Appeal No. 1999-1396
Application No. 08/524,668
antigens involved in the infection and invasion of host lymphocytes . . . [and] for detecting
the occurrence of parasite infection.” Page 3. Claims 1 and 2 are directed to a chicken
monoclonal antibody (and a chicken hybridoma secreting it) specific for antigens “located
on the conoid of the anterior tip of Eimeria acervulina sporozoites.”2
DISCUSSION
Murray describes preparation of an immunogenic extract from freeze thawed and
sonicated Eimeria acervulina sporozoites. Intramuscular immunization of young chickens
with the sporozoite extract protected them against subsequent oral challenge with infective
E. acervulina sporulated oocysts. Example 10. Coomassie blue staining and comparison
of the extract with molecular weight markers revealed 31 polypeptides ranging in size from
about 300 kD to about 13 kD. None of the polypeptides were isolated from the extract, but
Western Blot analysis using polyclonal rabbit anti-E. acervulina sporozoite immune serum
showed that “[o]f these polypeptides, 20 are immunodominant i.e., the 20, 21.5, 22.5, 23,
24, 26, 26.5, 27, 29, 31, 34, 37, 41.5, 45, 59, 65, 68, 74, 84 and 115 kD molecular weight
polypeptides.” Column 1, lines 59-68, and column. 3, lines 9-25. Polyclonal rabbit anti-E.
acervulina sporozoite immune serum was able to agglutinate sporozoites in vitro, and
preincubation of intact sporozoites with the rabbit immune serum neutralized the infectivity
of the sporozoites in chickens. Example 5, column 5, lines 26-68.
2According to the specification, the conoid is “a basket-like meshwork of spirally
woven microtubules” which “aids in the penetration of host cells.” Page 8. “[A]ntigens of
the conoid” are believed to “play a role in the parasites’s recognition and initial adherence
to the host cells.” Page 9.
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