Rev. Biol. Trop., 35(1): 69-71, 1987. Somatic antigens from male and female adults of Setaria cervi: immune reactions in guinea pigs Sanjeev Kumar Department of Zoology, Institute of Advaneed Studies, Meerut University, Meerut 250 005, U.P., India (Reeeived June 5, 1986) Abstraet: Antigens obtained from adult female Setaria cervi were more proteetive than those of males against the development of microfilaremia in guinea pigs (transplanted with 10 S. cervi). In high dose levels (2 mi 500 ¡.tI/mI) significant resistanee was indueed by antigens from male (52% of proteetion) and female (6 2%of proteetion) worms. The antigens from female worms were effeetive (40% proteetion) at low dose level (2 mi 50 ¡.tI/mI) also. Extensive studies on the development of saline and the two sexes were separated. immunity by somatic antigens obtained from Microfilariae (mf): Microfilariae were recov­ nematodes have been reviewed by Lal et al. , ered fron the peripheral blood of the infected (1985). In addition, studies on the somatic an­ animals by density gradient centrifugation on tigen-induced resistan ce in the host have Percoll in 0.25 M sucrose according to Chan­ produced contradictory results (Soulsby, 1963; drashekar et al. , (1984). The number of mf in a Crandall and Arean, 1965; Lehnert, 1967; Gue­ sample was estimated by dilution technique. rrero and Silverman, 1969, 1971; Stromberg and Soulsby, 1977; Horii et al. , 1985). A care­ Preparation of Antigens: A known number fui screening of literature reveals that Setaria of male and female worms was washed in cervi, the most prevalent cattle filarial worm in distilled water and extruded in a Pressure Cell the Meerut region, has remained untouched as Extruder at 20,000 psi. This somatic antigen, regards the immunological aspects. obtained separately fo r the sexes, was (reeze­ The antigenic activity of somatic extracts of dried and stored at 40C until needed. male and female adults of S. cervi is reported here. Adjuvant : 4% Sodium alginate in doses of MATERIAL AND METHODS 0.5 mi per animal. The Host : I used infection free male guinea Immunizing Schedule : Two injections of pigs of the Meerut strain, 90 days in age and antigens administered intraperitoneally: the weighing 560-600 g . The animals were housed first on day O and the second on day 14. 3-5 per cage with wire mesh floors, over sawdust at constant temperature and humidity. They Challenge Infection: 10 S. cen'¡ adult received balanced commercially prepared food females were transplanted into guinea pigs via in pellet form and water ad libitum. laparotomy as described by Ansari (1964) on day 21 (i.e., 7 days after the second immunizing The Parasite: Adult S. cervi: Motile S. cervi injection) . were recovered from the peritoneal cavity of cattle slaughtered freshly in a local abattoir. Experimental Design: The experiment in­ They were washed thoroughly in physiological volved 4 groups subdivided into 8 sub-groups 69 70 REVISTA DE BIOLOGIA TROPICAL TABLE 1 Recovery ofviable microfilariae (mf) fr om the peripheral blood circulation, 40 days after the challenge infection ofguinea pigs with 10 adult fe male Setaria cervi (after immunization) Group Description of group Antigens from ma1e worms Antigens from female worms Recovery of mf (mf/ml of blood) Recovery of mf (mf/ml of blood) Mean (N=10) ± S.D. %of protection Mean (N=10) ± S.D. %of protect (relative to (relative t( control) control) a 2 mi of 50 !JI/mi soma tic 1,621 ± 278 24 1,337 ±261 40 antigen + adju vant a a 2 2 mi of 500 !JI/mi somatic 1,016 ± 319 52 834 ± 208 62 antigen + adjuvant 3 Adjuvant alone (control) 2,137 ± 586 O 2,219 ± 612 O a 4 Infection immunity control 198 ± 73a 91 223 ± 86 90 a P < 0.01 (test vs. control); Student's t·test (Sokal and Rohlf, 1969). (2 sub·groups A and B per group) of 10 animals fJlaremia at higher dose (500 pI/mi) only, those each. Animals of the sub·groups A and B from the female worms did so significantly received antigens obtained from male and fe· (P < 0.01) at both doses (50 and 500 pJfrnl). male worms respectively. Infection immunity control group anirna1s Group 1: The animals received 2 mi of 50 pi/mi offered maximum resistance (90% of protec· of lyophilized somatic antigens in each in· tion). jection. Group 2: The animals received 2 rnl of 500 pl/ mI of Iyophilized somatic antigens in each DISCUSSION injection. Group 3 (Control): The animals received adju· A number of investigators have tried somatic vant alone in two injections. antigens obtained from nematode stages moulted Group 4 (Active immunization control): The in the host and recovered from it to induce re· animals used were transplanted with 10 fe· sistance against the respective nematode infec· male worms 240 days before the challenge in· tions. They have obtained contradictory results fection. In