The bursa dependence of chicken thymus-derived lymphocyte surface immunoglobulin.

Thirty-three plus or minus 5 per cent of chicken blood lymphocytes were positively labelled by radioiodinated rabbit anti-chicken light chain antibody within 7 days of exposure of autoradiographs. After thymectomy, 93 plus or minus 1 per cent of lymphocytes were positive: conversely, following bursectomy only 5 plus or minus 3 per cent of cells showed positive labelling and then at a very low level. Hence, under these conditions of short-term exposure autoradiography, only B cells carried readily demonstrable immunoglobulin. If the sensitivity of the technique was increased by long-term exposure of the autoradiographs, immunoglobulin was demonstrable on all blood lymphocytes, including the T cells. In addition, 39 plus or minus 6 per cent of thymocytes were shown to carry immunoglobulin by the more sensitive technique. In both cases, however, this T-lymphocyte surface immunoglobulin was reduced, and in some cases absent, after bursectomy. At no stage, with either technique, did the grain count on the erythrocytes reach the control level of lymphocytes treated with 125I-labelled anti-keyhole limpet haemocyanin antibody. It seems likely that T-cell immunoglobulin is not an endogenously synthesized product but is acquired indirectly from the B lymphocytes.     

Eotaxin-2 alters eosinophil integrin function via mitogen-activated protein kinases

Adhesion molecules and chemokines contribute to selective eosinophil recruitment in allergic inflammation. In this study, we examined the effects of eotaxin-2, a CCR3-specific chemokine, on integrin-mediated eosinophil adhesion to vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), or both using a parallel plate flow system. Tissue culture plates were coated with various combinations of VCAM-1, ICAM-1, and/or eotaxin-2. Human eosinophils were infused at physiologic shear stress (0.5 dyn/cm(2)) for 10 min, and the numbers of attached eosinophils were monitored using video microscopy. Cells accumulated efficiently on VCAM-1 and even better on surfaces co-coated with VCAM-1 and ICAM-1, but poorly on surfaces coated with ICAM-1 or bovine serum albumin alone. When eotaxin-2 was co-immobilized with adhesion proteins, fewer cells adhered to VCAM-1 and more adhered to ICAM-1, whereas levels of attachment to VCAM-1 plus ICAM-1 showed no net change. However, experiments with adhesion molecule blocking monoclonal antibody showed that the contribution of ICAM-1-mediated adhesion was always greater if eotaxin-2 was present. Pretreatment of cells with a CCR3-blocking mAb, or PD98059, a MAP-kinase inhibitor, prevented the eotaxin-2-induced changes in eosinophil attachment. These data suggest that eotaxin-2, acting via MAP kinases, may facilitate eosinophil recruitment at sites of allergic inflammation by shifting their adhesion molecule usage away from VCAM-1-dominated to ICAM-1-dominated pathways.     

Polydipsia in the monkey generated by visual display schedules.

Discussions of adjunctive behavior still largely refer to polydipsia induced by food delivery schedules to food deprived animals. In the present experiment polydipsia was induced when socially isolated monkeys housed in barren home cages were exposed to scheduled deliveries of film and scheduled viewing of other monkeys. These data suggest the greater generality and complexity of adjunctive behaviors and show that schedule-induced polydipsia cannot be regarded as an artifact of food associated drinking.     

Human and mouse sera recognize the same polypeptide associated with immunological resistance to Trypanosoma cruzi infection.

Effective immunological resistance to challenge with trypomastigotes of Trypanosoma cruzi has been linked to antibodies which are specific for determinants on live, but not fixed, trypomastigotes. In man and mouse, these antibodies can be detected specifically by viable immunofluorescence (VIF) and complement mediated lysis (CML) assays. VIF/CML positive sera from chagasic patients or experimentally infected mice recognize the same trypomastigote specific surface polypeptides of apparent Mr 70-160 kDa. VIF/CML negative chagasic sera fail to react with polypeptides of Mr 120, 145 and 160 kDa, whereas negative mouse sera lack antibodies to the 160 kDa component alone. Taken together, these clinical and experimental data suggest that the 160 kDa polypeptide should be tested for its potential in immunoprophylaxis.     

