Phagocytes in the kidney of kuruma prawn

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Eighth JADCI abstracts

function as a helper for in vivo chemotaxis of CD4’T cells by IL-8. 4) Infiltration of neutrophils is required for tumor associated antigen VAA) specific tumor transplantation immunity aud establishment of TAA specific CD8T effector cells. These results suggest that neutrophils function not only as killers of bacteria but also as modulators of responses from acute inflammation to immunity. IDENTITY OF THE S6. PRESUMPTIVE SECOND TYPE OF WAS THE MACROPHAGE Shigeru CELL. DENDRITIC Muramatsu. Kyoto University, Kyoto 606, Japan. Until about fifteen years ago, macrophages, especially Ia+ ones, were generally thought to be unique and highly active antigen presenting cells for helper T cells in the initiation of immune responses. At that time, we were investigating the ontogeny of phagocytic activity and antigen presenting activity of murine splenic and We found that peritoneal macrophages. phagocytic activity was considerably high and antigen presenting activity was negligibly low in newborn macrophages in comparison with those in adult macrophages. Thus, we assumed that the existence of a second type of macrophage which was Ia’ and its phagocytic activity was lower and antigen presenting activity higher than the first type of macrophage. Later we found that the identity of such a second type of macrophage per se was not a macrophage but a different type of nonphagocytic and macrophage-like cell, called lymphoid dendritic cell. Now, it is well known that a group of cells collectively called dendritic cells are unique antigen presenting cells for resting (Co) helper T cells, whereas Ia’ macrophages and B cells (all Ia’ ) are those for helper T cells in the cell cycle. Therefore, immune responses are not initiated without dendritic cells. Dendritic cells must have coevolved with lymphocytes, so thal their phylogenetic origin will be an

important and intriguing comparative immunology.

GENERAL

LECTURES

(A) Immunodefense Arthropods and Annelids

subject

in the

(A,B,C,D,E) System

in

THE Al. PHAGOCYTES IN KIDNEY OF KURUMA PRAWN. Masakazu Kondo, Toshiaki Itami*, Reiko Yukinori Takahashi*, Fujii**, and Susumu Tomonaga**. On0 Station, Limnological National 754-13, Fisheries Universiq, Vbe *Department of Aquaculture and Biology, National Fisheries University, Shimonoseki 759-65, **School of Allied Health Sciences, Yamaguchi University, Ube 755, Japan.

Mammals have phagocytic cells, the mesangial cells, in their kidneys. Crustaceans have an excretory organ, the so-called antenna1 gland or kidney which opens at the base of the second antenna, however, the presence of phagocytes in this organ has not yet been reported. ln the present study, we injected colloidal carbon and latex beads intramuscularly and investigated the occurrence of phagocytic cells in the kidney of kuruma prawn, Penueus juponicus. Injected colloidal carbon or latex beads were found in small cells located on the basement membrane of renal tubules. These cells were often observed as an aggregated cluster. ln addition, large cells with numerous lysosomal granules and a few phagosomes were observed consistently in the lumens of renal tubules, although injected substances were not found in the cells. These findings suggest that: 1) there are two types of phagocytes in the kidney of kuruma prawns; 2) those cells may participate actively in the host immunodefense mechanisms. A2. LIPOPOLY SACCHARIDEBINDING PROTEINS IN THE LARVAL HEMOLYMPH OF THE