Elevated proportion of TLR2- and TLR4-expressing Th17-like cells and activated memory B cells was associated with clinical activity of cerebral cavernous malformations

Camilla Castro; Hugo A A Oyamada; Marcos Octávio S D Cafasso; Lana M Lopes; Clarice Monteiro; Priscila M Sacramento; Soniza Vieira Alves-Leon; Gustavo da Fontoura Galvão; Joana Hygino; Jorge Paes Barreto Marcondes de Souza; Cleonice A M Bento

doi:10.1186/s12974-022-02385-2

Elevated proportion of TLR2- and TLR4-expressing Th17-like cells and activated memory B cells was associated with clinical activity of cerebral cavernous malformations

J Neuroinflammation. 2022 Feb 2;19(1):28. doi: 10.1186/s12974-022-02385-2.

Authors

Camilla Castro^{1

2}, Hugo A A Oyamada^{1

2}, Marcos Octávio S D Cafasso¹, Lana M Lopes^{1

2}, Clarice Monteiro^{1

2}, Priscila M Sacramento^{1

2}, Soniza Vieira Alves-Leon^{3

4}, Gustavo da Fontoura Galvão⁵, Joana Hygino^{1

3}, Jorge Paes Barreto Marcondes de Souza^{3

5

6}, Cleonice A M Bento^{7

8

9}

Affiliations

¹ Department of Microbiology and Parasitology, Federal University of the State of Rio de Janeiro, Frei Caneca 94, Rio de Janeiro, RJ, 20261-040, Brazil.
² Post-Graduate Program in Microbiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
³ Post-Graduate Program in Neurology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
⁴ Translational Neuroscience Laboratory (LabNet), University of the State of Rio de Janeiro, Rio de Janeiro, Brazil.
⁵ Service of Neurosurgery, University Hospital of the Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
⁶ Post-Graduate Program of Surgical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
⁷ Department of Microbiology and Parasitology, Federal University of the State of Rio de Janeiro, Frei Caneca 94, Rio de Janeiro, RJ, 20261-040, Brazil. cbento@unirio.br.
⁸ Post-Graduate Program in Microbiology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil. cbento@unirio.br.
⁹ Post-Graduate Program in Neurology, University of the State of Rio de Janeiro, Rio de Janeiro, Brazil. cbento@unirio.br.

Abstract

Background: Recent evidences have suggested the involvement of toll-like receptor (TLR)-4 in the pathogenesis of cerebral cavernous malformations (CCM). Elevated frequency of TLR⁺T-cells has been associated with neurological inflammatory disorders. As T-cells and B-cells are found in CCM lesions, the objective of the present study was to evaluate the cytokine profile of T-cells expressing TLR2 and TLR4, as well as B-cell subsets, in asymptomatic (CCM_Asympt) and symptomatic (CCM_Sympt) patients.

Methods: For our study, the cytokine profile from TLR2⁺ and TLR4⁺ T-cell and B-cell subsets in CCM_Asympt and CCM_Sympt patients was investigated using flow cytometry and ELISA. T-cells were stimulated in vitro with anti-CD3/anti-CD28 beads or TLR2 (Pam3C) and TLR4 (LPS) ligands.

Results: CCM_Symptc patients presented a higher frequency of TLR4⁺(CD4⁺ and CD8⁺) T-cells and greater density of TLR4 expression on these cells. With regard to the cytokine profile, the percentage of TLR2⁺ and TLR4⁺ Th17 cells was higher in CCM_Sympt patients. In addition, an elevated proportion of TLR4⁺Tc-1 cells, as well as Tc-17 and Th17.1 cells expressing TLR2 and TLR4, was observed in the symptomatic patients. By contrast, the percentage of TLR4⁺ IL-10⁺CD4⁺ T cells was higher in the CCM_Asympt group. Both Pam3C and LPS were more able to elevate the frequency of IL-6⁺CD4⁺T cells and Th17.1 cells in CCM_Sympt cell cultures. Furthermore, in comparison with asymptomatic patients, purified T-cells from the CCM_Sympt group released higher levels of Th17-related cytokines in response to Pam3C and, mainly, LPS, as well as after activation via TCR/CD28. Concerning the B-cell subsets, a higher frequency of memory and memory activated B-cells was observed in CCM_Sympt patients.

Conclusions: Our findings reveal an increase in circulating Th17/Tc-17 cell subsets expressing functional TLR2 and, mainly, TLR4 molecules, associated with an increase in memory B-cell subsets in CCM patients with clinical activity of the disease.

Keywords: B cells; Cerebral cavernous malformations; Cytokines; LPS; T cells; TLR; Th17 cells.

MeSH terms

Hemangioma, Cavernous, Central Nervous System* / metabolism
Humans
Memory B Cells
Th17 Cells / metabolism
Toll-Like Receptor 2* / metabolism
Toll-Like Receptor 4 / metabolism

Substances

TLR2 protein, human
TLR4 protein, human
Toll-Like Receptor 2
Toll-Like Receptor 4