Ribosome display and affinity maturation: from antibodies to single V-domains and steps towards cancer therapeutics

Vascular endothelium is an important site for a wide array of immunological processes such as inflammation, atherosclerosis and allograft rejection. Culture methods of mouse vascular endothelium would provide an important in vitro correlate to immunological murine in vivo models. We describe a simple method to culture mouse vascular endothelium from thoracic aorta. Our cultured cells express typical phenotypic (CD105, CD31, CD106), morphological and ultrastructural (intercellular junctions, Weibel-Palade bodies) markers of vascular endothelium. They also possess functional receptors for uptake and processing of acetylated low-density lipoproteins. The mouse vascular endothelium within our system expresses high levels of MHC class I and MHC class II after activation with IFN-gamma. In addition, these cells express the accessory molecules CD80 and CD54, while they lack constitutive expression of CD86 and CD40, providing them the means to function as antigen presenting cells. Alloreactive CD4(+) and CD8(+) T lymphocytes demonstrate evidence of DNA synthesis after co-culture with activated vascular endothelium indicating their commitment to proliferation. In conclusion, we describe a simple culture system to isolate and grow mouse vascular endothelium, which provides a powerful tool to study biological interactions in vitro.     

Vaccinia virus expression and sequence of an avian influenza nucleoprotein gene: potential use in diagnosis

Summary The nucleoprotein (NP) gene from avian influenza strain A/Shearwater/Aust/1/72 (H6N5) was cloned, sequenced, and expressed in vaccinia virus for the production of potent sera in immunised rabbits. The NP gene is 1565 bp and shares >95% amino acid sequence identity with other NPs of the avian subtype. The recombinant NP expressed by vaccinia virus comigrated with endogenous A/Shearwater/Aust/1/72 NP by Western blot analysis. Polyclonal rabbit sera raised against recombinant NP was evaluated in an antigen capture ELISA system as a potential diagnostic tool for the detection of avian influenza. All type A strains, comprising several HA and NA subtypes, but not type B nor other avian viruses, were detected.     

Geneticists' views on science policy formation and public outreach

Though much research about the public's views of scientists, genetic research and its moral, ethical, and social implications exists, little has been done to investigate how scientists view their own role(s) in public discussions and policy formation related to genetic research and technologies. We interviewed 20 academic geneticists in the United States about their perceptions of the roles they and others (e.g., professional societies, the public, ethicists, and elected officials) do and should play in the formation of science policy, the communication of science to the public, and the public discussions of moral and ethical issues raised by scientific advances. The participants in our study thought that scientists should be more actively involved in public outreach and science policy formation, but frequently they felt ill-equipped and unsupported by their peers and institutions to pursue these activities. Furthermore, many were skeptical of or did not trust elected officials--who they consider uninformed about the issues and too driven by political agendas--to formulate sound science policy. They do, however, have faith in the ability of scientific societies to influence policy effectively, and some thought that societies should play a larger role, both in science policy and as a liaison between scientists and the public. Finally, participants offered suggestions for increasing the involvement and influence of scientists in science-policy formation and public discourse.     

Rapid odor conditioning in newborn rabbits: amnesic effect of hypothermia.

Rabbit pups are completely dependent on a maternal pheromone for the release of suckling behavior. However, if the mother is perfumed prior to nursing, pups will learn to respond to the novel odor with the characteristic nipple-search behavior in just one 3-4 min nursing episode. In a first investigation of the processes underlying this recently developed learning paradigm, time-dependent effects of hypothermia on retention of the task could be demonstrated. Thus pups whose whole body was cooled to a mouth temperature of 7 degrees C immediately after conditioning (n = 10) and tested 24 h later for 3 min on a perfumed fur did not differ significantly in their search response from naive, untreated controls (n = 10). In contrast, pups cooled 4 h after conditioning (n = 10) demonstrated clear retention of the learned response and searched as vigorously as conditioned but uncooled animals (n = 10). As pups of all groups demonstrated normal nipple-search behavior when tested on a lactating doe, the deficits associated with immediate cooling appear to have been specific to the learning task and time of treatment.