Sex-specific Immune Responses Research Articles

Sex-specific immune responses to COVID-19 vaccination in end-stage renal disease patients

Abstract Background End-stage renal disease (ESRD) patients have muted memory B cell formation and reduced humoral responses to COVID-19 vaccination; however, early innate immune responses have yet to be characterized. Sex-stratification is also limited in COVID-19 vaccination research. Methods We collected blood before (BD1) and 1-4 days post-dose 1 (PD1) of BNT162b2 vaccination for RNA-sequencing in ESRD patients (n = 35 BD1; 18 PD1) and healthy controls (HC) (n = 31 BD1; 30 PD1). Additionally, 20 plasma cytokines were quantified in ESRD patients (n = 39 BD1, 35 PD1) and HC (34 BD1, 15 PD1). Results Transcriptional profiling of vaccine responses identified 125 significantly differentially expressed genes (DEG) (padj<0.04) in ESRD patients and 107 DEGs (padj<0.05) in HC. 71 DEGs were shared, 54 unique to ESRD, and 36 unique to HC. DEG, pathway analyses, and cytokine responses in the combined dataset showed ESRD patients were more inflamed than HC at baseline, with an elevated inflammatory cytokine profile compared to HC. These results were driven by female ESRD patients where IL-2, IL-10, and IP-10 were more significant in females (p < 0.001) compared to males (p < 0.01). While IL-6, IFN-γ, IL-13, eotaxin, were exclusively associated in females (p < 0.05). Healthy females also had a stronger immunological response to vaccination compared to healthy males. Conclusions Despite baseline inflammation, ESRD patients were able to mount similar early immune responses to vaccination as HC, with females in both populations more reactogenic than males. Sex-stratification is recommended for ongoing immunological research to better understand unique responses to COVID-19 vaccination. Key messages • End-stage renal disease patients have similar early innate immune responses to COVID-19 vaccination as healthy controls. • Sex-stratification is important to identify unique immunological responses that may be leveraged for sex-specific vaccination strategies.

Abstract Mo126: A sex-specific CD4 + T cell response limits Coxsackievirus B pathogenesis in mice.

Coxsackievirus B3 (CVB3) is an enteric virus that is a primary cause of inflammation of the heart muscle, known as viral myocarditis. Viral myocarditis is a significant cause of heart failure, and nearly 40,000 cases are reported each year. Unfortunately, approximately 5% of CVB3 infections are fatal. Unfortunately, no vaccines or drugs are available for this virus. Interestingly, there is a sex bias in viral myocarditis where men are more susceptible than women. Unfortunately, the underlying basis for the sex bias in infection is incompletely understood. We recently determined that T cells play an essential role in CVB3 clearance using a novel oral inoculation mouse model. Here, we show a sex difference in the CD4 + T cell response to CVB3 that is important in limiting viral pathogenesis. We found that CVB3 induced CD4 + cell expansion in female mice but not in male mice. CVB3 infection also led to the expansion of CD62L lo CD4 + T cells in the mesenteric lymph node and spleen of female but not male mice as early as five days post-inoculation, indicative of activation. Using a recombinant CVB3 virus expressing a model CD4 + T cell epitope, we found that the expansion of CD4 + T cells in females is viral-specific and not due to bystander activation. Finally, the depletion of CD4 + T cells before infection led to enhanced mortality, indicating that CD4 + T cells protect against CVB3 in female mice. We are also currently investigating the impact of CD4 + T cell subtypes, and the role of intestinal T cells play in limiting intestinal CVB3 replication and dissemination. These data demonstrate that CVB3 induces a CD4 + T cell response in female mice and highlight the importance of sex-specific immune responses to viral pathogens.

Sex differences in Huntington's disease from a neuroinflammation perspective.

Huntington's disease (HD) is a debilitating neurodegenerative condition characterized by motor, cognitive and psychiatric abnormalities. Immune dysregulation, prominently featuring increased immune activity, plays a significant role in HD pathogenesis. In addition to the central nervous system (CNS), systemic innate immune activation and inflammation are observed in HD patients, exacerbating the effects of the Huntingtin (HTT) gene mutation. Recent attention to sex differences in HD symptom severity underscores the need to consider gender as a biological variable in neurodegenerative disease research. Understanding sex-specific immune responses holds promise for elucidating HD pathophysiology and informing targeted treatment strategies to mitigate cognitive and functional decline. This perspective will highlight the importance of investigating gender influence in HD, particularly focusing on sex-specific immune responses predisposing individuals to disease.

