Comparative immune-profiling of three cattle breeds infested with Rhipicephalus microplus and Ixodes ricinus-infested BALB/c mice

Abstract

Ticks and tick-borne diseases have a negative impact on the quality and quantity of livestockderived products. As such, effective control strategies against these parasites are needed. Currently, acaricides are the most widely used control mechanism against ticks but due to the increase in resistance to these chemicals, new control strategies, like vaccination, need to be developed and improved. In cattle, increasing the understanding of the basic underlying variation in immunological responses to tick infestation may constitute the basis of improved tick control strategies in the future. While the identification of protective antigens is essential, the final formulation of vaccines is pivotal in the efficacy of a future vaccine. As such, increasing the understanding of the basic underlying variation in immunological responses to tick infestation may constitute the basis of improved tick control strategies in the future. Chapter 2 describes the differential regulation of T and B-lymphocyte subsets in the skin and lymph nodes amongst three cattle breeds as potential mediators of immune-resistance to Rhipicephalus microplus tick. This study has been the first to describe in detail the in vivo immune responses in lymph nodes of cattle following Rhipicephalus microplus infestation, attachment and continued feeding. To further compliment this study, Chapter 3 provides a temporal analysis of the bovine lymph node transcriptome during cattle tick (Rhipicephalus microplus) infestation. Here a detailed description on the specific transcriptional processes in the lymph nodes of Bonsmara cattle is given. These processes include: (1) Leukocyte recruitment to the lymph node via chemokines and chemotaxis, (2) Trans-endothelial and intranodal movement on the reticular network, (3) Active regulation of cellular transcription and translation in the lymph node (including leukocyte associated cellular regulatory networks) and (4) Chemokine receptors regulating the movement of cells out of the lymph node. In addition to studying the immune response in cattle, the viability of a mouse model was used for basic immune profiling during tick feeding and vaccination in Chapter 4. Here an in vivo evaluation of Ixodes ricinus induced effects on T and B-cell maturation in the spleen and lymph nodes of BALB/c mice is given.