Immune Response to LinB13, a Lutzomyia Intermedia Salivary Protein Correlates With Disease Severity in Tegumentary Leishmaniasis.

Abstract

BACKGROUND:

We have previously shown that seropositivity to rLinB-13, a salivary protein from Lutzomyia intermedia, predicted sand fly exposure and was associated with increased risk of developing cutaneous leishmaniasis (CL).

METHODS:

Here, we investigated the cellular immune response to saliva from Lu. intermedia, using rLinB-13 as a surrogate antigen in naturally exposed individuals presenting positive serology to LinB-13. We also investigated the response to rLinB-13 in leishmaniasis patients, displaying active ulcers and positive PCR for Leishmania braziliensis.

RESULTS:

Peripheral blood mononuclear cells (PBMCs) stimulated in vitro with rLinB-13 secreted elevated levels of interleukin-10 (IL-10), IL-4, IL-1β, IL-1α, IL-6, and chemokines (CCL3, CCL4, CCL5, and CXCL5). CL and disseminated leishmaniasis (DL) patients displayed a significantly higher immunoglobulin G (IgG) response to rLinB-13 compared with healthy subjects, and anti-rLinB-13 IgG was positively correlated with the number of lesions in DL patients. Positive serology to rLinB-13 was also associated with chemotherapy failure. PBMCs from DL patients stimulated with rLINB-13 secreted significantly higher levels of IL-10 and IL-1β compared with CL individuals.

CONCLUSIONS:

In this study, we observed an association between humoral and cellular immune response to the sand fly salivary protein rLinB-13 and disease severity in tegumentary leishmaniasis. This study brings evidence that immunity to rLinB-13 influences disease outcome in L. braziliensis infection and results indicate that positive serology to rLinB-13 IgG can be used as a marker of DL, an emerging and severe form of disease caused by L. braziliensis.

• Authors: Augusto M Carvalho, Sayonara M Viana, Bruno B Andrade, Fabiano Oliveira, Jesus G Valenzuela, Edgar M Carvalho, Camila I de Oliveira
• Journal: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (Clin Infect Dis) Vol. 75 Issue 10 Pg. 1754-1762 (11 14 2022) ISSN: 1537-6591 [Electronic] United States
• PMID: 35385578 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Intramural)
• Copyright: Published by Oxford University Press for the Infectious Diseases Society of America 2022.

Chemical References

• Interleukin-10
• Salivary Proteins and Peptides
• Immunoglobulin G

Topics

• Animals
• Interleukin-10 (metabolism)
• Leukocytes, Mononuclear
• Psychodidae
• Salivary Proteins and Peptides
• Leishmania braziliensis
• Leishmaniasis, Cutaneous
• Phlebotomus
• Immunity, Cellular
• Immunoglobulin G
• Severity of Illness Index