Sex-related immunity: could Toll-like receptors be the answer in acute inflammatory response?

An increasing number of studies have highlighted the existence of a sex-specific immune response, wherein men experience a worse prognosis in cases of acute inflammatory diseases. Initially, this sex-dependent inflammatory response was attributed to the influence of sex hormones. However, a growing body of evidence has shifted the focus toward the influence of chromosomes rather than sex hormones in shaping these inflammatory sex disparities. Notably, certain pattern recognition receptors, such as Toll-like receptors (TLRs), and their associated immune pathways have been implicated in driving the sex-specific immune response. These receptors are encoded by genes located on the X chromosome. TLRs are pivotal components of the innate immune system, playing crucial roles in responding to infectious diseases, including bacterial and viral pathogens, as well as trauma-related conditions. Importantly, the TLR-mediated inflammatory responses, as indicated by the production of specific proteins and cytokines, exhibit discernible sex-dependent patterns. In this review, we delve into the subject of sex bias in TLR activation and explore its clinical implications relatively to both the X chromosome and the hormonal environment. The overarching objective is to enhance our understanding of the fundamental mechanisms underlying these sex differences.

The Role of Biological Sex in Pre-Clinical (Mouse) mRNA Vaccine Studies.

In this study, we consider the influence of biological sex-specific immune responses on the assessment of mRNA vaccines in pre-clinical murine studies. Recognising the established disparities in immune function attributed to genetic and hormonal differences between individuals of different biological sexes, we compared the mRNA expression and immune responses in mice of both biological sexes after intramuscular injection with mRNA incorporated within lipid nanoparticles. Regarding mRNA expression, no significant difference in protein (luciferase) expression at the injection site was observed between female and male mice following intramuscular administration; however, we found that female BALB/c mice exhibit significantly greater total IgG responses across the concentration range of mRNA lipid nanoparticles (LNPs) in comparison to their male counterparts. This study not only contributes to the scientific understanding of mRNA vaccine evaluation but also emphasizes the importance of considering biological sex in vaccine study designs during pre-clinical evaluation in murine studies.

HLA-E and Its Soluble Form as Indicators of a Sex-Specific Immune Response in Patients with Oral Squamous Cell Carcinoma

HLA-E and Its Soluble Form as Indicators of a Sex-Specific Immune Response in Patients with Oral Squamous Cell Carcinoma

Sex-Specific Immune Responses to Seasonal Influenza Vaccination in Diabetic Individuals: Implications for Vaccine Efficacy.

Seasonal influenza vaccination has different implications on the immune response depending on the comorbidities. Diabetes is one such critical disease that increases the patient's susceptibility to influenza and suppresses vaccine efficacy and immunity. The sex of the individuals also plays a definitive role in the immune responses to both the vaccine and the infection. This study aims to understand the efficacy of the seasonal vaccine against influenza in diabetic groups and undergoing immune mechanisms in different sexes (females and males). In this study, we are reporting about a switching of the immune response of the infected and vaccinated diabetic females towards stronger Th1/Th17 responses with suppressed humoral immunity. They show increased cDC1, enhanced proinflammatory activities within T cells, CD8T activation, Th17 proliferation, and the majority of IgG2 antibody subtypes with reduced neutralization potential. Males with diabetes exhibit enhanced humoral Th2-immunity than the nondiabetic group. They exhibit higher cDC2, and DEC205 levels within them with an increase in plasma B lymphocytes, higher IgG1 subtypes in plasma cells, and influenza-hemagglutinin-specific IgG titer with stronger virus neutralization potential. Males with diabetes recovered better than the females as observed from the changes in their body weight. This study highlights the critical immune mechanisms and sex-specific swapping of their preferred immune response pathways against influenza after vaccination during diabetes. We propose a need for a sex-specific customized vaccine regimen to be implemented against influenza for individuals having diabetes to exploit the manifested strength and weakness in their protective immunity.

Coxsackievirus B3 elicits a sex-specific CD8+ T cell response which protects female mice.

