bluuebunny/crossref_metadata_2025 huggingface dataset:
Leukocyte function-associated antigen-1-dependent lysis of Fas+ (CD95+/Apo-1+) innocent bystanders by antigen-specific CD8+ CTL.
Authors: Kojima H , Eshima K , Takayama H , Sitkovsky M V
Published: December 2022

Exquisite specificity toward Ag-bearing cells (cognate targets) is one of the most important properties of CD8+ CTL-mediated cytotoxicity. Using highly Ag-specific CD8+ CTL lines and clones, which spare noncognate, Ag-free targets, we found that in the presence of Ag-bearing targets the CTL acquire the ability to lyse noncognate target cells (bystanders). It is shown that the unexpectedly rapid and efficient lysis of bystanders by Ag-activated CTL is mediated by a Fas ligand (FasL)/Fas-based mechanism and does not depend on perforin. The CTL lysed Fas-expressing bystanders, but spared the Fas-negative or anti-Fas mAb-resistant bystander cells. Accordingly, the FasL-deficient gld/gld CTL did not kill bystanders, while perforin-deficient CTL did. Unlike anti-Fas mAb-induced cell death, the lysis of bystanders was not only FasL/Fas dependent but also required adhesion molecule LFA-1 on the surface of the activated CTL. Lysis of bystanders is viewed as acceptable "collateral" damage, but the persistent presence of activated CTL could result in immunopathologies involving functional Fas-expressing tissues.
Expression in BALB/c and C57BL/6 mice of Rt6-1 and Rt6-2 ADP-ribosyltransferases that differ in enzymatic activity: C57BL/6 Rt6-1 is a natural transferase knockout.
Authors: Kanaitsuka T , Bortell R , Stevens L A , Moss J , Sardinha D , Rajan T V , Zipris D , Mordes J P , Greiner D L , Rossini A A
Published: December 2022

Several proteins with NAD+:arginine ADP-ribosyltransferase (ART) activity are expressed in T cells and affect their function. Rat T cells that express the ART designated RT6 are determinants of the expression of autoimmune diabetes. In the mouse, a 35-kDa ecto-ART modulates the proliferation and functional activity of CTL. Here we report on mouse ARTs designated Rt6-1 and Rt6-2 in BALB/c and C57BL/6 mice. mRNAs for Rt6-1 and Rt6-2 were found in spleen, thymus, and intestinal tissue of both strains, but Rt6-1 mRNA in C57BL/6 mice was detected only at low levels. Rt6-1 and Rt6-2 cDNAs from both strains were cloned and sequenced. Predicted amino acid sequences of Rt6-2 were identical in both strains, but there was an in-frame stop codon in the sequence of Rt6-1 in C57BL/6 mice not present in BALB/c mice. Recombinant C57BL/6 Rt6-2 and BALB/c Rt6-1 proteins expressed in COS1 cells exhibited ART activity and were documented to be glycosylphosphatidylinositol-linked membrane proteins. COS-1 cells transfected with a C57BL/6 Rt6-1 cDNA construct expressed a truncated protein consistent in size with that predicted by the presence of the stop codon. This approximately 21-kDa protein appeared not to be glycosylphosphatidylinositol linked to the cell surface and lacked ART activity. C57BL/6 Rt6-1 therefore appears to be a naturally occurring ART knockout. The expression of Rt6-1 and Rt6-2 mRNAs in lymphoid tissues suggests that these ARTs may regulate immune system functions. Expression of Rt6-2 or another redundant ART may compensate for the lack of enzymatically active Rt6-1 in C57BL/6 mice.
Novel HY peptide antigens presented by HLA-B27.
Authors: Simmons W A , Summerfield S G , Roopenian D C , Slaughter C A , Zuberi A R , Gaskell S J , Bordoli R S , Hoyes J , Moomaw C R , Colbert R A , Leong L Y , Butcher G W , Hammer R E , Taurog J D
Published: December 2022

We have identified two peptides corresponding to the male-specific HY minor histocompatibility Ags presented by HLA-B27 in transgenic rodents, isolated from whole cell extracts and from immunoprecipitated B27 molecules of male B27 rat spleen cells. HPLC peptide fractions that sensitized female B27 targets for lysis by B27-restricted anti-HY CTL were analyzed by electrospray tandem mass spectrometry using a new highly sensitive quadrupole/time-of-flight instrument. Two peptide sequences were obtained, KQYQKSTER and AVLNKSNREVR. Synthetic peptides corresponding to these sequences bound B27 in vitro and were recognized by distinct B27-restricted anti-HY CTL populations. Neither peptide sequence entirely matches known protein sequences or shows a resemblance to known Y chromosome genes, but both show homology to known autosomally encoded proteins. Both peptides were shown to be controlled by the Sxr(b) segment of the short arm of the mouse Y chromosome, a segment known to contain all previously identified HY Ags. Taken together, these findings suggest that the two peptides arise as a result of Y chromosome-regulated control of one or more autosomal gene products. Although arginine at position 2 is a dominant anchor residue for peptides bound to B27, neither B27-presented HY sequence contains this residue. These studies, employing sensitive new methodology for identification of MHC-bound peptides, significantly extend the complexity of the genetic basis of HY Ags and expand the repertoire of antigenically active peptides bound to B27.
Increased expression of signaling lymphocytic activation molecule in patients with rheumatoid arthritis and its role in the regulation of cytokine production in rheumatoid synovium.
Authors: Isomäki P , Aversa G , Cocks B G , Luukkainen R , Saario R , Toivanen P , de Vries J E , Punnonen J
Published: December 2022

