AEGiS-11IAC: IL-8 receptors are differentially regulated by TH1- and TH2-like cytokines in B lymphocytes from normal and HIV-infected individuals.

11th International AIDS Conference

Vancouver, British Columbia — July 7-12, 1996

IL-8 receptors are differentially regulated by TH1- and TH2-like cytokines in B lymphocytes from normal and HIV-infected individuals.

Int Conf AIDS 1996 Jul 7-12; 11:214 (abstract no. Th.A.164)
Moller B, Storgaard M, Jinquan T, Mukaida N, Matashima K, Thestrup-pedersen K, Black FT; Department of Medicine and Infectious Diseases, Marselisborg Hospital, Denmark.

OBJECTIVE: To investigate the effects of TH1- and TH2-like cytokines on the expression of IL-8RA and IL8-RB in B lymphocytes. We compared the effects in normal B lymphocytes and B lymphocytes from HIV-infected individuals.

METHODS: B lymphocytes were separated from whole blood by an immunomagnetic technique, followed by culturing for up to 24 hours in the presence or absence of cytokines. IL-8 receptors were detected by IL-8RA and IL-8RB specific polyclonal rabbit antibodies by flow cytometry.

RESULTS: In normals, approximately 10% of peripheral CD19+ lymphocytes were IL-8R+, and more than 90% were able to expres the receptor within 24 hours of culture in the presence of 10 ng/ml of IL-4 or IL-13. On the other hand, 10 ng/ml of IL-2 or IFN-gamma induced a downregulation of IL-8 receptor presentation, leaving less than 2% IL-8R+ B cells after 24 hours of stimulation. IL-10 had little or no effect in normal B cells, and IL-8R expression was not upregulated by TNFalpha. In B lymphocytes from HIV-infected individuals (HIV B cells), approximately 40% were IL8R+ in peripheral blood. Expression of IL-8R was induced in more than 90% within 16 hours by IL-4 and IL-10, whereas IL-13 had little or no effect. In HIV B cells, the downregulation of IL-8R by IL-2 and IFN-gamma was retained, but surprisingly IL-8R expression was induced in more than 90% of TNFalpha stimulated CD19+ cells within 16 hours. Generally, IL8RA and IL8RB were co-regulated.

CONCLUSIONS: IL-8 receptor expression in B lymphocytes is downregulated by TH1-like cytokines and upregulated by TH2-like cytokines in vitro. A larger fraction of unstimulated HIV B cells were IL-8R positive. The regulation in HIV B cells is faster, and the effect of IL-10, IL-13, and TNFalpha is different in normal and HIV B cells. The functional role of Il-8R presentation in B lymphocytes remains to be e elucidated.

Keywords: AEGIS, Interleukin-8, Cytokines, B-Lymphocytes, HIV, Receptors, Interleukin-8A, Interleukin-4, Interleukin-10, Receptors, Interleukin-8B, HIV Infections, HIV-1, Interleukin-2, Interleukin-13, Antigens, CD19, Lymphocytes, In Vitro, Animal, Rabbits, ICA11

960707
ThA164