The ratio of helper T4 cell to suppressor T cells is normally 2:1.A lower-than-normal ratio may indicate acquired immunodeficiency syndrome (AIDS).This is because T4 cells
A) enhance humoral immune response.
B) suppress the humoral response.
C) suppress the cell-mediated response.
D) are a feature of an autoimmune disease.

Question

Quizplus · Accepted Answer

Once contact is made with a specific antigen,the T lymphocyte differentiates into helper/inducer T cells,suppressor T cells,and cytotoxic killer cells.Although these T cells are microscopically identical,they can be distinguished by proteins present on the cell surface called cluster of differentiation (CD).Helper T cells (also known as T4 cells because they carry a CD4 marker)enhance the humoral immune response by stimulating B cells to differentiate and produce antibodies.Suppressor T cells downgrade and suppress the humoral and cell-mediated responses.The ratio of helper to suppressor T cells is normally 2:1,and an alteration in this ratio may cause disease.For example,a depressed ratio (a decrease of helper T cells in relation to suppressor T cells)is found in acquired immunodeficiency syndrome (AIDS),whereas a higher ratio (a decrease in suppressor T cells in relation to helper T cells)is a feature of an autoimmune disease.

The Ratio of Helper T4 Cell to Suppressor T Cells