Explain why expression of CD40 ligand by TFH cells is important in the boundary area of primary follicles in secondary lymphoid tissue as it relates to the targeted delivery of secreted cytokines to the B-cell surface
What will be an ideal response?
CD40 ligand on TFH cells binds to CD40 on B cells, signaling B cells to activate NF?B. NF?B is a transcription factor that upregulates ICAM-1 expression on B cells, which binds to LFA-1 on the TFH cell. As a result, cognate interactions between the B cell and TFH cell are strengthened, and a synapse at the point of contact facilitates the reorientation of the T-cell cytoskeleton and secretory apparatus of the Golgi. This ensures that T-cell cytokines are released onto a localized area of the B-cell surface.
You might also like to view...
Which of the following is (are) characteristic of B memory cells?
A) Die several weeks after antigen encounter unless the host is reexposed to the same antigen. B) Reside exclusively in the bone marrow. C) Express more complement receptors and adhesion molecules than a mature B cell. D) All of the above.
An alpha motor neuron and all the muscle fibers innervated by it make up the elementary component of motor control called the motor unit
Indicate whether this statement is true or false.
People with anorexia are usually healthy looking, well-educated, near recommended body weight, and seem to enjoy food and often socialize around it.
Answer the following statement true (T) or false (F)
Which of the following drugs is considered to be the most addictive?
A. heroin B. nicotine C. alcohol D. caffeine