RESUMO
Polymorphonuclear neutrophils (PMN) are part of the innate immune system and are first-line effector cells in acute inflammatory responses. On activation PMNs secrete cytokines and oxygen metabolites that might be involved in the regulation of the acquired immune response. We show here that peripheral blood PMNs constitutively express a B7-1-like molecule as detected by immunostaining with several B7-1 antibodies. Reverse transcriptase-polymerase chain reaction using three sets of primers spanning different regions of B7-1 indicate dissimilarities at the mRNA level. B7-1 mRNA is expressed in bone marrow cells and lipopolysaccharide (LPS)-stimulated but not in unstimulated PMNs. The B7-1-like molecule is localized to the cytoplasmic granules and translocated to the cell surface after stimulation with LPS or interleukin-12 in some donors. Binding of CTLA4-Ig suggests that the B7-1-like molecule can interact with functional B7 ligand and might be important in the immunobiology of PMNs.
Assuntos
Antígeno B7-1/biossíntese , Neutrófilos/metabolismo , Anticorpos Monoclonais , Antígenos CD/biossíntese , Antígenos CD/sangue , Antígenos CD/líquido cefalorraquidiano , Antígenos CD/genética , Antígenos de Superfície/biossíntese , Antígeno B7-1/sangue , Antígeno B7-1/líquido cefalorraquidiano , Antígeno B7-1/genética , Antígeno B7-2 , Células Cultivadas , Humanos , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/líquido cefalorraquidiano , Glicoproteínas de Membrana/genética , Meningites Bacterianas/sangue , Meningites Bacterianas/líquido cefalorraquidiano , Meningites Bacterianas/imunologia , Meningites Bacterianas/metabolismo , Ativação de Neutrófilo/imunologia , Neutrófilos/efeitos dos fármacos , RNA Mensageiro/biossíntese , RNA Mensageiro/metabolismo , Coloração e Rotulagem/métodosRESUMO
The aberrant expression of B7 costimulatory molecules is involved in the pathogenesis of autoimmune diseases and overexpression of B7-1 was found in inflammatory multiple sclerosis (MS) lesions. We here report that costimulatory molecules B7-1 and B7-2 are expressed on cerebrospinal fluid (CSF) monocytes and B-lymphocytes from patients with MS, optic neuritis (ON) and other inflammatory central nervous system (CNS) diseases. In patients with ON but not MS, increased expression of B7-2 was detected as compared to non-inflammatory controls. The expression of B7-1 in MS and ON patients correlates with disease duration but not with relapses in patients with MS indicating a role in early disease but not as a reliable marker of disease activity at later stages of MS.