CD4+ and CD8+ T cells reduce inflammation and promote bone healing in response to titanium implants.

T cells are adaptive immune cells essential in pathogenic response, cancer, and autoimmune disorders. During the integration of biomaterials with host tissue, T cells modify the local inflammatory environment by releasing cytokines that promote inflammatory resolution following implantation. T cells are vital for the modulation of innate immune cells, recruitment and proliferation of mesenchymal stem cells (MSCs), and formation of functional tissue around the biomaterial implant. We have demonstrated that deficiency of αß T cells promotes macrophage polarization towards a pro-inflammatory phenotype and attenuates MSC recruitment and proliferation in vitro and in vivo. The goal of this study was to understand how CD4+ and CD8+ T cells, subsets of the αß T cell family, impact the inflammatory response to titanium (Ti) biomaterials. Deficiency of either CD4+ or CD8+ T cells increased the proportion of pro-inflammatory macrophages, lowered anti-inflammatory macrophages, and diminished MSC recruitment in vitro and in vivo. In addition, new bone formation at the implantation site was significantly reduced in T cell-deficient mice compared to T cell-competent mice. Deficiency of CD4+ T cells exacerbated these effects compared to CD8+ T cell deficiency. Our results show the importance of CD4+ and CD8+ T cells in modulating the inflammatory response and promoting new bone formation in response to modified Ti implants. STATEMENT OF SIGNIFICANCE: CD4+ and CD8+ T cells are essential in modulating the peri-implant microenvironment during the inflammatory response to biomaterial implantation. This study shows that deficiency of either CD4+ or CD8+ T cell subsets altered macrophage polarization and reduced MSC recruitment and proliferation at the implantation site.

Contribution of αß T cells to macrophage polarization and MSC recruitment and proliferation on titanium implants.

Physiochemical cues like topography and wettability can impact the inflammatory response and tissue integration after biomaterial implantation. T cells are essential for immunomodulation of innate immune cells and play an important role in the host response to biomaterial implantation. This study aimed to understand how CD4+ and CD8+ T cell subsets, members of the αß T cell family, polarize in response to smooth, rough, or rough-hydrophilic titanium (Ti) implants and whether their presence modulates immune cell crosstalk and mesenchymal stem cell (MSC) recruitment following biomaterial implantation. Post-implantation in mice, we found that CD4+ and CD8+ T cell subsets polarized differentially in response to modified Ti surfaces. Additionally, mice lacking αß T cells had significantly more pro-inflammatory macrophages, fewer anti-inflammatory macrophages, and reduced MSC recruitment in response to modified Ti post-implantation than αß T cell -competent mice. Our results demonstrate that T cell activation plays a significant role during the inflammatory response to implanted biomaterials, contributing to macrophage polarization and MSC recruitment and proliferation, and the absence of αß T cells compromises new bone formation at the implantation site. STATEMENT OF SIGNIFICANCE: T cells are essential for immunomodulation and play an important role in the host response to biomaterial implantation. Our results demonstrate that T cells actively participate during the inflammatory response to implanted biomaterials, controlling macrophage phenotype and recruitment of MSCs to the implantation site.

Am I next? Men and women's divergent justice perceptions following vicarious mistreatment.

Though we would like to believe that people universally consider workplace mistreatment to be an indicator of injustice, we describe why bystanders can react to justice events (in this study, vicariously observing or becoming aware of others being mistreated) with diverging perceptions of organizational injustice. We show that a bystander's gender and their gender similarity to the target of mistreatment can produce identity threat, which affects whether bystanders perceive the overall organization to be rife with gendered mistreatment and unfairness. Identity threat develops via two pathways-an emotion-focused reaction and a cognitive-focused processing of the event-and each pathway distally relates to different levels of bystanders' justice perceptions. We test these notions in three complementary studies: two laboratory experiments (N = 563; N = 920) and a large field study (N = 8,196 employees in 546 work units). Results generally show that bystanders who are women or similar in gender to the target of mistreatment reported different levels of emotional and cognitive identity threat that related to psychological gender mistreatment climate and workplace injustice following the incident as compared to men and those not similar in gender to the target. Overall, by integrating and extending bystander theory and dual-process models of injustice perceptions, through this work, we provide a potentially overlooked reason why negative behaviors like incivility, ostracism, and discrimination continue to occur in organizations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Reduction of neutrophil extracellular traps accelerates inflammatory resolution and increases bone formation on titanium implants.

