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    My textbook says: T memory provides long term immunity and B memory provides immunological memory.

    Whats the difference?


    It is important to understand the difference between B lymphocytes and T lymphocytes in general first, after which the answer to your Q will follow.

    B lymphocytes (B cells) are derived from the Bursa of Fabricius of birds (now vestigial in humans after birth). They are involved in humoral immunity i.e. immunity executed by antibodies (if you are doing biology or immunology at degree level, you will know that there are five main classes of antibody: IgA, IgD, IgE, IgG and IgM, depending on the type of light chain they contain: alpha, delta, epsilon, gamma, or mu respectively), and the production of monoclonal antibody (immunoglobilin or gamma-globulin) is the job of plasma cells, which are derived from B cells when they are activated by the recognition of an antigen by antigen-presenting cells. Some of these persist to produce a very quick immune response in the form of prodution of large numbers of specific antibody on second-time exposure to the same antigen. THESE ARE MEMORY B CELLS.

    T cells are derived from the thymus gland (in the chest, just posterior to the sternum [breast bone]). They are concerned with cell-mediated immunity i.e. the engulfment (phagocytosis: phago = ingest cyte = cell therefore phgocyte = "eating cell"). When stimulated by specific antigen, these T cells engulf organisms (usually viruses - this is the reason for AIDs patients acquring severe viral infections like CMV and toxoplasmosis, since HIV attacks T cells mainly) and then break them down in their lysosomes (Greek lysis = breakdown as in haemolysis = destruction of blood cells). This process is aided by some types of antibodies = opsonisation. In case of invasion by the same organism again, MEMORY T CELLS multiply very fast to produce a massive army of T cells (phagocytes: other phagocytes are neutrophils and macrophages) that will hopefully "eat up and digest" all organisms, thus containing the infection.

    There are also helper B cells and helper T cells that assist in cell-mediated and humoral immunity, respectively

    I hope this helps.

    M (Biology tutor)

    T memory cells don't secrete into amtibodies because T cells don't produce antibodies. Instead the t memory cells activate killer T cells which puncture the cell wall of the bacteria. B memory cells divide into plasma cells which secrete thousands of antibodies per second
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