M150 modulates the costimulatory signals delivered by B cells to T cells and enhances their ability to help B cells.
There is a prerequirement of at least two sets of signals delivered by the antigen-presenting cell (APC) for the optimal activation of T helper (Th) cells. The first signal is provided by the engagement of T cell receptor with the antigen-MHC class II complex, followed by a second stimulus in the form of costimulatory signals. In the present study, we provide evidence that in a T-dependent antigen-driven system, the signals generated by hapten-specific B cells to stimulate Th cells for the secretion of interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and IL-4 were differentially modified by M150, a 150-kDa molecule expressed on the surface of macrophages. When ovalbumin-specific Th cells were cultured in the presence of 2,4,6 trinitrophenol (TNP)-specific B cells, M150 significantly increased the proliferation of Th cells and the secretion of IL-2 and IFN-gamma and decreased the production of IL-4. Further, Th cells stimulated with M150 acquired improved ability to help B cells, resulting in an increase in the number of antibody-secreting cells and in the production of TNP-specific IgG2a antibodies. M150 possibly promotes Th1-like cell activity, as evidenced by predominant secretion of IL-2, IFN-gamma, and IgG2a but not IL-4 and IgG1.
Agrewala
J N
JN
Institute of Microbiol Technology, Chandigarh, India.
Suvas
S
S
Joshi
A
A
Bhatnagar
A
A
Vinay
D S
DS
Mishra
G C
GC
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002450:Cell Communication / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D000939:Epitopes; D005260:Female; D006825:Hybridomas; D008264:Macrophages / Q000276:immunology; D008565:Membrane Proteins / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000939:Epitopes; D008565:Membrane Proteins