bluuebunny/crossref_metadata_2025 huggingface dataset:
FIELD TESTS OF A HIGHLY CONCENTRATED FORMULATION OF BACILLUS THURINGIENSIS AGAINST SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA; LEPIDOPTERA: TORTRICIDAE)
Authors: Smirnoff W.A.
Published: December 2009

During the summer of 1982, aerial experimental sprayings were carried out with a new formula of Bacillus thuringiensis named Futura®. This formula provided a treatment of the 20 × 109 IU of B. thuringiensis/ha required for suppression of spruce budworm (Choristoneura fumiferana), in a final volume of 2.5 L/ha. Results of spraying with Grumman AgCat and DC-4G aircraft are presented. These results were compared with those obtained with formulas of B. thuringiensis used in the past at 4.7 L/ha. Futura® caused 91.1 and 88.7% larval mortality and resulted in 86.6 and 75.1% foliage protection with the Grumman AgCat and DC-4G aircraft, respectively. Such results were equal to or better than those obtained with the formulas used earlier at 4.7 L/ha and confirm the feasibility of using B. thuringiensis operationally in an efficient and economical way.
THE VALUE OF FUNDAMENTAL RESEARCH IN ENTOMOLOGY
Authors: Gillott C.
Published: December 2009

“Fundamental” or “basic” entomological research may be defined as any research that has insects as the organisms under study and that does not have as its immediate objective the eradication or reduction in numbers of these insects. Within the framework of this deliberately broad definition may be included:

(1) Most, but not all, research done by entomologists in universities, closeted away in their “ivory towers” and generally appearing to the public not to care much about what goes on in the rest of the world. The motivation behind this research is the intrinsic curiosity of the scientist towards insects.
ECONOMICS OF VETERINARY–MEDICAL ENTOMOLOGY
Authors: Haufe W.O. , Weintraub J.
Published: December 2009

The economic importance of research in veterinary–medical entomology is inadequately defined. In this paper we attempt to assess progress in bioeconomics and feasible approaches to estimate benefits from this field of study.

Benefits accruing from veterinary–medical entomology are in improved efficiency or increased productivity of man and his animals. Assessing this effort has been neglected because of difficulty and expense in measuring loss. Even if direct losses were known, indirect ones due to insect-borne diseases and other health-related factors are generally immeasurable.
IPS TRIDENS (COLEOPTERA: SCOLYTIDAE) ATTRACTED BY IPSDIENOL PLUS CIS-VERBENOL
Authors: Moeck H.A. , Safranyik L. , Simmons C.S. , Lawko C.M.
Published: December 2009

Norwegian pipe traps, used with pheromones to mass-trap Ips typographus (L.) in Scandinavia, were used in central British Columbia to determine whether any native beetles would respond to the pheromone of I. typographus. The spruce-infesting Ips tridens (Mannerheim) was the only species captured. Traps baited with “Ipslure” packets (1400 mg 2-methyl-3-buten-2-ol, 70 mg (S)-(−)-cis-verbenol, 15 mg racemic ipsdienol), ipsdienol, or ipsdienol plus cis-verbenol, caught significantly more beetles than unbaited traps. cis-Verbenol, which attracted no beetles when used alone, acted synergistically when added to ipsdienol. Methylbutenol used alone was no more attractive to beetles than the control, and inhibited the response of female beetles when added to traps baited with ipsdienol or ipsdienol plus cis-verbenol. Ipsenol alone attracted no beetles. The sex ratios of responding beetles (mean 1 male: 7.15 females) did not differ among treatments, but all differed significantly from the ratio of 1 male: 3.12 female beetles emerging from naturally infested spruce bolts.
IMPLANTATION AND INJECTION OF SYSTEMICS TO SUPPRESS SEED AND CONE INSECTS IN DOUGLAS FIR IN MONTANA,
Authors: Reardon R.C. , Barrett L.J. , Koerber T.W. , Stipe L.E. , Dewey J.E.
Published: December 2009

The systemic insecticides oxydemeton-methyl and acephate were injected at 10- and 15-cm spacings, and acephate and dimethoate were implanted at 10-cm spacing in Douglas fir, Pseudotsuga menziesii var. glauca (Beissn.) Franco, to improve seed yield. Nutrients were also injected at 15-cm spacing. All treatments except nutrients and dimethoate increased the yield of filled seeds when compared with the checks. The western spruce budworm, Choristoneura occidentalis Freeman, and spruce coneworm, Dioryctria reniculelloides Mutuura and Munroe, caused most of the damage to cones.
ARTHROPOD FOOD OF SOME FOREST-INHABITING BIRDS
Authors: Otvos Imre S. , Stark R.W.
Published: December 2009

The diets of 25 species of forest-inhabiting birds were examined in California from 1962 to 1968. Coleoptera and Hymenoptera comprised the bulk of the diets. Coleopterans were, in decreasing amounts, the most common food of the three-toed woodpecker, Steller's jay, American robin, brown creeper, hairy woodpecker (both sexes), dark-eyed junco, downy woodpecker (both sexes), olive-sided flycatcher, western wood-pewee, and white-headed woodpecker (both sexes). Hymenopterans, mainly ants, were the most common food of the northern flicker, Williamson's sapsucker, red-breasted sapsucker, and acorn woodpecker. White-headed woodpecker (both sexes) also ate ponderosa-pine seeds in the fall. Hairy woodpecker (both sexes) fed on the seeds of ponderosa pine and sugar pine. Detailed estimates of foods consumed by item and volume from analyses of stomach contents of 241 specimens are presented.
MORTALITY OF EGGS OF THE LARCH CASEBEARER (LEPIDOPTERA: COLEOPHORIDAE) IN OREGON
Authors: Ryan R.B.
Published: December 2009

