Sperm competition is a potent postcopulatory selective force where sperm from rival males compete to fertilize a limited set of ova. Considering that sperm production is costly, we expect males to strategically allocate sperm in accordance with the level of competition. Accordingly, previous work has examined a male's strategic allocation in terms of sperm number. However, the seminal fluid proteins (Sfps) transferred along with sperm may also play a crucial role in competition. Surprisingly, the strategic allocation of Sfps has remained largely unexplored. Using Drosophila melanogaster, we examined the expression of three seminal fluid and four spermatogenesis genes in response to perceived sperm competition intensity by manipulating male density in a pre-mating and courtship environment. In the pre-mating environment, we found that males modified Sfp ratios by reducing the production of two spfs when potential rivals were present, while one Sfp and all spermatogenesis genes remained unaltered. In the courtship environment, males did not modify spermatogenesis or Sfp production in response to either rival males or female presence. Our data suggest that perceived competition in the pre-mating environment places a significant influence on Sfp allocation, which may be a general trend in promiscuous animal systems with internal fertilization.K E Y W O R D S : Acps, Drosophila melanogaster, ejaculate, gene expression, spermatogenesis.

Lymphocyte activation is regulated by costimulatory and inhibitory receptors of which both B and T lymphocyte attenuator (BTLA) and CD160 engage Herpesvirus entry mediator (HVEM). Notably, it remains unclear how HVEM functions with each of its ligands during immune responses. Here, we show that HVEM specifically activates CD160 on effector NK cells challenged with virus-infected cells. Human CD56dim NK cells were costimulated specifically by HVEM, but not by other receptors that share the HVEM ligands LIGHT, Lymphotoxin-α, or BTLA. HVEM enhanced human NK cell activation by type I IFN and IL-2, resulting in increased IFN-γ and TNF-α secretion, and tumor cell-expressed HVEM activated CD160 in a human NK cell line causing rapid hyper-phosphorylation of serine kinases ERK1/2 and AKT, and enhanced cytolysis of target cells. In contrast, HVEM activation of BTLA reduced cytolysis of target cells. Together, our results demonstrate that HVEM functions as a regulator of immune function that activates NK cells via CD160, and limits lymphocyte-induced inflammation via association with BTLA.

The recent Ebola epidemic exemplified the importance of understanding and controlling emerging infections. Despite the importance of T cells in clearing virus during acute infection, little is known about Ebola-specific CD8 T cell responses. We investigated immune responses of individuals infected with Ebola virus (EBOV) during the 2013-2016 West Africa epidemic in Sierra Leone, where the majority of the >28,000 EBOV disease (EVD) cases occurred. We examined T cell memory responses to seven of the eight Ebola proteins (GP, sGP, NP, VP24, VP30, VP35, and VP40) and associated HLA expression in survivors. Of the 30 subjects included in our analysis, CD8 T cells from 26 survivors responded to at least one EBOV antigen. A minority, 10 of 26 responders (38%), made CD8 T cell responses to the viral GP or sGP. In contrast, 25 of the 26 responders (96%) made response to viral NP, 77% to VP24 (20 of 26), 69% to VP40 (18 of 26), 42% (11 of 26) to VP35, with no response to VP30. Individuals making CD8 T cells to EBOV VP24, VP35, and VP40 also made CD8 T cells to NP, but rarely to GP. We identified 34 CD8 T cell epitopes for Ebola. Our data indicate the immunodominance of the EBOV NP-specific T cell response and suggest that its inclusion in a vaccine along with the EBOV GP would best mimic survivor responses and help boost cell-mediated immunity during vaccination.

The detection of foreign antigens in vivo has relied on fluorescent conjugation or indirect read-outs such as antigen presentation. In our studies, we found that these widely used techniques had several technical limitations that have precluded a complete picture of antigen trafficking or retention across lymph node cell types. To address these limitations, we developed a 'molecular tracking device' to follow the distribution, acquisition, and retention of antigen in the lymph node. Utilizing an antigen conjugated to a nuclease-resistant DNA tag, acting as a combined antigen-adjuvant conjugate, and single-cell mRNA sequencing we quantified antigen abundance in lymph node. Variable antigen levels enabled the identification of caveolar endocytosis as a mechanism of antigen acquisition or retention in lymphatic endothelial cells. Thus, these molecular tracking devices enable new approaches to study dynamic tissue dissemination of antigen-adjuvant conjugates and identify new mechanisms of antigen acquisition and retention at cellular resolution in vivo.

Blockade of IFN-α but not IFN-β signaling using either an antibody or a selective S1PR1 agonist, CYM-5442, prevented type 1 diabetes (T1D) in the mouse Rip-LCMV T1D model. First, treatment with antibody or CYM-5442 limited the migration of autoimmune "antiself" T cells to the external boundaries around the islets and prevented their entry into the islets so they could not be positioned to engage, kill, and thus remove insulin-producing β cells. Second, CYM-5442 induced an exhaustion signature in antiself T cells by up-regulating the negative immune regulator receptor genes Pdcd1, Lag3, Ctla4, Tigit, and Btla, thereby limiting their killing ability. By such means, insulin production was preserved and glucose regulation maintained, and a mechanism for S1PR1 immunomodulation described.type I interferon | IFN-alpha | S1PR1 | type 1 diabetes T ype 1 diabetes (T1D) is an autoimmune disorder defined by infiltration of autoreactive lymphoid cells into the islets of Langerhans that destroy insulin-producing β cells (1). By the time of clinical diagnosis, T cells have destroyed 60-80% or more of total β cells, resulting in high blood glucose levels as a result of low insulin production. Prevention of ketoacidosis and death require lifelong delivery of exogenous insulin. However, daily insulin therapy is associated with increased prevalence of debilitating pathologies of cardiovascular, central and peripheral nervous, ophthalmic, and peripheral vascular systems among others.A role for type I IFN in autoimmune disease was first reported by Notkins' laboratory (2) and pancreata removed at necropsy from humans with T1D displayed significant increases in type I IFN (3, 4). Treatment of humans having hairy cell leukemia (5) or hepatitis C virus (6) with IFN-α was associated with induction or acceleration of the diabetogenic process, and recent longitudinal studies demonstrated that a IFN-I gene signature of individuals at risk for developing T1D preceded clinical onset (7,8). Direct evidence for an association of IFN-I with T1D was shown by Stewart et al. (9) in transgenic (tg) mice and strengthened in studies with NOD mice (10, 11). Unanue and coworkers (10) found IFN-I transcriptional signatures within the islets preceded T-cell activation. McDevitt and coworkers (11) reported treatment of 2-to 3-wk-old NOD mice with antibody to IFNAR1 delayed the onset and decreased the incidence of T1D. Using the virusinduced Rip-LCMV T1D model, Zinkernagel and coworkers (12) demonstrated that genetic ablation of Ifnar could delay onset of T1D. However, the mechanism of action by type I IFN was unknown. Here, we report studies that define the species of type I IFN and mechanism involved causing T1D and therapeutic approaches to prevent diabetes by preserving β-cell function. Results and DiscussionTo uncover the pathological role(s) of IFN-I, a viral mouse model of T1D (13) was used in which several parameters mimic immunological and histopathological components of human T1D and the "self" antigen recognized by specific autoimmune T cells ca...