Plasmablasts represent a specialized class of antibody-secreting effector B cells that transiently appear in blood circulation following
infection or vaccination. The expansion of these cells generally tends to be massive in patients with systemic
infections such as
dengue or Ebola that cause hemorrhagic
fever. To gain a detailed understanding of human plasmablast responses beyond antibody expression, here, we performed immunophenotyping and
RNA sequencing (
RNA-seq) analysis of the plasmablasts from
dengue febrile children in India. We found that plasmablasts expressed several adhesion molecules and
chemokines or
chemokine receptors that are involved in endothelial interactions or homing to inflamed tissues, including skin, mucosa, and intestine, and upregulated the expression of several
cytokine genes that are involved in leukocyte extravasation and angiogenesis. These plasmablasts also upregulated the expression of receptors for several B-cell prosurvival
cytokines that are known to be induced robustly in systemic
viral infections such as
dengue, some of which generally tend to be relatively higher in patients manifesting
hemorrhage and/or
shock than in patients with mild febrile
infection. These findings improve our understanding of human plasmablast responses during the acute febrile phase of systemic
dengue infection. IMPORTANCE
Dengue is globally spreading, with over 100 million clinical cases annually, with symptoms ranging from mild self-limiting febrile illness to more severe and sometimes life-threatening
dengue hemorrhagic fever or
shock, especially among children. The pathophysiology of
dengue is complex and remains poorly understood despite many advances indicating a key role for antibody-dependent enhancement of
infection. While serum
antibodies have been extensively studied, the characteristics of the early cellular factories responsible for antibody production, i.e., plasmablasts, are only beginning to emerge. This study provides a comprehensive understanding of the transcriptional profiles of human plasmablasts from
dengue patients.