Cocaine abuse is common in pregnant and nursing women. Newborns depend on maternal immune components, passaged during gestation and lactation, for protection during the neonatal period. This protection is derived from placental transmission of antibodies and lactational transfer of both antibodies and leukocytes in milk. Recognition that cocaine is immunosuppressive, that it passes through the placenta and appears in milk, lead to the concern that infants of mothers using cocaine may be immunologically compromised. The objective of this study is to determine the periods at which maternally ingested cocaine interferes with the immunological protection of the neonate. A well established model using rats infected with Trichinella spiralis (T. spiralis) will be used in this investigation. The aims are to determine if maternal cocaine use: 1) affects the capacity of maternal lymphoid tissues to generate adequate numbers of T cells (including helper and suppressor/cytotoxic subsets), B cells, accessory cells or levels of specific antibodies adequate for transferring immunity to neonates; 2) alters the tissue distribution and numbers of immune cells or levels of specific antibody in the mammary gland and milk; and 3) affects the placental and lactational transfer of cellular and humoral immunity to the neonate. Pregnant rats infected with T. spiralis will be used to study maternal immune reactions. Lactational transfer will be studied by immunizing the dams with the antigen and assaying the pups for specific immunity. FACS analysis and immunocytochemistry will be used to assess the effects of cocaine on the numbers and distribution of T, B and macrophages subsets in maternal and neonatal lymph nodes and milk. The capacity of T and B lymphocytes to proliferate in response to mitogens and antigen stimulation will be determined with in vitro proliferation assays. ELISA will be used to detect specific antibodies. A functional test will include worm expulsion for T. spiralis. An understanding of the effects of maternal cocaine on the passage of immunity during pregnancy and nursing and on neonatal immune development may help to explain the increased risk infants have to disease during the neonatal period. Since an increasing number of women in high risk populations for AIDS abuse cocaine and are already immunocompromised, this research has significant implications to the well-being of infants born to these women.