Immune response and evasive strategies of helminth parasites – a review

Umapati Sahay^a*, Anita Jha^b & A.P.V.Khalkho^c
*aDepartment of Zoology, Ranchi University, Ranchi, Jharkhand, India
^bDept. of Zoology, Govt. Girls College, Gardanibagh, Patna
^cDept. of Zoology, Womens College, Chaibasa

Received 25th May, 2012; Revised:10 th August., 2012

Abstract : All animals inclusive of man are exposed to various types of infections (viruses to worms) and the host must defend themselves in case they want to survive. The parasite must also device strategies to adjust within the host’s environment. Once an invasion and establishment is achieved by the parasite, it is exposed to innate defences posed by phagocytic and inflammatory cells. The parasite either gets killed (phagocytosis) or has to face toxicity of cells.
The parasites are also exposed to host’s antibodies released from lymphocytes (T&B cells). The antibodies recognize the foreign molecules (antigens with epitopes) associated with invaders. Thus an immune response is created. In mammals & birds the adaptive immune response is linked to innate immunity.
The authors have incorporated and compiled in this article such immune responses in vertebrates with respect to helminth infection (Trematodes, cestodes & Nematodes) and have tried to mention the strategies taken by helminths to safeguard themselves from the immune attack of the host.
Although many a times, adults of the parasite are expelled in response to immune response yet the parasites are no less explorative, they as invaders have tried to explore the biology of the host during the course of evolution and by virtue of their trial, have become one of the most successful group, so much so that for evading host’s immune responses they have devised varieties of strategies. These strategies have been described and discussed.
Key words: Helminths, immune responses, evading strategies.