a separate experiment it was pre· in their efforts (Lal et al., 1985). Present stud· deterrnined that the mf are c1eared from the ies reveal that the Iyophilized somatic antigens peripheral blood circulation of the animals from the two sexes of S. cervi are potent implanted with 10 female worrns, by the enough (at high dose levels, 500 pI/mI; 2 mI: day 240 after the worm implantation. females at dose 50 pI/mi; 2 mI, also) to induce resistance into the host. The degree of resistance, For the collection of mf, the blood samples however, is not that which may be expected as were taken on day 40 after the challenge in· required to eliminate completely the mf from fe ction. The peak microfJlaremia was prede· the host, or to protect it from the development termined the day 40 after the worrn trans· of any micromaremia. Results with control plantation, in a separate experimento group animals support a number of previous reports (Levine, 1968): the repeated infections RESULTS result in development of resistance in the host. Studying Ascaris suum, Guerrero and Results are summarized in Table 1. Although Silverrnan (1969) obtained similar results and the lyophilized somatic antigens obtained from conc1uded that somatic antigens from third·stage the male worms reduced (P < 0.01) the micro· larvae induce a limited protection to infection KUMAR: Somatic antigens from male and female adults of Setaria cervi 71 in mice. Earlier, Soulsby (1963) reported a microfilariae free of blood cells on Percollgradients. 92.3% protection in guinea pigs when injected Journal of Helminthology 58: 69-70. with lyophilized somatic antigens of the same Guerrero, 1. and P. H. Silverman. 1969. Ascaris suum: kind used here. He, however, obtained variable Immune reactions in mice 1. Larval metabolic and results later on; he found a 63% and 82% resist­ somatic antigens. Experimental Parasitology 26: ance to infections with embryonated eggs of A. 272-28l. suum using fresh antigens. This induced resist­ Guerrero, J. and P. H. Silverman.197l.Ascaris suum: ance was previously suggested by Soulsby Immune reactions in mice II. Metabolic and (1958) to be due to the release of functional somatic antigens from in vitro cultured larva e . Experimental Parasitology 29: 110-115. antigens when the larvae were disrupted. It can be safely conc1uded that lyophilized Horii, Y., A. Ishii, M. Owhashi, & M. Usui. 1985. somatic antigens obtained from the two sexes Neutrophillic nodules in the intestinal walls of of S. cervi may be used in dose level of 2 mI of Japanese monkeys associated with the neutrophil chemotactic activity of larval extracts and 500 /1l/ml of antigen, to induce partial pro­ secretions of Oesophagostomum aculeatum. tective immunity in guinea pigs against the mar­ Reviews ofVeterinary Sciences 38: 115-119. ial worm. Lal, S. S., D. Bhatnagar, & Sanjeev Kumar. 1985. ACKNOWLEDGMENTS Progress in immunization studies using life-cycle stages against respective parasitic diseases. In recent advances in developmental biology of The author is grateful to S. S. Lal and K. C. animals. S. C. Goel & C.B.L. Srivastava (editors). Pandey (Meerut University) for the facilities. Rastogi Publications, Meerut 153-158. Lehnert, 1. P. 1,967. Studies on the biology and RESUMEN immunology ofAscaris suum in mice. Ph. D. Thesis, University of IIIinois, Urbana, Illinois. Los antígenos de Setaria cervi hembra son Levine, N. D. 1968. Nematode parasites of domestic más eficaces que los de macho para evitar el de­ animals and of mano Burgess Publications, sarrollo de micromaremia en cobayos (10 pa­ Minneapolis, Minnesota. rásitos por individuo). Con dosis altas (2 mI Sokal, R. R. & F. 1. RohIf. 1969. Introduction to 500 /1l/ml) se obtuvo resistencia significativa a biostatistics. W. H. Freeman and Company, San partir de antígenos de parásitos machos (52% de Francisco. protección) y hembras (62% ). Los antígenos de hembra también protegieron (40% ) con dosis Soulsby, E. J. L. 1958. Studies on heterophile anti­ bodies associated with helminth infections. 1. het­ bajas (2 mI 50 /1l/ml). erophile antibody in Ascaris lumbricoides infection in rabbits. Journal of Comparative Pathology and Therapeutics 68: 71-81. REFERENCES Soulsby, E. J. L. 1963. The nature and origin of the Ansari, J. A. 1964. Studies on Setaria cervi (Nematoda: functional antigens in helminth infections. Annals Filarioidea) Part 11. Its peritoneal transplant and of New York Academy of Science 113: 492-509. periodicity of the microfilariae in white rats. Zeitschrift fu r Parasitenkunde 24: 105-11l. Stromberg, B. E. & E. J. L. Soulsby. 1977. Ascaris suum: Immunization with soluble antigens in the Chandrashekar, R., U. R., Rao, G. R. Rajasekariah, & guinea pigs. International Journal for Parasitology D. Subrahmanyam. 1984. Separation of viable 7: 287-29l. .