Is there a direct correlation between high testosterone level and weak immune system?

Question

I tried googling it, the only credible link I found is this: https://med.stanford.edu/news/all-news/2013/12/in-men-high-testosterone-can-mean-weakened-immune-response-study-finds.html

---

Can someone please tell me whether this is true. If yes, why?

Answer 1

According to this 2016 Nature Review article (which cites the article from your link):

Androgens have been show to reduce immune response in a variety of studies. For example:

• In vivo exposure to testosterone reduces NK cell activity in mice [1]
• In vivo and in vitro exposure to testosterone decreases TLR4 expression on macrophages in mice [2]
• Testosterone reduces synthesis of TNF, iNOS and NO by macrophages and increases anti-inflammatory response through TGF-b and Il-10 [3]

The mechanism of action of androgenic immunosuppression seems to be due to androgen receptor's inhibitory effect on pro-inflammatory transcription factors [4].

Sources:

1. https://www.ncbi.nlm.nih.gov/pubmed/3366506
2. https://www.ncbi.nlm.nih.gov/pubmed/18003947
3. https://www.ncbi.nlm.nih.gov/pubmed/10415638
4. https://www.ncbi.nlm.nih.gov/pubmed/10453354