In the present study the expression and function of signaling lymphocytic activation molecule (SLAM) in lymphocytes from patients with rheumatoid arthritis (RA) were investigated. The expression levels of SLAM were significantly up-regulated on synovial fluid and synovial tissue T cells from patients with RA compared with peripheral blood T cells from the same patients or from healthy volunteers. In addition, the expression of SLAM on peripheral blood B cells from patients with RA was elevated compared with that in healthy volunteers. SLAM+ T cells in synovial fluid coexpressed CD45RO and demonstrated decreased expression of CD27, indicative of a primed phenotype. In addition, the activation state of SLAM+ T cells was enhanced, as judged by increased expression of CD25, CD28, CD69, and CD95 on these cells. Interestingly, SLAM expression on activated CD4+ and CD8+ T cells from both patients and healthy individuals could be down-regulated by IL-10, which has been previously shown to function as an anti-inflammatory molecule in rheumatoid synovium. Furthermore, anti-SLAM mAbs increased the production of IL-10, IFN-gamma, and TNF-alpha by in vitro activated synovial fluid mononuclear cells, supporting the idea that signaling through SLAM may play a role in the regulation of synovial inflammation in patients with RA. Given the fact that SLAM was recently shown to be a high affinity self ligand, our data suggest that synovial T cells may stimulate their own cytokine production through homophilic SLAM-SLAM interactions.
Tumor-induced suppression of T lymphocyte proliferation coincides with inhibition of Jak3 expression and IL-2 receptor signaling: role of soluble products from human renal cell carcinomas.
Authors: Kolenko V , Wang Q , Riedy M C , O'Shea J , Ritz J , Cathcart M K , Rayman P , Tubbs R , Edinger M , Novick A , Bukowski R , Finke J
Published: December 2022

The proliferative capacity of T cells infiltrating human tumors is known to be impaired, possibly through their interaction with tumor. Here we demonstrate that soluble products derived from renal cell carcinoma (RCC-S) explants but not normal kidney can inhibit an IL-2-dependent signaling pathway that is critical to T cell proliferation. A major target of the immunosuppression was the IL-2R-associated protein tyrosine kinase, Janus kinase 3 (Jak3). RCC-S suppressed basal expression of Jak3 and its increase following stimulation with anti-CD3/IL-2. Jak3 was most sensitive to suppression by RCC-S; however, reduction in expression of p56(lck), p59(fyn), and ZAP-70 was observed in some experiments. Expression of other signaling elements linked to the IL-2R (Jak1) and the TCR (TCR-zeta, CD3-epsilon, and phospholipase C-gamma) were minimally affected. In naive T cells, RCC-S also partially blocked induction of IL-2R alpha-, beta- and gamma-chain expression when stimulating via the TCR/CD3 complex with anti-CD3 Ab. To determine whether RCC-S suppressed IL-2-dependent signaling, primed T cells were employed since RCC-S had no effect on IL-2R expression but did down-regulate Jak3 expression and, to a lesser degree, p56(lck) and p59(fyn). Reduction in Jak3 correlated with impaired IL-2-dependent proliferation and signal transduction. This included loss of Jak1 kinase tyrosine phosphorylation and no induction of the proto-oncogene, c-Myc. These findings suggest that soluble products from tumors may suppress T cell proliferation through a mechanism that involves down-regulation of Jak3 expression and inhibition of IL-2-dependent signaling pathways.
Phenotypic and functional characterization of mice that lack the type I receptor for IL-1.
Authors: Glaccum M B , Stocking K L , Charrier K , Smith J L , Willis C R , Maliszewski C , Livingston D J , Peschon J J , Morrissey P J
Published: December 2022

IL-1 alpha and IL-1 beta bind to receptors termed the type I and type II IL-1 receptors. The type I IL-1 receptor is responsible for specific signaling, while the type II IL-1 receptor functions as a nonsignaling decoy receptor. To determine the effect of a defect in IL-1-mediated signaling, mice have been produced with a genetically disrupted type I IL-1 receptor gene. Mice lacking type I IL-1 receptors are of normal vigor and exhibit no overt phenotype. B cells from type I IL-1R-/- mice activated in vitro with anti-IgM do not proliferate in response to IL-1, but do so in response to IL-4. Injection of murine IL-1 alpha does not induce detectable serum IL-6 levels in type I IL-1R-/- mice, but equivalent levels are produced in response to LPS. Type I IL-1R-/- mice have normal serum Ig levels and generate equivalent primary and secondary Ab responses as wild-type mice. In response to LPS, acute phase protein mRNA induction are equivalent in type I IL-1R-/- and wild-type mice. Type I IL-1R-/- mice do not differ from control mice in susceptibility to either a lethal challenge with D-galactosamine plus LPS or high dose LPS. Interestingly, ICE-/-/type I IL-1R-/- double mutant mice are resistant to high dose LPS. Type I IL-1R-/- mice backcrossed to the C57BL/6 background were as equally resistant as wild-type mice to Listeria monocytogenes.
Characterization of T cell-mediated responses in nonhealing and healing Leishmania major infections in the absence of endogenous IL-4.
Authors: Kropf P , Etges R , Schopf L , Chung C , Sypek J , Müller I
Published: December 2022

IL-4 drives polarized Th2 responses, and differentiating Th2 cells down-regulate their sensitivity to IL-12. Therefore, the failure of BALB/c mice to heal Leishmania major infection could be due to an IL-4-dependent biased Th2 response or to a reduced capacity of Leishmania-specific Th cells to respond to IL-12. We examined the ability of CD4+ Th cells from L. major-infected wild-type and IL-4-deficient BALB/c mice to respond to IL-12. We show that the inability of normal and IL-4-deficient BALB/c mice to heal L. major infections is due to their inability to generate effective Th1 responses and not to persistent IL-4-dominated Th2 responses. Redirection of immune responses in vivo by administration of IL-12 or anti-CD4 mAb treatment in the early phase of infection (+/-12 days) allows both normal and IL-4-deficient BALB/c mice to heal their lesions by allowing them to develop an efficient Th1 response regardless of the presence or the absence of IL-4. Finally, on a population level, Ag-specific Th cells from infected animals induced to heal display a strongly elevated response to IL-12.
V delta 1 T cells expanded in the blood throughout HIV infection display a cytotoxic activity and are primed for TNF-alpha and IFN-gamma production but are not selected in lymph nodes.
Authors: Boullier S , Dadaglio G , Lafeuillade A , Debord T , Gougeon M L
Published: December 2022

