Mouse Anti-Bovine CD8 Hybridoma [DD69]

Information about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in HIV-infected individuals is scarce. In this prospective study, we included HIV (human immunodefeciency virus)-infected individuals (people living with HIV [PLWHIV]) with confirmed SARS-CoV-2 infection and compared them with PLWHIV negative for SARS-CoV-2. We compared 55 cases of SARS-CoV-2 infection with 69 asymptomatic PLWHIV negative for SARS-CoV-2 reverse transcription-polymerase chain reaction and/or serology. There was no significant difference between SARS-CoV-2 positive or negative patients for age distribution, gender, time with HIV infection, nadir CD4-cell counts, type and number of co-morbidities, current CD4 and CD8 counts and type of anti-HIV therapy. Positive patients presented with a median of three symptoms (interquartile range, 1-3). Most common symptoms were fever (76%), dyspnea (35%), anosmia (29%) non-productive cough (27%), fatigue 22%), and ageusia (20%). Ten patients (18%) were completely asymptomatic. Four (7.2%) subjects died of coronavirus disease 2019. Factors significantly (P < .05) associated with death included age and number of co-morbidities, while time from HIV infection and lower current CD4 counts were significant only in univariate analysis. HIV-infected individuals are not protected from SARS-CoV-2 infection or have a lower risk of severe disease. Indeed, those with low CD4 cell counts might have worse outcomes. Infection is asymptomatic in a large proportion of subjects and this is relevant for epidemiological studies.

Initially described as Th2 promoter cytokine, more recently, IL-33 has been recognized as an alarmin, mainly in epithelial and endothelial cells. While localized in the nucleus acting as a gene regulator, it can be also released after injury, stress or inflammatory cell death. As proinflammatory signal, IL-33 binds to the surface receptor ST2, which enhances mast cell, Th2, regulatory T cell, and innate lymphoid cell type 2 functions. Besides these Th2 roles, free IL-33 can activate CD8(+)T cells during ongoing Th1 immune responses to potentiate its cytotoxic function. Celiac Disease (CD) is a chronic inflammatory disorder characterized by a predominant Th1 response leading to multiple pathways of mucosal damage in the proximal small intestine. By immunofluorescence and western blot analysis of duodenal tissues, we found an increased expression of IL-33 in duodenal mucosa of active CD (ACD) patients. Particularly, locally digested IL-33 releases active 18/21kDa fragments which can contribute to expand the proinflammatory signal. Endothelial (CD31(+)) and mesenchymal, myofibroblast and pericyte cells from microvascular structures in villi and crypts, showed IL-33 nuclear location; while B cells (CD20(+)) showed a strong cytoplasmic staining. Both ST2 forms, ST2L and sST2, were also upregulated in duodenal mucosa of CD patients. This was accompanied by increased number of CD8(+)ST2(+)T cells and the expression of T-bet in some ST2(+)intraepithelial lymphocytes andlamina propriacells. IL-33 and sST2 mRNA levels correlated with IRF1, an IFN induced factor relevant in responses to viral infections and interferon mediated proinflammatory responses highly represented in duodenal tissues in ACD. These findings highlight the potential contribution of IL-33 and its fragments to exacerbate the proinflammatory circuit and potentiate the cytotoxic activity of CD8(+)T cells in CD pathology.