Gene expression of acute-phase and complement system proteins in the liver of frogs of the genus Rhinella submitted to immunological challenge with lipopolysaccharide (LPS).

• Grant number: 23/07913-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2023
• End date: July 31, 2024
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Fernando Ribeiro Gomes
• Grantee: Marina Zenga Carrenho
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Amphibians are currently the most endangered group of vertebrates due to, among many other factors, pandemics caused by fungi, viruses and bacteria. Among the targets of recent immunological studies in vertebrates, the liver stands out as a complex immune organ and primarily responsible for the synthesis of inflammatory proteins, such as acute phase proteins (e.g., C-reactive protein - CRP, serum amyloid A - SAA) and of the complement system (e.g., C4, C3, C5, C9). Such proteins are shown to be structurally and functionally conserved among vertebrates, with an important role in maintaining the plasma bactericidal capacity (CBP), among other functions. There is already evidence that the synthesis of these proteins during the first hours of bacterial infection takes place in the liver in amphibians, similarly to other vertebrates. However, the temporal dynamics of the synthesis of these proteins in amphibians during the inflammatory response is still poorly known. Therefore, the general objective of this project is to investigate the temporal dynamics of the gene expression of acute phase proteins and the complement system in the liver of individuals of the species Rhinella diptycha submitted to an immunological challenge with lipopolysaccharide (LPS), in addition to relating the temporal variation of the complement system action with data already collected from CBP for these individuals. For this, we will monitor the expression of the proteins of interest in the liver of male individuals of R. diptycha at four times after LPS injection (1, 3, 6 and 18 hours). Thus, it is expected that the expression of acute phase and complement system proteins occurs mainly in the first hours (1 and 3 hours) after LPS injection, and that it is directly related to the high CBP values already collected for these organisms.