We have previously reported significant alterations of gamma delta subset distribution in the peripheral blood of HIV-infected donors. These modifications are characterized by the depletion of the V delta 2 subset associated with a strong increase in peripheral V delta 1 T cells. In addition, the latter exhibit ex vivo an activated phenotype and show a restricted complementarity-determining region 3 (CDR3) repertoire. In the present report we first address the question of the origin of these expanded cells. The lack of expansion and the Gaussian complementarity-determining region 3 size distribution of lymph node V delta 1 T cells suggest that lymph nodes do not represent the site of specific activation of this subset. The function of blood V delta 1 T cells was also explored. We report that patients' V delta 1 T cells express high levels of perforin and display an in vitro cytotoxic activity, whose characteristics are different from those of NK and LAK cells. In addition, single cell analysis of cytokine production revealed that, in contrast to V delta 1 T cells from control donors, patients' V delta 1 T cells are primed in vivo for IFN-gamma and TNF-alpha production. Together, these results indicate that in the course of HIV infection, expanded blood V delta 1 T cells are differentiated into a functional subset and raise the question of the contribution of this subset to AIDS pathogenesis.
Intranasal immunization of a DNA vaccine with IL-12- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-expressing plasmids in liposomes induces strong mucosal and cell-mediated immune responses against HIV-1 antigens.
Authors: Okada E , Sasaki S , Ishii N , Aoki I , Yasuda T , Nishioka K , Fukushima J , Miyazaki J , Wahren B , Okuda K
Published: December 2022

A DNA vaccine constructed with the CMV promoter conjugated to env gp160 and rev genes has been shown to induce an effective Th1-type immune response when inoculated via an intramuscular route. In the present study, we obtained high levels of both humoral and cell-mediated immune activity by intranasal administration of this DNA vaccine. The production of mucosal IgA Ab in feces and vaginal fluid was stimulated significantly by intranasal DNA administration. This route of administration resulted in a significant level of HIV-1-neutralizing Abs in feces and serum. Cytokine assays revealed that intranasal administration of this DNA vaccine induces a Th2-type immune response. Interestingly, cationic liposomes greatly enhanced these activities. Abs against HIV-1 were present for at least 10 mo. Coadministration of the DNA vaccine with IL-12- and granulocyte/macrophage-CSF-expressing plasmids induced high levels of HIV-specific CTLs and an increase in delayed type hypersensitivity when administered by the intranasal route. These results clearly demonstrate that intranasal administration of this DNA vaccine with liposomes, together with IL-12- and/or granulocyte/macrophage-CSF-expressing plasmids, induces a strong level of anti-HIV-1 immune response.
Phenotypic and cytokine analysis of human peripheral blood gamma delta T cells expressing NK cell receptors.
Authors: Battistini L , Borsellino G , Sawicki G , Poccia F , Salvetti M , Ristori G , Brosnan C F
Published: December 2022

The presence of NK receptors (NKR) on populations of T cells has been proposed to play a regulatory role in T cell function, fine tuning the response to Ag, and influencing the nature of the immune response through rapid secretion of large amounts of cytokines. In this study, we assessed the nature and distribution of NKR on human peripheral blood gamma delta T cells and established clones to study cytokine release. In circulating gamma delta T cells, approximately 80% expressed CD94, approximately 25% expressed NKR-P1A, and approximately 20% expressed p58, values substantially higher than those found on alpha beta T cells from the same donors. When cloned for specific NKR expression, most cells in culture were NKR-P1A+ whereas p58 expression was variable, suggesting that the NKR-P1A phenotype can be acquired in culture whereas expression of p58 is more stable. Some clones were triple positive for CD94, NKR-P1A, and p58. V delta 2+ cells generally expressed a wider range of NKR than V delta 1+ cells. Following activation through CD3, all gamma delta T cell clones released large amounts of IFN-gamma, commencing as early as 4 h postactivation. Some clones also released TNF-alpha and IL-4, but no correlation with specific NKR expression was noted. Activation through NKR-P1A induced moderate levels of IFN-gamma without inducing IL-4. The results suggest that activation of most gamma delta T cells is regulated by signaling events occurring via both the TCR and the NKR. They further show that peripheral blood gamma delta T cells may function as a source of the proinflammatory cytokines IFN-gamma and TNF-alpha.
In vivo association of CD5 with tyrosine-phosphorylated ZAP-70 and p21 phospho-zeta molecules in human CD3+ thymocytes.
Authors: Gary-Gouy H , Lang V , Sarun S , Boumsell L , Bismuth G
Published: December 2022

CD5 is a 67-kDa T cell surface Ag that can be found physically associated with the CD3-TCR molecular complex. In different experimental models it has been shown to act as a costimulatory receptor for T cell activation. Unexpectedly, studies in CD5-deficient mice suggested a negative role for the CD5 Ag in CD3-TCR signaling in the thymus. In this report we assessed the constitutive interactions of CD5 in freshly isolated human thymocytes with signaling elements of the CD3-TCR complex. We determined that the ZAP-70 protein tyrosine kinase was present in CD5 immunoprecipitates. The two molecules were constitutively tyrosine phosphorylated in a complex also associating with unphosphorylated as well as phosphorylated zeta-chains. Although both p21 and p23 tyrosine-phosphorylated forms of zeta as well as phospho-CD3 epsilon molecules were constitutively present in human thymocytes and could be immunoprecipitated with ZAP-70- or CD3 epsilon-specific Abs, the p21 species of zeta was predominant in CD5 immune complexes. The interaction between CD5 and ZAP-70 was not observed in CD3-negative thymocytes, where the constitutive tyrosine phosphorylation of ZAP-70 was very low. We conclude that CD5 may affect in vivo the signaling capacity of TCRs expressed by human thymocytes by altering the phosphorylation state of CD3 and/or by retaining ZAP-70 with the p21 species of zeta.
The affinity threshold for human B cell activation via the antigen receptor complex is reduced upon co-ligation of the antigen receptor with CD21 (CR2).
Authors: Mongini P K , Vilensky M A , Highet P F , Inman J K
Published: December 2022