Eggs of the larch casebearer, Coleophora laricella (Hübner), were sampled for 6 years at 3 sites in Oregon to determine causes of mortality. Infertility was of minor importance. Predation by Deraeocoris diveni Knight, Phytocoris calli Knight (Heteroptera: Miridae), and perhaps other predators caused up to 28.4% mortality. Up to 58.5% of the remaining embryos died before or at the time of hatching, probably as a result of high temperatures.
Direct CD1d-Mediated Stimulation of APC IL-12 Production and Protective Immune Response to Virus Infection In Vivo
Authors: Yue Simon C. , Nowak Michael , Shaulov-Kask Angela , Wang RuoJie , Yue Dominic , Balk Steven P. , Exley Mark A.
Published: December 2009

CD1d-restricted NKT cells rapidly stimulate innate and adaptive immunity through production of Th1 and/or Th2 cytokines and induction of CD1d+ APC maturation. However, therapeutic exploitation of NKT cells has been hampered by their paucity and defects in human disease. NKT cell–APC interactions can be modeled by direct stimulation of human APCs through CD1d in vitro. We have now found that direct ligation with multiple CD1d mAbs also stimulated bioactive IL-12 release from CD1d+ but not CD1d knockout murine splenocytes in vitro. Moreover, all of the CD1d mAbs tested also induced IL-12 as well as both IFN-γ and IFN-α in vivo from CD1d+ but not CD1d-deficient recipients. Unlike IFN-γ, CD1d-induced IFN-α was at least partially dependent on invariant NKT cells. Optimal resistance to infection with picornavirus encephalomyocarditis virus is known to require CD1d-dependent APC IL-12–induced IFN-γ as well as IFN-α. CD1d ligation in vivo enhanced systemic IL-12, IFN-γ, and IFN-α and was protective against infection by encephalomyocarditis virus, suggesting an alternative interpretation for previous results involving CD1d “blocking” in other systems. Such protective responses, including elevations in Th1 cytokines, were also seen with CD1d F(abʹ)2s in vivo, whereas an IgM mAb (with presumably minimal tissue penetration) was comparably effective at protection in vivo as well as cytokine induction both in vivo and in vitro. Although presumably acting immediately “downstream,” CD1d mAbs were protective later during infection than the invariant NKT cell agonist α-galactosylceramide. These data indicate that NKT cells can be bypassed with CD1d-mediated induction of robust Th1 immunity, which may have therapeutic potential both directly and as an adjuvant.
Biodegradable Polyelectrolyte Microcapsules: Antigen Delivery Tools with Th17 Skewing Activity after Pulmonary Delivery
Authors: De Koker Stefaan , Naessens Thomas , De Geest Bruno G. , Bogaert Pieter , Demeester Jo , De Smedt Stefaan , Grooten Johan
Published: December 2009

Because of their large surface area, the lungs appear an attractive route for noninvasive vaccine delivery, harboring the potential to induce local mucosal immune responses in addition to systemic immunity. To evoke adaptive immunity, Ags require the addition of adjuvants that not only enhance the strength of the immune response but also determine the type of response elicited. In this study, we evaluate the adjuvant characteristics of polyelectrolyte microcapsules (PEMs) consisting of the biopolymers dextran-sulfate and poly-l-arginine. PEMs form an entirely new class of microcapsules that are generated by the sequential adsorption of oppositely charged polymers (polyelectrolytes) onto a sacrificial colloidal template, which is subsequently dissolved leaving a hollow microcapsule surrounded by a thin shell. Following intratracheal instillation, PEMs were not only efficiently taken up by APCs but also enhanced their activation status. Pulmonary adaptive immune responses were characterized by the induction of a strongly Th17-polarized response. When compared with a mixture of soluble Ag with empty microcapsules, Ag encapsulation significantly enhanced the strength of this local mucosal response. Given their unique property to selectively generate Th17-polarized immune responses, PEMs may become of significant interest in the development of effective vaccines against fungal and bacterial species.
IL-10 Mediates Resistance to Adoptive Transfer Experimental Autoimmune Encephalomyelitis in MyD88−/− Mice
Authors: Cohen Shmuel J. , Cohen Irun R. , Nussbaum Gabriel
Published: December 2009

MyD88 is an adaptor molecule that functions in the innate signaling induced by proinflammatory adjuvants that interact with TLRs. Mice lacking MyD88, for example, resist active experimental autoimmune encephalomyelitis (EAE) induced by immunization with an encephalitogenic myelin oligodendrocyte glycoprotein (MOG) peptide in CFA. We reasoned that MyD88−/− mice, nevertheless, should be susceptible to EAE mediated by adoptive transfer of activated encephalitogenic T cell lines, which do not require adjuvant signaling for their effector functions. We now report, however, that mice lacking MyD88 also resist adoptive EAE mediated by an anti-MOG T cell line that is strongly encephalitogenic in wild-type (WT) mice. The transferred anti-MOG T cells proliferated, secreted INF-γ, and migrated to the CNS in the MyD88−/− mice, as they did in WT mice, but inflammatory infiltrates did not progress and clinical EAE did not develop. The resistance of the MyD88−/− mice to adoptive EAE mediated by the otherwise encephalitogenic T cells was found to result from the secretion of IL-10 by recipient T cells of two different specificities: those specific for MOG and those responding to the T cell clone itself—both anticlonotypic and antiergotypic T regulators were detected. IL-10–producing anti-MOG T cells isolated from immunized MyD88−/− mice suppressed the induction of active EAE in WT recipients. Moreover, the absence of IL-10 production in MyD88/IL-10 double-knockout mice rendered the mice susceptible to adoptive transfer of EAE. Thus, MyD88 signaling appears to be a key factor in determining the cytokine phenotype of T cells involved in autoimmune inflammation and regulation.
Caveolin-1 Modifies the Immunity to Pseudomonas aeruginosa
Authors: Gadjeva Mihaela , Paradis-Bleau Catherine , Priebe Gregory P. , Fichorova Raina , Pier Gerald B.
Published: December 2009