Sex is a significant contributor to the outcome of human infections. Males are frequently more susceptible to viral, bacterial, and fungal infections, often attributed to weaker immune responses. In contrast, a heightened immune response in females enables better pathogen elimination but leaves females more predisposed to autoimmune diseases. Unfortunately, the underlying basis for sex-specific immune responses remains poorly understood. Here, we show a sex difference in the CD8+ T cell response to an enteric virus, Coxsackievirus B3 (CVB3). We found that CVB3 induced expansion of CD8+ T cells in female mice but not in male mice. CVB3 also increased the proportion and number of CD11ahiCD62Llo CD8+ T cells in female mice, indicative of activation. This response was independent of the inoculation route and type I interferon. Using a recombinant CVB3 virus expressing a model CD8+ T cell epitope, we found that the expansion of CD8+ T cells in females is viral-specific and not due to bystander activation. Finally, the depletion of CD8+ T cells, prior to infection, led to enhanced mortality, indicating that CD8+ T cells are protective against CVB3 in female mice. These data demonstrate that CVB3 induces a CD8+ T cell response in female mice and highlight the importance of sex-specific immune responses to viral pathogens.

Sex Differences in Depression: An Immunological Perspective.

Depression is a heterogenous disorder with symptoms that present differently across individuals. In a subset of people depression is associated with alterations of the immune system that may contribute to disorder onset and symptomology. Women are twice as likely to develop depression and on average have a more sensitive adaptive and innate immune system when compared to men. Sex differences in pattern recognition receptors (PRRs), release of damage-associated molecular proteins (DAMPs), cell populations, and circulating cytokines play a critical role in inflammation onset. Sex differences in innate and adaptive immunity change the response of and repair to damage caused by dangerous pathogens or molecules in the body. This article reviews the evidence for sex specific immune responses that contribute to the sex differences in symptoms of depression that may account for the higher rate of depression in women.

Coxsackievirus B3 elicits a protective, sex-specific CD8 +T cell response in female mice

Abstract Sex is a significant contributor to the outcome of human infections. Males are frequently more susceptible to viral, bacterial, and fungal infections, often attributed to weaker immune responses. In contrast, a heightened immune response in females enables better pathogen elimination but leaves females more predisposed to autoimmune diseases. Unfortunately, the underlying basis for sex-specific immune responses remains poorly understood. Here, we show a sex difference in the CD8 +T cell response to an enteric virus, Coxsackievirus B3 (CVB3). We found that CVB3 induced expansion of CD8 +T cells in female Ifnar −/−mice but not in male Ifnar −/−mice. Using a recombinant CVB3 virus expressing a model CD8 +T cell epitope, we found that the expansion of CD8 +T cells is viral-specific and not due to bystander activation. CVB3 also increased the proportion and number of CD11a hiCD62L loCD8 +T cells in female mice, indicative of T cell activation. However, CD8 +T cell activation is dampened by the primary male sex hormone, testosterone, in male mice. Finally, using antibodies to deplete CD8 +T cells, we found that CD8 +T cells are required to limit CVB3-induced disease in female mice. These data demonstrate that CVB3 induces a sex-dependent CD8 +T cell response that is important for viral clearance in female mice and highlights the importance of sex differences in the immune response to viral pathogens. This work was funded by a K01 DK110216, R03 DK124749, and a Biomedical Research Grant from the Indiana Clinical and Translational Sciences Institute to CMR.

Influence of sex on global myocardial ischemia tolerance and mitochondrial function in circulatory death donor hearts.

Donation after circulatory death (DCD) donor hearts are not routinely used for heart transplantation (HTx) because of ischemic damage, which is inherent to the DCD process. HTx outcomes are suboptimal in males who received female donor hearts. The exact mechanism for suboptimal outcomes from female donor hearts has not been defined. Differential susceptibility to ischemia tolerance, which would play a significant role in DCD donation, could be a reason but has not been studied. We studied the influence of sex on global myocardial ischemia tolerance and mitochondrial function. Sprague-Dawley rats of both sexes were assigned to DCD (n = 32) or control beating-heart donor (CBD, n = 28) groups. DCD hearts underwent 25 min of in vivo global myocardial ischemia and 90 min of ex vivo Krebs-Henseleit buffer perfusion at 37°C. CBD hearts were procured without ischemia. Infarct size was determined in hearts following 90 min of reperfusion, and in another set of hearts, mitochondrial function (oxidative-phosphorylation) was studied following 60 min of reperfusion. Infarct size was increased 3.3-fold in male and 3.1-fold in female DCD hearts compared with CBD hearts. However, infarct size (%) was comparable in female and male DCD hearts (male: 25.4 ± 3.7 vs. female 19.0 ± 3.3, P = NS). Oxidative phosphorylation was similarly decreased in male and female DCD hearts' mitochondria compared with CBD hearts' mitochondria. Thus, neither infarct size nor mitochondrial dysfunction was higher in female DCD hearts. These results suggest that the susceptibility to ischemia is not the reason for suboptimal HTx outcomes with female donor hearts.NEW & NOTEWORTHY The current study shows cardiac injury is not increased in female DCD hearts following global ischemia-reperfusion compared with male DCD hearts. In addition, mitochondrial dysfunction with DCD ischemia-reperfusion is comparable in both sexes. Sex-specific immune responses and hormone receptor modulation may contribute to suboptimal outcomes in male HTx recipients with female donor hearts.

