Sheep form of leucocyte function antigen-3 (T11TS) exerts immunostimulatory and anti-tumor activity against experimental brain tumor. A new approach to biological response modifier therapy.

In order to establish the mechanism(s) of immunomodulatory and anti-tumor properties of sheep erythrocytes (SRBC), the T11 target structure (T11TS) or CD58 molecule as a pertinent component of SRBC was isolated, purified and finally administered in rats with experimentally induced brain tumor. Results showed inhibition and/or abrogation of tumor growth. Subsequent studies on cellular immunity also revealed potentiation of lymphocytes and PMNs at peripheral level. Presence of activated lymphocytes as revealed through flowcytometric analysis of CD25 expression evidenced infiltration of activated lymphocytes in the brain tumor tissues. The analysis of data suggests that T11TS or sheep form of LFA3 is capable of inhibiting/preventing tumor growth in rat brain by way of immunopotentiation (CMI) at the peripheral immune system and thereby facilitating infiltration of the activated lymphocytes into the brain cavity through the blood brain barrier.