The inflammatory response to Pseudomonas aeruginosa is not properly regulated in the lungs of patients with cystic fibrosis (CF). In the lung epithelium of individuals with wild-type CF transmembrane conductance regulator, lipid rafts containing CF transmembrance conductance regulator are rapidly formed in response to P. aeruginosa infection, and this response is closely linked to resistance to infection and disease. We found these rafts also contained high levels of caveolin-1 and thus examined the sensitivity of cav1 knockout (KO) mice to P. aeruginosa challenge in both acute and chronic P. aeruginosa infection models. We found that cav1 KO mice had increased sensitivity to P. aeruginosa infection, as represented by an increased mortality rate, elevated bacterial burdens recovered from lungs and spleens, and elevated inflammatory responses. These findings correlated with the decreased ability of cav1-deficient neutrophils to phagocytose P. aeruginosa. In addition, P. aeruginosa colonized cav1 KO mice much better compared with the wild-type controls in a model of chronic infection, indicting an important contribution of Cav-1 to innate host immunity to P. aeruginosa infection in the setting of both acute pneumonia and chronic infection typical of CF.
Human IgG2 Antibodies against Epidermal Growth Factor Receptor Effectively Trigger Antibody-Dependent Cellular Cytotoxicity but, in Contrast to IgG1, Only by Cells of Myeloid Lineage
Authors: Schneider-Merck Tanja , Lammerts van Bueren Jeroen J. , Berger Sven , Rossen Kai , van Berkel Patrick H.C. , Derer Stefanie , Beyer Thomas , Lohse Stefan , Bleeker Wim K. , Peipp Matthias , Parren Paul W. H. I. , van de Winkel Jan G. J. , Valerius Thomas , Dechant Michael
Published: December 2009

Ab-dependent cellular cytotoxicity (ADCC) is usually considered an important mechanism of action for immunotherapy with human IgG1 but not IgG2 Abs. The epidermal growth factor receptor (EGF-R) Ab panitumumab represents the only human IgG2 Ab approved for immunotherapy and inhibition of EGF-R signaling has been described as its principal mechanism of action. In this study, we investigated effector mechanisms of panitumumab compared with zalutumumab, an EGF-R Ab of the human IgG1 isotype. Notably, panitumumab was as effective as zalutumumab in recruiting ADCC by myeloid effector cells (i.e., neutrophils and monocytes) in contrast to NK cell-mediated ADCC, which was only induced by the IgG1 Ab. Neutrophil-mediated tumor cell killing could be stimulated by myeloid growth factors and was triggered via FcγRIIa. Panitumumab-mediated ADCC was significantly affected by the functional FcγRIIa-R131H polymorphism and was induced more effectively by neutrophils from FcγRIIa-131H homozygous donors than from -131R individuals. This polymorphism did not affect neutrophil ADCC induced by the IgG1 Ab zalutumumab. The in vivo activity of both Abs was assessed in two animal models: a high-dose model, in which signaling inhibition is a dominant mechanism of action, and a low-dose model, in which effector cell recruitment plays a prominent role. Zalutumumab was more effective than panitumumab in the high-dose model, reflecting its stronger ability to induce EGF-R downmodulation and growth inhibition. In the low-dose model, zalutumumab and panitumumab similarly prevented tumor growth. Thus, our results identify myeloid cell-mediated ADCC as a potent and additional mechanism of action for EGF-R–directed immunotherapy.
Altered CD8+ T Cell Immunodominance after Vaccinia Virus Infection and the Naive Repertoire in Inbred and F1 Mice
Authors: Flesch Inge E. A. , Woo Wai-Ping , Wang Yang , Panchanathan Vijay , Wong Yik-Chun , La Gruta Nicole L. , Cukalac Tania , Tscharke David C.
Published: December 2009

Previous studies of CD8+ T cell immunodominance after primary virus infection of F1 mice compared with their inbred parents have generally concluded that no dramatic changes occur. In this study, we revisit this issue using vaccinia virus (VACV), which has a large genome, a recently defined immunodominance hierarchy in mice, and is a candidate vector for vaccines. We found that immunogenicity of VACV peptides defined using inbred mice was highly variable in F1 progeny: some peptides were equally immunogenic in F1 and inbred, whereas others elicited responses that were reduced by >90% in F1 mice. Furthermore, the dominance of a peptide in the relevant inbred parent did not predict whether it would be poorly immunogenic in F1 mice. This result held using F1 hybrids of MHC-congenic mice, suggesting that MHC differences alone were responsible. It was also extended to foreign epitopes expressed by an rVACV vaccine. F1 mice were less able to mount responses to the poorly immunogenic peptides when used as a sole immunogen, ruling out immunodomination. In addition, conserved TCR Vβ usage between inbred and F1 mice did not always correlate with strong responses in F1 mice. However, direct estimation of naive precursor numbers showed that these were reduced in F1 compared with inbred mice for specificities that were poorly immunogenic in the hybrids. These data have implications for our understanding of the extent to which MHC diversity alters the range of epitopes that are immunogenic in outbred populations.
Cutting Edge: Limited Specialization of Dendritic Cell Subsets for MHC Class II-Associated Presentation of Viral Particles
Authors: Keller Susanne A. , Bauer Monika , Manolova Vania , Muntwiler Simone , Saudan Philippe , Bachmann Martin F.
Published: December 2009

