Tional states provides valuable insight into pathways involved in the cross talk between the CNS and the immune system. In addition to acute sickness and depression, TLR4 activation in microglia has also been linked to neurodegeneration [30]. Therefore, Tat-interfering peptide strategies may also be useful for investigations of potential therapeutic interventions in CNS diseases in which activated microglia may be a causal factor in the underlying pathology. Ultimately, these findings allow for the further translation of our knowledge about the communicationMicroglia and Sickness Behaviorbetween the brain and the immune system and will create new therapeutics to increase the quality of life for sick patients.Materials and Methods Peptide DesignThe generated peptides (Anaspec, San Jose, CA.) were based on epta peptides [17] with sequences mimicking the BB-loop of TLR4 and MyD88 TIR domains, preceded by a truncated Tat sequence (2). Sequences for the peptides are as follows: Tat-TLR4: YGRKK RRQRRR-RDFIPGV; Tat-MyD88: YGRKKRRQRRR-RDV LPGT; Tat-Scram: YGRKKRRQRRR-PTDLVRG1 mM EGTA, 150 mM NaCl) plus 0.2 SDS and 0.8 TWEEN, supplemented with PMSF, and protease inhibitor tablet (1 for 10 mL; Roche Applied Science). Following a 30 min lysis, samples were spun at 14000 rpm for 10 min at 4uC, and the supernatant was transferred to a clean tube. Lysed protein was incubated with either anti-TLR4 (Cedarlane) or anti-MyD88 (Cedarlane) for 1 hr at 4uC. Sepharose beads (company) were washed 36 in TEEN buffer and added to tubes containing lysed protein-antibody, and incubated at 4uC for 1 hr. Following incubations, beads were washed 36 in the above described TEEN buffer, and subjected to SDS-page 
described above.LPS and Peptide AdministrationLPS was dissolved in saline at a concentration of 40 mg/mL and either injected intraperitoneally for in vivo experiments, or bath applied for experiments conducted in slice. Both the Tat-TLR4 and Tat-MyD88 peptides were dissolved in saline to a concentration of 20 mg/mL, and again were either bath applied or injected depending upon the experiment. In experiments where both LPS and peptide treatments were used, peptide injection preceded LPS by 30 min.ELISAEnzyme-linked immunosorbent assays (ELISA) were performed according to manufacturer instructions (R D systems, Minneapolis, MN). In brief, hippocampal brain slices were incubated and treated in a homemade chamber (using 12 multi-well plates) equipped with continuous aeration with 15755315 95 O2/5 CO2. Slices were treated with LPS (40 mg/ml) in the absence or presence of Tat peptides. The latter were pretreated for 30 min prior to LPS application. The cell-free supernatants were used for analysis of TNF-a production. For in vivo experiments, mice were i.p. injected with LPS (0.5 mg/kg) and hippocampi were surgically removed for protein assay and mouse TNF-a ELISA (eBioscience, San Diego, CA). Tat peptides (6 mg/kg of body weight) were intraperitoneally injected 30 min prior to LPS administration.Slice preparation and solutionsBrain slices were obtained as described previously [31] from CX3CR1-EGFP [21] transgenic mice aged 21?0 days postnatal. Slices were stored at room temperature (20 to 23uC) for 1 hr before imaging in an oxygenated artificial cerebrospinal fluid (aCSF) containing (in mM): NaCl 126, KCl 2.5 or 4.2, NaHCO3 26, glucose 10, MgCl2 2, NaH2PO4 1.25 and CaCl2 2. Slices were transferred to a recording chamber and perfused with oxygenated aCSF at a rate of 1? m.Tional states provides valuable insight into pathways involved in the cross talk between the CNS 
and the immune system. In addition to acute sickness and depression, TLR4 activation in microglia has also been linked to neurodegeneration [30]. Therefore, Tat-interfering peptide strategies may also be useful for investigations of potential therapeutic interventions in CNS diseases in which activated microglia may be a causal factor in the underlying pathology. Ultimately, these findings allow for the further translation of our knowledge about the communicationMicroglia and Sickness Behaviorbetween the brain and the immune system and will create new therapeutics to increase the quality of life for sick patients.Materials and Methods Peptide DesignThe generated peptides (Anaspec, San Jose, CA.) were based on epta peptides [17] with sequences mimicking the BB-loop of TLR4 and MyD88 TIR domains, preceded by a truncated Tat sequence (2). Sequences for the peptides are as follows: Tat-TLR4: YGRKK RRQRRR-RDFIPGV; Tat-MyD88: YGRKKRRQRRR-RDV LPGT; Tat-Scram: YGRKKRRQRRR-PTDLVRG1 mM EGTA, 150 mM NaCl) plus 0.2 SDS and 0.8 TWEEN, supplemented with PMSF, and protease inhibitor tablet (1 for 10 mL; Roche Applied Science). Following a 30 min lysis, samples were spun at 14000 rpm for 10 min at 4uC, and the supernatant was transferred to a clean tube. Lysed protein was incubated with either anti-TLR4 (Cedarlane) or anti-MyD88 (Cedarlane) for 1 hr at 4uC. Sepharose beads (company) were washed 36 in TEEN buffer and added to tubes containing lysed protein-antibody, and incubated at 4uC for 1 hr. Following incubations, beads were washed 36 in the above described TEEN buffer, and subjected to SDS-page described above.LPS and Peptide AdministrationLPS was dissolved in saline at a concentration of 40 mg/mL and either injected intraperitoneally for in vivo experiments, or bath applied for experiments conducted in slice. Both the Tat-TLR4 and Tat-MyD88 peptides were dissolved in saline to a concentration of 20 mg/mL, and again were either bath applied or injected depending upon the experiment. In experiments where both LPS and peptide treatments were used, peptide injection preceded LPS by 30 min.ELISAEnzyme-linked immunosorbent assays (ELISA) were performed according to manufacturer instructions (R D systems, Minneapolis, MN). In brief, hippocampal brain slices were incubated and treated in a homemade chamber (using 12 multi-well plates) equipped with continuous aeration with 15755315 95 O2/5 CO2. Slices were treated with LPS (40 mg/ml) in the absence or presence of Tat peptides. The latter were pretreated for 30 min prior to LPS application. The cell-free supernatants were used for analysis of TNF-a production. For in vivo experiments, mice were i.p. injected with LPS (0.5 mg/kg) and hippocampi were surgically removed for protein assay and mouse TNF-a ELISA (eBioscience, San Diego, CA). Tat peptides (6 mg/kg of body weight) were intraperitoneally injected 30 min prior to LPS administration.Slice preparation and solutionsBrain slices were obtained as described previously [31] from CX3CR1-EGFP [21] transgenic mice aged 21?0 days postnatal. Slices were stored at room temperature (20 to 23uC) for 1 hr before imaging in an oxygenated artificial cerebrospinal fluid (aCSF) containing (in mM): NaCl 126, KCl 2.5 or 4.2, NaHCO3 26, glucose 10, MgCl2 2, NaH2PO4 1.25 and CaCl2 2. Slices were transferred to a recording chamber and perfused with oxygenated aCSF at a rate of 1? m.
