Dynamics of humoral immune response in SARS-CoV-2 infected individuals with different clinical stages.

Background: The COVID-19 pandemic remains a global health problem. As in other viral infections, the humoral immune response against SARS-CoV-2 is thought to be crucial for controlling the infection. However, the dynamic of B cells in the clinical spectrum of this disease is still controversial.

Functional Profile of CD8 T-Cells in Response to HLA-A*02:01-Restricted Mutated Epitopes Derived from the Gag Protein of Circulating HIV-1 Strains from Medellín, Colombia.

CD8 T-cells play a crucial role in the control of HIV replication. HIV-specific CD8 T-cell responses rapidly expand since the acute phase of the infection, and it has been observed that HIV controllers harbor CD8 T-cells with potent anti-HIV capacity. The development of CD8 T-cell-based vaccine against HIV-1 has focused on searching for immunodominant epitopes.

Chikungunya Virus and Zika Virus, Two Different Viruses Examined with a Common Aim: Role of Pattern Recognition Receptors on the Inflammatory Response.

Chikungunya virus (CHIKV) and Zika virus (ZIKV) are 2 reemerging arboviruses that have been the focus of public health institutions worldwide, since the last decades and following a spate of outbreaks in tropical and subtropical areas. The disease caused by both viruses manifests itself first as an acute stage of severe inflammation into the infected tissues, which later progresses to arthritis and chronic polyarthralgia in the case of CHIKV or congenital microcephaly and neurological disorders such as Guillain-Barré syndrome in the case of ZIKV. This review aims to summarize on current knowledge of the role of different pattern recognition receptors that leads to an elevated production and secretion of antiviral response (interferon) and severe inflammation in response to CHIKV and ZIKV infection.

Role of Monocytes in the Pathogenesis of Dengue.

Diseases caused by dengue virus (DENV) are a major public health problem worldwide, considered one of the infections with more prevalence in tropical and subtropical zones of the world. Despite the intense research in the pathogenesis of DENV, this feature is not well understood. One of the main target cells for DENV infection is monocytes; these phagocytes can play a dual role, since they are essential to control viremia, but they also participate in the induction of tissue damage during DENV infection.

Increase of Frequency and Modulation of Phenotype of Regulatory T Cells by Atorvastatin Is Associated with Decreased Lung Inflammatory Cell Infiltration in a Murine Model of Acute Allergic Asthma.

Regulatory T cells (Tregs) play an important role by controlling allergic inflammation of airways. Recently, it has been shown that statins have immunomodulatory properties, probably mediated by their effects on Tregs. Therefore, we evaluated the effect of atorvastatin (ATV) on Tregs and its association with the inflammatory process in a model of allergic asthma.

Chronically HIV-1 Infected Patients Exhibit Low Frequencies of CD25+ Regulatory T Cells.

The characterization of regulatory T cells (Treg) during HIV infection has become of particular interest considering their potential role in the pathogenesis of the acquired immunodeficiency syndrome. Different reports on Tregs in HIV-infected patients vary greatly, depending on the state of disease progression, anatomical compartment, and the phenotypic markers used to define this cell subpopulation. To determine the frequency of Tregs we included paired samples from peripheral blood and rectal biopsies from controls and chronic HIV patients with or without detectable viral load.

HIV-induced T-cell activation/exhaustion in rectal mucosa is controlled only partially by antiretroviral treatment.

Peripheral blood T-cells from untreated HIV-1-infected patients exhibit reduced immune responses, usually associated with a hyperactivated/exhausted phenotype compared to HAART treated patients. However, it is not clear whether HAART ameliorates this altered phenotype of T-cells in the gastrointestinal-associated lymphoid tissue (GALT), the main site for viral replication. Here, we compared T-cells from peripheral blood and GALT of two groups of chronically HIV-1-infected patients: untreated patients with active viral replication, and patients on suppressive HAART.

HIV-1-driven regulatory T-cell accumulation in lymphoid tissues is associated with disease progression in HIV/AIDS.

Regulatory T (Treg) cells accumulate in the lymphoid tissues of human immunodeficiency virus (HIV)-infected individuals, contributing to the inability of the immune system to control virus replication. We investigate here Treg-cell numbers and functional markers (FOXP3, CTLA-4, IDO, and TGF-beta1) in lymphoid tissues from untreated infected hosts with progressive or nonprogressive disease (HIV-infected humans and simian immunodeficiency virus [SIV]-infected macaques). We found that increased numbers of FOXP3(+) T cells as well as increased expression of Treg-cell-associated functional markers were detected only during progressive disease.

Increased IFN-gamma production by NK and CD3+/CD56+ cells in sexually HIV-1-exposed but uninfected individuals.

The mechanisms involved in controlling the establishment of HIV-1 infection are not fully understood. In particular, the role of innate immunity in natural resistance exhibited by individuals who are continuously exposed to HIV-1 but remain seronegative (ESN) has not been thoroughly evaluated. We determined the frequency and function of peripheral blood innate immune cells (plasmacytoid and myeloid dendritic cells, monocytes, NK cells, CD3+/CD56+ cells and invariant NKT cells) in ESN, chronically HIV-1-infected and low-risk HIV-1 seronegative individuals.

[Evaluation as a function of granulocytes in hyperimmunoglobulinemia E syndrome with recurrent infections].

The hyper-IgE syndrome with recurrent infections (HIESRI) is characterized by skin and respiratory infections due to Staphylococcus aureus and several fungi infections which are frequently associated with tissue damage. A deficiency in the chemotaxis of phagocytic cells has been documented to explain these findings; however, the expression of adhesion molecules, the secretion of cytokines that activate granulocytes and the production of oxygen reactive molecules have not been evaluated in HIESRI. Six HIESRI patients were evaluated for the following parameters: (1) secretion of GM-CSF and IL-5 by mitogen and antigen-activated mononuclear cells, (2) the chemotactic response of FMLP-activated granulocytes, (3) the respiratory burst of PMA-activated granulocytes, and (4) the expression of L-selectin and CD11b in PMA-activated granulocytes.