The present studies have examined whether the potential of an Ag to co-ligate the complement (C3d)-binding CD21 receptor complex with the membrane IgM (mIgM) receptor complex can reduce the mIgM:Ag affinity threshold for triggering human B cell S phase entry. A series of Ab:dextran conjugates consisting of affinity-diverse anti-IgM mAb, with and without anti-CD21 mAb, were synthesized as polyclonally reactive, moderately multivalent ligands that mimic C3d-bearing and non-C3d-bearing Ag. Co-ligation of mIgM and CD21 significantly diminished both the ligand concentration threshold and the IgM:ligand affinity threshold for eliciting S phase entry in the presence of IL-4. Furthermore, such co-engagement ablated the triggering bonus associated with high mlgM:ligand affinity, suggesting that B cells with a high affinity for Ag are not preferentially activated over B cells of intermediate affinity upon encountering a multivalent Ag with bound C3d. The enhancing effects of mIgM:CD21 co-ligation were restricted to low concentrations of ligand; at high concentrations, a decrease in B cell DNA synthesis was often observed. The findings suggest that the ability a moderately multivalent Ag substrate to engage B cells through both mIgM and CD21 is critical for B cell activation at limiting Ag concentrations, and furthermore, that mIgM:CD21 co-engagement may be particularly important in eliciting an immune response to such Ags in unprimed individuals in whom the majority of specific B cells are of low affinity.
CD9-mediated costimulation of TCR-triggered naive T cells leads to activation followed by apoptosis.
Authors: Tai X G , Toyooka K , Yashiro Y , Abe R , Park C S , Hamaoka T , Kobayashi M , Neben S , Fujiwara H
Published: December 2022

The induction of full activation or death in TCR-triggered T cells depends largely on whether appropriate costimulatory signals are provided. In this study, we show that the costimulation of CD9 on naive T cells during TCR stimulation results in transient, albeit potent, activation followed by apoptosis, rather than full activation. Anti-CD9 mAb synergized with suboptimal doses of anti-CD3 mAb in inducing T cell activation. [3H]TdR incorporation determined 2 days after CD9 costimulation was as potent as that induced by CD28 costimulation. In contrast to progressive T cell proliferation induced by CD28 costimulation, CD9 costimulation led to the induction of apoptosis of once-activated T cells. Although IL-2R expression was induced significantly earlier and to a greater degree after CD9 costimulation than after CD28 costimulation, CD9 costimulation only transiently produced a small amount of IL-2 and induced apparently low levels of bcl-xL compared with those observed in CD28 costimulation. Addition of rIL-2 to cultures of CD9 costimulation induced strikingly enhanced expression of bcl proteins, especially of bcl-xL, and protected TCR-stimulated T cells from apoptosis. These data indicate that CD9-mediated costimulation of TCR-triggered naive T cells leads to activation followed by apoptosis as the result of failure to generate a positive signal for sufficient levels of IL-2 production.
P-selectin, L-selectin, and alpha 4 integrin have distinct roles in eosinophil tethering and arrest on vascular endothelial cells under physiological flow conditions.
Authors: Kitayama J , Fuhlbrigge R C , Puri K D , Springer T A
Published: December 2022

The adhesive interactions of eosinophils with purified E-, P-, and L-selectins; vascular cell adhesion molecule-1 molecule; and HUVEC were examined in shear flow. Compared with neutrophils, eosinophils showed markedly less binding to E-selectin, but significantly stronger avidity for P-selectin. Both cell types showed a similar level of tethering and rolling on L-selectin. Eosinophils tethered and arrested abruptly on vascular cell adhesion molecule-1. However, some of the tethers were detached within several seconds; this was prevented by stimulation with eotaxin. Eosinophils also showed immediate arrest on HUVEC stimulated with 100 U/ml TNF-alpha for 6 h. Treatment with L-selectin mAb decreased eosinophil accumulation on the HUVEC by abrogating secondary tethers through interactions between flowing and attached eosinophils. mAb to P-selectin but not to E-selectin strongly inhibited primary tethers and accumulation of eosinophils. mAb to the integrin alpha 4 subunit inhibited arrest, induced rolling or detachment of tethered eosinophils, and resulted in partial reduction of eosinophil accumulation. mAb to the integrin beta 2 subunit had only a slight effect, whereas treatment with mAb to the integrin alpha 4 and beta 2 subunits together abolished rolling interactions as well as arrest, and thus almost totally inhibited eosinophil accumulation. Our data indicate that P-selectin, but not E-selectin, is directly involved in eosinophil tethering on inflammatory endothelium while L-selectin mainly mediates intereosinophil interaction. VLA-4 has a crucial role in eosinophil arrest, and arrest is enhanced by exposure to chemoattractants.
Role of alpha L beta 2 integrin avidity in transendothelial chemotaxis of mononuclear cells.
Authors: Weber C , Lu C F , Casasnovas J M , Springer T A
Published: December 2022

