Characterization of an MLP Homologue from Haemaphysalis longicornis (Acari: Ixodidae) Ticks

Abstract

Members of the cysteine-rich protein (CRP) family are known to participate in muscle development in vertebrates. Muscle LIM protein (MLP) belongs to the CRP family and has an important function in the differentiation and proliferation of muscle cells. In this study, the full-length cDNA encoding MLP from Haemaphysalis longicornis (H. longicornis; HLMLP) ticks was obtained by 5′ rapid amplification of cDNA ends (RACE). To verify the transcriptional status of MLP in ticks, HLMLP gene expression was assessed during various developmental stages by real-time PCR (RT-PCR). Interestingly, HLMLP expression in the integument was significantly (P < 0.01) higher than that observed in other tested tissues of engorged adult ticks. In addition, HLMLP mRNA levels were significantly downregulated in response to thermal stress at 4 °C for 48 h. Furthermore, recombinant HLMLP was expressed in Escherichia coli, and Western blot analysis showed that rabbit antiserum against H. longicornis adults recognized HLMLP and MLPs from different ticks. Ten 3-month-old rabbits that had never been exposed to ticks were used for the immunization and challenge experiments. The rabbits were divided into two groups of five rabbits each, where rabbits in the first group were immunized with HLMLP, while those in the second group were immunized with phosphate-buffered saline (PBS) diluent as controls. The vaccination of rabbits with the recombinant HLMLP conferred partial protective immunity against ticks, resulting in 20.00% mortality and a 17.44% reduction in the engorgement weight of adult ticks. These results suggest that HLMLP is not ideal as a candidate for use in anti-tick vaccines. However, the results of this study generated novel information on the MLP gene in H. longicornis and provide a basis for further investigation of the function of this gene that could potentially lead to a better understanding of the mechanism of myofiber determination and transformation

Extracellular Vesicles and Post-Translational Protein Deimination Signatures in Mollusca—The Blue Mussel (Mytilus edulis), Soft Shell Clam (Mya arenaria), Eastern Oyster (Crassostrea virginica) and Atlantic Jacknife Clam (Ensis leei)

“…Furthermore, LIM-motif containing proteins play various roles in differentiation, cell fate, and cytoskeletal organization [133]. Interestingly, other diverse functions in immunity have also been identified in alternative taxa such as insects [134,135]. In Mollusca, changes in LIM expression is associated to immune and stress responses to Vibrio challenge in gills and digestive tract of the disk abalone (Haliotis discus discus) [136].…”

Role of Recognition MicroRNAs in Hemaphysalis longicornis and Theileria orientalis Interactions

“…The midgut is an important digestive and immune organ in ticks that can secrete many immune factors and participate in the identification and elimination of pathogens [ 39 ]. On the one hand, these factors protect the host from pathogen invasion, and on the other hand, pathogen surface proteins bind to host cell surface factors to obtain the materials needed for survival [ 40 ]. However, the abovementioned studies only analyzed the functional issues of some genes and did not truly address the interactions between genes and pathogens.…”

Resistance to Ticks and the Path to Anti-Tick and Transmission Blocking Vaccines

“…A range of different internal tick antigens have been considered as anti-tick vaccine antigens. An interesting vaccination trial antigen choice was a cysteine-rich protein associated with muscle development in Haemaphysalis longicornis that provided minimal protection with 20% adult challenge mortality and a 17.4% decrease in engorgement weights [ 240 ].…”