Lack of Disease Specificity Limits the Usefulness of In Vitro Costimulation in HIV- and HCV-Infected Patients

Measurements of antigen-specific T cell responses in chronic diseases are limited by low frequencies of antigen-specific cells in the peripheral blood. Therefore, attempts have been made to add costimulatory molecules such as anti-CD28 or IL-7/IL-15 to ELISPOT assays to increase sensitivity. While this approach has been successful under certain circumstances, results are often inconsistent. To date, there are no comprehensive studies directly comparing the in vitro effects of multiple costimulatory molecules in different disease settings. Therefore, in the present study we tested the effects of IL-7/IL-15, IFN-α, anti-ICOS, and anti-CD28 on antigen-specific T cell responses in patients infected with HCV or HIV versus healthy individuals. Our data show that none of the aforementioned molecules could significantly increase ELISPOT sensitivity, neither in HCV nor in HIV. Moreover, all of them caused false-positive responses to HCV and HIV antigens in healthy individuals. Our results question the broad use of in vitro costimulation

Stability of SARS-CoV-2 spike antigens against mutations

Modern health care needs preventive vaccines and therapeutic treatments with stability against pathogen mutations to cope with current and future viral infections. At the beginning of the COVID-19 pandemic, our analytic and predictive tool identified a set of eight short SARS-CoV-2 S-spike protein epitopes that had the potential to persistently avoid mutation. Here a combination of genetic, Systems Biology and protein structure analyses confirm the stability of our identified epitopes against viral mutations. Remarkably, this research spans the whole period of the pandemic, during which 93.9% of the eight peptides remained invariable in the globally predominant 43 circulating variants, including Omicron. Likewise, the selected epitopes are conserved in 97% of all 1,514 known SARS-CoV-2 lineages. Finally, experimental analyses performed with these short peptides showed their specific immunoreactivity. This work opens a new perspective on the design of next-generation vaccines and antibody therapies that will remain reliable against future pathogen mutations.Dr. Lozano-Perez acknowledges the European Commission ERDF/FEDER Operational Program 'Murcia' CCI No. 2007ES161PO001 (Project No. 14-20/20). Miodrag Grbic acknowledges support from the NSERC Discovery grant (Canada). This work also has received funding from the Department of Education of the Basque Government via the Consolidated Research Group MATH MODE (IT1456-22). Besides, Ildefonso Martinez De la Fuente and Iker Malaina were supported by the UPV/EHU and Basque Center of Applied Mathematics, grant US21/27N

Involvement of brain-derived neurotrophic factor (BDNF) in MP4-induced autoimmune encephalomyelitis

The role of brain-derived neurotrophic factor (BDNF) in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) is still unclear. Here we investigate the clinical course, CNS histopathology and peripheral antigen-specific immunity in MP4-induced EAE of BDNF (-/+) mice. We demonstrate that these mice displayed less severe disease compared to BDNF (+/+) mice, reflected by decreased inflammation and demyelination. In correspondence to diminished frequencies of T and B cells in CNS infiltrates, the peripheral MP4-specific T(H)1/T(H)17 response was attenuated in BDNF (-/+), but not in wild-type animals. In contrast, immunization with ovalbumin triggered similar frequencies of IFN-gamma- and IL-17-secreting T cells in both groups. The cytokine secretion and proliferative activity upon mitogen stimulation did not reveal any global defect of T cell function in BDNF (-/+) mice. By influencing the antigen-specific immune response in autoimmune encephalomyelitis, BDNF may support and maintain the disease in ways that go beyond its alleged neuroprotective role. (C) 2010 Elsevier Inc. All rights reserved