The lymphocyte chemoattractant factor.
The LCF is a unique interleukin without significant homology to other interleukins or chemokines. It is a chemoattractant factor for all CD4+ cells and either uses CD4 as its receptor or utilizes a cell surface complex of molecules for which there is an absolute requirement for the presence of CD4. In addition to its chemoattractant activity, it is a growth factor for CD4+ T cells, inducing resting cells to enter G1, as evidenced by the expression of MHC II molecules and IL-2R. Once induced by LCF to express IL-2R, CD4+ T cells become competent to respond to LCF and progress through the cell cycle to proliferation. LCF's activity on CD4 cells defines a role for CD4 on the eosinophil and monocyte and broadens the scope of functions of CD4 on the T cell. In this regard it may have importance in human disease states that are characterized by increased numbers of activated CD4+ cells, such as sarcoidosis, rheumatoid arthritis, or asthma. Likewise, it may play a key role in monocyte and eosinophil chemotaxis into tissues, being important in the latter in concert with hematopoietic factors that increase the available eosinophil pool.
Pulmonary Center, Boston University School of Medicine, MA 02118-2394.
D M
DM
Center
J S
JS
Berman
H
H
Kornfeld
A C
AC
Theodore
W W
WW
Cruikshank
D015704:CD4 Antigens / Q000502:physiology; D002630:Chemotactic Factors; D003001:Cloning, Molecular; D006801:Humans; D007249:Inflammation; D019410:Interleukin-16; D008222:Lymphokines / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology
D015704:CD4 Antigens; D002630:Chemotactic Factors; D019410:Interleukin-16; D008222:Lymphokines