Changes in adult Nippostrongylus brasiliensis during the development of immunity to this nematode in rats

Abstract

Ultrastructural studies on adult Nippostrongylus brasiliensis removed at varying stages after infection from rats given a single dose of 2000 infective larvae have shown that changes in their cytology occur and that these can be correlated with the onset and development of immunity to this nematode in the host. The most noticeable changes are resorption of spermatozoa by the male reproductive tract, a drop in egg production, changes in the cytology of the intestinal cells, and the appearance of many large droplets, which look like droplets of lipid, in the cytoplasm of the hypodermis, muscles, excretory glands, reproductive system and the intestine. There are no obvious changes in the structure of the cuticle of the nematode during the course of infection. Possible reasons for the onset of these changes in the nematode are discussed.Much of this work was carried out during the tenure of grants from the U.S. Public Health Service (grant number AI 04275) and from the Agricultural Research Council while I was working at the Molteno Institute in Cambridge. I wish to thank the late Professor J. D. Boyd and Dr C. C. D. Shute of the Department of Anatomy, Cambridge, for permission to use the electron microscopes, Mrs B. Fisher for technical assistance and Mr Paul Rogers for assistance with the photography.

Expulsion of Nematospiroides dubius from the intestine of mice treated with immune serum

“…Protective activity associated with IgG in transferred immune serum has also been described in other gut dwelling helminth parasites (Di Conza 1969, Jones, Edwards & Ogilvie 1970, but it has recently been pointed out that there is no convincing evidence that the severe cytopathological changes seen in N . brasiliensis immediately preceding worm expulsion (Lee 1969, Ogilvie & Hockley 1968) are the direct consequence of antibody activity (Love, Ogilvie & McLaren 1975, Wakelin, 1978. Similar changes can be induced in in vitro culture (Love et al 1975), and worm expulsion can take place normally in mice incapable of detectable antibody synthesis (Jacobson, Reed & Manning 1977).…”

Ultrastructural plasticity in the plant-parasitic nematode, Bursaphelenchus xylophilus

“…The alae have a complex structure, which differs from that of the general body cuticle, and they may provide a degree of longitudinal stiffening. Furthermore, because nematodes lie and move on their sides 28 , the alae are in contact with the substrate, rather like the tread of a car tire 27 , where they probably assist in locomotion by increasing traction and preventing All numerical values are reported as the means ± standard deviation (SD). The measurements were carried out using ImageJ software version 1.52v (https ://image j.nih.gov/ij/) 41 .…”

“…The alae have a complex structure, which differs from that of the general body cuticle, and they may provide a degree of longitudinal stiffening. Furthermore, because nematodes lie and move on their sides 28 , the alae are in contact with the substrate, rather like the tread of a car tire 27 , where they probably assist in locomotion by increasing traction and preventing slipping, although their absence in some forms does not appear to inhibit movement. For example, the lateral alae in the dauer stage in Caenorhabditis elegans are different from that in other developmental stages and are mushroom-shaped 29 .…”

The anterior central nervous system of male Onchocerca volvulus (Nematoda: Filarioidea) as a target for chemotherapy: results of an electron microscopy study

“…The use of organs in this body part should therefore facilitate the histological analysis of eects related to an intervention by chemotherapy. Additional evidence that the gut and reproductive tract, the most prominent organ systems in the midbody and posterior parts of parasitic nematodes, underlie progressive degenerative changes caused by aging was provided by studies with other parasitic nematodes (Ogilvie and Hockley 1968;Lee 1969;Mallet and Kerboeuf 1993). Although most of these worms are short-lived, they demonstrated indications for age-dependent alterations comparable with those reported from studies with adult O. volvulus (Franz 1988;Schulz-Key 1988).…”