The leukocyte integrin alpha L beta 2 (LFA-1) is important in transendothelial migration. Since it is not fully understood how LFA-1 mediates transmigration, we studied the effects of alpha L and beta 2 cytoplasmic domain mutants that alter LFA-1 adhesiveness for intercellular adhesion molecule-1. Monocyte chemotactic protein-1 (MCP-1) induced LFA-1-dependent transendothelial migration of Jurkat and J-beta 2.7 transfectants coexpressing the MCP-1 receptor CCR2B and wild-type alpha L. No transendothelial chemotaxis was observed with truncation mutants of the alpha L cytoplasmic tail, which rendered LFA-1 constitutively active or locked LFA-1 in a low avidity state unresponsive to cellular activation. Moreover, transendothelial chemotaxis of lymphoblastoid SLA transfectants was abolished by truncation of the beta 2 cytoplasmic domain, but not by mutation of its TTT motif, which is important in phorbol ester-induced adhesion. These data indicate that transmigration may require both alpha L and beta 2 cytoplasmic domains. We further show that MCP-1-induced transendothelial chemotaxis of PBMC was inhibited by sustained activation of LFA-1 with Mn2+ or a stimulatory mAb to beta 2. Dimeric soluble intercellular adhesion molecule-1 also reduced transendothelial chemotaxis of PBMC. Taken together, our data suggest that transendothelial chemotaxis of mononuclear cells may involve dynamic changes in LFA-1 avidity.
In vivo inhibition of nuclear factor-kappa B activation prevents inducible nitric oxide synthase expression and systemic hypotension in a rat model of septic shock.
Authors: Liu S F , Ye X , Malik A B
Published: December 2022

We determined the in vivo function of LPS-induced nuclear factor-kappa B (NF-kappa B) activation in mediating inducible nitric oxide synthase (iNOS) mRNA and protein expression, and systemic arterial hypotension in a rat model of septic shock. LPS (8 mg/kg i.v.) challenge of rats activated NF-kappa B within 15 min in lung tissue, and the response persisted up to 4 h. NF-kappa B activation preceded the induction of iNOS mRNA. Pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappa B effective in cellular studies, prevented NF-kappa B activation in vivo and reduced iNOS mRNA expression and the increase in iNOS activity activated by LPS. At PDTC concentrations of 50, 100, and 200 mg/kg, the reductions of iNOS mRNA were 20, 46, and 48%, and the reductions in iNOS activity were 59, 66, and 75%, respectively. The PDTC concentration-dependent reductions in iNOS activity produced similar decreases in plasma nitrite/nitrate concentrations. PDTC also prevented the decrease in arterial blood pressure induced by LPS. These results demonstrate that activation of NF-kappa B is a critical in vivo regulatory mechanism mediating LPS-induced iNOS expression and the resultant systemic hypotension.
Role of passenger leukocytes in allograft rejection: effect of depletion of donor alveolar macrophages on the local production of TNF-alpha, T helper 1/T helper 2 cytokines, IgG subclasses, and pathology in a rat model of lung transplantation.
Authors: Sekine Y , Bowen L K , Heidler K M , Van Rooijen N , Brown J W , Cummings O W , Wilkes D S
Published: December 2022

Acute lung allograft rejection is believed to be initiated by passenger leukocytes, such as alveolar macrophages (AM), in the donor organ, which release TNF-alpha, and present alloantigens to host lymphocytes, to up-regulated Th1 cellular and humoral immunity. However, the role of donor AM in local TNF-alpha synthesis, and their ability to induce local Th1 cellular and humoral immunity have not been evaluated. By depleting Brown Norway (BN, RT1n) rat lung allografts of AM before transplantation into Lewis rat (LEW, RT1(1)) recipients, the current study determined the role of donor AM in including the production of TNF-alpha, IFN-gamma (Th1 cytokine), IL-4 (Th2 cytokine), IgG subtypes, and rejection pathology in the allograft. The data show that compared with untreated BN allografts, pretransplant depletion of donor lung AM resulted in significantly less TNF-alpha, and IFN-gamma production in allograft bronchoalveolar lavage fluid with variable effects on local IL-4 production. Depletion of AM in the donor lung before transplantation affected the local production of several IgG subclasses. However, pretransplant depletion of donor AM had no effect on the development of the pathology of severe acute rejection. These data show that donor AM have a central role in the local synthesis of TNF-alpha and induce the production of IFN-gamma and IgG subtypes, locally, during acute lung allograft rejection. However, depletion of AM before transplantation does not prevent the development of severe acute rejection in BN rat lungs, transplanted into LEW recipients.
Dual role of IL-12 in early and late stages of murine collagen type II arthritis.
Authors: Joosten L A , Lubberts E , Helsen M M , van den Berg W B
Published: December 2022

IL-12 can promote Th1 responses, and early administration of IL-12 during immunization was shown to enhance expression of autoimmune collagen-induced arthritis (CIA). We now studied the impact of IL-12 at the stage of disease expression and during established CIA in DBA-1 mice. Accelerated onset and enhanced severity were provoked when i.p. injections of 100 ng of murine IL-12 (mIL-12) were given around the time of arthritis onset. Moreover, the onset of CIA could be ameliorated with anti-mIL-12 Abs, indicating that IL-12 is a pivotal mediator in the expression of CIA. In addition, the effect of anti-mIL-12 treatment was analyzed in established CIA. Continued treatment did not suppress established arthritis. Instead, these mice showed an impressive exacerbation of arthritis shortly after cessation of anti-mIL-12 treatment, indicative of impairment of endogenous control. Exaggerated disease was characterized by massive granulocyte influx and enhanced expression of IL-1 beta and TNF-alpha mRNA in the synovial tissue. Subsequently, we treated established collagen arthritis with recombinant mIL-12 for 7 days. Profound suppression of the arthritis score was noted, including reduced influx of cells and diminished cartilage damage. Tenfold enhanced levels of IL-10 were detected in sera of mIL-12-treated mice, and up-regulated mRNA levels of IL-10, IFN-gamma, and IL-12 were measured in synovial tissue. Finally, the anti-inflammatory effect of IL-12 on CIA could be reversed by coadministration of anti-IL-10 Abs. This study indicates that IL-12 has a stimulatory role in early arthritis expression, whereas it has a suppressive role in the established phase of collagen arthritis.
Up-regulation of Fas and the costimulatory molecules B7-1 and B7-2 on peripheral lymphocytes in autoimmune B6/gld mice.
Authors: Weintraub J P , Eisenberg R A , Cohen P L
Published: December 2022

