A study of the secretory immune system of the female genital tract.

Immunocytes in the female genital tract are found principally in the endocervix. The predominant immunoglobulin produced in this site is IgA and this, together with the presence of secretory component in endocervical epithelium, indicates that a local secretory immune system, similar to that found in the gastrointestinal and respiratory tracts, exists in the endocervix. This local secretory immune system appears to be the major source of immunoglobulins in cervical mucus and the presence of secretory IgA in cervico-vaginal secretions provides an effective protection mechanism against viral and bacterial infections. Secretory IgA also acts non-specifically against exogenous antigens and may, by binding spermatozoal antigens, play a role in immunologically mediated infertility.