Physiological and immunological profiles after intrauterine immunization

The ability to respond to antigen by production of specific antibodies without disturbance of the physiological integrity of the organism (physiological immunocompetence) was studied in pig fetuses. Closed surgery technique was used to expose the fetuses. Flagellin in non-complete adjuvant was used as antigen. Fetuses were immunized on day 54 of gestation, i.e. in the period when T-B dichotomy in secondary lymphatic organs (SLO) as principal sign of differentiation is already present. The intrauterine immunization resulted in increased numbers of agranulocytes in SLO and blood and increased activity of their gamma-glutamyl transpeptidase. Increased concentration of total proteins with predominant increase of albumins and gamma globulins along with a decrease of actual amount of alpha-1-fetoprotein was found in blood serum of immunized fetuses. Shift of maturation curves of erythroid and myeloid line to younger developmental forms appeared in haemopoietic organs of these fetuses. In fetuses immunized on day 74 of gestation a typical cytological immune reaction "of adult type" was observed. It was characterized by multiplication of lymphocytes of all size categories and their differentiation to plasma cells.