CD11c) integrin was the predominant species. 2E6 inhibited the binding function of the CD11a and CD11b integrins on B cells and macrophages in appropriate assays, but 2E6 exerted little or no inhibition on the clustering of dendritic cells to T cells early in primary MLR, suggesting a CD11/CD18-independent mechanism for this binding. The second mAb, N418, precipitated a 150, 90 kD heterodimer that shared the 2E6 CD18 epitope. This N418 epitope may be the murine homologue of the previously characterized human CD11c molecule, but the epitope was only detected on dendritic cells. N418 did not react with peritoneal macrophages, anti-Ig-induced spleen B blasts, or bulk lymph node cells. When used to stain sections of spleen, N418 stained dendritic cells in the T-dependent areas, much like anti-class II mAbs that were also generated in these fusions. In addition, N418 revealed nests of dendritic cells that punctuated the rim of marginal zone macrophages between red and white pulp. This localization positioned most dendritic cells at regions where arterial vessels and T cells enter the white pulp. We conclude that the p150, 90 heterodimer is the major beta 2 integrin of spleen dendritic cells, and we speculate that it may function to localize these APC at sites that permit access to the recirculating pool of resting T cells.
Antiviral cytotoxic T cell response induced by in vivo priming with a free synthetic peptide.
Authors: Aichele P , Hengartner H , Zinkernagel R M , Schulz M
Published: June 2004

Induction in vivo of antiviral cytotoxic T cell response was achieved in a MHC class I-dependent fashion by immunizing mice three times with a free unmodified 15-mer peptide derived from the nucleoprotein of lymphocytic choriomeningitis virus in IFA. The effector T cells are CD8+, restricted to the class I Ld allele of the analyzed mouse strain, and are specific both at the level of secondary restimulation in vitro and at the effector T cell level. These results suggest that cocktails of viral peptides may be used as antiviral T cell vaccines.
Expression and role of p75 interleukin 2 receptor on human monocytes.
Authors: Espinoza-Delgado I , Ortaldo J R , Winkler-Pickett R , Sugamura K , Varesio L , Longo D L
Published: June 2004

We investigated the expression of IL-2R subunits in human monocytes using the TU27 mAb, which recognizes the p75 chain, and anti-Tac mAb, which recognizes the p55 moiety of the IL-2R. We found that p75 but not p55 is constitutively expressed in more than 90% of fresh human monocytes. Antibody to p75, but not to p55, inhibited the activation of monocytes to a cytotoxic stage induced by IL-2 but did not block IFN-gamma-induced cytotoxicity. Our data demonstrate that the p75 chain is expressed on human monocytes and is involved in the activation of monocytes by IL-2.
Knob-independent cytoadherence of Plasmodium falciparum to the leukocyte differentiation antigen CD36.
Authors: Biggs B A , Goozé L , Wycherley K , Wilkinson D , Boyd A W , Forsyth K P , Edelman L , Brown G V , Leech J H
Published: June 2004

The survival of Plasmodium falciparum-infected erythrocytes is enhanced by the sequestration of mature trophozoites and schizonts from the peripheral circulation. Cytoadherence of infected erythrocytes in vivo is associated with the presence of knobs on the erythrocyte surface, but we and others have shown recently that cytoadherence to C32 melanoma cells may occur in vitro in the absence of knobs. We show here that a knobless clone of P. falciparum adheres to the leukocyte differentiation antigen, CD36, suggesting that binding to CD36 is independent of the presence of knobs on the surface of the infected erythrocyte. This clone showed little cytoadherence to immobilized thrombospondin or to endothelial cells expressing the intercellular adhesion molecule 1. Furthermore, an Mr approximately 300-kD trypsin-sensitive protein doublet was immunoprecipitated from knobless trophozoite-infected erythrocytes. Finding a P. falciparum erythrocyte membrane protein 1 (PfEMP1)-like molecule on these infected erythrocytes is consistent with a role for PfEMP1 in cytoadherence to CD36 and C32 melanoma cells.
Definition of a specific interaction between the early T lymphocyte activation 1 (Eta-1) protein and murine macrophages in vitro and its effect upon macrophages in vivo.
Authors: Singh R P , Patarca R , Schwartz J , Singh P , Cantor H
Published: June 2004