Dendritic cells (DCs) are the most important APC. It was recently reported that there is a dichotomy for Ag presentation by DC subsets; exogenous Ags reach the MHC class I pathway, but not the MHC class II pathway, in CD8+ DCs, whereas CD8− DCs only process Ags for the MHC class II pathway. In this study, we used virus-like particles (VLPs) to show that CD8+ and CD8− DCs efficiently capture and process VLPs for presentation in association with MHC class II in vivo. In contrast, CD8+ DCs, but not CD8− DCs, cross presented VLP-derived peptides. This pattern was changed in an FcγR-dependent fashion in the presence of VLP-specific Abs, because under those conditions both DC subsets failed to efficiently cross present. Thus, the presentation of viral particles to CD4+ T cells is not restricted to distinct DC subsets, whereas the presentation of viral particles to CD8+ T cells is limited to CD8+ DCs.
A Minor Catalytic Activity of Src Family Kinases Is Sufficient for Maximal Activation of Mast Cells via the High-Affinity IgE Receptor
Authors: Poderycki Michael , Tomimori Yoshiaki , Ando Tomoaki , Xiao Wenbin , Maeda-Yamamoto Mari , Sauer Karsten , Kawakami Yuko , Kawakami Toshiaki
Published: December 2009

Src family kinases (SFK) are critical for initiating and regulating the response of mast cells activated by engagement of the high-affinity IgE receptor, FcεRI. Lyn is the predominant SFK in mast cells and has been ascribed both positive and negative roles in regulating mast cell activation. We analyzed the mast cell phenotype of WeeB, a recently described mouse mutant that expresses a Lyn protein with profoundly reduced catalytic activity. Surprisingly, we found that this residual activity is sufficient for wild-type levels of cytokine production and degranulation in bone marrow-derived mast cells after low-intensity stimulation with anti-IgE. High-intensity stimulation of lyn−/− bone marrow-derived mast cells with highly multivalent Ag resulted in enhanced cytokine production as previously reported, and WeeB cells displayed an intermediate phenotype. Under this latter condition, SFK inhibition using PP2 increased cytokine production in wild-type and WeeB but not lyn−/− cells, resulting in substantially higher levels in the PP2-treated WeeB than in lyn−/− cells. Restoration of wild-type and WeeB lyn alleles in lyn−/− cells generated activation phenotypes similar to those in nontransduced wild-type and WeeB cells, respectively, whereas a kinase-dead allele resulted in a phenotype similar to that of empty-vector–transduced cells. These data indicate that inhibition of Lyn and/or SFK activity can result in higher levels of mast cell activation than simple deletion of lyn and that only near-complete inhibition of Lyn can impair its positive regulatory functions. Furthermore, the data suggest that both positive and negative regulatory functions of Lyn are predominantly carried out by its catalytic activity and not an adaptor function.
Autoimmunity against Fibrinogen Mediates Inflammatory Arthritis in Mice
Authors: Ho Peggy P. , Lee Lowen Y. , Zhao Xiaoyan , Tomooka Beren H. , Paniagua Ricardo T. , Sharpe Orr , BenBarak Maya J. , Chandra Piyanka E. , Hueber Wolfgang , Steinman Lawrence , Robinson William H.
Published: December 2009

Rheumatoid arthritis (RA) is an autoimmune synovitis characterized by the presence of anticitrullinated protein Abs, although the exact targets and role of anticitrullinated protein autoimmunity in the pathogenesis of RA remain to be defined. Fibrinogen, which can be citrullinated, has recently emerged as a candidate autoantigen. To determine whether autoimmunity against fibrinogen can mediate inflammatory arthritis, we immunized a variety of common mouse strains with fibrinogen and found that DBA/1 and SJL mice developed an inflammatory and erosive arthritis. Mice with fibrinogen-induced arthritis (FIA) possess fibrinogen-reactive T cells that produce the proinflammatory cytokines IL-6, IL-17, TNF-α, and IFN-γ. FIA can be adoptively transferred with either plasma or fibrinogen-specific T cells from diseased mice. Mice with FIA possess rheumatoid factor, circulating immune complexes, and anticyclic citrullinated peptide Abs, all of which are characteristic of human RA. These observations demonstrate that fibrinogen is arthritogenic in mice and that the pathogenesis of FIA is mediated by both autoantibodies and fibrinogen-reactive T cells.
Requisite Role of the Cholinergic α7 Nicotinic Acetylcholine Receptor Pathway in Suppressing Gram-Negative Sepsis-Induced Acute Lung Inflammatory Injury
Authors: Su Xiao , Matthay Michael A. , Malik Asrar B.
Published: December 2009

Although activation of the α7 nicotinic acetylcholine receptor (α7 nAChR) modulates the response to sepsis, the role of this pathway in the development of sepsis-induced acute lung injury (ALI) is not known. In this study, we addressed the contribution of α7 nAChR in mediating endotoxin- and live Escherichia coli–induced ALI in mice. Because we found that α7 nAChR+ alveolar macrophages and neutrophils were present in bronchoalveolar lavage and injured lungs of mice, we tested whether acetylcholine released by lung vagal innervation stimulated these effector cells and thereby down-regulated proinflammatory chemokine/cytokine generation. Administration of α7 nAChR agonists reduced bronchoalveolar lavage MIP-2 production and transalveolar neutrophil migration and reduced mortality in E. coli pneumonia mice, whereas vagal denervation increased MIP-2 production and airway neutrophil accumulation and increased mortality. In addition, α7 nAChR−/− mice developed severe lung injury and had higher mortality compared with α7 nAChR+/+ mice. The immunomodulatory cholinergic α7 nAChR pathway of alveolar macrophages and neutrophils blocked LPS- and E. coli–induced ALI by reducing chemokine production and transalveolar neutrophil migration, suggesting that activation of α7 nAChR may be a promising strategy for treatment of sepsis-induced ALI.
Anti-CD3 Antibody Decreases Inflammation and Improves Outcome in a Murine Model of Pneumocystis Pneumonia
Authors: Bhagwat Samir P. , Wright Terry W. , Gigliotti Francis
Published: December 2009

