ARS | Publication request: B cells have distinct roles in host protection against different nematode parasites

Submitted to: Journal of Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 31, 2010
Publication Date: May 1, 2010
Citation: Liu, Q., Kreider, T., Bowdridge, S., Liu, Z., Song, Y., Gaydo, A.G., Urban, J.F. Jr., Gause, W.C. 2010. B cells have distinct roles in host protection against different nematode parasites. Journal of Immunology. 184(9):5213-5223.

Interpretive Summary: Helminth (worm) parasites affect the immune response in the animal or human similar to allergens, in that they induce hypersecretion of mucus, hyper-reactivity in the breathing airway, and re-structuring of tissue. These components of the host response to worms or allergens are essentially side effects of the mechanisms needed to eliminate parasites, but become annoying and sometimes unhealthy consequences of the response to parasites or allergens. Control of these side effects could be useful in limiting the symptoms of the disease. The current study showed that with the absence of B cells (immune cells that produce specific antibodies against the worm), orally ingested parasites were able to penetrate the intestines to a greater extent, and fewer of them were eliminated via the bowel. A similar situation could operate with allergens in thegut, resulting in decreased removal. The information is important to researchers that study the control of infectious diseases in humans and livestock, and the relationship between parasitic infection and allergic disease.

Technical Abstract: B cells may mediate protective responses against nematode parasites by supporting Th2 cell development and/or by producing antibodies. To examine this, B cell-deficient mice were inoculated with Nippostrongylus brasiliensis (Nb) or Heligmosomoides polygyrus (Hp). B cell-deficient and wild type (WT) mice showed similar elevations in Th2 cytokines and worm expulsion following Nb inoculation. Worm expulsion was inhibited in Hp-inoculated B cell-deficient mice, although Th2 cytokine elevations in mucosal tissues were unaffected. Impaired larval migration and development was compromised as early as day 4 after Hp challenge, and administration of immune serum restored protective immunity in B cell-deficient mice, indicating a primary role for antibody. Immune serum even mediated protective effects when administered to naïve mice prior to primary Hp inoculation. Taken together, these studies suggest variability in the importance of B cells in mediating protection against intestinal nematode parasites and indicate an important role for antibody in resistance to tissue-dwelling parasites.