However, the mechanisms of HIV-1 infection-mediated T cell dysfunction are not completely understood. Here, we provide evidence that expansion of monocytic myeloid-derived suppressor cells (M-MDSCs) suppressed T cell function in HIV-1-infected individuals. We observed a dramatic elevation of M-MDSCs (HLA-DR-/low CD11b(+) CD33(+/high) CD14(+) CD15(-) cells) in the peripheral blood of HIV-1-seropositive subjects (n = 61) compared with healthy controls (n = 51), despite efficacious antiretroviral therapy for
nearly 2 years. The elevated M-MDSC frequency in HIV-1(+) subjects correlated with prognostic HIV-1 disease markers, including the HIV-1 load (r = 0.5957; P < 0.0001), CD4(+) T cell loss (r = -0.5312; P < 0.0001), and activated T cells (r = 0.4421; EPZ004777 supplier P = 0.0004). Functional studies showed that M-MDSCs from HIV-1(+) subjects suppressed T cell responses in both HIV-1-specific and antigen-nonspecific manners; this effect was dependent on the induction of arginase 1 and required direct
cell-cell contact. Further investigations revealed that direct HIV-1 infection or culture with HIV-1-derived Tat protein significantly selleck chemicals llc enhanced human MDSC generation in vitro, and MDSCs from healthy donors could be directly infected by HIV-1 to facilitate HIV-1 replication and transmission, indicating that a positive-feedback loop between HIV-1 infection and MDSC expansion existed. In summary, our studies revealed a novel mechanism of T cell dysfunction in HIV-1-infected individuals and suggested that targeting MDSCs may be a promising strategy for HIV-1 immunotherapy.”
“Reduced motor activity has been reported in schizophrenia and was associated with subtype, psychopathology and medication. Still, little is known about the neurobiology of motor retardation. To identify neural correlates of motor activity, resting state cerebral blood flow (CBF) was correlated with objective motor activity of the same day. Participants
comprised 11 schizophrenia patients and 14 controls who underwent magnetic resonance imaging with arterial spin labeling and wrist actigraphy. Patients had reduced activity levels and reduced perfusion of the left parahippocampal gyrus, left middle temporal gyms, right selleck products thalamus, and right prefrontal cortex. In controls, but not in schizophrenia, CBF was correlated with activity in the right thalamic ventral anterior (VA) nucleus, a key module within basal ganglia-cortical motor circuits. In contrast, only in schizophrenia patients positive correlations of CBF and motor activity were found in bilateral prefrontal areas and in the right rostral cingulate motor area (rCMA). Grey matter volume correlated with motor activity only in the left posterior cingulate cortex of the patients. The findings suggest that basal ganglia motor control is impaired in schizophrenia.