The T cell–mediated immune response elicited by Pneumocystis plays a key role in pulmonary damage and dysfunction during Pneumocystis carinii pneumonia (PcP). Mice depleted of CD4+ and CD8+ T cells prior to infection are markedly protected from PcP-related respiratory deficit and death, despite progressive lung infection. However, the therapeutic effectiveness of Ab-mediated disruption of T cell function in mice already displaying clinical symptoms of disease has not been determined. Therefore, a murine model of PcP-related immune reconstitution inflammatory syndrome was used to assess whether Ab to the pan-T cell molecule CD3 is effective for reducing the severity of PcP when administered after the onset of disease. Mice that received anti-CD3 Ab exhibited a rapid and dramatic halt in the PcP-associated pulmonary function decline within 1 week after treatment, and a striking enhancement of survival rate compared with mice receiving the control Ab. Physiologic improvement in anti-CD3 treated mice was associated with a significant reduction in the number of CD4+ and CD8+ T cells recovered in lung lavage fluid. This effectiveness of anti-CD3 was noted whether the mice also received antibiotic therapy with trimethoprim-sulfamethoxazole. These data suggest that monoclonal Ab-mediated disruption of T cell function may represent a specific and effective adjunctive therapy to rapidly reverse the ongoing pathologic immune response occurring during active PcP. Thus, the anti-human CD3 monoclonal Ab OKT3, which is already in clinical use, has the potential to be developed as an adjunctive therapy for PcP.
Dynamics and Consequences of IL-21 Production in HIV-Infected Individuals: A Longitudinal and Cross-Sectional Study
Authors: Iannello Alexandre , Boulassel Mohamed-Rachid , Samarani Suzanne , Debbeche Olfa , Tremblay Cécile , Toma Emil , Routy Jean-Pierre , Ahmad Ali
Published: December 2009

IL-21 is a relatively newly discovered immune-enhancing cytokine that plays an essential role in controlling chronic viral infections. It is produced mainly by CD4+ T cells, which are also the main targets of HIV-1 and are often depleted in HIV-infected individuals. Therefore, we sought to determine the dynamics of IL-21 production and its potential consequences for the survival of CD4+ T cells and frequencies of HIV-specific CTL. For this purpose, we conducted a series of cross-sectional and longitudinal studies on different groups of HIV-infected patients and show in this study that the cytokine production is compromised early in the course of the infection. The serum cytokine concentrations correlate with CD4+ T cell counts in the infected persons. Among different groups of HIV-infected individuals, only elite controllers maintain normal production of the cytokine. Highly active antiretroviral therapy only partially restores the production of this cytokine. Interestingly, HIV infection of human CD4+ T cells inhibits cytokine production by decreasing the expression of c-Maf in virus-infected cells, not in uninfected bystander cells. We also show that the frequencies of IL-21–producing HIV-specific, but not human CMV-specific, Ag-experienced CD4+ T cells are decreased in HIV-infected viremic patients. Furthermore, we demonstrate in this study that recombinant human IL-21 prevents enhanced spontaneous ex vivo death of CD4+ T cells from HIV-infected patients. Together, our results suggest that serum IL-21 concentrations may serve as a useful biomarker for monitoring HIV disease progression and the cytokine may be considered for immunotherapy in HIV-infected patients.
The Host Defense Peptide Cathelicidin Is Required for NK Cell-Mediated Suppression of Tumor Growth
Authors: Büchau Amanda S. , Morizane Shin , Trowbridge Janet , Schauber Jürgen , Kotol Paul , Bui Jack D. , Gallo Richard L.
Published: December 2009

Tumor surveillance requires the interaction of multiple molecules and cells that participate in innate and the adaptive immunity. Cathelicidin was initially identified as an antimicrobial peptide, although it is now clear that it fulfills a variety of immune functions beyond microbial killing. Recent data have suggested contrasting roles for cathelicidin in tumor development. Because its role in tumor surveillance is not well understood, we investigated the requirement of cathelicidin in controlling transplantable tumors in mice. Cathelicidin was observed to be abundant in tumor-infiltrating NK1.1+ cells in mice. The importance of this finding was demonstrated by the fact that cathelicidin knockout mice (Camp−/−) permitted faster tumor growth than wild type controls in two different xenograft tumor mouse models (B16.F10 and RMA-S). Functional in vitro analyses found that NK cells derived from Camp−/− versus wild type mice showed impaired cytotoxic activity toward tumor targets. These findings could not be solely attributed to an observed perforin deficiency in freshly isolated Camp−/− NK cells, because this deficiency could be partially restored by IL-2 treatment, whereas cytotoxic activity was still defective in IL-2-activated Camp−/− NK cells. Thus, we demonstrate a previously unrecognized role of cathelicidin in NK cell antitumor function.
Dissemination of Mycobacteria to the Thymus Renders Newly Generated T Cells Tolerant to the Invading Pathogen
Authors: Nobrega Claudia , Roque Susana , Nunes-Alves Cláudio , Coelho Angela , Medeiros Irene , Castro António Gil , Appelberg Rui , Correia-Neves Margarida
Published: December 2009

The ability of the thymus to generate a population of T cells that is, for the most part, self-restricted and self-tolerant depends to a great extent on the Ags encountered during differentiation. We recently showed that mycobacteria disseminate to the thymus, which raised the questions of how mycobacteria within the thymus influence T cell differentiation and whether such an effect impacts host–pathogen interactions. Athymic nude mice were reconstituted with thymic grafts from Mycobacterium avium-infected or control noninfected donors. T cells generated from thymi of infected donors seemed generally normal, because they retained the ability to reconstitute the periphery and to respond to unspecific stimuli in vitro as well as to antigenic stimulation with third-party Ags, such as OVA, upon in vivo immunization. However, these cells were unable to mount a protective immune response against a challenge with M. avium. The observation that thymic infection interferes with T cell differentiation, generating T cells that are tolerant to pathogen-specific Ags, is of relevance to understand the immune response during chronic persistent infections. In addition, it has potential implications for the repertoire of T cells generated in patients with a mycobacterial infection recovering from severe lymphopenia, such as patients coinfected with HIV and receiving antiretroviral therapy.
Selective Mobilization of Cytotoxic Leukocytes by Epinephrine
Authors: Dimitrov Stoyan , Lange Tanja , Born Jan
Published: December 2009

