Category: Basic Sciences

Introduction to the complement system Term ‘complement’ means to augment the effect of other components of the immune system. The complement system is a group of more than 23 proteins that interact with each other to opsonize the pathogen and induce a series of inflammatory responses that help to generate an immune response against that…

Introduction to cellular immune response During embryonic development, the blood cell precursors originate mainly in the yolk sac and fetal liver. These cells differentiate into myeloid and lymphoid series. Lymphoid series leads to the development of B-lymphocytes, T-lymphocytes, and NK cells, and myeloid series leads to the formation of monocytes and macrophages, erythrocytes,  neutrophils, basophils,…

Introduction to the major histocompatibility complex Cellular interactions are very important for the recognition and presentation of antigens to the immune system by antigen-presenting cells 13, 14. The primary components of these interactions are the T-cell antigen receptor (TCR) and the Major histocompatibility complex (MHC)/human leukocyte antigen (HLA) molecules. The major function of the TCR…

Introduction to humoral immunity Humoral immunity is the type of host defense that is mediated by antibodies, the products of B-cells. Antibodies are secreted into mucosal lumens, blood, and interstitial fluids, and combat microbes at all these sites. As already stated, B-cells are the source of antibodies, let us first understand the development and maturation…

Introduction to congenital immunodeficiency conditions Immunodeficiency can be broadly classified as primary or secondary. Primary immunodeficiency results from inherited immune disorders associated with genetic mutations, usually present at birth and diagnosed in childhood. On the other hand, secondary immunodeficiency is also referred to as acquired immunodeficiency that results from disease or environmental factors, such as…

Introduction to hypersensitivity Hypersensitivity is an exaggerated or inappropriate reaction harmful to the host. The first response sensitizes the immune system and subsequent contacts cause an allergic reaction. Hypersensitivity is of four types; Type I hypersensitivity – Anaphylactic shock. Type II hypersensitivity – Cytotoxic hypersensitivity Type III hypersensitivity – Immune complex hypersensitivity.  TYPE IV hypersensitivity…

Introduction to immunity Immunity is defined as resistance to disease, specifically infectious disease. The immune system is the collection of cells, tissues, and molecules that functions to defend us against infectious microbes. The main function of the immune system is to prevent or limit infections. This defense function of the immune system is essential for…