Neutrophils are the most abundant immune cells in the blood and the first cells to be recruited to the biomaterial implantation site. Neutrophils are fundamental in recruiting mononuclear leukocytes to mount an immune response at the injury site. Neutrophils exert significant pro-inflammatory effects through the release of cytokines and chemokines, degranulation and release of myeloperoxidase (MPO) and neutrophil elastase (NE), and the production of large DNA-based networks called neutrophil extracellular traps (NETs). Neutrophils are initially recruited and activated by cytokines and pathogen- and damage-associated molecular patterns, but little is known about how the physicochemical composition of the biomaterial affects their activation. This study aimed to understand how ablating neutrophil mediators (MPO, NE, NETs) affected macrophage phenotype in vitro and osseointegration in vivo. We discovered that NET formation is a crucial mediator of pro-inflammatory macrophage activation, and inhibition of NET formation significantly suppresses macrophage pro-inflammatory phenotype. Furthermore, reducing NET formation accelerated the inflammatory phase of healing and produced greater bone formation around the implanted biomaterial, suggesting that NETs are essential regulators of biomaterial integration. Our findings emphasize the importance of the neutrophil response to implanted biomaterials and highlight innate immune cells' regulation and amplification signaling during the initiation and resolution of the inflammatory phase of biomaterial integration. STATEMENT OF SIGNIFICANCE: Neutrophils are the most abundant immune cells in blood and are the first to be recruited to the injury/implantation site where they exert significant pro-inflammatory effects. This study aimed to understand how ablating neutrophil mediators affected macrophage phenotype in vitro and bone apposition in vivo. We found that NET formation is a crucial mediator of pro-inflammatory macrophage activation. Reducing NET formation accelerated the inflammatory phase of healing and produced greater appositional bone formation around the implanted biomaterial, suggesting that NETs are essential regulators of biomaterial integration.

Immune cell response to orthopedic and craniofacial biomaterials depends on biomaterial composition.

Materials for craniofacial and orthopedic implants are commonly selected based on mechanical properties and corrosion resistance. The biocompatibility of these materials is typically assessed in vitro using cell lines, but little is known about the response of immune cells to these materials. This study aimed to evaluate the inflammatory and immune cell response to four common orthopedic materials [pure titanium (Ti), titanium alloy (TiAlV), 316L stainless steel (SS), polyetheretherketone (PEEK)]. Following implantation into mice, we found high recruitment of neutrophils, pro-inflammatory macrophages, and CD4+ T cells in response to PEEK and SS implants. Neutrophils produced higher levels of neutrophil elastase, myeloperoxidase, and neutrophil extracellular traps in vitro in response to PEEK and SS than neutrophils on Ti or TiAlV. Macrophages co-cultured on PEEK, SS, or TiAlV increased polarization of T cells towards Th1/Th17 subsets and decreased Th2/Treg polarization compared to Ti substrates. Although SS and PEEK are considered biocompatible materials, both induce a more robust inflammatory response than Ti or Ti alloy characterized by high infiltration of neutrophils and T cells, which may cause fibrous encapsulation of these materials. STATEMENT OF SIGNIFICANCE: Materials for craniofacial and orthopedic implants are commonly selected based on their mechanical properties and corrosion resistance. This study aimed to evaluate the immune cell response to four common orthopedic and craniofacial biomaterials: pure titanium, titanium-aluminum-vanadium alloy, 316L stainless steel, and PEEK. Our results demonstrate that while the biomaterials tested have been shown to be biocompatible and clinically successful, the inflammatory response is largely driven by chemical composition of the biomaterials.

Canonical Wnt signaling enhances pro-inflammatory response to titanium by macrophages.

Biomaterial characteristics like surface roughness and wettability can determine the phenotype of macrophages following implantation. We have demonstrated that inhibiting Wnt ligand secretion abolishes macrophage polarization in vitro and in vivo; however, the role of canonical Wnt signaling in macrophage activation in response to physical and chemical biomaterial cues is unknown. The aim of this study was to understand whether canonical Wnt signaling affects the response of macrophages to titanium (Ti) surface roughness or wettability in vitro and in vivo. Activating canonical Wnt signaling increased expression of toll-like receptors and interleukin receptors and secreted pro-inflammatory cytokines and reduced anti-inflammatory cytokines on Ti, regardless of surface properties. Inhibiting canonical Wnt signaling reduced pro-inflammatory cytokines on all Ti surfaces and increased anti-inflammatory cytokines on rough or rough-hydrophilic Ti. In vivo, activating canonical Wnt signaling increased total macrophages, pro-inflammatory macrophages, and T cells and decreased anti-inflammatory macrophages on both smooth and rough-hydrophilic implants. Functionally, canonical Wnt activation increases pro-inflammatory macrophage response to cell and cell-extracellular matrix lysates. These results demonstrate that activating canonical Wnt signaling primes macrophages to a pro-inflammatory phenotype that affects their response to Ti implants in vitro and in vivo.