It is well-known that acute stress, presumably as a first defense against pathogens, enhances PBMC counts by mobilizing these β2-adrenoceptor positive cells from the marginal pool. Yet, only select leukocyte subsets participate in this phenomenon of adrenergic leukocytosis and underlying mechanisms are obscure. In this study, we analyzed in human blood adhesion molecule and chemokine receptor profiles in 14 leukocyte subsets, and responsiveness of subsets to epinephrine in vivo and in vitro. Five subsets, namely, CCR7−CD45RA+CD8+ effector T cells, CD4−CD8− γ/δ T cells, CD3+CD56+ NKT-like cells, CD16+CD56dim cytotoxic NK cells, and CD14dimCD16+ proinflammatory monocytes showed a rapid and transient increase after infusion of epinephrine at physiological concentrations. These cells were characterized by a CD62L−CD11abrightCX3CRbright phenotype, whereby expression of both CD11a and CX3CR1 was strongly correlated with adrenergic leukocytosis in vivo (r = 0.86 and 0.78, p < 0.005). The same subsets showed highest adherence to activated endothelium in vitro, which (except for proinflammatory monocytes) was reversed by epinephrine. We conclude that these five cytotoxic effector leukocyte subsets comprise the marginal pool by a CD11a/CX3CR1-mediated attachment to the endothelium. Epinephrine rapidly attenuates this attachment to allow demargination and release of the cells into the circulation that, because of their cytotoxic effector function, provide immediate protection from invading pathogens.
A Heat Shock Protein 70-Based Vaccine with Enhanced Immunogenicity for Clinical Use
Authors: Gong Jianlin , Zhang Yunfei , Durfee John , Weng Desheng , Liu Chunlei , Koido Shigeo , Song Baizheng , Apostolopoulos Vasso , Calderwood Stuart K.
Published: December 2009

In previous studies, we have shown that heat shock protein 70-peptide complexes (HSP70.PCs) derived from the fusion of dendritic cells (DCs) to tumor cells (HSP70.PC-F) possess superior properties compared with HSP70.PCs from tumor cells. HSP70.PC-F are more effective in stimulation of DC maturation and induction of CTL that are able to provide protection of mice against challenge with tumor cells. To develop an improved formulation of HSP70.PC-based tumor vaccine for patient use, we extracted HSP70.PC-F from DCs fused to patient-derived ovarian cancer cells or established human breast cancer cells and examined their properties as tumor vaccines. HSP70.PC-F induced T cells that expressed higher levels of IFN-γ and exhibited increased levels of killing of tumor cells, compared with those induced by HSP70.PC derived from tumor cells. Enhanced immunogenicity of HSP70.PC-F was associated with improved composition of the vaccine, including increased content of tumor Ags and their processed intermediates, and the detection of other heat shock proteins (HSPs) such as HSP90 and HSP110. The present study has therefore provided an alternative approach to preparation of HSP-based vaccines using DC/tumor fusion technology and gentle and rapid isolation of HSP peptide complexes.
Lysine Acetylation Regulates Bruton’s Tyrosine Kinase in B Cell Activation
Authors: Liu Zhijian , Mai Antonello , Sun Jian
Published: December 2009

Bruton’s tyrosine kinase (Btk) is essential for BCR signal transduction and has diverse functions in B cells. Although Btk has been extensively studied, the role of lysine acetylation in Btk regulation has not been reported. In this study, we show that BCR cross-linking induces histone lysine acetylation at the Btk promoter, correlating with marked recruitment of histone acetyltransferase E1A-associated 300-kDa protein (p300) to the locus. These effects enhance Btk promoter activity and increase the expression of Btk mRNA and protein. Consistent with these results, activated B cells display increased p300 expression and total histone acetyltransferase activity in vitro and in vivo, resulting in global histone acetylation. Interestingly, we found that BCR signaling induces Btk lysine acetylation mediated by p300. Moreover, lysine acetylation of Btk promotes its phosphorylation. Together, our results indicate a novel regulatory mechanism for Btk transcription and reveal a previously unrecognized posttranslational modification of the Btk protein and its association with phosphorylation in B cell activation.
Conserved Amino Acids within the Adenovirus 2 E3/19K Protein Differentially Affect Downregulation of MHC Class I and MICA/B Proteins
Authors: Sester Martina , Koebernick Katja , Owen Douglas , Ao Minghui , Bromberg Yana , May Ed , Stock Emily , Andrews Lawrence , Groh Veronika , Spies Thomas , Steinle Alexander , Menz Beatrice , Burgert Hans-Gerhard
Published: December 2009

