We report that human immunodeficiency virus type 1 (HIV-1) has evolved a self-perpetuating mechanism to actively generate cells permissive for productive and cytopathic infection. Only activated T cells can be productively infected, which leads to their rapid depletion (2 x 10(9)/day in an infected individual). Establishment of productive HIV-1 infection therefore requires continual activations...

The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APCs) in the T cell area of secondary lymphoid organs and the formation of highly organized intercellular junctions referred to as immune synapses (IS). In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dic...

Given its population of CCR5-expressing, immunologically activated CD4(+) T cells, the gastrointestinal (GI) mucosa is uniquely susceptible to human immunodeficiency virus (HIV)-1 infection. We undertook this study to assess whether a preferential depletion of mucosal CD4(+) T cells would be observed in HIV-1-infected subjects during the primary infection period, to examine the anatomic subcomp...

Although CD8(+) T cells initially suppress human immunodeficiency virus (HIV) replication, cytotoxic T-cell precursor frequencies eventually decline and fail to prevent disease progression. In a longitudinal study including 16 individuals infected with HIV-1, we studied both the number and function of HIV-specific CD8(+) T cells by comparing HLA-peptide tetramer staining and peptide-induced int...

Major histocompatibility complex (MHC) class II deficiency is a primary immunodeficiency disease characterized by abnormality of MHC class II molecules surface expression on peripheral blood lymphocytes and monocytes. Clinical manifestations include extreme susceptibility to viral, bacterial, and fungal infections but the immunodeficiency is not as severe as SCID (severe combined immunodeficien...

Epstein-Barr virus (EBV) is associated with several different types of aggressive non-Hodgkin lymphoma (NHL). Individuals with primary or secondary immunodeficiency are susceptible to developing B cell lymphoproliferation due to outgrowth of EBV-infected B cells that express type III latency characterized by expression of all nine latent-cycle EBV antigens. These cells would normally be suscept...

A prospective observational cohort study was conducted in 302 human immunodeficiency virus-infected patients who had a CD4 T-cell count <100 cells/µL and negative serum cryptococcal antigen initiating antiretroviral therapy in a resource-limited setting. During 2-year follow-up, there were no differences of survival rates and occurrences of newly diagnosed cryptococcosis between patients with a...

The human CXCR-4 molecule serves as a second receptor for primary, T-cell-tropic, and laboratory-adapted human immunodeficiency virus type 1 (HIV-1) isolates. Here we show that murine CXCR-4 can support the entry of some of these HIV-1 isolates. Differences between mouse and human CXCR-4 in the ability to function as an HIV-1 receptor are determined by sequences in the second extracellular loop...

Background Encephalitis is defined by the presence of brain inflammation associated with clinical evidence of neurological dysfunction. It can be due to infection (most common cause is viruses) or not (like post vaccine or auto immune). Primary immunodeficiency is defined as a genetic basis that leads any alteration in immune system (innate or adaptative) predisposing to infections, auto immuni...