Immunoregulatory and antiviral effect mediated by TLR7 and BMAP28 interaction in bovine alphaherpesvirus-infected respiratory primary cultures.

Varicellovirus bovinealpha 1 and 5 (formerly bovine alphaherpesvirus type 1 and 5, BoAHV-1 and BoAHV-5) are closely related and can be isolated from similar clinical conditions, including respiratory and nervous diseases, genital infections and abortion. Pathogens' activation of toll-like receptors (TLRs) induces the expression of proinflammatory cytokines and antimicrobial peptides such as cathelicidins. Cathelicidins are presumed to act as endogenous ligands of TLRs, stimulating, in turn, their activation.

Individual differences in behaviour are related to metabolism, stress response, testosterone, and immunity in the subterranean rodent Ctenomys talarum.

The growth of personality research has led to the integration of consistent variation of individual behaviour in multidimensional approaches including physiological variables, which are required to continue building a more comprehensive theory about coping strategies. In this study, we used wild-caught males of Ctenomys talarum (tuco-tucos), a solitary subterranean rodent, to assess the relationships among personality traits and several physiological variables, namely stress response, testosterone, immunity, and energy metabolism. Subjects (n = 21) were used in experimental tests assessing behaviour, energy metabolism, testosterone levels, inflammatory cell-mediated and humoral immunity, and stress response to a simulated predator attack.

Assessment of Trade-Offs between Simultaneous Immune Challenges in a Slow-Living Subterranean Rodent.

The coexistence of two or more infectious agents in the same host is common in nature. Given this, the study of trade-offs within the immune system itself is key to understanding how immune defenses act in wild species in their natural environment. Here we assessed the possible trade-off between an inflammatory response (induced by phytohemagglutinin [PHA]; involving innate and adaptive responses in the study species) and an antibody response (induced by sheep red blood cells [SRBC]; adaptive response) in a slow-living subterranean rodent, the Talas tuco-tuco (Ctenomys talarum Thomas, 1898).

Selection on MHC in a Context of Historical Demographic Change in 2 Closely Distributed Species of Tuco-tucos (Ctenomys australis and C. talarum).

Selection necessarily acts within the same current and historical demographic framework as neutral evolutionary processes, and the outcome of the interplay between these forces may vary according to their relative strength. In this study, we compare the variation at a major histocompatibility complex (MHC) locus (DRB exon 2), typically subject to strong diversifying selection, and mitochondrial diversity (D-loop) across populations encompassing the entire distribution of 2 species of South American subterranean rodents: Ctenomys australis and C. talarum (tuco-tucos).

Food Restriction Affects Inflammatory Response and Nutritional State in Tuco-tucos (Ctenomys talarum).

Insufficient or unbalanced food intake typically has a negative impact on immune responses. The understanding of this effect is, however, hampered by the effect that food has on general condition, which, in turn, affects immunity, and the interaction among general condition, immunocompetence, and concurrent infections. The goal of this study was to determine the effects of food restriction and methionine supplementation on immunity in tuco-tucos (Ctenomys talarum).

Assessing the energetic costs and trade-offs of a PHA-induced inflammation in the subterranean rodent Ctenomys talarum: immune response in growing tuco-tucos.

A traditional approach used to assess whether immune defense is costly is to explore the existence of trade-offs between immunity and other functions; however, quantitative studies of the energetic costs associated with the activation of the immune system are scarce. We assessed the magnitude of a PHA-triggered immune response and the associated energetic costs in 60-day old Ctenomys talarum. We expected that the magnitude of the macroscopic inflammatory response to PHA is lower in young tuco-tucos compared with that of adults, given the allocation of substantial energy to growth, and that the magnitude of the inflammation is lower in male pups compared to females, due to the higher investment in growth of the larger sex.

MHC variation, multiple simultaneous infections and physiological condition in the subterranean rodent Ctenomys talarum.

Parasites and pathogens can play a significant role in shaping the genetic diversity of host populations, particularly at genes associated with host immune response. To explore this relationship in a natural population of vertebrates, we characterized Major Histocompatibility Complex (MHC) variation in the subterranean rodent Ctenomys talarum (the talas tuco-tuco) as a function of parasite load and ability to mount an adaptive immune response against a novel antigen. Specifically, we quantified genotypic diversity at the MHC class II DRB locus in relation to (1) natural variation in infection by multiple genera of parasites (potential agents of selection on MHC genes) and (2) antibody production in response to injection with sheep red blood cells (a measure of immunocompetence).

Trans-species polymorphism and evidence of selection on class II MHC loci in tuco-tucos (Rodentia: Ctenomyidae).

Balancing selection acting over the evolutionary history of a lineage can result in the retention of alleles among species for longer than expected under neutral evolution. The associated pattern of trans-species polymorphism, in which similar or even identical alleles are shared among species, is often used to infer that balancing selection has occurred. The genes of the major histocompatibility complex (MHC) are thought to be subject to balancing selection that maintains alleles associated with response to specific pathogens.

Thermoregulatory development in pups of the subterranean rodent Ctenomys talarum.

The effect of the mother's contact and huddling with nest mates on the mass-specific metabolic rate (RMR) and body temperature (T(b)) of pups of Ctenomys talarum from 2 to 45 days of age was evaluated at ambient temperatures (T(a)) within and below the adult thermoneutrality range (25 and 19 degrees C, respectively, the latter corresponding to the one recorded in burrows during the spring, when pups are born). Under these conditions, we recorded the percentage of time that pups spent huddled with nest mates, with their mother and suckling. At 19 degrees C, huddling and contact with the mother significantly reduced pups' body heat loss until they were 15 days old but did not affect their RMR.