Relationship between an inflammatory mucosal T cell response and susceptibility of sheep to Teladorsagia circumcincta infection

Control strategies against the parasitic nematode Teladorsagia circumcincta are problematic under current sheep management systems. Infection with the parasite, particularly in young lambs, results in significant production losses therefore sustainable worm control is being sought. It has been established that variation in resistance to T. circumcincta is under genetic control and the development of resistance is an acquired characteristic and has an immunological basis. This project investigated the immunological response to infection, of lambs with predicted resistance or susceptibility to T. circumcincta. Specifically, the study aimed to identify immune response-associated genes that were differentially-expressed in resistant and susceptible lambs and attempted to identify mutations in these genes. This study was part of a long term project that aims to identify genetic marker/s to aid in marker-assisted selection (MAS) for resistance to T. circumcincta. Real time reverse transcription-quantitative polymerase chain reaction (real time RTqPCR) was performed on abomasal mucosa and lymph nodes from 55 lambs used in a previous experiment. The lambs had been either trickle-infected with 2,300 infective larvae every two days over three months (infected resistant/susceptible, n=45) or sham-dosed (non-infected control, n=10). Lambs were ranked in relation to faecal egg count (FEC) and adult worm count (AWC) at post mortem; zero or low FEC (resistant) to high FEC (susceptible). Histopathology showed only mild pathological changes in the abomasal mucosa of resistant lambs but heavy lymphocytic inflammatory infiltration in the mucosa and submucosa of infected susceptible animals. Measurements of a range of cytokine transcripts and cell markers associated with the four major CD4+ T cell subsets identified IL6, IL21, and IL23A as significantly increased by at least two-fold in abomasal lymph nodes and abomasal mucosa of susceptible lambs in comparison to resistant animals. Highly significant (P<0.02) positive correlations were found between IL6 (ρ=0.35), IL21 (ρ=0.54) and IL23A (ρ=0.38) transcript levels and AWC. Similarly, there were highly significant (P<0.01) positive correlations between FEC and IL6 (ρ=0.41), IL21 (ρ=0.65) and IL23A (ρ=0.31). In contrast, significant negative correlation (P<0.04) between IL23A with IgA antibody levels (ρ=-0.31) was found. There was also a significant positive correlation (P<0.03) of TGFB1 levels with AWC (ρ=0.42) and FEC (ρ=0.32) in the abomasal mucosa. These data suggests that susceptibility to T. circumcincta is linked to the activation of the inflammatory TH17 T cell subset and that this chronic inflammatory response was inappropriate to clear worm infection. High resolution melt analysis failed to identify single nucleotide polymorphisms in the coding regions of IL21 and IL21R. This is the first report of the involvement of TH17 response in GI worm infection in sheep. Similar gene expression studies involving the known upstream and downstream players of the TH17 response could be done

TRYPANOSOMA EVANSI AND NEOSPORA CANINUM AMONG WATER BUFFALOES (BUBALUS BUBALIS) IN THE PHILIPPINES

The study determined the positivity rate of Trypanosoma evansi and Neospora caninum antibodies in water buffaloes in the province of Nueva Ecija, Philippines using Polymerase Chain Reaction (PCR) for T. evansi and competitive Enzyme-linked Immunosorbent Assay (cELISA) for N. caninum antibodies . A total of 100 whole blood and 100 serum samples were collected to test for T. evansi and N. caninum , respectively. Rotat 1.2 VSG gene was target using PCR for T. evansi detection. Neospora caninum antibody detection was done from the serum samples using cELISA test kit.Results revealed that the positivity rate of T. evansi in Nueva Ecija was 11% (11/100). The positive animals identified were from the municipalities of Muñoz (4/16; 25%), Sta. Rosa (3/13; 23.08%) and Talugtug (4/16; 25%). The seropositive rate of Nueva Ecija for N. caninum. was 46% (46/100), seropositive animals were identified in Cabanatuan City, 57.14% (4/7); Science City of Muñoz, 43.14% (22/51); Sta. Rosa, 40% (4/10); Sto. Sunday, 50% (6/12); and Talugtug 50% (10/20). The seropositivity rate of N. caninum and the presence of T. evansi in Nueva Ecija may contribute to the cases of abortions in the province and further studies should be employed to confirm the association of these organisms to abortion cases on water buffaloes

Relationship between susceptibility of Blackface sheep to Teladorsagia circumcincta infection and an inflammatory mucosal T cell response

<p>Abstract</p> <p><it>Teladorsagia circumcincta</it> is the most economically important gastrointestinal (abomasal) nematode parasite of sheep in cool temperate regions, to which sheep show genetically-varying resistance to infection. Lambs, from parents with genetic variation for resistance<it>,</it> were trickle infected with L3 larvae over 12 weeks. 45 lambs were identified with a range of susceptibilities as assessed by: adult worm count at post mortem, faecal egg count (FEC) and IgA antibody levels. This project investigated the correlation of T cell cytokine expression and resistance to infection at the mature stage of response, when the resistant lambs had excluded all parasites.</p> <p>Histopathology showed only minor changes in resistant animals with a low level lymphocyte infiltration; but in susceptible lambs, major pathological changes were associated with extensive infiltration of lymphocytes, eosinophils and neutrophils.</p> <p>Absolute quantitative RT-qPCR assays on the abomasal lymph node (ALN) revealed a significant positive correlation between IL6, IL21 and IL23A transcript levels with adult worm count and FEC. IL23A was also negatively correlated with IgA antibody levels. Significantly positive correlation of TGFB1 levels with adult worm count and FEC were also seen in the abomasal mucosa. These data are consistent with the hypothesis that the inability to control L3 larval colonization, adult worm infection and egg production is due to the activation of the inflammatory Th17 T cell subset.</p

Molecular detection of pathogens in ticks and fleas collected from companion dogs and cats in East and Southeast Asia

Background: Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia. Methods: A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested for Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp. and Hepatozoon spp. while fleas were screened for the presence of Rickettsia spp. and Bartonella spp. Result: Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen with Hepatozoon canis being the most prevalent (5.4%), followed by Ehrlichia canis (1.8%), Babesia vogeli (1%), Anaplasma platys (0.8%) and Rickettsia spp. (1%) [including Rickettsia sp. (0.5%), Rickettsia asembonensis (0.3%) and Rickettsia felis (0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen with R. felis being the most common (19.4%), followed by Bartonella spp. (16.5%), Rickettsia asembonensis (10.9%) and “Candidatus Rickettsia senegalensis” (0.4%). Furthermore, 35 Rhipicephalus sanguineus ticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus (sensu stricto)). Conclusion: Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field