Murine alveolar macrophages rapidly accumulate intranasally administered SARS-CoV-2 Spike protein leading to neutrophil recruitment and damage.

The trimeric SARS-CoV-2 Spike protein mediates viral attachment facilitating cell entry. Most COVID-19 vaccines direct mammalian cells to express the Spike protein or deliver it directly via inoculation to engender a protective immune response. The trafficking and cellular tropism of the Spike protein in vivo and its impact on immune cells remains incompletely elucidated.

Murine Alveolar Macrophages Rapidly Accumulate Intranasally Administered SARS-CoV-2 Spike Protein leading to Neutrophil Recruitment and Damage.

The trimeric SARS-CoV-2 Spike protein mediates viral attachment facilitating cell entry. Most COVID-19 vaccines direct mammalian cells to express the Spike protein or deliver it directly via inoculation to engender a protective immune response. The trafficking and cellular tropism of the Spike protein and its impact on immune cells remains incompletely elucidated.

Neutralizing and Targeting Properties of a New Set of α4β7-Specific Antibodies Are Influenced by Their Isotype.

The homing of lymphocytes to the mucosa is mainly controlled by α4β7 integrin, and it is amplified during gut chronic inflammation, as occurs with HIV and/or inflammatory bowel diseases. We designed and applied an improved immunization strategy based on an innovative selection process to isolate new α4β7 lymphocyte-specific monoclonal antibodies that are able to prevent their migration into inflamed gut tissues and/or to counteract HIV infection in vitro. First, 5 monoclonal antibodies (1 IgA, 1 IgM, and 4 IgGs) were selected based on their capacity to recognize α4 or β7 homodimers and α4β7 heterodimers in transfected human cells.

Beta-turn Phe in HIV-1 Env binding site of CD4 and CD4 mimetic miniprotein enhances Env binding affinity but is not required for activation of co-receptor/17b site.

HIV-1 enters a host cell after an initial interaction between viral envelope glycoprotein gp120 and cell surface receptor CD4, followed by a second interaction between gp120 and a cell surface chemokine receptor. CD4 residue Phe43 makes a significant contribution to the high-affinity interaction between CD4 and env. We and others have used scorpion toxin scaffolds to display and examine CD4 epitopes used for gp120 recognition.