Successful establishment and persistence of adenovirus (Ad) infections are facilitated by immunosubversive functions encoded in the early transcription unit 3 (E3). The E3/19K protein has a dual role, preventing cell surface transport of MHC class I/HLA class I (MHC-I/HLA-I) Ags and the MHC-I–like molecules (MHC-I chain-related chain A and B [MICA/B]), thereby inhibiting both recognition by CD8 T cells and NK cells. Although some crucial functional elements in E3/19K have been identified, a systematic analysis of the functional importance of individual amino acids is missing. We now have substituted alanine for each of 21 aas in the luminal domain of Ad2 E3/19K conserved among Ads and investigated the effects on HLA-I downregulation by coimmunoprecipitation, pulse-chase analysis, and/or flow cytometry. Potential structural alterations were monitored using conformation-dependent E3/19K-specific mAbs. The results revealed that only a small number of mutations abrogated HLA-I complex formation (e.g., substitutions W52, M87, and W96). Mutants M87 and W96 were particularly interesting as they exhibited only minimal structural changes suggesting that these amino acids make direct contacts with HLA-I. The considerable number of substitutions with little functional defects implied that E3/19K may have additional cellular target molecules. Indeed, when assessing MICA/B cell-surface expression we found that mutation of T14 and M82 selectively compromised MICA/B downregulation with essentially no effect on HLA-I modulation. In general, downregulation of HLA-I was more severely affected than that of MICA/B; for example, substitutions W52, M87, and W96 essentially abrogated HLA-I modulation while largely retaining the ability to sequester MICA/B. Thus, distinct conserved amino acids seem preferentially important for a particular functional activity of E3/19K.
Cutting Edge: TNF-Induced MicroRNAs Regulate TNF-Induced Expression of E-Selectin and Intercellular Adhesion Molecule-1 on Human Endothelial Cells: Feedback Control of Inflammation
Authors: Suárez Yajaira , Wang Chen , Manes Thomas D. , Pober Jordan S.
Published: December 2009

MicroRNAs (miRNAs) pair with target sequences in the 3′ untranslated region of mRNAs to posttranscriptionally repress gene expression. In this study, we report that TNF-mediated induction of endothelial adhesion molecules can be regulated by miRNAs that are induced by TNF. Specifically, E-selectin and ICAM-1 are targets of TNF-induced miRNAs miR-31 and miR-17-3p, respectively. Specific antagonism of these TNF-induced miRNAs increased neutrophil adhesion to cultured endothelial cells. Conversely, transfections with mimics of these miRNAs decreased neutrophil adhesion to endothelial cells. These data suggest that miRNAs provide negative feedback control of inflammation.
ATP-Binding Cassette Transporter G1 Negatively Regulates Thymocyte and Peripheral Lymphocyte Proliferation
Authors: Armstrong Allison J. , Gebre Abraham K. , Parks John S. , Hedrick Catherine C.
Published: December 2009

Cholesterol is a key component of cell membranes and is essential for cell growth and proliferation. How the accumulation of cellular cholesterol affects lymphocyte development and function is not well understood. We demonstrate that ATP-binding cassette transporter G1 (ABCG1) regulates cholesterol homeostasis in thymocytes and peripheral CD4 T cells. Our work is the first to describe a cell type in Abcg1-deficient mice with such a robust change in cholesterol content and the expression of cholesterol metabolism genes. Abcg1-deficient mice display increased thymocyte cellularity and enhanced proliferation of thymocytes and peripheral T lymphocytes in vivo. The absence of ABCG1 in CD4 T cells results in hyperproliferation in vitro, but only when cells are stimulated through the TCR. We hypothesize that cholesterol accumulation in Abcg1−/− T cells alters the plasma membrane structure, resulting in enhanced TCR signaling for proliferation. Supporting this idea, we demonstrate that B6 T cells pretreated with soluble cholesterol have a significant increase in proliferation. Cholesterol accumulation in Abcg1−/− CD4 T cells results in enhanced basal phosphorylation levels of ZAP70 and ERK1/2. Furthermore, inhibition of ERK phosphorylation in TCR-stimulated Abcg1−/− T cells rescues the hyperproliferative phenotype. We describe a novel mechanism by which cholesterol can alter signaling from the plasma membrane to affect downstream signaling pathways and proliferation. These results implicate ABCG1 as an important negative regulator of lymphocyte proliferation through the maintenance of cellular cholesterol homeostasis.
Early CD4+ T Cell Help Prevents Partial CD8+ T Cell Exhaustion and Promotes Maintenance of Herpes Simplex Virus 1 Latency
Authors: Frank Gregory M. , Lepisto Andrew J. , Freeman Michael L. , Sheridan Brian S. , Cherpes Thomas L. , Hendricks Robert L.
Published: December 2009

HSV-specific CD8+ T cells provide constant immunosurveillance of HSV-1 latently infected neurons in sensory ganglia, and their functional properties are influenced by the presence of latent virus. In this study, we show that ganglionic HSV-specific CD8+ T cells exhibit a higher functional avidity (ability to respond to low epitope density) than their counterparts in noninfected lungs, satisfying a need for memory effector cells that can respond to low densities of viral epitopes on latently infected neurons. We further show that lack of CD4+ T cell help during priming leads to a transient inability to control latent virus, which was associated with a PD-1/PD-L1 mediated reduced functional avidity of ganglionic HSV-specific CD8+ T cells. CD4+ T cells are not needed to maintain CD8+ T cell memory through 34 d after infection, nor do they have a direct involvement in the maintenance of HSV-1 latency.
CD4+ CD25+ Foxp3+ T Regulatory Cells with Limited TCR Diversity in Control of Autoimmunity
Authors: Adeegbe Dennis , Matsutani Takaji , Yang Jing , Altman Norman H. , Malek Thomas R.
Published: December 2009

