Lymphoblasts: What They Are, Characteristics And Functions In The Human Body
The immune system, made up of cells, proteins, tissues and organs, defends the human species and the rest of complex living beings against germs and microorganisms on a daily basis. If the skin, saliva and mucous membranes are the primary biological barriers of the body, the immune system encompasses the secondary and tertiary defense.
Our body is not a sealed compartment, since the airways and mouth, for example, are ideal conduits for the entry of pathogens into our body. Beyond the skin and mucous membranes, therefore, there must be an intricate defense system that protects us once the germ is already inside us.
To give you an idea, approximately 20% of the world’s population has the flu at the time you are reading these lines. This data underlines that, of course, our immune system fights pathogens at practically every moment of our lives. Lymphoblasts are the precursors of lymphocytes, the immune cells par excellence If you want to know everything about them, continue reading.
According to the National Cancer Institute (NIH), a lymphoblast is defined as an immature cell that serves as a precursor to lymphocytes, the cell bodies responsible for tertiary immune barriers
In any case, as soon as we begin we find a clear terminological conflict, since a lymphoblast also refers to a lymphocyte that has enlarged after having been stimulated by an antigen. Both events are completely different, but the same word is used to designate them. We describe each of them in detail in the following lines.
1. The lymphoblast as a precursor
Under normal circumstances, lymphoblasts (assumed to be the cells that give rise to lymphocytes) They are found in the bone marrow of the long bones of healthy people If we take the meaning of the term “lymphoblast” as a progenitor, this could be interchangeable with “common lymphocytic progenitor,” since both give rise to the prolymphocyte, the intermediate form that finally leads to the desired cell type.
In general terms, we can describe the transformation of the lymphoblast to the functional lymphocyte in the following steps:
Without wanting to get into overly complex terminology, we will say that this last step refers to the fact that the selection of one lymphocyte or another is based on the expression of intact components of the receptor for the antigen and what they recognize.
At the end of this entire process, lymphocytes have receptors for specific antigens, which enables them to produce antibodies and, therefore, for the destruction of abnormal cells (ideally germs and other pathogens). These cell bodies represent 30% of the total leukocytes in the peripheral blood and, as we have said, represent the tertiary immune barriers.
T lymphocytes act directly on the pathogenic agent and destroy it, while B lymphocytes detect the antigen (a foreign substance, presumably produced by a pathogen) and generate specific antibodies for it. When an antibody binds to its antigen, the invading microorganism loses its pathogenic capacity. As you can imagine, this entire process is much more complex than what is described here, but it is enough for us to show a general image of it.
2. The lymphoblast as a lymphocyte with altered morphology
On the other side of the coin, and as confusing as it may sound, A lymphocyte that has enlarged after being stimulated by an antigen is also called a lymphoblast In this case, upon recognizing the antigen, this type of white blood cell is activated, which causes growth at the cytoplasmic and nuclear levels and in the production of messenger RNA and certain proteins.
Thus, the large lymphoblast begins to divide 2-4 times every 24 hours for 3-4 days, giving rise to 1000 clones of the original lymphocyte, with each of the clones presenting specificity for the same antigen that activated it in the first place. instance. Finally, the cells obtained can be differentiated into specific cell types that will combat the pathogen in one way or another.
We have already shown you what a lymphoblast is, but to get a general idea of this very peculiar cell body, we still have to describe it at a morphological level These are some of the most relevant data on its physiology:
Acute lymphoblastic leukemia
Leukemias are cancers that occur in cells that would normally differentiate into different types of blood cells, in this case B and T lymphocytes When an uncontrolled proliferation of lymphoblasts occurs (again, if we conceive of a lymphoblast as the precursor of a lymphocyte), they invade the bone marrow, preventing the production of other cells, such as red blood cells and platelets. This pathology is known as acute lymphoblastic leukemia (ALL) and is very dangerous to health.
This pathology does not know gender, ethnicity or age, although it is very rare to present, since foundations calculate that its prevalence is 1.29 patients per 100,000 inhabitants. Despite being a very rare disease, ALL is the most common type of cancer in children under 20 years of age (almost 60% of leukemias occur in this age group).
Acute lymphoblastic leukemia It is caused by the mutation of a single lymphoblast in the bone marrow that triggers the reaction described above , but researchers around the world have not yet managed to discover what really causes this event. According to the Spanish Association of People Affected by Lymphoma, Myeloma and Leukemia (AEAL), these are some of the risk factors that can favor ALL:
Genetic factors, that is, individual chromosomal alterations determined from the moment of the patient’s birth.
Being exposed to X-rays or ionizing radiation before or after birth.
Having had a treatment based on chemotherapy.
Infections due to some types of viruses (specifically some types of retroviruses).
Being in contact with certain chemicals, such as benzene and certain alkylating compounds.
Not everything is bad news at first glance, because The survival rates of patients with acute lymphoblastic leukemia 5 years after diagnosis less than 20 years of age is 90% Unfortunately, if we analyze the data of patients over 20 years of age, the survival rate 5 years after diagnosis does not reach 40%. All these data are only estimated figures, since each case depends on the physiological characteristics of the individual and their development of the disease.
As indicated by the Chronic Lymphoblastic Leukemia Research Consortium, a lymphoblast is defined as “a lymphocyte that has become larger after being stimulated by an antigen. “Lymphoblasts look like immature lymphocytes, and were once thought to be precursor cells.” So what are we left with? Multiple bibliographic sources use the term lymphoblast as a precursor, which transforms into a prolymphocyte and this will give rise to the well-known B and T lymphocytes in charge of the immune response.
On the other hand, for other sources such as the one we just cited, a lymphoblast is a stimulated lymphocyte, and not a precursor. Of course, spaces like this show that, in some specific cases, the medical terminology of a specific event does not have to be the same in all the sources consulted.
What is acute lymphoblastic leukemia?, Spanish Association of People Affected by Lymphoma, Myeloma and Leukemia. Collected on December 13 at http://www.aeal.es/leucemia-linfoblastica-aguda-espana/2-que-es-la-leucemia-linfoblastica-aguda/
ATLAS OF HEMATOLOGY, collected on December 13 at http://www.qualitat.cc/sitebuildercontent/sitebuilderfiles/atlas.hematologia.pdf
Definition of lymphoblast, National Cancer Institute (NIH). Collected on December 13 at https://www.cancer.gov/espanol/publicaciones/diccionario/def/linfoblasto
Lymphoblast, the free dictionary. Collected on December 13 at https://es.thefreedictionary.com/linfoblastos
Immune system, Radyschildren.org. Collected on December 13 at https://www.rchsd.org/health-articles/sistema-inmunolgico-3/#:~:text=El%20sistema%20inmunol%C3%B3gico%20es%20la,el%20cuerpo% 20and%20cause%20diseases.
Vásquez Palacio, G., Ramírez Castro, JL, Posada Díaz, A., Sierra, M., Botero, OL, Durango, NE,… & Tabares, JG (2002). Acute lymphoid leukemia: cytogenetic study in children treated at the San Vicente de Paúl University Hospital in Medellín in the period 1998-2001. Iatreia, 15(4), 217-225.
