C1qa, a component of the complement system, is emerging as a significant gene with multiple functions. The complement system is crucial in the host immune response, and C1qa plays a role in various immune-related pathways. It is associated with macrophage functions, which are pivotal in immune responses, especially in tissue-based anti-microbial defense [1].

In gene-knockout (KO) mouse models, C1qa deficiency has been shown to increase susceptibility to mouse hepatitis virus A59 infection. C1qa KO mice exhibited severe histopathological changes like hepatocellular necrosis and interstitial pneumonia, along with higher viral loads in organs such as the olfactory bulb, liver, and lungs compared to wild-type mice. This indicates that activation of the classical complement pathway, involving C1qa, may be important for protecting the host against this viral infection [2].

In conclusion, C1qa is essential in the immune-related functions of the complement system. The use of C1qa KO mouse models has revealed its significance in protecting against viral infections, highlighting its potential as a key factor in understanding host-pathogen interactions and developing strategies to enhance the host's ability to combat infections.

References:

1. Horowitz, Amir, Yu, Haocheng, Pandey, Sonalisa, Mishra, Bud, Sahoo, Debashis. 2024. C1QA is an invariant biomarker for tissue macrophages. In bioRxiv : the preprint server for biology, , . doi:10.1101/2024.01.26.577475. https://pubmed.ncbi.nlm.nih.gov/38328228/

2. Kim, Han Woong, Seo, Sun Min, Kim, Jun Young, Lee, Han Woong, Choi, Yang Kyu. . C1qa deficiency in mice increases susceptibility to mouse hepatitis virus A59 infection. In Journal of veterinary science, 22, e36. doi:10.4142/jvs.2021.22.e36. https://pubmed.ncbi.nlm.nih.gov/34056877/