T cell immune responses seen a year after infection

Subject: Science and Tech

Section: Basic science

Context: Omicron variant was found to cause only mild disease in fully vaccinated people and in those with previous infection.

Findings of new study from Wuhan:

protective effect of t cell immunity

About T Cells

Cells also called T lymphocyte, type of leukocyte (white blood cell) that is an essential part of the immune system.
T cells are one of two primary types of lymphocytes—B cells being the second type—that determine the specificity of the immune response to antigens (foreign substances) in the body.
T cells originate in the bone marrow and mature in the thymus.
In the thymus, T cells multiply and differentiate into helper, regulatory, or cytotoxic T cells or become memory T cells.
They are then sent to peripheral tissues or circulate in the blood or lymphatic system.
Once stimulated by the appropriate antigen, helper T cells secrete chemical messengers called cytokines, which stimulate the differentiation of B cells into plasma cells (antibody-producing cells).

T cells role in controlling immunity

Regulatory T cells act to control immune reactions, hence their name.
Cytotoxic T cells, which are activated by various cytokines, bind to and kill infected cells and cancer cells.
Because the body contains millions of T and B cells, many of which carry unique receptors, it can respond to virtually any antigen.