Immunoblotting using Strongyloides venezuelensis larvae, parthenogenetic females or eggs extracts for the diagnosis of experimentally infected immunosuppressed rats

Abstract

The nematode Strongyloides stercoralis is responsible for strongyloidiasis in humans. Diagnosis of infection occurs through detection of larvae in feces, but low elimination of larvae often hampers the detection of disease, particularly in cases of patient immunosuppression. Immunodiagnostic tests have been developed; however obtaining S. stercoralis larvae for the production of homologous antigen extract is technically difficult. Thus, the use different developmental forms of Strongyloides venezuelensis has become an alternative method for the production of antigen extracts. The aim of this study was to evaluate immunoblotting using alkaline extracts from S. venezuelensis L3 larvae, parthenogenetic females or eggs to test detection of experimental strongyloidiasis associated with immunosuppression. Immunocompetent and immunosuppressed male rats were experimentally infected, and serum sample from all animals were obtained at 0, 5, 8 13, and 21 days post infection (d.p.i.). Immunoblotting was evaluated for use in detection of anti-S. venezuelensis IgG in both experimental rat groups. The larval extract immunoblotting profile had the most immunoreactive fractions in the immunosuppressed group beginning at 5 d.p.i., while the immunocompetent group reactivity began on 8 d.p.i. Immunoreactive protein fractions of 17 kDa present in larval alkaline extract presented as possible markers of infection in immunosuppressed rats. It is concluded that all extracts using immunoblotting have diagnostic potential in experimental strongyloidiasis, particularly larval extract in immunosuppressed individuals.

Strongyloidiasis Current Status with Emphasis in Diagnosis and Drug Research

“…Several immunologic techniques have been studied, including enzyme-linked immunosorbent assay (ELISA), indirect agglutination, indirect immunofluorescence, and western blot, all with different sensitivities and specificities, depending on the antigen and isotopic antiglobulin preparation [ 6 , 9 , 66 – 78 ]. Immunologic methods show a higher sensitivity than the conventional parasitological ones; nevertheless, there are concerns with its specificity due to cross-reactions with other [ 6 , 67 , 68 ] helminthes and with false positives due to antibody persistence.…”

Route of dexamethasone administration influences parasite burden in Strongyloides hyperinfection model

“…A signi cant difference between S. stercoralis, the human pathogen, and S. venezuelensis, the rodent one, life cycles is that hyperinfection and extremely chronic infections are present only in S. stercoralis infection (Breloer and Abraham 2017). Studies have used murine infected with S. venezuelensis and pharmacologically immunosuppressed by glucocorticoid treatments as an experimental model of chronic and complicated forms of strongyloidiasis (Carvalho et al 2015;Chaves et al 2015;Couto et al 2020).…”

Proteomic Analysis Of Trichuris Trichiura Egg Extract Reveals Potential Immunomodulators And Diagnostic Targets

“…While T. trichiura somatic and excretion/secretion products from the adults have been studied in depth and have been shown to elicit protective immune responses [13][14][15][16], other life-cycle stages of the parasite, such as the eggs, have not been fully investigated. Only a few reports indicate that they may be modulators of the immune system, and recognize them as potential sources of diagnostic antigens [17,18]. Interestingly, the administration of embryonated eggs from the animal species Trichuris suis or Trichuris muris to humans has been described as potential therapeutic agents for immune-related pathologies such as chronic intestinal in ammatory diseases, emphasizing their capacity to downregulate aberrant intestinal in ammation [6,[19][20][21][22].…”