Cellular Immunity

In cellular immunity, cells play the most important role in destroying foreign invaders. The cells involved are macrophages and the various subsets of T cells: helper CD4+ cells, suppressor CD8+ cells, cytotoxic T killer cells, and natural (NK) killer cells. Monokines and lymphokines secreted by macrophages and CD4+ helper cells, respectively, play an important role in directing and augmenting both cellular and humoral immune responses.

Cellular Cooperation

Macrophages, CD4 (helper) cells, CD8 (suppressor) cells, cytotoxic T killer cells (also CD8+), and B cells all cooperate to produce and regulate the immune response (Figure 2-4).

Enrichment activity #2

Visit Cells of the immune system and, based on the information, answer the following questions. E-mail responses to Pat.

  1. In the blood film shown at the bottom of the page, click on the picture of the monocyte. By which name are monocytes known as

    (a) in the liver?

    (b) in the brain?

    (c) in the kidney?

    (d) in bone?

    (e) in other tissues and organs?

  2. Phagocytosis includes several stages. Using your own words, briefly describe

    (a) chemotaxis

    (b) adherence

    (c) pseudopodium formation

    (d) phagosome formation

    (e) phago-lysosome formation

    (f) antigen presentation

    (g) opsonization

  3. At Specific immunity , read the following sections:

    (a) Concisely explain the Jerne-Burnet theory of clonal selection.

    (b) According to this theory, the immune system needs to be able to create an enormous number of antibodies, e.g., perhaps 10 billion B lymphocytes, each able to produce more than 100 million different antibody proteins. Since humans have only about 100,000 genes, it becomes impossible for our genes to specify each one of these proteins. What did Tonegawa discover about immunoglobulin genes that accounts for the the tremendous diversity of antibodies that humans are capable of producing?

Cellular Immunity