york academy

RECOGNITION MOLECULES OF THE ADAPTIVE IMMUNE RESPONSE

In the adaptive immune response, lymphocytes have unique recognition structures that allow them to see antigen. ♦B cell receptor (BCR)…

ANTIGEN PRESENTATION

The protective function of T cells depends on their ability to detect cells that harbour or internalise pathogens. T cells…

ANTIGEN (HLA) MOLECULES

HLA molecules are the human MHC molecules. HLA molecules play a pivotal role in the normal immune response, and inability…

ANTIGENS

The term antigen originally described any substance that could induce antibody formation. Antigens include proteins, carbohydrates, lipids and nucleic acids.…

THE DEFENCE SYSTEMS OF THE BODY FALL INTO THREE CATEGORIES

Non-immunological external defences ♦Innate immunity ♦Adaptive immunity. The principle difference between innate and adaptive immune responses is in pathogen recognition.…

THE MAJOR DEFENCE MECHANISMS AGAINST INFECTIONS

Microorganisms come in all shapes and sizes, with some penetrating into cells and others entering the body but remaining outside…

OVERVIEW OF CLINICAL MANIFESTATIONS AND TESTING FOR SPECIFIC COMPONENTS OF THE IMMUNE SYSTEM

Antibody deficiency most frequently results in recurrent and severe sinopulmonary infections with encapsulated bacterial strains (eg, Streptococcus pneumoniae, Haemophilus influenzae).…

INITIAL APPROACH TO THE PATIENT

Immune deficiency disorders should be considered once the more common causes of recurrent infection have been excluded. The initial approach…

CYTOTOXIC T CELLS

Cell mediated immunity involves two separate populations of T cells: helper T cells (THs) and cytotoxic T cells (TCs). Viruses…

IMMUNOGLOBULIN FUNCTION

Antibody binding to pathogen is not sufficient to kill the organism. The Fc portion of immunoglobulin (Ig) can recruit complement…