Sex differences in the inflammatory response to stroke.

Ischemic stroke is a leading cause of morbidity and mortality and disproportionally affects women, in part due to their higher longevity. Older women have poorer outcomes after stroke with high rates of cognitive deficits, depression, and reduced quality of life. Post-stroke inflammatory responses are also sexually dimorphic and drive differences in infarct size and recovery. Factors that influence sex-specific immune responses can be both intrinsic and extrinsic. Differences in gonadal hormone exposure, sex chromosome compliment, and environmental/social factors can drive changes in transcriptional and metabolic profiles. In addition, how these variables interact, changes across the lifespan. After the onset of ischemic injury, necrosis and apoptosis occur, which activate microglia and other glial cells within the central nervous system, promoting the release of cytokines and chemokines and neuroinflammation. Cells involved in innate and adaptive immune responses also have dual functions after stroke as they can enhance inflammation acutely, but also contribute to suppression of the inflammatory cascade and later repair. In this review, we provide an overview of the current literature on sex-specific inflammatory responses to ischemic stroke. Understanding these differences is critical to identifying therapeutic options for both men and women.

Sex-specific and hormone-related differences in vascular remodelling in atherosclerosis.

Atherosclerosis, a lipid-driven inflammatory disease, is the main underlying cause of cardiovascular diseases (CVDs) both in men and women. Sex-related dimorphisms regarding CVDs and atherosclerosis were observed since more than a decade ago. Inflammatory mediators such as cytokines, but also endothelial dysfunction, vascular smooth muscle cell migration and proliferation lead to vascular remodelling but are differentially affected by sex. Each year a greater number of men die of CVDs compared with women and are also affected by CVDs at an earlier age (40-70 years old) while women develop atherosclerosis-related complications mainly after menopause (60+ years). The exact biological reasons behind this discrepancy are still not well-understood. From the numerous animal studies on atherosclerosis, only a few include both sexes and even less investigate and highlight the sex-specific differences that may arise. Endogenous sex hormones such as testosterone and oestrogen modulate the atherosclerotic plaque composition and the frequency of such plaques. In men, testosterone seems to act like a double-edged sword as its decrease with ageing correlates with an increased risk of atherosclerotic CVDs, while testosterone is also reported to promote inflammatory immune cell recruitment into the atherosclerotic plaque. In premenopausal women, oestrogen exerts anti-atherosclerotic effects, which decline together with its level after menopause resulting in increased CVD risk in ageing women. However, the interplay of sex hormones, sex-specific immune responses and other sex-related factors is still incompletely understood. This review highlights reported sex differences in atherosclerotic vascular remodelling and the role of endogenous sex hormones in this process.

Effects of biological sex mismatch on neural progenitor cell transplantation for spinal cord injury in mice

Despite advancement of neural progenitor cell transplantation to spinal cord injury clinical trials, there remains a lack of understanding of how biological sex of transplanted cells influences outcomes after transplantation. To address this, we transplanted GFP-expressing sex-matched, sex-mismatched, or mixed donor cells into sites of spinal cord injury in adult male and female mice. Biological sex of the donor cells does not influence graft neuron density, glial differentiation, formation of the reactive glial cell border, or graft axon outgrowth. However, male grafts in female hosts feature extensive hypervascularization accompanied by increased vascular diameter and perivascular cell density. We show greater T-cell infiltration within male-to-female grafts than other graft types. Together, these findings indicate a biological sex-specific immune response of female mice to male donor cells. Our work suggests that biological sex should be considered in the design of future clinical trials for cell transplantation in human injury.

Sex-Specific Immune Responses in Stroke.

