LFA-1 expression on CD4(+)CD45RO(+) peripheral blood T-lymphocytes in RR MS: effects induced by rIFNbeta-1a.
We investigate the in vivo and in vitro effects of short-term treatment with recombinant Interferon beta-1a (rIFNbeta-1a) on CD4(+)CD45RO(+) activated/memory peripheral blood T-lymphocytes (PBTLs) expressing Leukocyte Function Antigen-1 (LFA-1; CD11a/CD18) in relapsing-remitting (RR) Multiple Sclerosis (MS) patients. Blood samples were obtained from 10 RR MS patients before and after 2, 4 and 6 months of rIFNbeta-1a (Avonex) treatment. For each sample, the percentage of CD4(+)CD45RO(+)CD11a(+) (CD11a(dim) and CD11a(bright)) T-cells was evaluated in in vivo PBTLs and in untreated or rIFNbeta-1a (1000 U/ml) or recombinant soluble Intercellular Adhesion Molecule-1 (ICAM-1, the ligand for LFA-1) (400 ng/ml) treated cultured PBTLs by triple fluorescence flow-cytometry (FACS analysis). Soluble ICAM-1 (sICAM-1) serum levels were evaluated by ELISA. In vivo, the percentage of CD4(+)CD45RO(+), CD4(+)CD45RO(+)CD11a(+), CD4(+)CD45RO(+)CD11a(dim) PBTLs increased after 4 and 6 months of rIFNbeta-1a treatment compared to pretreatment and 2 months of treatment (p<0.05). The CD11a expression per se did not change during the time course. Soluble ICAM-1 (sICAM-1) serum levels also increased (p<0.05) after 4 and 6 months of treatment. When T-cells, obtained from the blood of the same patients before and during in vivo treatment, were cultured either untreated or treated with rIFNbeta-1a, they showed an increase in the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a(bright) (p<0.05). The addition of recombinant sICAM-1 to untreated cultures decreased the percentage of CD4(+)CD45RO(+) T-cells expressing CD11a. This last finding seems to support an indirect effect in vivo of rIFNbeta-1a via sICAM-1 on this T-cell subset, since the ICAM-1 soluble form, induced in vivo in serum by rIFNbeta-1a but lacking in in vitro conditions, keeps the percentage of CD11a(+) unchanged within CD4(+)CD45RO(+) T-cells and induces their expression of CD11a(dim), probably preventing T-cells from transmigrating.
Avolio
C
C
Chair of Neurology, University of Foggia, Foggia, Italy. avolio@neurol.uniba.it
Ruggieri
M
M
Cafforio
P
P
Giuliani
F
F
Silvestris
F
F
Dammacco
F
F
Livrea
P
P
Trojano
M
M
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects / Q000276:immunology; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000008:administration & dosage*; D017493:Leukocyte Common Antigens / Q000032:analysis*; D008137:Longitudinal Studies; D016169:Lymphocyte Function-Associated Antigen-1 / Q000096:biosynthesis*; D008297:Male; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy* / Q000276:immunology*; D012995:Solubility
D000276:Adjuvants, Immunologic; D016169:Lymphocyte Function-Associated Antigen-1; D018799:Intercellular Adhesion Molecule-1; D016899:Interferon-beta; D017493:Leukocyte Common Antigens; D000068556:Interferon beta-1a