Multiple oral inoculations with Cryptosporidium parvum as a means of immunization for production of monoclonal antibodies.

Oral immunization of suckling mice with Cryptosporidium parvum results in a humoral response to a limited set of antigens. Six-day-old BALB/c mice were each inoculated orally with 1 x 10(6) viable oocysts and subsequently administered oral inoculations of 2 x 10(6) viable oocysts at 30 and 60 days following the primary infection. After 45 days, mice were boosted with 1 x 10(6) oocysts orally, plus soluble extracts equivalent to 2 x 10(6) and 1 x 10(6) oocysts given intravenously and intraperitoneally, respectively. Four days later, splenic lymphocytes were fused to Ag8 myeloma cells. Using this method, we have been able to select for monoclonal antibodies that predominantly recognize sporozoite surface and apical complex antigens.