What is T-cell independent antigen?
Christopher Harper
Updated on April 02, 2026
T-independent (TI) antigens are typically polysaccharides with the ability to induce B-cell proliferation and antibody secretion in the absence of T cells.
What is the difference between T dependent and T-independent antigens?
T-dependent antigens can stimulate B cells to become activated but require cytokine assistance delivered by helper T cells. T-independent antigens can stimulate B cells to become activated and secrete antibodies without assistance from helper T cells.
What types of antigens are used in vaccines?
Inactivated (killed antigen) Subunit (purified antigen)
What type of antigens are T dependent?
Thymus-dependent antigens include proteins, polypeptides, hapten-carrier complexes, erythrocytes, and many other antigens that have diverse epitopes. T dependent antigens contain some epitopes that T cells recognize and others that B cells identify.
Where does antigen independent differentiation of T lymphocytes occur?
T-cell differentiation occurs within the thymus and is characterized by ordered expression of various CD surface molecules and V, D, and J gene rearrangements. Progenitor cells originating in the bone marrow migrate to the thymus.
What is the key difference between AT cell dependent and T cell independent immune response?
Difference between T dependent Antigen and T independent Antigen
| T dependent (TD) Antigen | T independent Antigen |
|---|---|
| Isotype switching occurs (i.e. antibodies of all classes are produced) | No isotype switching ( Antibody response is restricted to IgM and IgG3) |
| Activate mature B cells only | Activate both mature and immature B cells |
Where are T lymphocytes mature?
the thymus
Precursors of T cells migrate from the bone marrow and mature in the thymus.
What are the 4 main types of vaccines?
There are four categories of vaccines in clinical trials: whole virus, protein subunit, viral vector and nucleic acid (RNA and DNA). Some of them try to smuggle the antigen into the body, others use the body’s own cells to make the viral antigen.
Are pathogens and antigens the same?
The invading microbe or pathogen is called an antigen. It is regarded as a threat by the immune system and is capable of stimulating an immune response. Antigens are proteins that are found on the surface of the pathogen. Antigens are unique to that pathogen.
Are T cells made in bone marrow?
T lymphocytes develop from a common lymphoid progenitor in the bone marrow that also gives rise to B lymphocytes, but those progeny destined to give rise to T cells leave the bone marrow and migrate to the thymus (see Fig. 7.2). This is the reason they are called thymus-dependent (T) lymphocytes or T cells.
