Immunization against Lamb Haemonchosis with a Recombinant Somatic Antigen ofHaemonchus contortus(rHcp26/23)

Abstract

Haemonchosis, caused by the abomasal nematode Haemonchus contortus, is a common parasitic disease of sheep. Our previous results showed that a soluble fraction from adult stages of the nematode (p26/23) induced partial protection against challenge. Recombinant DNA technology was applied to obtain a synthetic protein (rHcp26/23). Immunological assays (ELISA, Western blotting, and immunolocalization), using sera from lambs immunized with p26/23, confirmed the identity of the recombinant protein and demonstrated that the synthetic protein is equivalent to the purified protein employed in the previous immunoprophylaxis studies. Vaccination of lambs with 300 μg of rHcp26/23 and Freund's adjuvant elicited a notable specific antibody response. Immunization did not induce any significant protection after challenge with 16000 infective larvae of H. contortus, and comparable values for parasite faecal egg output, packed cell volume, and abomasal parasite burdens were found in vaccinated and control animals.

The Serine/Threonine-Protein Phosphatase 1 From Haemonchus contortus Is Actively Involved in Suppressive Regulatory Roles on Immune Functions of Goat Peripheral Blood Mononuclear Cells

“…Identification and development of novel drug targets are always a primacy in the biological study of socio-economically important parasites. Helminths ESPs including some antigens with unknown biological functions were characterized ( 31 – 33 ), and due to their sequences homology, these molecules have been proven as promising vaccine candidate against nematodes infections ( 34 , 35 ). Among PPs, PP1 elaborate numerous biological activities, such as membrane receptors/channels regulations, protein synthesis, glycogen metabolism, transcription, cellular division, and apoptosis ( 36 ).…”

Evaluation of crude larval protein and recombinant somatic protein 26/23 (rHcp26/23) immunization against Haemonchus contortus in sheep

“…On contrary, Garcıa-Coiradas et al . [ 14 ] reported that regardless of the strong immune response elicited by the immunization of lambs with the recombinant protein (rHcp26/23) no protection against the H. contortus challenge was found. They recommended numerous explanations behind the lacking denaturalization of the recombinant proteins and glycosylation of the defensive antigens.…”

“…Adult male H. contortus was used in an RNA extraction kit protocol (Qiagen, Germany) according to Garcıa-Coiradas et al . [ 14 ]. Reverse transcriptase polymerase chain reaction (PCR) was carried out in two independent steps: Synthesis of cDNA (1 st strand cDNA Synthesis Kit, AMV, Roche) using hexanucleotide random primers with BamHI and HindIII restriction targets:…”

“…The protein fraction p26/23 from adult worms was immunoprotective in lambs challenged with H. contortus [ 12 ]. As of late, the substance of this fraction protein has been analyzed, and the real protein present has been purified, immunolocalized, and mostly sequenced, cloned and expressed [ 13 , 14 ]. What’s more, the two antigens H-gal-GP and H11 isolated from intestinal cells of H. contortus have continually protection to a degree which would surpass antihelmintic treatment administration (i.e., >80% adequacy in >80% of the herd; and which would in this way be financially helpful.…”

Intranasal Immunization of Lambs with Serine/Threonine Phosphatase 2A against Gastrointestinal Nematodes

“…Greatest efficacy has been achieved with vaccines that use irradiated larvae (5), but the logistical problems involved in their production and administration (6) have led to a search for native antigens or recombinant ones (7). The latter are easier to produce and distribute, and many of them are proteases, cysteine proteases, metalloproteases, aspartyl proteases (PEPs), all proteins from the helminth intestine, and some with unknown biological functions (8)(9)(10)(11). Due to the homology in their sequences, some of these antigens have proved to be effective against different nematode species (3,12,13).…”