Induction of T Lymphocytes Specific for Bovine Viral Diarrhea Virus in Calves with Maternal Antibody

Passive antibody to bovine viral diarrhea virus (BVDV) acquired through colostrum intake may interfere with the development of a protective immune response by calves to this virus. The objective of this study was to determine if calves, with a high level of maternal antibody to bovine viral diarrhea virus (BVDV), develop CD4+, CD8+, or γδ T lymphocyte responses to BVDV in the absence of a measurable humoral immune response. Colostrum or milk replacer fed calves were challenged with virulent BVDV at 2-5 weeks of age and/or after maternal antibody had waned. Calves exposed to BVDV while passive antibody levels were high did not mount a measurable humoral immune response to BVDV. However, compared to nonexposed animals, these animals had CD4+, CD8+, and γδ T lymphocytes that were activated by BVDV after exposure to in vitro BVDV. The production of IFNγ by lymphocytes after in vitro BVDV exposure was also much greater in lymphocytes from calves exposed to BVDV in the presence of maternal antibody compared to the nonexposed calves. These data indicate that calves exposed to BVDV while maternal antibody levels are high can develop antigen specific CD4+, CD8+, and γδ T lymphocytes in the absence of an active antibody response. A manuscript presented separately demonstrates that the calves with T lymphocytes specific for BVDV in this study were also protected from virulent BVDV genotype 2 challenge after maternal antibody became undetectable

Paleobiology of titanosaurs: reproduction, development, histology, pneumaticity, locomotion and neuroanatomy from the South American fossil record

Fil: García, Rodolfo A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Salgado, Leonardo. Instituto de Investigación en Paleobiología y Geología. General Roca. Río Negro; ArgentinaFil: Fernández, Mariela. Inibioma-Centro Regional Universitario Bariloche. Bariloche. Río Negro; ArgentinaFil: Cerda, Ignacio A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Carabajal, Ariana Paulina. Museo Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Otero, Alejandro. Museo de La Plata. Universidad Nacional de La Plata; ArgentinaFil: Coria, Rodolfo A.. Instituto de Paleobiología y Geología. Universidad Nacional de Río Negro. Neuquén; ArgentinaFil: Fiorelli, Lucas E.. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica. Anillaco. La Rioja; Argentin

Evidence of mixed persistent infections in calves born to cows challenged with a pool of bovine viral diarrhea virus isolates Evidências de infecção persistente mista em bezerros nascidos de vacas inoculadas com um pool de isolados do vírus da diarréia viral bovina

Pregnant cows infected with noncytopathic (NCP) isolates of bovine viral diarrhea virus (BVDV) between days 40 and 120 days of gestation frequently deliver immunotolerant, persistently infected (PI) calves. We herein report the characterization of PI calves produced experimentally through inoculation of pregnant cows with a pool of Brazilian BVDV-1 (n=2) and BVDV-2 isolates (n=2) between days 60 and 90 of gestation. Two calves were born virus positive, lacked BVDV antibodies, but died 7 and 15 days after birth, respectively. Six other calves were born healthy, seronegative to BVDV, harbored and shed virus in secretions for up to 210 days. Analysis of the antigenic profile of viruses infecting these calves at birth and 30 days later with a panel of monoclonal antibodies indicated two patterns of infection. Whereas three calves apparently harbored only one isolate (either a BVDV-1 or BVDV-2), co-infection by two antigenically distinct challenge viruses was demonstrated in three PI calves. Moreover, testing the viruses obtained from the blood of PI calves by an RT-PCR able to differentiate between BVDV-1 and BVDV-2 confirmed the presence/persistence of two co-infecting viruses of different genotypes (BVDV-1 and BVDV-2) in these animals. These findings indicate that persistent infection of fetuses/calves - a well characterized consequence of fetal infection by BVDV - may be established concomitantly by more than one isolate, upon experimental inoculation. In this sense, mixed persistent infections with antigenically distinct isolates may help in understanding the immunological and molecular basis of BVDV immunotolerance and persistence.<br>Vacas prenhes infectadas com isolados não-citopáticos (NCP) do vírus da diarréia viral bovina (BVDV) entre os dias 40 e 120 de gestação frequentemente produzem bezerros imunotolerantes, persistentemente infectados (PI). Este artigo relata a caracterização de bezerros PI produzidos experimentalmente, pela inoculação de vacas prenhes com um pool de isolados brasileiros de BVDV-1 (n=2) e BVDV-2 (n=2) entre os dias 60 e 90 de gestação. Dois bezerros nasceram positivos para vírus, negativos para anticorpos, mas morreram aos dias 7 e 15 pós-nascimento, respectivamente. Outros seis bezerros nasceram saudáveis, soronegativos para o BVDV, replicaram e excretaram o vírus em secreções por até 210 dias. Análise antigênica dos vírus presentes nos bezerros PI com anticorpos monoclonais, ao nascimento e 30 dias após, revelou dois padrões de infecção. Três bezerros apresentavam apenas um dos vírus utilizados no desafio (BVDV-1 ou BVDV-2), enquanto outros três bezerros apresentavam co-infecção com mais de um vírus. Além disso, testando-se o sangue dos animais PI com um PCR capaz de diferenciar entre BVDV-1 e BVDV-2 observou-se a presença concomitante de vírus dos dois genótipos (BVDV-1 e BVDV-2) nestes três animais. Esses resultados indicam que infecção persistente - uma consequência bem conhecida da infecção fetal pelo BVDV - pode ser estabelecida concomitantemente por mais de um vírus, após infecção experimental. Nesse sentido, infecções persistentes mistas com isolados antigenicamente distintos podem ser úteis para o estudo das bases imunológicas e moleculares da imunotolerância e infecção persistente pelo BVDV