The Eta-1 gene specifies a secreted product of activated T cells and is associated with genetic resistance to infection by an obligate intracellular bacterium. Previous studies have suggested that eta-1 might affect the ability of macrophages to migrate to the site of bacterial infection and/or to inhibit intracellular bacterial growth. We therefore examined the interaction of eta-1 with macrophages in vitro and in vivo. We find that macrophages express approximately 10(4) eta-1 receptors/cell and each receptor has a Kd of approximately 5 x 10(-10) M. The subsequence of eta-1 containing an RGD motif is required for binding because a synthetic peptide containing the eta-1 RGD domain inhibited protein attachment to macrophages. We also found that subcutaneous inoculation of mice with eta-1 resulted in a cellular infiltrate comprised primarily of macrophages. We propose that the interaction between eta-1 and its receptor on macrophages results in a change in macrophage physiology resulting in accumulation of these cells at extravascular sites.
Spontaneous loss and alteration of antigen receptor expression in mature CD4+ T cells.
Authors: Kyoizumi S , Akiyama M , Hirai Y , Kusunoki Y , Tanabe K , Umeki S
Published: June 2004

The TCR/CD3 complex plays a central role in antigen recognition and activation of mature T cells, and, therefore, abnormalities in the expression of the complex should induce unresponsiveness of T cells to antigen stimulus. Using flow cytometry, we detected and enumerated variant cells with loss or alteration of the surface TCR/CD3 expression among human mature CD4+ T cells. The presence of variant CD4+ T cells was demonstrated by isolating and cloning them from peripheral blood, and their abnormalities can be accounted for by alterations in TCR expression such as defects of protein expression and partial protein deletion. The variant frequency in peripheral blood increased with aging in normal donors and was highly elevated in patients with ataxia telangiectasia, an autosomal recessive inherited disease with defective DNA repair and variable T cell immunodeficiency. These findings suggest that such alterations in TCR expression are induced by somatic mutagenesis of TCR genes and can be important factors related to age-dependent and genetic disease-associated T cell dysfunction.
Hyaluronic acid accumulation and redistribution in rejecting rat kidney graft. Relationship to the transplantation edema.
Authors: Hällgren R , Gerdin B , Tufveson G
Published: June 2004

By using biotin-labeled proteoglycan core protein and an avidin-enzyme system, hyaluronic acid (HA) was visualized in rat kidney. In the normal kidney, HA was localized in the extracellular space of the inner medulla and increased markedly towards the papillary tip. No staining for HA was seen in the interstitial tissue of the cortex or the outer medulla. During the development of rejection of allogeneic renal grafts, a progressive increase in accumulated HA was seen in the interstitial tissue of the cortex and outer medulla. The extractable amounts of HA increased, on average, 40 times in the cortex and outer medulla; no increase was measured in the inner medulla and papilla. The relative water content of the cortex and outer medulla also increased progressively and correlated with the HA accumulation. The extractable amounts of HA in syngeneic grafts increased by day 2 and then leveled off, indicating that surgical trauma may induce some transient HA accumulation after transplantation. Interstitial accumulation of HA, a glycosaminoglycan with unique water-binding qualities, would presumably influence water transport and osmotic activity and should thereby be implicated in the normal papillary function, but also in the development of the interstitial edema of the cortex and outer medulla during rejection of renal grafts.
Viruses as therapeutic agents. I. Treatment of nonobese insulin-dependent diabetes mice with virus prevents insulin-dependent diabetes mellitus while maintaining general immune competence.
Authors: Oldstone M B
Published: June 2004

A situation in which virus can be used as a therapeutic agent to prevent a lethal autoimmune disease is explored. Nonobese insulin-dependent diabetes (NOD) mice spontaneously develop insulin-dependent diabetes mellitus (IDDM), characterized by lymphocytic infiltration into the islets of Langerhans and beta cell destruction, resulting in hypoinsulinemia, hyperglycemia, ketoacidosis, and death. Infection of NOD mice with lymphocytic choriomeningitis virus (LCMV) aborts the autoimmune manifestations and resultant IDDM. The viruses' effect is on a subset of CD4+ lymphocytes. Ablating this autoimmune diabetes does not significantly alter immune responses to a variety of non-LCMV antigens that require CD4+ lymphocyte participation. The prevention of IDDM associated with viral therapy is maintained throughout the life spans of NOD mice.
Piliation changes in transformation-defective gonococci.
Authors: Swanson J , Morrison S , Barrera O , Hill S
Published: June 2004

Recombination-dependent alterations of their expressed pilin gene (pilE) enable gonococci to synthesize a myriad of structurally/antigenically different pili and to reversibly switch their pilus production on and off. These changes have been ascribed both to DNA transformation and to intragenomic recombination between pilE and silent pilin genes (pilS). We examined the pilus changes in gonococci that are incompetent for transformation because of their DNA uptake deficiency (dud) mutation, pilus- (P-) phenotype, or both. Though incompetent for DNA transformation, dud cells displayed pilus antigenic variation and underwent reversible pilus variations much like their wild-type parent. Wild-type P- with a pilE nonsense mutation were also virtually nontransformable, but they reverted to P+ at high frequencies. The pilin mRNA sequence changes that accompanied pilus transitions in these nontransformable dud and P- gonococci represent insertion of pilS stretches into their respective pilE, apparently via intragenomic recombination.