Preprint Review Version 1 Preserved in Portico This version is not peer-reviewed

B Cells Over-Activation by Viral Proteins <70 kDa Causes Th2 Immune Suppression in COVID-19 Sepsis

Version 1 : Received: 13 May 2020 / Approved: 14 May 2020 / Online: 14 May 2020 (15:19:53 CEST)

How to cite: Martín, J. B Cells Over-Activation by Viral Proteins <70 kDa Causes Th2 Immune Suppression in COVID-19 Sepsis. Preprints 2020, 2020050244. Martín, J. B Cells Over-Activation by Viral Proteins . Preprints 2020, 2020050244.


COVID-19 sepsis immune response remains unclear. Here we propose a new perspective in host response against pathogenic proteins that may lead to a vaccine design by polymerization of antigens of <70 kDa. In COVID-19, initial Th1 response kills infected cells releasing viral proteins. SARS-CoV-2 viral structural proteins are Spike (140 kDa), Nucleocapsid (50 kDa), Membrane (25 kDa) and Envelope (10 kDa). B cell receptor cannot capture antigens >70 kDa. The Spike protein (140 kDa) cannot be captured by B cells and triggers inflammatory Th1 response via the macrophages. Only proteins with a size <70 kDa can activate B cell receptor and trigger Th2 adaptative humoral response. Moreover, M-25 kDa and E-12 kDa glycoproteins can activate IgM-BCR like oligovalent or monovalent antigens. The sustained infected cells lysis overfeeds high levels of viral proteins <70 kDa, increases B cells activation and, in the shift from Th1 to Th2 immune response, triggers the cytokine storm. The continuous BCR activation increases IL-10 releasing and may lead to immune paralysis.

Supplementary and Associated Material


COVID-19; SARS-CoV-2; antigen; monovalent; oligovalent; protein; kilodalton (kDa); Th1 response; Th2 response; B cell activation; B cell receptor (BCR); macrophage; dendritic cell; apoptosis; subcapsular sinus; immunoglobulin; interleukin; cytokine; Cytokine Storm Syndrome (CSS); allergen; immune paralysis; vaccine; polymer


Biology and Life Sciences, Anatomy and Physiology

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