Bargaining while Black: The role of race in salary negotiations.

The influence of race in negotiations has remained relatively underexplored. Across three studies, we theorize and find that Black job seekers are expected to negotiate less than their White counterparts and are penalized in negotiations with lower salary outcomes when this expectation is violated; especially when they negotiate with an evaluator who is more racially biased (i.e., higher in social dominance orientation). Specifically, on the basis of the prescriptive stereotype held by those higher in racial bias-that Black (as compared to White) negotiators deserve lower salaries-we predicted that Black negotiators who behave in counterstereotypical ways encounter greater resistance and more unfavorable outcomes from more biased evaluators. We tested this argument in a stepwise fashion: In Study 1, we found that more biased evaluators expect Black job seekers to negotiate less as compared to White job seekers. When Black negotiators violate those expectations, evaluators award them lower starting salaries (Study 2), which appears to occur because evaluators become more resistant to making concessions to Black than to White job seekers (Study 3). Collectively, our findings demonstrate that racially biased perceptual distortions can be used to justify the provision of smaller monetary awards for Black job seekers in negotiations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Composition and compensation: The moderating effect of individual and team performance on the relationship between Black team member representation and salary.

Despite considerable focus on how the demographic composition of a workplace (e.g., the representation of minorities, women) may adversely affect the salaries of all individuals within that workplace, few researchers have investigated the factors that may impede this deleterious effect. In two distinct samples of multiracial work teams and one experiment, we test the moderating factors that attenuate or exacerbate these demographic influences on the monetary assessments of individuals' worth. Specifically, we demonstrate that the proportion of Black coworkers on a team is more negatively related to individual compensation for poorer, rather than higher, performing individuals or teams. Experimentally, we show that when performance is lower (individual or team), having more Black coworkers on a work team is related to greater stigmatization and, consequently, lower salaries. No such indirect effect is present, however, when performance is higher. These studies demonstrate that, under poor performance, the pernicious effects of stigma may have a wider reach than previously believed. Theoretical and practical implications of this finding are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Minimizing cross-cultural maladaptation: How minority status facilitates change in international acculturation.

Culturally savvy organizations recognize that selecting and developing people who can be effective in a global workforce is important in today's business environment. Nevertheless, many companies struggle to identify and develop talent who are happy and successful working and living outside their home country. We examine 1 factor that may foster success in a host country-minority status in 1's home country-as a predictor of change in acculturation over time. Specifically, we draw on the conservation of resources model to suggest that international students who have been a member of more minority groups in their home country have unique experiences working with dissimilar others that offer advantages when acculturating to new cultures and novel situations. Then, change in host country acculturation is explored as a mechanism to explain how minority status in the home country relates to intentions to leave the host country and psychological well-being 6 months after entry. Two moderators (cultural intelligence, perceived diversity climate of the host institution) of these relationships are also examined. Results revealed that the relationship between minority status in the home country and change in host country acculturation was positive and stronger for those with higher cultural intelligence. Further, the relationship between change in host country acculturation and psychological well-being was positive when perceived diversity climate of the host institution was high, but was not significant when perceived diversity climate was low. (PsycINFO Database Record

Investigating why and for whom management ethnic representativeness influences interpersonal mistreatment in the workplace.

Preliminary research suggests that employees use the demographic makeup of their organization to make sense of diversity-related incidents at work. The authors build on this work by examining the impact of management ethnic representativeness-the degree to which the ethnic composition of managers in an organization mirrors or is misaligned with the ethnic composition of employees in that organization. To do so, they integrate signaling theory and a sense-making perspective into a relational demography framework to investigate why and for whom management ethnic representativeness may have an impact on interpersonal mistreatment at work. Specifically, in three complementary studies, the authors examine the relationship between management ethnic representativeness and interpersonal mistreatment. First, they analyze the relationship between management ethnic representativeness and perceptions of harassment, bullying, and abuse the next year, as moderated by individuals' ethnic similarity to others in their organizations in a sample of 60,602 employees of Britain's National Health Service. Second, a constructive replication investigates perceived behavioral integrity as an explanatory mechanism that can account for the effects of representativeness using data from a nationally representative survey of working adults in the United States. Third and finally, online survey data collected at two time points replicated these patterns and further integrated the effects of representativeness and dissimilarity when they are measured using both objective and subjective strategies. Results support the authors' proposed moderated mediation model in which management ethnic representation is negatively related to interpersonal mistreatment through the mediator of perceived behavioral integrity, with effects being stronger for ethnically dissimilar employees. (PsycINFO Database Record