The importance of high TCR diversity of T regulatory (Treg) cells for self-tolerance is poorly understood. To address this issue, TCR diversity was measured for Treg cells after transfer into IL-2Rβ−/− mice, which develop lethal autoimmunity because of failed production of Treg cells. In this study, we show that high TCR diversity of pretransferred Treg cells led to selection of therapeutic Treg cells with lower TCR diversity that prevented autoimmunity. Pretransferred Treg cells with lower diversity led to selection of Treg cells through substantial peripheral reshaping with even more restricted TCR diversity that also suppressed autoimmune symptoms. Thus, in a setting of severe breakdown of immune tolerance because of failed production of Treg cells, control of autoimmunity is achieved by only a fraction of the Treg TCR repertoire, but the risk for disease increased. These data support a model in which high Treg TCR diversity is a mechanism to ensure establishing and maintaining self-tolerance.
Distribution, Persistence, and Efficacy of Adoptively Transferred Central and Effector Memory-Derived Autologous Simian Immunodeficiency Virus-Specific CD8+ T Cell Clones in Rhesus Macaques during Acute Infection
Authors: Minang Jacob T. , Trivett Matthew T. , Bolton Diane L. , Trubey Charles M. , Estes Jacob D. , Li Yuan , Smedley Jeremy , Pung Rhonda , Rosati Margherita , Jalah Rashmi , Pavlakis George N. , Felber Barbara K. , Piatak Michael , Roederer Mario , Lifson Jeffrey D. , Ott David E. , Ohlen Claes
Published: December 2009

Plasma viremia decreases coincident with the appearance of virus-specific CD8+ T cells during acute HIV or SIV infection. This finding, along with demonstrations of viral mutational escape from CD8+ T cell responses and transient increase in plasma viremia after depletion of CD8+ T cells in SIV-infected monkeys strongly suggest a role for CD8+ T cells in controlling HIV/SIV. However, direct quantitative or qualitative correlates between CD8+ T cell activity and virus control have not been established. To directly assess the impact of large numbers of virus-specific CD8+ T cells present at time of SIV infection, we transferred in vitro expanded autologous central and effector memory-derived Gag CM9-, Nef YY9-, and Vif WY8-specific CD8+ T cell clones to acutely infected rhesus macaques. The cells persisted in PBMCs between 4 and 9 d, but were not detected in gut-associated lymphoid tissue or lymph nodes. Interestingly, a high frequency of the infused cells localized to the lungs, where they persisted at high frequency for >6 wk. Although persisting cells in the lungs were Ag reactive, there was no measurable effect on virus load. Sequencing of virus from the animal receiving Nef YY9-specific CD8+ T cells demonstrated an escape mutation in this epitope <3 wk postinfection, consistent with immune selection pressure by the infused cells. These studies establish methods for adoptive transfer of autologous SIV-specific CD8+ T cells for evaluating immune control during acute infection and demonstrate that infused cells retain function and persist for at least 2 mo in specific tissues.
The Pleckstrin Homology Domain Adaptor Protein Bam32/DAPP1 Is Required for Germinal Center Progression
Authors: Zhang Ting-ting , Al-Alwan Monther , Marshall Aaron J.
Published: December 2009

Ab affinity maturation within germinal centers (GCs) requires weeks to complete. Several signaling pathways in B cells have been shown to be required for initiation of the GC response; however, the signaling checkpoints controlling progression and eventual dissolution of the GC reaction are poorly understood. The adaptor protein Bam32/DAPP1 was originally isolated from human GCs and functions downstream of phosphoinositide 3-kinase enzymes, which are known to have critical roles in B cell activation and GC responses. In this study we identify a unique role of Bam32/DAPP1 in promoting GC progression. Bam32-deficient mice show normal GC initiation, but premature GC dissolution after immunization with protein Ag in alum or low doses of sheep red blood cells. Adoptive transfer studies confirmed that Bam32-deficient B cells have an intrinsic impairment in the ability to mount sustained GC responses. Bam32 deficiency was also associated with impaired Ab affinity maturation. Proliferation of Bam32-deficient GC B cells was not compromised; however, these cells show impaired switch to IgG1 and increased apoptosis in situ. GCs formed by Bam32-deficient B cells contain fewer T cells, indicating that Bam32 is required for B cell–dependent T cell accumulation within established GCs. Exogenous CD40 ligand restored GC B cell numbers and switch to IgG1, indicating that Bam32-deficient B cells are competent to respond to CD40 stimulation when ligand is available. These data demonstrate that Bam32 is not required for GC initiation, but rather functions in a late checkpoint of GC progression associated with T cell recruitment and GC B cell survival.
CD8+ T Cell Control of Hepatitis B Virus Replication: Direct Comparison between Cytolytic and Noncytolytic Functions
Authors: Phillips Sandra , Chokshi Shilpa , Riva Antonio , Evans Alexander , Williams Roger , Naoumov Nikolai V.
Published: December 2009

Resolution of hepatitis B virus (HBV) infection was believed to be attributed to the cytotoxic T cell–mediated killing of infected hepatocytes. However, studies in HBV transgenic mice and HBV-infected chimpanzees revealed that T cell control of HBV replication also involves cytokine-mediated noncytolytic mechanisms. The relative role of cytolytic and noncytolytic functions of virus-specific CD8+ T cells during interaction with HBV-producing hepatocytes is not well understood. By using HLA-A2 matched effector cells (CD8+ T cell line or clone) and target cells supporting full HBV replication, we demonstrate that virus-specific CD8+ T cells can inhibit HBV replication in HBV-producing hepatocytes with minimal cell lysis. Although CD8+ T cells kill a fraction of infected cells, this effect is minimal, and most of the viral inhibition is mediated by noncytolytic mechanisms. CD8+ T cells produce an array of cytokines, among which IFN-γ and TNF-α are responsible for HBV inactivation in the target cells. Blockade of IFN-γ and TNF-α abrogated the noncytolytic inhibition of HBV, indicating that these two cytokines mediate the control of HBV by noncytolytic mechanisms. Furthermore, treatment of the HBV-producing hepatocytes with rIFN-γ and rTNF-α resulted in an efficient suppression of viral replication without cytotoxicity. In contrast, coculture of the same target cells with activated HLA-mismatched mitogen-activated lymphomononuclear cells caused a marked cytolytic effect and was less effective in HBV control. These results provide direct evidence that virus-specific CD8+ T cells efficiently control HBV replication by noncytolytic mechanisms, and this effect is mediated by IFN-γ and TNF-α.