Immune System of Animals

Shyamasree Ghosh

• Publisher: De Gruyter
• Year: 2022
• eBook ISBN: 9783110654172
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Biochemistry

Applications of nanoparticles to the human life and tools in diagnosis and therapy in field of clinical medicine holds importance and has been an prime focus of biomedical and clinical research for quite sometime, though their application in veterinary medicine is a relatively new focus area of research. Prior to human applications, studies are initially conducted on animals models. Thus toxicity based studies and study of impact of nanoparticles on animal immune system finds importance. In the second volume of the book we discuss the immune system in animals across invertebrates and vertebrate phylas and discuss the impact of nanoparticles in animals life, health, survival and immune system. The book highlights the toxic effects of nanoparticles as environmental pollutants and their adverse impact on animal life forms. Both volumes are also included in a set ISBN 978-3-11-065666-4.

1 Nanoparticles and porifera

Shyamasree Ghosh

School of Biological Sciences, National Institute of Science Education and Research (NISER)Bhubaneswar an OCC of Homi Bhabha National Institute, Bhubaneswar, India

Abstract

Sponges are primitive organisms without organs but with cells to perform vital and different functions. Inhabiting the marine habitat, they are often exposed to harmful stress factors of the environment. In this chapter, we highlight the immune molecules in sponges and reveal the impact of exposure of sponges to nanoparticles and the negative impact of nanoparticles on sponge health, physiology, and immune responses.

Keywords: Sponge, porifera, nanoparticles, oxidative stress,

Abbreviations

Suberites domuncula

S. domuncula

Geodia cydonium

G. cydonium

Cysteine

C

Toll-like receptors

TLRs

Pattern recognition receptors

PRRs

Lipopolysaccharide

LPS

2′,5′-Oligoadenylate synthetase

OAS

Mesencephalic astrocyte-derived neurotrophic factor

MANF

Silver nanoparticle

AgNP

1.1 Introduction

Sponge or phylum Porifera (Fig. 1.1) includes the most primitive group of multicellular animals, lacking organs, but has a well-developed connective tissue and cells with different functions. Sessile forms are with well-developed water canal systems. With a few freshwater species, most of the 5,000 described species reveal marine existence. Rocks, shells, coral, soft sand, and mud act as their substratum. They may live in shallow waters or in deep waters. Sponges are of different sizes ranging from the size of a grain to more than a meter in height ad diameter. They exhibit radial symmetry. Most species are brightly colored like green, orange, red, and purple.

Fig. 1.1: Some common sponges from India. Picture courtesy Director, Zoological Survey of India, Kolkata 700053, India.

The sponge architecture reveals a water canal system, the simplest being in the asconoid sponges, for example, Leucosolenia. Here the body is perforated by several pores called ostia, which are the incurrent pores that open into the interior cavity called spongocoel, which then opens out through a large opening called as osculum. The body wall is simple with the outer face covered by pinacocytes and together comprises the pinacoderm which secretes the material that enables the sponge to attach to the substratum. The skeleton is rather complex comprising calcareous or siliceous spicules, protein spongin fibers, or combination of all of the three components.

The skeleton is located in the mesohyl with spicules projecting through the pinacoderm which may remain in interlocked or fused form. Mesohyl contains collagen fibrils, and some sponges contain skeleton comprising interconnected fibers. Sponges bearing excessive spongin make them tough and rubbery and with the siliceous spicules embedded partially in the fibers that stiffen them.

Ameboid cells in the mesohyl include archeocytes with large sized nucleus, which are phagocytic with roles in digestion. They bear the property of totepotency that gives rise to new and different cells. The other types of cells include the collencytes which are fixed by long cytoplasmic strands and play a role in secretion of collagen fibers. Sclerocytes secrete single spicules in calcareous sponges while spongocytes secrete the spongin skeleton. In the interior side of the mesohyl, the spongocoel is lined by the ovoid-shaped choanocytes, bearing similarity to protozoan choanoflagellate. On the one side, the choanocyte projects into the spongocoel, bearing a flagellum surrounded by microvilli. Sponges are devoid of gut.

The Syconoid sponges exhibit radial symmetry and folded body, for example, genus Grantia and Sycon. Choanocytes here line the invaginations called the radial canals. The invaginations extend outward from the spongocoel. In more complex forms, the choanocytes line the radial canals. The invaginations from the pinacoderm end are lined by pinacocytes and termed as incurrent canals and the two canals are interconnected by prosopyles. Water enters through the incurrent canals, passes through the prosopyles, flagellated canals, spongocoel, and moves out of the osculum. In further complex forms, pinacocytes and mesohyl block the open ends of the incurrent canals, and only water enters through ostia into incurrent canals.

Leuconoid sponges reveal the most complex form, where the flagellated canals form small flagellated chambers. Water flows in through ostia, passes into spaces flowing into branched incurrent canals that open into flagellated chambers through prosopyles, and water leaves through the apopyle and flows out through excurrent canals, and all canals open out through osculum. Pinacocytes line the inner side of all canals. Due to the efficient water canal system, they are large sized with greater mass. They reveal diversity in body forms of erect, flattened, vase shaped, or tubular forms, that is, body with many ostia and one osculum [1, 2, 3, 4].

The World Porifera Database has been designed with updated global biodiversity of Porifera with members of known classes [2].

Over more than 3,500 compounds, identified till 1998, isolated from Porifera have been applied to sponge systematics, and classification and identification of 475 species of marine sponges. However, this mode of classification faces the challenges of lack of identification of source of chemicals from the endosymbionts of poriferan host [4], and thus reliability of classification based on these chemicals is difficult.

1.2 Immune molecules and Porifera

Porifera or sponges are a primitive metazoan phylum with common ancestor with other metazoan phyla. Most of our knowledge on the immune molecules of sponge is based on studies from marine demosponges including Geodia cydonium (G. cydonium) and Suberites domuncula (S. domuncula). Sponges have immune molecules bearing similarity in structure to mammalian innate immune system molecules including molecules with scavenger receptor cysteine (C)-rich domains, cytokine-like molecules released by macrophages, 2′,5′ oligoadenylate synthetase (OAS) as revealed from grafting experiments in marine demosponges including G. cydonium and S. domuncula. Molecules with properties of the adaptive immune system have been recorded in sponges, including cytokines from lymphocytes that enable self- versus non-self-recognition in S. domuncula and in G. cydonium, and receptors with Ig-like domains including receptor tyrosine kinases and sponge adhesion molecules with polymorphic Ig-like domains that reveal to be overexpressed during grafting, thereby playing a role in adaptive immune recognition [5].

Molecules recognizing cell–cell and cell–matrix have been reported in the immune system of sponge. They reveal the evolution of antimicrobial and antiparasitic defense mechanisms by engulfment and killing of bacteria by lipopolysaccharide (LPS)-mediated pathway, role played by kinase, and presence of interferons. Cytokines like allograft inflammatory factor 1 play a ro...

Table of contents

• Title Page
• Copyright
• Contents
• 1 Nanoparticles and porifera
• 2 Cnidaria immune system and nanoparticles
• 3 Caenorhabditis elegans and nanoparticles
• 4 Insects and nanoparticles
• 5 Nanoparticles and the immune system in Mollusca
• 6 Echinodermata and the immune system
• 7 Fish and nanoparticles
• 8 Nanoparticles and bird’s immune system
• Index