Serological evidences for a membrane structure related to human β₂‐microglobulin expressed by certain earthworm leukocytes

Abstract

Indirect immunofluorescence performed with 2 polyclonal and 4 monoclonal antibodies directed against human beta 2-microglobulin (beta 2m) revealed the presence of a beta 2m-like determinant on the membrane of a subpopulation of earthworm leukocytes classified as weakly adherent acidophils. Two out of the 4 monoclonal antibodies were found to bind to 15% of the earthworm leukocytes. Similar results were obtained with antibodies specific for beta 2m and isolated by affinity chromatography from either polyclonal antiserum or anti-beta 2m hybridoma supernatant. Additional binding inhibition and competition experiments strengthened the results and suggested that the homology between the structure present on earthworm leukocytes and human beta 2m may be restricted to only one major determinant. The existence of a beta 2m-like molecule in earthworms may provide important clues for understanding protein evolution and basic immune mechanisms.

Digging for innate immunity since Darwin and Metchnikoff

“…Positive responses of these cells to Thy-1 (CD90) and b 2 m confirm previous observations. (75,76) Large coelomocytes do not bind to K562 target cells but are mostly phagocytic and negative for the above markers. Both small coelomocytes and large coelomocytes are negative for other CD and MHC class I and class II markers.…”

Morphology, cytogenesis and functions of Annelida coelomocytes

“…Процесс фагоцитоза изучался на клетках дождевых червей как на модельном объекте, еще начиная с первых исследований Мечникова (Metchnikoff, 1893). Фагоцитарной активности целомоцитов олигохет посвящено достаточно много работ (Stein, Cooper, 1981;Shalev et al, 1981;Roch et al, 1983;Bilej et al, 1990;Dales, Kalaç, 1992;Cooper, 1996;Adamowicz, Wojtaszek, 2001), однако большинство носит морфологический или описательный характер. Изучение конкретных физиологических механизмов осуществления фагоцитоза у олигохет велось не так активно.…”

Innate Immunity in Lophotrochozoans: The Annelids

“…The use of monoclonal antibodies directed against several human CD markers enabled Cossarizza et al to focus on these two coelomocytes in E. fetida [14]: (1) the SC also called killer cells which are positive for CD11a + , CD45RA + , CD45RO + , CDw49b + , CD54 + , β 2 -m + and Thy-1 + (CD90) and (2) the phagocytic LC that are negative for these markers [15,16]. Both cell types were negative for numerous other CD and MHC class I and class II markers.…”