Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Biology and Microbiology


The lymphatic system of an animal is optimally developed to protect the body from antigenic invasion. The epithelial and subepithelial compartments of the body are provided with a vast number of wandering cells and a network of centralized lymphorecticular tissues. All of these are capable of reacting to intruding foreign antigens. Upon antigentic challenge, immunocompetent cells (ICC) or antigen specific lymphocytes are activated; this leads either to cell mediated and/or humoral antibody immune responses. The subsequent effect is an accumulation of the responding cells, both by local proliferation and recruitment from the circulation. Through the interaction of both cellular and humoral components of the immune system, the phagocytic cells and the complement system are activated, thereby leading to the localization, destruction, and elimination of the actigen. Collectively, this set of phenomena is called an immune response. In the course of this response, immunologically committed cells are released from initially activated lymphoid tissue via the efferent lymphatic ducts and the bloodstream to other lymphoid organs with resulting logarithmic amplification of the immune response and the development of the capacity to respond much more efficiently to the second encounter with the same antigen. The immune response to most pathogenic antigens (such as bacterial, fungal, and viral infections) cannot be initiated without the complex reaction of phagocytosis by the macrophages and, probably, by the monocytes.

Library of Congress Subject Headings

Equine encephalomyelitis

Immune response


Computer simulation



Number of Pages



South Dakota State University