C57BL/6-gld/gld (B6/gld) mice have a point mutation in the gene for Fas ligand (FasL) resulting in nonfunctional FasL protein. We hypothesized that the lack of normal Fas/FasL interactions in these mice might result in abnormalities of Fas expression. Thus, we compared spleen cells from B6/gld mice and normal B6 control mice. While B6 spleen cells consisted of two main populations, Fashigh (high Fas expression) and Faslow (low Fas expression), nearly all B6/gld spleen cells were Fashigh. Two-color immunofluorescence revealed that the Fashigh and Faslow populations in the B6 spleen were Thy-1.2+ (T cells) and IgM+ (B cells), respectively, whereas both T cells and B cells in the B6/gld spleen were Fashigh, indicating that Fas expression is increased on B cells in the B6/gld spleen. This phenomenon was age related and restricted to peripheral lymphocytes. In addition to Fas, B6/gld splenic B cells showed increased expression of the costimulatory molecule B7-2, while the related costimulatory molecule B7-1 was up-regulated on both B cells and T cells in the B6/gld spleen. In vitro, both B cells and T cells from the B6/gld spleen showed an increase in susceptibility to apoptosis mediated by soluble anti-Fas Ab. These results suggest that some lymphocytes in B6/gld mice are primed to undergo Fas-mediated apoptosis, but are unable to do so due to the absence of functional FasL. Further study of such abnormal lymphocytes in the B6/gld spleen may elucidate the nature of autoimmunity in these mice.
Venoms of North American Snakes and Their Relationship
Authors: Githens Thomas S. , Butz Lewis W.
Published: December 2022

Summary and Conclusions

The venoms of six species of North American rattlesnakes, which were studied, contain identical or almost identical toxic principles. The toxic principles of the copperhead and moccasin are identical or almost so, but differ to some extent from those of the rattlesnakes. The venom of Crotalus terrificus the dog-faced rattlesnake of Central and South America, and the venom of Bothrops atrox, the fer de lance, contain principles differing entirely from those of the Nearctic rattlesnakes as regards their antigenic properties. Rattlesnake venoms contain, in addition to their acutely toxic principles, other components, which have the power to bind antibodies, but which are not acutely toxic to the pigeons.
Immunization and the Nitrogenenous Constituents of the Blood
Authors: Guyer M. F. , Lepkovsky S.
Published: December 2022

In connection with teh studies of the senior author (Guyer,1918, 1920, 1924), on the possibilities of modifying the germ plasm through serological reaction, it speedily became evident that if one is not to work wholly in the dark more must be known of the chemical changes which occur in the blood incident to the building of antibodies against foreign proteins or against the products of injury to an animal's own tissues (Guyer, 1923,1926).

In a study on the amino-nitrogen of the blood of rabbits, made in this laboratory, Mabel G. Boyden, research assistant of the senior author, found that in 48 rabbits the average content of amino-nitrogen for normal whole rabbit blood was 10.814 mgm.per 100cc.
Heterophile Antibodies in Serum Sickness
Authors: Davidsohn I.
Published: December 2022

The sera of 21 patients afflicted with horse serum sickness, whose blood was obtained during or at various intervals following the disease, were examined for agglutinins and hemolysins for sheep blood. Every one of them contained agglutinins for sheep blood, in titers varying from 1:4 to 1:64. Of 450 cases with no history of serum sickness, only 19 or 4.2 per cent showed agglutinins for sheep blood. All these 19 positive cases agglutinated only in the lowest dilution used (1:4). Four of the 21 cases showed a very remarkable increase of antisheep hemolysin, complete hemolysis occurring in dilutions: (1:192) (= 0.0026 cc.), (1:384) (= 0.0013 cc.), (1:768) (= 0.0006 cc.), (1:1536) (= 0.00032 cc.), while the highest titer found normally in a large series of control cases was 1:128 (= 0.004 cc.). Very fresh sheep erythrocytes were somewhat less agglutinable than older ones; their hemolysis was not influenced by age. Only one serum lost its antisheep agglutinins on standing. An immediate reaction in one patient (case 2) following injection of horse serum is brought in connection with the finding of agglutinins in a blood specimen obtained 20 hours following injection. The agglutinins were probably present before the injection of serum. In one of the serum sickness cases (no. 9) and one of the control cases (no. 13) the development of agglutinins following the injection of horse serum was observed by repeated titrations. Two cases (nos. 13 and 22) developed agglutinins following injection of horse serum, but no serum sickness. Three cases (nos. 10, 11 and 19) showed no agglutinins and no serum sickness following injection, while 6 cases found free from agglutinins before injection of serum did not develop serum sickness. A case of bovine serum sickness did not develop antisheep hemolysins. The heterophile nature of the agglutinins and hemolysins found in the serum of patients with horse serum sickness was established by absorption experiments.
Ricinoleated Vaccines
Authors: Kozlowski Anthony
Published: December 2022

