A common problem for the purple leaf plum tree is blossom blight, in which first the flowers, then young leaves, turn brown and wither, according to Grow Fruit by Alan Buckingham.
Once activated, helper T cells start to divide and to produce proteins that activate B and T cells as well as other immune cells. The killer T cell is specialized in attacking cells of the body infected by viruses and sometimes also by bacteria.
The thymus, a specialized organ of the immune system, is primarily responsible for the T cellâs maturation. There are six types of T-cells, namely: Helper T-cells, Cytotoxic T-cells, Memory T-cells, Regulatory T-cells, Natural Killer T-cells (NKT) and Gamma Delta T-cells. B-cells, on the other hand, play a principal role in humoral immunity (with antibody involvement).