Paleobiología de Titanosaurios de Sudamérica: reproducción, desarrollo, histología, neumaticidad, locomoción y neuroanatomía

Much of the current paleobiological knowledge on titanosaur sauropods was attained in just the last fifteen years, in particular that related to reproductive and developmental biology. Recent years have also seen progress on other poorly explored topics, such as pneumaticity, muscle architecture and locomotion, and endocast reconstruction and associated structures. Some titanosaurs laid numerous, relatively small Megaloolithidae eggs (with diameters ranging from 12 to 14 cm) in nests dug In the ground and, as known from the South American records, probably eggs of the multispherulitic morphotype. During ontogeny, certain titanosaurs displayed some variations in cranial morphology, some of them likely associated with the differing feeding habits between hatchlings and adults. The bone tissue of some adult titanosaurs was rapidly and cyclically deposited and shows a greater degree of remodeling than in other sauropods. Saltasaurines in particular show evidence of postcranial skeletal pneumaticity in both axial and appendicular skeleton, providing clues about soft tissue anatomy and the structure of the respiratory system. Titanosaurs, like all sauropods, were characterized by being fully quadrupedal, although some appendicular features and putative trackways indicate that their stance was not as columnar as in other sauropods. These anatomical peculiarities are significantly developed In saltasaurines, a derived group of titanosaurs. Compared with other sauropods, some titanosaurs seem to have had very poor olfaction but would have been capable of capturing sounds In a relatively wide range of high frequencies, although not to the extent of living birds.El conocimiento paleobiológico de los saurópodos titanosaurios, particularmente su reproducción y biología del desarrollo, fue alcanzado recién en los últimos quince años. En estos últimos años también se ha avanzado en temas poco explorados hasta el momento, como la neumatización, su arquitectura muscular y locomoción y la reconstrucción de partes blandas como el cerebro y estructuras asociadas. Algunos titanosaurios depositan sus numerosos y pequeños huevos megaloolitidos en nidos excavados sobre el suelo. Durante la ontogenia ciertos titanosaurios exponen algunas variaciones en su morfología craneana, algunas de estas probablemente asociadas con las diferentes maneras de alimentarse que tendrían los juveniles y los adultos. El tejido óseo de algunos titanosaurios adultos se habría depositado rápido y cíclicamente, exponiendo una mayor remodelación que en otros saurópodos. Los titanosaurios, particularmente los saltasaurinos, exponen una neumaticidad postcraneal en el esqueleto axial y apendicular, este carácter permite Inferir la anatomía de sus tejidos blandos y de su sistema respiratorio. Los titanosaurios, como todos los saurópodos, estaban caracterizados por ser cuadrúpedos, aunque algunos caracteres apendiculares y las huellas indican que su postura no habría sido tan columnar como en otros saurópodos. Aquellas peculiaridades anatómicas están notoriamente desarrolladas en los saltasaurinos, un grupo de titanosaurios derivados. Comparado con otros saurópodos, algunos titanosaurios parecen haber tenido un pobre sentido del olfato, sin embargo estos habrían tenido la capacidad de captar sonidos de alta frecuencia en un rango relativamente amplio, aunque no tanto como las aves actuales.Fil: Garcia, Rodolfo Andres. Provincia de Río Negro. Museo Provincial “Carlos Ameghino”. Instituto de Investigación en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salgado, Leonardo. Provincia de Río Negro. Instituto de Investigación en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; ArgentinaFil: Cerda, Ignacio Alejandro. Provincia de Río Negro. Museo Provincial “Carlos Ameghino”. Instituto de Investigación en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paulina Carabajal, Ariana. Provincia del Neuquen. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otero, Alejandro. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico de Paleontología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Coria, Rodolfo Anibal. Universidad Nacional de Rio Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiologia y Geologia; Argentina. Provincia del Neuquen. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; Argentin