In his recent explanation of the phenomenon of ulceration caused by the injection of sodium-ricinoleate solution into animals, Larson (1) suggested that it is due to the use of barium in the preparation of ricinoleic acid because it is practically impossible to remove traces of barium. As regards the author's recent work (2), however, Larson is not justified in attributing the ulcerative action of the vaccine to that cause. The method of purification of ricinoleic acid which was used and which will appear shortly in the Journal of Bacteriology, insures a preparation of the fatty acid free from barium. Moreover, even if there had been traces of barium in the ricinoleic-acid preparation, which had not been removed by sulfuric acid and repeated extraction of the fatty acid with ether, the minute amounts of that element not detectable by the usual chemical methods would not have been sufficient to cause any irritation of the animal tissues when injected with a 1-per-cent solution of sodium ricinoleate.
Dual Role of Dendritic Cells in the Induction and Down-Regulation of Antigen-Specific Cutaneous Inflammation
Authors: Krasteva Maya , Kehren Jeanne , Horand Françoise , Akiba Hitoshi , Choquet Geneviève , Ducluzeau Marie-Thérèse , Tédone Rosine , Garrigue Jean-Luc , Kaiserlian Dominique , Nicolas Jean-François
Published: December 2022

We have previously reported that contact sensitivity (CS) to dinitrofluorobenzene (DNFB) in C57BL/6 mice was mediated by MHC class I-restricted CD8+ T cells and down-regulated by MHC class II-restricted CD4+ T cells. In this study, we analyzed the contribution of dendritic cells (DC) in the induction of these two T cell subsets endowed with opposite functions. Hapten-pulsed skin- and bone marrow-derived DC, obtained from either normal C57BL/6 mice or from MHC class II (I+II−) and MHC class I (I−II+)-deficient mice, were tested for their ability to prime normal mice for CS to dinitrofluorobenzene. Expression of MHC class I molecules by transferred DC was mandatory both for the induction of CS and for the generation of hapten-specific CD8+ T cells in lymphoid organs. I+II− DC were as potent as I+II+ DC in priming for CS, demonstrating that activation of effector CD8+ T cells can occur independently of CD4+ T cell help. I−II+ DC could not immunize for CS, although they could sensitize for a delayed-type hypersensitivity reaction to protein Ags. Moreover, I−II+ DC injected simultaneously with cutaneous sensitization down-regulated the inflammatory response, suggesting that hapten presentation by MHC class II molecules could prime regulatory CD4+ T cells. These results indicate that DC can present haptenated peptides by both MHC class I and class II molecules and activate Ag-specific CD8+ effector and CD4+ regulatory T cell subsets, concurrently and independently.
CpG DNA Rescue from Anti-IgM-Induced WEHI-231 B Lymphoma Apoptosis via Modulation of IκBα and IκBβ and Sustained Activation of Nuclear Factor-κB/c-Rel
Authors: Yi Ae-Kyung , Krieg Arthur M.
Published: December 2022

Unmethylated CpG dinucleotides in particular base contexts in oligonucleotides (CpG DNA) rescue WEHI-231 cells from anti-IgM-induced cell cycle arrest and apoptosis. Anti-IgM rapidly elevated the levels of NFκB p50/c-Rel heterodimers followed by a decline of p50/c-Rel heterodimers by 3 h and a concomitant increase of p50/p50 homodimers. In contrast, CpG DNA induced and maintained the levels of p50/c-Rel heterodimers in the presence or absence of anti-IgM, while control non-CpG DNA failed to induce NFκB activation. Anti-IgM induced IκBα degradation followed by increased IκBα protein levels. The levels of IκBβ were increased after anti-IgM treatment. In contrast, CpG DNA, but not non-CpG DNA, induced sustained IκBα and IκBβ degradation in the presence or absence of anti-IgM. Inhibition of IκB degradation blocked CpG DNA-induced NFκB activation and expression of c-myc. Prevention of NFκB activation by inhibiting IκB degradation also suppressed the ability of CpG DNA to rescue WEHI-231 cells from anti-IgM-induced apoptosis. These results indicate that CpG DNA-mediated sustained activation of NFκB depends on the degradation of IκBα and IκBβ and is required for the CpG DNA-mediated anti-apoptosis gene expression and the protection against anti-IgM-induced apoptosis of WEHI-231 cells.
Decreased Resistance of TNF Receptor p55- and p75-Deficient Mice to Chronic Toxoplasmosis Despite Normal Activation of Inducible Nitric Oxide Synthase In Vivo
Authors: Yap George S. , Scharton-Kersten Tanya , Charest Hugues , Sher Alan
Published: December 2022

The importance of TNF-α in host defense to the intracellular parasite, Toxoplasma gondii, was investigated in mice lacking both the p55 and p75 receptors for this cytokine. Upon i.p. infection with the avirulent ME49 strain, knockout mice were capable of limiting acute i.p. infection, but succumbed within 3 to 4 wk to a fulminant necrotizing encephalitis. Receptor-deficient mice harbored higher cyst burdens and exhibited uncontrolled tachyzoite replication in the brain. The lack of TNF receptors did not adversely affect the development of a type 1 IFN-γ response. In vitro studies with peritoneal macrophages stimulated with IFN-γ and tachyzoites indicated that under limiting concentrations of IFN-γ, nitric oxide-mediated toxoplasmastatic activity is TNF-α dependent. However, this requirement is overcome by increasing the dose of IFN-γ. Furthermore, both ex vivo and in vivo studies demonstrated that inducible nitric oxide synthase induction in the peritoneal cavity and brain is unimpaired in receptor-deficient mice. Thus, TNF-dependent immune control of T. gondii expansion in the brain involves an effector function distinct from inducible nitric oxide synthase activation.
Activation of Complement by Mannose-Binding Lectin on Isogenic Mutants of Neisseria meningitidis Serogroup B
Authors: Jack Dominic L. , Dodds Alister W. , Anwar Natasha , Ison Catherine A. , Law Alex , Frosch Matthias , Turner Malcolm W. , Klein Nigel J.
Published: December 2022

