Studies with<i>Brugia pahangi</i>. 14. Intrauterine development of the microfilaria and a comparison with other filarial species

Rogers, Rosemary; Ellis, D. S.; Denham, D. A.

doi:10.1017/s0022149x00026675

Cited by 46 publications

(29 citation statements)

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“…Female adults of Brugia spp. shed live mf, which retain a remnant of their eggshells as the extracuticular sheath (20). This sheath is maintained while the mf circulate in the vertebrate bloodstream but is lost during the initial phases of development in the arthropod vector.…”

Section: Discussionmentioning

confidence: 99%

“…are born without sheaths and therefore do not need a mechanism for exsheathment in the vector. Brugian mf do not hatch from their eggshells in utero but seem to remodel the shell and elongate it ultimately to form the sheath (20). This remodeling may also involve chitinase, but this enzyme should be antigenically distinct from the chitinase sequenced here, as the MF1 antibody does not react with extracts of adult female B. malayi (6 Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Transmission-blocking antibodies recognize microfilarial chitinase in brugian lymphatic filariasis.

Fuhrman

Lane

Smith

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

100

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Brugia malayi is a parasitic nematode that causes lymphatic filariasis in humans. The monoclonal antibody MF1, which mediates clearance of peripheral microfilaremia in a gerbil infection model, recognizes two stage-specific proteins, p70 and p75, in B. malayi microrflariae. cDNA coding for the MF1 antigen was sequenced, and the predicted protein sequence shows significant similarities to chitinases from bacteria and yeast. When microfilarial extracts and purified preparations of the MF1 antigen were tested for chitinase activity, strong bands of chitin-degrading activity comigrated in SDS/PAGE with p70 and p75 and showed a reductiondependent mobility shift characteristic of the MFl antigen. Thus, the MF1 antigen is microfrarial chitinase, which may function to degrade chitin-containing structures in the microfilaria or in its mosquito vector during parasite development and transmission.Lymphatic filariasis afflicts nearly 100 million people worldwide (1). Of the three species of lymphatic filariids that infect humans, Brugia malayi can most readily be maintained in the laboratory by passage between gerbils (another natural host) and a mosquito vector. Thus, B. malayi has been useful for studying pathogenesis and transmission of filariasis at the molecular level.Passive transfer of the monoclonal antibody MF1 was previously shown to mediate the transient clearance of first stage larvae, or microfilariae (mf), from the peripheral blood of gerbils infected with B. malayi (2). The MF1 antibody recognizes two stage-specific proteins (p70 and p75) in extracts of mf that appear only after the mf have matured for several days in the vertebrate host (3). The appearance of the MF1 antigen corresponds with the onset of the parasite's ability to infect the mosquito (3).It was thus of great interest to define more precisely the role of the MF1 antigen in filarial development and transmission. With the expectation that the proteins' sequences might clarify their function, we obtained partial amino acid sequences for p70 and p75 and then used this information to isolate and to sequence the corresponding cDNA.1 We report here that the predicted protein sequence of the MF1 antigen has several regions of significant similarity to bacterial and yeast chitinases. Furthermore, the native MF1 antigen is demonstrated to degrade chitin in vitro.MATERIALS AND METHODS Parasite Material. Gerbils (Meriones unguiculatus) were infected intraperitoneally with B. malayi either in our own facilities or at the Filariasis Repository Research Service, Athens, GA. mf were purified and proteins were extracted as described (3). Poly(A) mRNA was isolated from purified mf according to Cox and Smulian (4). Genomic DNA was made from adult B. malayi as described (5).Protein Purification and Amino Acid Sequencing. The MF1 antigen was partially purified from extracts of mf by DE-52 chromatography as described (6). N-terminal sequence analysis was performed on the combined p70 and p75 following elution with 0.5 M NaCI from DE-52, using an ABI model 4...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Transmission-blocking antibodies recognize microfilarial chitinase in brugian lymphatic filariasis.

Fuhrman

Lane

Smith

et al. 1992

Proc. Natl. Acad. Sci. U.S.A.

100

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“…However, L. carinii and D. viteae mf fail to activate complement although their eggs do so. This is somewhat surprising, because during maturation the outer layer of the eggs becomes the sheath of mf (21). Presumably, changes in the biochemical composition of the sheath during maturation account for this.…”

Section: Discussionmentioning

confidence: 99%

Complement activation by eggs and microfilariae of filarial parasites

Rao¹,

Chandrashekar²,

Subrahmanyam³

1987

Immunol Cell Biol

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Summary. The complement of fresh normal rat serum was activated by filarial eggs and microfilariae (mf). C3 was deposited on the surface of Litomosoides carinii, Brugia pahangi, Brugia malayi and Dipetaionema vifeae as seen by i mm u no fluorescence. Inira-uterine and in v/7ro-derived mf did not bind C3. In contrast, C3 bound to the blood-derived mf of B. pahangi and B. malayi as well as exsheathed mf of L. carinii and B. malay\ Significant consumption of complement was observed with eggs of all filarial species, as well as sheathed mf of B. pahangi, B. malayi and exsheathed mf of L. carinii and fl malayi. These experiments indicated that complement was activated by filarial parasites via the alternative pathway. The bound complement promoted neutrophil-mediated adherence and cytotoxicity.

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“…Microfilariae of different species were observed by transmission electron microscopy (TEM) (McLaren 1973;Moraes-Neto et al 2001). Rogers et al (1976) studied the development of B. pahangi Buckley and Edeson 1956 from embryos to microfilariae and Peixoto (2005) described some aspects of the Wuchereria bancrofti Cobbold 1877 uterus.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructure of reproductive system of female Litomosoides chagasfilhoi Moraes-Neto, Lanfredi and De Souza, 1997 (Nematoda: Filarioidea)

Cárdenas

Lanfredi

2008

Parasitol Res

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The ultrastructure of the female reproductive system of the filariid Litomosoides chagasfilhoi by transmission electron microscopy (TEM) is described for the first time. The ovary is composed of primary oocytes surrounded by a single layer of epithelial cells apposed on the basal laminae. The ovarian wall is completely filled with primary oocytes, which are arranged radially and are centrally connected around the rachis. The uterine wall consists of muscular fibers surrounded by a basal lamina and the epithelium underlying the lamina. Ameboid and aflagellate spermatozoa are present inside the distal portion of the uterus, some of them near oocytes, which present bacteria in its cytoplasm. An eletrondense well-defined eggshell covers the zygotes, which presents in its cytoplasm bacteria arranged in groups. These bacteria are also observed in embryos and in the hypodermal cord. These ultrastructural aspects of L. chagasfilhoi female worms presented herein contribute to the knowledge of the morphology and embryonary development of this filariid, providing means for further comparative analyses of the action of anti-filarial drugs. Besides this, the presence of bacteria Wolbachia-like is being reported for the first time in this species, showing the great importance of this experimental model of study.

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Studies withBrugia pahangi. 14. Intrauterine development of the microfilaria and a comparison with other filarial species

Cited by 46 publications

References 23 publications

Transmission-blocking antibodies recognize microfilarial chitinase in brugian lymphatic filariasis.

Transmission-blocking antibodies recognize microfilarial chitinase in brugian lymphatic filariasis.

Complement activation by eggs and microfilariae of filarial parasites

Ultrastructure of reproductive system of female Litomosoides chagasfilhoi Moraes-Neto, Lanfredi and De Souza, 1997 (Nematoda: Filarioidea)

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