Trichinella spiralis: a 76-kDa excretory/secretory larval antigen identified by a monoclonal antibody.

Spleen cells from BALB/c mice were fused with myeloma cells following infection of the mice with Trichinella spiralis larvae and an ip booster injection with larval homogenate antigen. A monoclonal antibody (Mab), designated as TS 3G6 which did not react with sera or tissue extracts from noninfected mice, rats, and guinea pigs, was selected for further studies because of its high activity and specificity. When tested in ELISA TS 3G6 did not cross-react with Ascaris suum, A. lumbricoides, Toxocara canis, E. granulosus (larvae), Trichiuris suis, or T. ovis. Western blot analysis showed that Mab 3G6 recognized an antigen of 76 kDa located in the stichosome of the larvae as well as on the surface of the larval cuticle. Digestion of a larval extract with different enzymes suggests that the Mab TS 3G6 corresponding epitope is a polypeptide. The TS 3G6 antigen was detected in culture supernatants of Trichinella muscle larvae and in sera of experimentally infected animals using a sensitive ELISA assay. This secretory antigen also seemed to induce a specific immune response in the host since sera from infected animals could block the binding of Mab TS 3G6 to its target antigen when tested in a competitive ELISA.

Antigenic differences between Trichinella spiralis and T. pseudospiralis detected by monoclonal antibodies.

Antigenic differences between Trichinella spiralis and T. pseudospiralis were established using two monoclonal antibodies (mAbs) that show different specificities to muscle larvae of the two variants. Enzyme-linked immunosorbent assay (ELISA) revealed that mAb 3G6 reacts positively against T. spiralis, T. nelsoni, T. nativa and T. pseudospiralis, whereas mAb 3E10 does not react with T. pseudospiralis under the same experimental conditions. These antigenic differences were confirmed after preabsorption of the antibodies with serial dilutions of extracts of T. spiralis or T. pseudospiralis muscle larvae. The indirect immunofluorescence technique showed that the antigen corresponding to mAb 3G6 is located in the stichosomes and the cuticle surface of both T. spiralis and T. pseudospiralis. In contrast, mAb 3E10 positively stained cryostat sections of T. spiralis, forming a dense reaction product on the surface of the whole larvae and the surrounding capsule. This antibody can be quite useful as a specific probe for distinguishing T. spiralis from T. pseudospiralis in taxonomic studies. Using an avidin-biotin system, we could prove that mAb 3G6 recognizes an excretory/secretory-type antigen.

Antigen-antibody complexes in experimental infection with Trichinella spiralis and their role in the development of kidney lesions.

The kidneys of rats, experimentally infected with Trichinella spiralis were studied by means of light and fluorescent microscopy. The results obtained suggest that this is a case of a proliferative intra- and extracapillary nephritis. Highest intensity of the pathological process was noted between the 30th and 50th day of the infection. The immunofluorescent reaction of kidney glomeruli demonstrated that the immune complexes were located predominantly in the basal membrane and the mesangium. The serological investigation showed that the maximum level of circulating immune complexes existed between 14th and 21st day after the infection.

[Comparative immunoelectrophoretic studies of total water-soluble extracts of Trichomonas vaginalis, T. tenax and T. hominis]. / Vergleichende immunelektrophoretische Untersuchungen totaler wasserlöslicher Extrakte von Trichomonas vaginalis, T. tenax und T. hominis.

An antigen characterization was carried out by the method of two-dimensional immunoelectrophoresis, and on this basis the antigen community and the antigenic differences between the 3 Trichomonas species parasitic in man were investigated. In the homologous antigen-antibody-systems a maximum number of precipitation curves is formed--21 in T. vaginalis and 20 each in T. tenax and T. hominis. According to our setting of the experiment T. vaginalis has 5 specific antigens in regard to T. tenax and 3 in regard to T. hominis. T. tenax has 2 specific antigens in regard to T. vaginalis and 7 in regard to T. hominis, T. hominis has 2 specific antigens in regard to T. vaginalis and 3 in regard to T. tenax. The presence of antigenic differences is important for the immunological characterization of the 3 species and demonstrates their validity.

The karyotype of four Trichinella species.

Karyological studies of Trichinella spiralis, T. pseudospiralis, T. nativa and T. nelsoni were undertaken. Comparison of the karyotypes of these Trichinella species showed that the chromosome number of all four species is 2n = 6 for female specimens and 2n = 5 for males. The differences found in the relative chromosome lengths of the individual Trichinella species are not significant. Centromeric index data indicate that T. nativa and T. spiralis have similar centromere dispositions and differ from the other two species by the disposition of the centromere of the first submetacentric chromosome pair. In T. nativa and T. nelsoni the univalent sex chromosome is the second in size. It is slightly submetacentric chromosome, while in T. spiralis and T. pseudospiralis it is the third metacentric chromosome. The data from the karyological investigations may be used as additional karyosystematic characteristics when differentiating the Trichinella species studied.

Scanning electron microscopic studies on males of trichinella species.

Ultrastructure of the cuticle and pseudobursa of adult males of four species of Trichinella has been studied by SEM. T. nativa differs markedly from T. spiralis, T. nelsoni and Trichinella sp. in the form of the pseudobursa. Trichinella sp. differs only slightly from T. spiralis and T. nelsoni. The ultrastructure of the cuticle revealed no characters suitable for the differentiation of the taxons under study.

On the karyotype of a laboratory Trichinella strain from Bulgaria.

The karyotype of male and female individuals of the species Trichinella nelsoni was studied. It was found that the number of chromosomes in females individuals is 2n = 6 and in males 2n = 5. Each pair of chromosomes differs from one another as to dimensions and location of the centromere. The univalent chromosome that was found in the chromosome set containing five chromosomes is the second largest submetacentric chromosome. It is suggested that this chromosome is the sex chromome of the studied Trichinellae.

[Comparative study of various antigens of D. filaria by disc electrophoresis]. / Sravnitelno izsledvane na razlichni antigeni ot D. filaria chrez diskova elektroforeza

Somatic and functional antigens of Dictyocaulus filaria were comparatively studied by means of disk electrophoresis. Established were the protein fractions of the different antigens. The preliminary fractionation of the antigens on Sephadex G-200 made it possible (at a second concentration and separation through disk electrophoresis) to obtain fewer, but richer and better distinguishable fractions each one of which could be used alone as a specific antigen. The complement-fixation test, the indirect hemagglutination, and the latex agglutination reaction revealed that most specific and sensitive proved the antigen obtained after Stewart (II fraction), this method being more sensitive and specific, as compared with others. The c. f. test performed with this antigen gave consistently better results showing higher titers as against other antigens.