We investigated Compact disc45RA and CCR7 expression in CD4+ and CD8+ subsets of cerebrospinal fluid (CSF) lymphocytes both immediately ex vivo and after stimulation from 134 patients with a variety of inflammatory and non-inflammatory neurological diseases. with a concomitant increase in TEM. We also found that samples with elevated IgG index or presence of oligoclonal bands had a significantly higher CD4+:CD8+ ratio than normal samples consistent with increased CD4+ help for intrathecal IgG synthesis by B cells. Keywords: CSF T lymphocytes effector memory T cells immunoglobulin multiple sclerosis 1 Introduction Inflammation in the central nervous system (CNS) whether of infectious or autoimmune etiology is associated with infiltration of immune cells into the cerebrospinal fluid (CSF) and brain parenchyma. This infiltration has been described to occur via three distinct routes of entry: 1. from the blood to CSF across the choroid plexus 2 from blood to the subarachnoid space and 3. from blood BIBX 1382 to parenchymal perivascular space (Ransohoff et al. 2003 Harvesting the CSF by lumbar puncture is valuable both for refining a differential diagnosis and for investigating the BIBX 1382 etiology of various diseases. The chemokine receptor profile and activation kinetics of immune cells infiltrating the subarachnoid space may offer a window into the pathogenic effects of these cells by highlighting their migratory and effector functions. During inflammation activated cells are known to preferentially enter the CNS via a process involving selectins chemokines chemokine receptors and cell adhesion molecules (Hickey 1991 Hickey et al. 1991 Springer 1994 Wekerle 1986 These cells are not necessarily antigen-specific although antigen-specific cells have been located in the CNS (Hafler and Weiner 1987 Olsson et al. 1990 It is not known however whether the cells in the CSF of a patient with an autoimmune disease such as multiple sclerosis (MS) represent a select subset of effector cells already primed to cause damage to the CNS or if local conditions within the perivascular space or brain parenchyma in MS induce reactivation of a subset of circulating cells that secondarily become pathogenic in the CNS. It has been shown recently that infiltrating CD8+ T cells found in the CSF of MS patients are mostly of the effector-memory phenotype (Ifergan 2011 Herein we analyzed whether CSF lymphocytes are mainly effector-memory cells (TEM) or primed however not chronically turned on central storage cells (TCM) in a number of inflammatory and noninflammatory CNS conditions noticed at our middle. Characterization from the CSF surface area receptor profile might provide insight in to the timing and area (peripheral versus central) of activation of cells recruited over the blood-CSF hurdle in to the subarachnoid space. Appearance of CCR7 a chemokine receptor which recruits cells BIBX 1382 towards the lymph nodes in conjunction with the na?ve cell marker CD45RA has been shown to discriminate na?ve (CD45RA+CCR7+) and TCM (CD45RA?CCR7+) from TEM (CD45RA?CCR7?) and TEM-RA+ (CD45RA+CCR7? found mainly in CD8+ cells) subsets (Sallusto et al. 1999 (Sallusto et al. 1999 CCR7 has been shown to be Rabbit Polyclonal to NDUFA4. highly expressed on BIBX 1382 CSF cells while cells within MS brain lesions have a CCR7? effector phenotype(Giunti et al. 2003 Kivisakk et al. 2004 Kivisakk et al. 2003 Kivisakk et al. 2003 Rus et al. 2005 Previous studies have used such markers as CD25 CD26 CD29 and chemokine receptors such as CXCR3 to differentiate between active and quiescent stages of MS (Kraus et al. 2000 Kraus et al. 2000 Matsui et al. 2004 Okuda et al. 2005 Sindern et al. 2002 Herein we demonstrate that CSF cells from a variety of inflammatory and non-inflammatory diseases are more likely to be TEM than peripheral blood cells both immediately ex vivo and after T cell stimulation with anti-CD3 and anti-CD28 antibodies. CSF cells from inflammatory disease processes tend to have a higher percentage of TEM cells and fewer TCM cells as compared to noninflammatory controls. Further the CD4+:CD8+ ratio in CSF was markedly increased in most inflammatory diseases particularly RRMS compared to noninflammatory diseases. Exceptions included PPMS and active contamination. We also found that samples with elevated IgG index or presence of oligoclonal bands (OCB) had a significantly higher CD4+:CD8+ ratio than normal samples consistent with increased CD4+ help for BIBX 1382 intrathecal IgG synthesis by B cells. 2 Materials and Methods 2.1 BIBX 1382 CSF collection and ethics statement CSF was collected at the Johns Hopkins Lumbar Puncture Clinic or the Johns Hopkins Hospital from 210 patients referred for diagnostic lumbar puncture. All patients gave.