In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

Restriction factors are antiviral components of intrinsic immunity which constitute a first line of defense by blocking different steps of the human immunodeficiency virus (HIV) replication cycle. In immune cells, HIV infection is also sensed by several pattern recognition receptors (PRRs), leading to type I interferon (IFN-I) and inflammatory cytokines production that upregulate antiviral interferon-stimulated genes (ISGs). Several studies suggest a link between these two types of immunity. Indeed, restriction factors, that are generally interferon-inducible, are able to modulate immune responses. This review highlights recent knowledge of the interplay between restriction factors and immunity inducing antiviral defenses. Counteraction of this intrinsic and innate immunity by HIV viral proteins will also be discussed. of PAMPs by PRRs induces signaling cascades and leads to the transcription of pro-inflammatory cytokines and type I interferons (IFN-I), the most powerful antiviral effectors. Once produced by cells in which PRRs have been activated, IFN-I are secreted and bind, in an autocrine or paracrine manner, to the membrane receptor IFNAR (IFN-/ receptor chain) to induce signal transduction driving the transcription of interferon-stimulated genes (ISGs). There are hundreds of ISGs encoding antiviral proteins such as the protein kinase R (PKR) or the 2 -5 -oligoadenylate synthetase 1 (OAS1) [13, 14] . Thus, ISGs are crucial to switch cells into an antiviral state. Interestingly, even if HIV restriction factors have been described as intrinsic immune effectors, most of them are IFN-inducible and can be defined as ISGs linking intrinsic and innate immunity. Moreover, by exerting their antiviral functions or by additional pathways, some restriction factors have been described to shape innate and adaptive immune responses highlighting an intimate relationship between restriction factors and immunity [15, 16] . In this review, we summarize the recent knowledge of the interplay between restriction factors and immunity focusing only on restriction factors that belong to the ISG family. After a description of restriction factors antiviral mechanisms and their induction by IFN, we will discuss how they can modulate immunity, in particular, innate immune responses. Moreover, since HIV-1 proteins are able to counteract many restriction factors, we will also mention viral mechanisms used to escape from intrinsic and innate immunity. Taken together, this review will allow a better understanding of the intricate interplay between restriction factors-mediated intrinsic immunity and innate immunity.
cells Interplay between Intrinsic and Innate Immunity during HIV Infection