In both acute and chronic diseases, functional differences in host immune responses arise from a multitude of intrinsic and extrinsic factors. Two of the most important factors affecting the immune response are biological sex and aging. Ischemic stroke is a debilitating disease that predominately affects older individuals. Epidemiological studies have shown that older women have poorer functional outcomes compared with men, in part due to the older age at which they experience their first stroke and the increased comorbidities seen with aging. The immune response also differs in men and women, which could lead to altered inflammatory events that contribute to sex differences in poststroke recovery. Intrinsic factors including host genetics and chromosomal sex play a crucial role both in shaping the host immune system and in the neuroimmune response to brain injury. Ischemic stroke leads to altered intracellular communication between astrocytes, neurons, and resident immune cells in the central nervous system. Increased production of cytokines and chemokines orchestrate the infiltration of peripheral immune cells and promote neuroinflammation. To maintain immunosurveillance, the host immune and central nervous system are highly regulated by a diverse population of immune cells which are strategically distributed within the neurovascular unit and become activated with injury. In this review, we provide a comprehensive overview of sex-specific host immune responses in ischemic stroke.

Differential sex-specific immune responses following Prime-and-Trap vaccination alters protection against malaria in mice

Abstract Generating liver resident-memory CD8+ T cells (TRM cells) is critical for effective liver-stage malaria vaccine. The role of biological sex in liver-stage vaccine protection is understudied. Here we report sex-specific immune responses and protection outcomes for the two-step heterologous ‘Prime-and-Trap’ liver-stage malaria vaccine designed to induce liver TRM cells. The Prime-and-Trap strategy combines sporozoite antigen DNA priming with a single intravenous dose of liver-homing radiation-attenuated sporozoites (RAS) to direct and “trap” activated and expanding T cells in the liver. This strategy induces robust liver CD8+ TRM cell responses and confers sterile protection in the P. yoelii (Py) rodent malaria model in female mice. However, when tested in male mice, it induces weaker liver CD8+ TRM cell responses and little to no protection from sporozoite challenge. We examined sex-divergent immune responses in the spleen and liver following each step of the Prime-and-Trap regimen. We found that sexually dimorphic activation of certain immune pathways drives attenuated downstream retention of TRM cells in the liver, leading male mice to generate a sub-optimal immune response that ultimately fails to protect from Py sporozoite challenge. Our findings emphasize the importance of incorporating sex as a variable for evaluation in the design of robust liver-stage malaria vaccines. Supported by grants from NIH (R01 AI141857).

Kynurenic acid may underlie sex-specific immune responses to COVID-19.

Coronavirus disease 2019 (COVID-19) has poorer clinical outcomes in males than in females, and immune responses underlie these sex-related differences. Because immune responses are, in part, regulated by metabolites, we examined the serum metabolomes of COVID-19 patients. In male patients, kynurenic acid (KA) and a high KA-to-kynurenine (K) ratio (KA:K) positively correlated with age and with inflammatory cytokines and chemokines and negatively correlated with T cell responses. Males that clinically deteriorated had a higher KA:K than those that stabilized. KA inhibits glutamate release, and glutamate abundance was lower in patients that clinically deteriorated and correlated with immune responses. Analysis of data from the Genotype-Tissue Expression (GTEx) project revealed that the expression of the gene encoding the enzyme that produces KA, kynurenine aminotransferase, correlated with cytokine abundance and activation of immune responses in older males. This study reveals that KA has a sex-specific link to immune responses and clinical outcomes in COVID-19, suggesting a positive feedback between metabolites and immune responses in males.

Abstract WP343: Machine Learning Predicts Sex Difference in Acute Ischemic Stroke

