Question

Q. Give one word answer for the following and briefly explain each. (Draw diagram wherever required to explain)

1. Dendritic cell found in T-cell rich region of Lymphoid organ.

2. Antigen binding site on antibody.

3. Light chain secreted in urine of Myeloma patients.

4. Granulocyte providing immunity against parasitic infection.

5.APC which express B7 molecule only after its activation.

6.B cell rich areas in lymph nodes.

7. Antibody-binding sites on antigen.

8.First antibody secreted against the antigen during immune response.

9. Non-phagocytic granulocyte releasing pharmacologically active substances.

10. Hemolytic disease of newborn.

Please answer all.

Thank you very much !

Answer 1

Ans 1

Steinman RM(1), Pack M, Inaba K. Substantial numbers of dendritic cells (DCs) are found in the T-cell areas of peripheral lymphoid organs such as the spleen, lymph node and Peyer's patch. By electron microscopy these DCs (also called interdigitating cells) form a network through which T-cells continually recirculate.

Ans 2

Antigen-binding site. (A) The hinge region of an antibody molecule opens and closes to allow better binding between the antibody and antigenic determinants on the surface of an antigen. (B) Hinge flexibility also facilitates the cross-linking of antigens into large antigen-antibody complexes.

Ans 3

Excessive light chains produced normally are easily excreted in the urine because of their small size. With monoclonal gammopathy, some of the excess light chains can get trapped in the kidneys and damage kidney function.

Ans 4

The main activity of the immune system is protection against infections. Immunocytes (leukocytes) are mainly lymphocytes and they produce humoral (antibody; mainly B-cell) or cell-mediated (mainly T-cell) responses that are central to the immune defences

Ans 5

Ans 6

the B-cell containing lymphoid follicles located in the cortex. Between the cortex and medulla lies an ill-defined region called the paracortex which is rich in T-cells. The hilum of the lymph node is the location where blood vessels enter and exit the node

​​​​​Ans 7

an antibody, the Fab (fragment, antigen-binding) region is formed from the amino-terminal end of both the light and heavy chains of the immunoglobulin polypeptide. ... Thus these regions are the paratope, the binding site of an antigen.

Ans 8

They have different roles in immune responses; IgG, IgA, and IgM are commonly produced after viral infection. During the first encounter with a virus, a primary antibody response occurs. IgM antibody appears first, followed by IgA on mucosal surfaces or IgG in the serum.

Ans 9

These granulocytes are non-phagocytic cell that function by releasing pharmacologically active substances (e.g., histamine, prostaglandins, serotonin, and leucotrienes) from their cytoplasmic granules upon appropriate stimulation.

Ans 10

Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules (one of the five main types of antibodies) produced by the mother pass through the placenta.