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cellular, molecular and immunological basis of host- parasite relationship: special emphasis on protozoa

ROLL NO- PS-211-805-0011 DEPT. OF BIOTECHNOLOGY 4TH SEMESTER GAUHATI UNIVERSITY

contents

1. WHAT IS HOST PARASITE RELATIONSHIP ?

2. general aspects of the host-parasite relationship

3. general aspects of the host-parasite relationship

4. examples of host-parasite relationships

5. Protozoa: Overview

6. Cellular Basis of Host-Parasite Relationships

7. Molecular Basis of Host-Parasite Relationships

8. Immunological Basis of Host-Parasite Relationships

9. Thanks

WHAT IS HOST PARASITE RELATIONSHIP ?

The host-parasite relationship refers to the dynamic interaction between a host organism and a parasite, where the parasite relies on the host for survival, reproduction, and/or nourishment, while the host is harmed or affected in some way by the presence of the parasite. This relationship can occur in various organisms, including animals, plants, and even humans.

general aspects of the host-parasite relationship

Parasites are organisms that cannot survive independently and require a host organism to complete their life cycle, obtain nutrients, and reproduce. The presence of a parasite within the host typically triggers a response from the host's immune system, aiming to eliminate or control the parasite. The host-parasite relationship often involves coevolution, where the parasite and host continually adapt to each other. The cellular, molecular, and immunological aspects of host-parasite relationship to gain insights into parasite biology, host immune responses, and factors influencing disease outcomes. This knowledge helps in developing strategies to prevent or minimize the impact of parasitic infections on human, animal, and plant health.

examples of host-parasite relationships

Human intestinal parasites

Dog heartworm (Dirofilaria immitis and dogs)

Cuckoo and host birds

Malaria (Plasmodium and humans)

Dirofilaria immitis is a nematode parasite transmitted to dogs through mosquito bites.

Ascaris lumbricoides is a large roundworm that infects the human intestines.

Cuckoos are brood parasites that lay their eggs in the nests of other bird species.

The protozoan parasite Plasmodium causes malaria in humans.

Protozoa: Overview

Protozoa are single-celled organisms that can infect humans and animals. They are classified based on their mode of movement, shape, and other characteristics.Some common protozoan parasites include Plasmodium (which causes malaria), Trypanosoma (which causes African sleeping sickness), and Giardia (which causes diarrhea).

Cellular Basis of Host-Parasite Relationships

Protozoa enter the host's body and interact with various cells, including macrophages and dendritic cells. These cells play a crucial role in the immune response to the parasite.Protozoa can also invade host cells and replicate within them, leading to tissue damage and inflammation.

Molecular Basis of Host-Parasite Relationships

Protozoa can secrete molecules that help them evade the host's immune system and establish an infection. For example, some protozoa can modify their surface proteins to avoid detection by antibodies.In response, the host can produce antibodies that target specific molecules on the surface of the parasite, leading to its destruction.

Immunological Basis of Host-Parasite Relationships

The immune response to a protozoan infection involves both innate and adaptive immunity. Innate immunity provides immediate protection against the parasite, while adaptive immunity develops over time and provides long-lasting protection.However, some protozoa can evade or suppress the host's immune response, leading to chronic infections and disease.

Thanks!