Mannose-binding lectin (MBL) is a serum protein that has been demonstrated to activate the classical complement pathway and to function directly as an opsonin. Although MBL deficiency is associated with a common opsonic defect and a predisposition to infection, the role of the protein in bacterial infection remains unclear. We have investigated MBL binding to Neisseria meningitidis serogroup B1940 and three isogenic mutants, and the subsequent activation of the two major isoforms of C4 (C4A and C4B) by an associated serine protease, MASP. The mutants lacked expression of the capsular polysaccharide (siaD−), the lipo-oligosaccharide (LOS) outer core that prevented LOS sialylation (cpsD−), or both capsule and LOS outer core (cps−). Using flow cytometry, it was possible to detect strong MBL binding to the cps− and cpsD− mutants over a wide range of concentrations. In contrast, minimal or no MBL binding was detected on the parent organism, with binding to siaD− only at higher MBL concentrations. C4 was activated and bound by mutants that had previously bound MBL/MASP, but there was no significant difference in the amounts of C4A and C4B bound. When sialic acid residues were removed from the parent organism by neuraminidase treatment, the binding of both MBL and C4 increased significantly. Our results suggest that MBL may bind to and activate complement on these encapsulated organisms, and the major determinants of these effects are the LOS structure and sialylation.
Differences in Nitric Oxide Production by Superficial and Deep Human Articular Chondrocytes: Implications for Proteoglycan Turnover in Inflammatory Joint Diseases
Authors: Häuselmann H. J. , Stefanovic-Racic M. , Michel B. A. , Evans C. H.
Published: December 2022

During inflammatory joint diseases, chondrocytes are exposed to cytokines such as IL-1 that induce the synthesis of nitric oxide (NO). Chondrocytes from different zones of the articular cartilage are known to have different metabolic properties. In the present study, we have demonstrated that chondrocytes recovered from the superficial zone of normal, human, articular cartilage synthesize approximately 2 to 3 times as much NO in response to IL-1 as chondrocytes recovered from the deep zone of the same cartilage. Production of NO by normal cartilage in response to IL-1 was also found to decrease with age. Addition of the NO synthase inhibitor NG-monomethyl-l-arginine (l-NMA, 1 mM) blocked NO production by cells of both zones. l-NMA completely reversed the suppression of proteoglycan synthesis imposed by IL-1 in deep chondrocytes, but produced only partial reversal in superficial cells. As noted previously, IL-1 failed to elicit a strong catabolic response in cultures of human cartilage. In the presence of l-NMA, however, IL-1 reduced the metabolic t1/2 of proteoglycans by approximately 50% in both the superficial and deep zones. This suggests that NO has, directly or indirectly, an anticatabolic effect in human cartilage. These data confirm the metabolic heterogeneity of human chondrocytes, and suggest that NO may be involved to different degrees as an endogenous modulator of the turnover of the cartilaginous matrix in different zones of articular cartilage.
Streptococcal Cell Wall-Induced Arthritis: Requirements for IL-4, IL-10, IFN-γ, and Monocyte Chemoattractant Protein-1
Authors: Schimmer Ralph C. , Schrier Denis J. , Flory Craig M. , Laemont Keith D. , Tung David , Metz Alan L. , Friedl Hans P. , Conroy Mary Carol , Warren Jeffrey S. , Beck Beatrice , Ward Peter A.
Published: December 2022

Intra-articular injection of streptococcal cell wall Ag followed by i.v. challenge (“reactivation”) results in a destructive lymphocyte-dependent monoarticular arthritis. To further define the role of immune mechanisms in the model, Abs to Th1 and Th2-related cytokines were evaluated. Treatment of rats with antibodies to IL-4 reduced swelling, while treatment with anti-IL-10 or anti-IFN-γ either had no effect or slightly enhanced the inflammatory response. These results suggest that Th-2 immune mechanisms may be, at least in part, operative in the model. To more precisely define the role of IL-4, the effects of anti-IL-4 on monocyte chemoattractant protein-1 (MCP-1) expression were evaluated. Initial studies demonstrated that mRNA (as determined by in situ hybridization) and protein (as determined by immunofluorescence) for MCP-1 were detectable in inflamed synovial tissue in a time-dependent manner. Anti-IL-4 treatment significantly reduced the expression of mRNA for MCP-1 24 and 72 h after reactivation. In addition, anti-MCP-1 inhibited swelling and reduced influx of 111In-labeled T cells. These data suggest that the reactivation model of streptococcal cell wall Ag-induced arthritis is Th-2 dependent, and that an inter-relationship exists between IL-4 and the expression of MCP-1.
Cutting Edge: Antisense Knockdown of Inducible Nitric Oxide Synthase Inhibits Induction of Experimental Autoimmune Encephalomyelitis in SJL/J Mice
Authors: Ding Minzhen , Zhang Ming , Wong Joyce L. , Rogers Norma E. , Ignarro Louis J. , Voskuhl Rhonda R.
Published: December 2022

We used an antisense oligodeoxynucleotide (ODN) complementary to inducible nitric oxide synthase (iNOS) to inhibit experimental autoimmune encephalomyelitis (EAE) in female SJL/J mice, an animal model for multiple sclerosis. The antisense ODN was administered intraventricularly to mice daily for 10 days beginning at the time of adoptive transfer of myelin basic protein-specific T lymphocytes. The antisense ODN treatment significantly reduced the clinical score of EAE and blocked iNOS mRNA and protein synthesis, as well as iNOS enzyme activity within the central nervous system. The levels of nitric oxide and cyclic guanosine monophosphate were also significantly reduced by the antisense ODN treatment. Neither sense nor random ODN affected clinical EAE or iNOS expression. Moreover, the protein and enzyme activity level of constitutive neuronal nitric oxide synthase was not affected by the antisense ODN. Thus, we have shown that the iNOS antisense ODN specifically blocked iNOS expression and ameliorated the induction of EAE.