Introduction: Stroke is a common cause of physical disability. Women generally suffer from more severe strokes, have poorer stroke outcomes, and higher mortality than that of men. Cytokines play an important role in post-stroke inflammation. Prior studies have examined differences in individual cytokine levels in patients with acute ischemic stroke (AIS), but comprehensive cytokine expression profiling across different sex and clinical characteristics are lacking. Hypothesis: Stroke is a sexually dimorphic disease with well-known sex differences in immune cell prevalence, cytokine expression, and outcome. A comprehensive cytokine and immune cell network may help identify sex-specific immune response and further provide guidance for stroke research in females. Methods: Patients with AIS were recruited from 2011-2015 at a Comprehensive Stroke Center. Multiplex analysis (Luminex 200 IS) was used to measure serum levels of 30 common cytokines. Data were analyzed with SPSS 26.0 (IBM) and machine learning algorithms. Spearman’s correlation, Mann-Whitney U test, and two-way ANOVA analyses were used to determine the relationships among the variables. The network between cytokines and immune cell types was predicted by CIBERSORT and modified ssGSEA in R package. Results: We examined sex differences in serum cytokine profiles on stroke severity and immune cells profiles using 144 patients with AIS. Among 30 cytokines, IFN-A2, IFNγ, IL-1RA, IL-6, IL-8, IP-10, RANTES, TNFα, and VEGF were found to have statistically significant differences between male and female. Additionally, female survivors with higher admission NIHSS exhibited higher levels of IFN-A2, IFNγ, IL-6, and IL-8 (F=2.722, p=.011; F=2.245, p=.034; F=7.626, p<.001; F=4.599, p<.001, respectively). A cytokine-immune cell network was created using computer algorithms resulting in identification of an upregulation of Th22 in the female. Sex-specific expression of Th22 cells was then validated in human PBMC. Conclusion: Our study suggests sex is an important factor which determines clinical outcome. Reducing Th22 may improve stroke recovery in females. Analyzing clinical data using machine learning algorithms can identify prognostic indicators of stroke.

Irradiated sporozoite vaccination induces sex-specific immune responses and protection against malaria in mice

In both preclinical animal studies and human clinical trials, adult females tend to develop greater adaptive immune responses than males following receipt of either viral or bacterial vaccines. While there is currently no approved malaria vaccine, several anti-sporozoite vaccines, including RTS,S/AS01 and attenuated sporozoite vaccines, are in development, but the impact of sex and age on their efficacy remains undefined. To examine sex differences in the efficacy of anti-sporozoite stage malaria vaccination, adult (10 weeks of age) or juvenile (11 days of age) male and female C3H mice were twice vaccinated with irradiated transgenic Plasmodium berghei sporozoites expressing the P. falciparum circumsporozoite (CSP) protein and 45 days post boost vaccination, mice were challenged with transgenic P. berghei via mosquito bite or intradermal challenge. Immunization with irradiated sporozoites resulted in greater protection against challenge in adult females, which was associated with greater anti-CSP antibody production and avidity, as well as greater hepatic, but not splenic, CD8+ T cell IFNƴ production in adult females than adult males. No sex differences in adaptive immune responses or protection were observed in mice vaccinated prior to puberty, suggesting a role for sex steroid hormones. Depletion of testosterone in males increased, whereas rescue of testosterone decreased, anti-CSP antibody production, the number of antigen-specific CD8+ T cells isolated from the liver, and protection following parasite challenge. Conversely, depletion of sex steroids in female mice did not alter vaccine-induced responses or protection following challenge. These data suggest that elevated testosterone concentrations in males reduce adaptive immunity and contribute to sex differences in malaria vaccine efficacy.

Epigenetic Mechanisms Are Involved in Sex-Specific Trans-Generational Immune Priming in the Lepidopteran Model Host Manduca sexta.

Parents invest in their offspring by transmitting acquired resistance against pathogens that only the parents have encountered, a phenomenon known as trans-generational immune priming (TGIP). Examples of TGIP are widespread in the animal kingdom. Female vertebrates achieve TGIP by passing antibodies to their offspring, but the mechanisms of sex-specific TGIP in invertebrates are unclear despite increasing evidence suggesting that both male-specific and female-specific TGIP occurs in insects. We used the tobacco hornworm (Manduca sexta) to investigate sex-specific TGIP in insects because it is a model host for the analysis of insect immunity and the complete genome sequence is available. We found that feeding larvae with non-pathogenic Escherichia coli or the entomopathogen Serratia entomophila triggered immune responses in the infected host associated with shifts in both DNA methylation and histone acetylation. Maternal TGIP was mediated by the translocation of bacterial structures from the gut lumen to the eggs, resulting in the microbe-specific transcriptional reprogramming of genes encoding immunity-related effector molecules and enzymes involved in the regulation of histone acetylation as well as DNA methylation in larvae of the F1 generation. The third-instar F1 larvae displayed sex-specific differences in the expression profiles of immunity-related genes and DNA methylation. We observed crosstalk between histone acetylation and DNA methylation, which mediated sex-specific immune responses in the F1 generation derived from parents exposed to a bacterial challenge. Multiple routes for TGIP seem to exist in M. sexta and – partially sex-specific – effects in the offspring depend on the microbial exposure history of their parents. Crucially, the entomopathogen S. entomophila appears to be capable of interfering with TGIP in the host.