SOME IMMUNE RESPONSE MECIIAMSMES OF THE COTTON LEAF WORM SPODOPTERA LITTURALIS AND THE SILK WORM BOMBYX MORITO SOMI BIOLOGICAL AND NON-BIOLOGICAL AGENTS

Abstract

The immune system of invertebrates increases attention for many workers in recent years (Brehelin, 1986; Lackie, 1986; Riley and Chappel, 1992 and Amen et al 1992).

Invertebrate defence mechanisms are less complex than those of vertebrates which exhibit integrated cell-mediated and humoral immunity, complex immunoregulatory mechanisms and multiple molecular classes of immunoglubulins (Brehelin, 1986). In mammals, this is known to be accomplished through

specific antibodies, T-lymphocytes and/or the complement

pathway.

Invertebrates by

contrast, do

not

express

immunoglobulin and do not have cell analogues to mammalian

lymphocytes. However, a number of workers, not;ably Day et al

(1970)

and

Bertheussen

(1984)

have suggested that

invertebrates might possess molecules akin to complement, for arthropods at least, the prophenoloxidase activating system constitutes such a complement-like pathway in host immunity (Soderhiill, 1982 and Wheeler et al, 1993). J t is also noted that substances with agglutinating activity serve recognition molecules in the immunoserveillance system of some insects, thus facilitating the detection and uptake of foreign materials by phagocytes (Scott, 197m). Agglutinins (haemagglutinin, lectin) are proteins or glucoproteins that specifically bind to carbohydrates and glucoconjugates frequently causing their precipitation or agglutination (Lis and Sharon, 1986), they occur upiquitously throught plants,