A Comprehensive Review on Haemonchus contortus Excretory and Secretory Proteins (HcESPs): TH-9 stimulated ESPs as a potential candidate for Vaccine Development and Diagnostic Antigen.

Haemonchus contortus (Barber pole worm) is one of the dominant helminth parasitic infections in small ruminants which is economically important and causes severe losses in the livestock industry, particularly in tropical and subtropical regions. This parasite resides in the abomasum and is responsible for severe blood loss, leading to anemia, emaciation, hypoproteinemia, weight loss, and potentially death. The economic impact of H. contortus on the livestock industry necessitates effective control measures, including early diagnosis and the development of effective vaccines. H. contortus secretes a variety of excretory and secretory proteins (ESPs), which are glycoproteins that play a crucial role in modulating the host's immune response. These ESPs are not only vital for understanding the immunological interactions between the parasite and the host but also serve as potential diagnostic tools and vaccine candidates. Similar ESPs have been identified in other parasitic species such as Cooperia spp, Ostertagia ostertagia, Teladorsagia circumcincta, Ascaris sum, Schistosoma japonicum, and Echinococcus multilocularis, underscoring their importance in both detection and vaccine development. In addition, there is a lack of highly potential specific proteins which having immunogenic properties that can be used for the accurate, early diagnosis serologically and serve as a potential candidate for the vaccine development against H. contortus. Recent research highlights that TH-9 stimulated proteins from H. contortus are emerging as promising candidates for vaccine development due to their immunomodulatory effects. These proteins have been shown to induce a TH-9 immune response, characterized by increased production of interleukin-9 (IL-9), which is critical for enhancing protective immunity against helminth infections. It is suggested to investigate TH-9 stimulated protein as potential candidates for vaccine development and diagnostic antigen.