Q.Explain the prevention of graft rejection in the clinical field.

B-lymphocytes produce antibodies and mediate the humoral immune response; T-lymphocytes handle cell-mediated immunity.

Acquired immunity has two arms. In the humoral immune response (also called antibody-mediated immune response, AMIR), B-lymphocytes produce antibodies (proteins) that circulate in the blood plasma ('humor') and fight pathogens. In contrast, T-lymph …

T-Lymphocytes carry out cell-mediated immunity; B-Lymphocytes carry out antibody (humoral) immunity.

The adaptive immune system has two arms:

• Humoral immunity — carried out by B-Lymphocytes, which differentiate into plasma cells that secrete antibodies into blood/lymph to neutralise pathogens/toxins. …

Antibodies are produced by plasma cells, which arise when B-lymphocytes are activated by exposure to a specific antigen.

B-lymphocytes are the cells responsible for humoral immunity. When a B cell encounters and recognises an antigen (often with the help of helper T cells), it becomes activated and proliferates, differentiating into two main types of cells: plasma cells, which actively secrete large amounts of antibodies specific to that antigen, and memory B cells, which persist …

'T-Lymphocytes' pairs with option (a) 'bone marrow' — the site where these immune cells originate.

Lymphocytes, the key cells of the specific (adaptive) immune system, are of two main types — B-lymphocytes and T-lymphocytes. Both types originate from stem cells present in the bone marrow.

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Immunity is mediated chiefly by two classes of lymphocytes — B-cells, responsible for antibody-mediated (humoral) immunity, and T-cells, responsible for cell-mediated immunity.

The adaptive immune system relies on two major populations of lymphocytes that mature in different primary lymphoid organs. B-lymphocytes mature in the bone marrow and, upon activation, differentiate into plasma cells that secrete antibodies, providing humoral (antibody-mediated) immunity. T-lymphocytes mature in the thymus and are responsible for cell-mediated immunity, which includes helper T-cells (that assist B- …

Cyclosporin A is the classic immunosuppressive drug used to prevent transplant rejection.

Cyclosporin, originally isolated from the fungus Tolypocladium inflatum, blocks the activation of T-lymphocytes (by inhibiting calcineurin and IL-2 production), dampening the immune response that would otherwise attack a transplanted organ as foreign — this is why it is a mainstay of post-transplant therapy. Anthromycin and Amantadine are antimicrobial/antiviral agents, and Imidazole compounds are mai …

Humoral immunity is antibody-mediated; it is executed by B-lymphocytes, in contrast to cell-mediated immunity executed by T-lymphocytes.

The adaptive (acquired) immune response has two arms: humoral immunity (antibody-mediated immunity, AMI) and cell-mediated immunity (CMI). Humoral immunity is carried out by B-lymphocytes: when a B-cell encounters its specific antigen (with helper-T-cell assistance), it proliferates and differentiates into plasma cells that secrete large quantities of soluble antibodies into blood and lymph (the body's "humors" — hence the name); some B-cells become long-lived memory cells. These circulating antibodies neutralise or tag extracellular pathogens and toxins for destruction.

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