The cellular responses inMarisa cornuarietis experimentally infected withAngiostrongylus cantonensis

Abstract

The cellular responses in the poorly susceptible ampullariid snail Marisa cornaurietis to Angiostrongylus cantonensis, during a period of 40 days, involved focal and generalized proliferative reactions. The focal reactions appeared around all larvae as accumulations of variable numbers of amoebocytes at 24 h after infection in the loose connective tissues and somewhat later in the dense tissues. This cellular infiltration intensified gradually with time leading to the encapsulation of the parasite. At 18 days after infection a central zone formed mainly of hypertrophic, granular, highly acidophilic amoebocytes and a peripheral zone of fibrous appearance were conspicuous in most capsules. The generalized proliferative reaction appeared at about day 4 after infection as leucocytosis in the vascular system of the snail and in the connective tissue. At 25 days after infection many leucocytes which are markedly hypertrophic, highly eosinophilic, and densely granulated were found in the vascular system. These cells were spread in the connective tissues and contributed to the formation of the capsules at 40 days after infection. The sources of amoebocytes appear to be mainly several hyperactive areas in the loose connective tissue and in the lung, some active foci in the body wall at the head region, and also in an amoebocyte-producing organ which lies in the roof of the lung.

Immune Defenses of the Invasive Apple Snail Pomacea canaliculata (Caenogastropoda, Ampullariidae): Phagocytic Hemocytes in the Circulation and the Kidney

“…canaliculata as the most frequent intermediate host in China, i.e., in the native range of the parasite [ 52 ]. Experimental infection with parasitic larvae has been obtained in another ampullariid snail, Marisa cornuarietis , and hemocyte aggregates have also been reported in the lung of infected snails [ 53 ]. Even though the lung of uninfected P .…”

Insights from an Integrated View of the Biology of Apple Snails (Caenogastropoda: Ampullariidae)

“…However, "amoebocyteproducing organs" have also been reported in the pericardial wall of some heterobranchs (Lie et al, 1975;Rondelaud & Barthe, 1982;Jeong et al, 1983;Ruellan & Rondelaud, 1992) and in the roof of the lung of M. cornuarietis (see Yousif et al, 1980). No such organs have been found in P. canaliculata, although spheroidal hemocyte aggregates, similar to those formed in vitro (Cueto et al, 2013), were found in the lung following injection of yeast cells into the visceral hump (Rodriguez et al, 2012), suggesting a role of the hemocytes in fighting infection.…”

“…They serve a variety of functions, such as recognition and phagocytosis of invaders (Bayne, 1983), capsule formation around parasites (e.g., Yousif et al, 1980;Lv et al, 2009b), hemostasis, wound healing, shell formation and repair (Franchini & Ottaviani, 2000) and storage/transport of nutrients (e.g., Travers et al, 2008). Hemocytes have also been involved in stress response through the release of vertebrate-like endocrine molecules .…”

Assessment of the kidney and lung as immune barriers and hematopoietic sites in the invasive apple snail Pomacea canaliculata

“…Gastropod hemocytes recognize and phagocytize invaders, entrap them through nodulation ( Sminia, 1981 ) and/or they also encapsulate foreign objects too large to be engulfed ( Godoy et al, 1997 ; Lemos & Andrade, 2001 ; Lv et al, 2009b ; Sminia, Borghart-Reinders & Van de Linde, 1974 ; Van der Knaap, Adema & Sminia, 1993 ; Yousif, Blähser & Lämmler, 1980 ). Knowledge on the immune system of Pomacea canaliculata (Lamarck 1822, Ampullariidae) is becoming increasingly important, because of the role of this species as an intermediate host and vector of the nematode Angiostrongylus cantonensis (Chen 1935, Metastrongylidae), the major etiologic agent of eosinophilic meningitis, a parasitic disease that can be disabling in humans, and may be even fatal ( Cowie, 2017 ; Martins, Tanowitz & Kazacos, 2015 ).…”