Thymus vs Bone Marrow, Two Cell Types in Human Immunology: B- and T-cell differences
Reporter: Larry H. Bernstein, MD, FCAP
Differences Between B-Cells and T-Cells
http://www.microbiologyinfo.com/differences-between-b-cells-and-t-cells/
Aryal Sagar
Although mature lymphocytes all look pretty much alike, they are extraordinarily diverse in their functions. The most abundant lymphocytes are:
B lymphocytes (often simply called B cells) and
T lymphocytes (likewise called T cells)
S.N. |
Properties |
B-Cells |
T-Cells |
1 | Name | B lymphocytes | T lymphocytes |
2 | Origin | Bone Marrow | Thymus |
3 | Position | Outside Lymph Node | Interior of Lymph Node |
4 | Membranereceptor | BCR (= immunoglobulin) for antigen | TCR for antigen |
5 | Connections | B-cells can connect to antigens right on the surface of the invading virus or bacteria. | T-cells can only connect to virus antigens on the outside of infected cells. |
6 | Tissue Distribution | Germinal centres of lymph nodes, spleen, gut, respiratory tract; also subcapsular and medullary cords of lymph nodes | Parafollicular areas of cortex innodes, periarteriolar in spleen |
7 | Life Span | Life span is short | Life span is long |
8 | Surface Antibodies | Surface Antibodies present | Absence of surface antibodies |
9 | Secretion | They secrete antibodies | They secrete Lymphokines |
10 | Function | В-cells form humoral or antibody-mediated immune system (AMI). | T-cells form cell-mediated immune system (CMI). |
11 | Blood | 20% of lymphocytes | 80% of lymphocytes; CD4 > CD8 |
12 | Formation | They form plasma cells and memory cells. | They form killer, helper and suppressor cells. |
13 | Movement to Infection Site | Plasma cells do not move to the site of infection. | Lymphoblasts move to the site of infection. |
14 | Function | Plasma cells do not react against transplants and cancer cells. | Killer cells react against transplants and cancer cells. |
15 | Function | Plasma cells have no inhibitory effect on immune system. | Suppressor cells inhibit immune system. |
16 | Function | They defend against viruses and bacteria that enter the blood and lymph. | They defend against pathogens including protists and fungi that enter the cells. |
Differences Between B-Cells and T-Cells
This is very insightful. There is no doubt that there is the bias you refer to. 42 years ago, when I was postdocing in biochemistry/enzymology before completing my residency in pathology, I knew that there were very influential mambers of the faculty, who also had large programs, and attracted exceptional students. My mentor, it was said (although he was a great writer), could draft a project on toilet paper and call the NIH. It can’t be true, but it was a time in our history preceding a great explosion. It is bizarre for me to read now about eNOS and iNOS, and about CaMKII-á, â, ã, ä – isoenzymes. They were overlooked during the search for the genome, so intermediary metabolism took a back seat. But the work on protein conformation, and on the mechanism of action of enzymes and ligand and coenzyme was just out there, and became more important with the research on signaling pathways. The work on the mechanism of pyridine nucleotide isoenzymes preceded the work by Burton Sobel on the MB isoenzyme in heart. The Vietnam War cut into the funding, and it has actually declined linearly since.
A few years later, I was an Associate Professor at a new Medical School and I submitted a proposal that was reviewed by the Chairman of Pharmacology, who was a former Director of NSF. He thought it was good enough. I was a pathologist and it went to a Biochemistry Review Committee. It was approved, but not funded. The verdict was that I would not be able to carry out the studies needed, and they would have approached it differently. A thousand young investigators are out there now with similar letters. I was told that the Department Chairmen have to build up their faculty. It’s harder now than then. So I filed for and received 3 patents based on my work at the suggestion of my brother-in-law. When I took it to Boehringer-Mannheim, they were actually clueless.