the thymus gland serves as a primary lymphoid organ where immature lymphocytes migrate to differentiate into antigen-sensitive T-lymphocytes These T-lymphocytes are specifically responsible for providing cell-mediated immunity (CMI) Because the thymus provides the essential micro-environment required for the maturation of these cells, damage to the organ in a child would directly result in a failure to produce functional T-cells, leading to a loss of cell-mediated immunity While the thymus also helps B-cells produce antibodies for humoral immunity, its most direct and fundamental role is the mediation of CMI