Blaming the building: How venue quality influences consumer bias against stigmatized leaders.

Because stigmatized individuals are viewed as incongruent with commonly held implicit leadership theories, they are often deemed less fit to lead than their nonstigmatized counterparts (Eagly & Karau, 2002). This suggests consumers might use such views to discredit not only stigmatized leaders, but also the companies they represent. However, cognition based on social categories (1 potential form of stigma) may be more likely when there are readily available alternative factors to account for one's decisions via casuistry. Across 2 complementary studies (field and experiment), we find that customers react negatively to stigmatized leaders only when the physical state of the company venue provides an ostensible defense to mask their biased behavior. When facilities are of lower quality, consumers appear to use a leader's stigma to infer lower product quality, coinciding in less patronage for companies with stigmatized as opposed to nonstigmatized leaders. Thus, consumers penalize companies with stigmatized leaders only when doing so can easily be attributed to an alternative factor (e.g., a lower quality venue) not involving the leader's stigma. (PsycINFO Database Record

The role of proximal social contexts: Assessing stigma-by-association effects on leader appraisals.

Prior research suggests that segregation in the U.S. workplace is on the rise (Hellerstein, Neumark, & McInerney, 2008); as such, leaders are more likely to lead groups of followers composed primarily of their own race (Elliot & Smith, 2001; Smith & Elliott, 2002). Drawing from theory on stigma-by-association, the authors posit that such segregated proximal social contexts (i.e., the leader's group of followers) can have detrimental effects on leader appraisals. Specifically, they argue that leaders of mostly Black follower groups experience stigmatization based on race stereotypic beliefs, which affects how they are viewed in the eyes of observers. The results of a large field study show performance evaluations generally tend to be lower when the proportion of Black followers is higher. Moreover, 3 experiments demonstrate that the impact of proximal social contexts extends to other outcomes (i.e., perceptions of market value and competency) but appears limited to those who are less internally and externally motivated to control their prejudice. Taken together, these findings explain how workplace segregation systematically can create a particular disadvantage for Black leaders.

It is worse when you do it: Examining the interactive effects of coworker presenteeism and demographic similarity.

Presenteeism (showing up for work while sick) is detrimental for employee productivity, yet little is known about its impact on coworkers. Presenteeism may be particularly important when considering coworker reactions that may depend on how similar the sick person is to the coworker. The black sheep hypothesis suggests that the detrimental effects of coworker presenteeism on emotional and behavioral reactions will be exacerbated when there is greater demographic similarity to the perpetrator because the violation of norms of reciprocity, empathy, and concern for others' well-being reflects negatively on one's in-group. We tested the black sheep hypothesis in 2 samples: (a) 81 short-term teams (N = 254) where we manipulated presenteeism using confederates who acted as either sick or healthy coworkers and (b) 34 student project teams (N = 104) that collaborated for 3 months and we measured coworker presenteeism. Across the studies, mediated moderation results yielded some support for the black sheep hypothesis. When they were of the same race or sex, coworker presenteeism led participants to feel less positively and exhibit lower physical engagement and more organizational deviance (Study 1). When coworkers were more racially similar to the participant, coworker presenteeism triggered fear of contagion and negative affect resulting in more organizational and interpersonal deviance (Study 2).

The subjective well-being political paradox: happy welfare states and unhappy liberals.

Political scientists traditionally have analyzed the effect of politics on subjective well-being (SWB) at the collective level, finding that more liberal countries report greater SWB. Conversely, psychologists have focused primarily on SWB at the individual level and shown that being more conservative corresponds in greater SWB. We integrate the theoretical foundations of these 2 literatures (e.g., livability and system justification theories) to compare and contrast the effects of country- and individual-level political orientation on SWB simultaneously. Using a panel of 16 West European countries representative of 1,134,384 individuals from 1970 to 2002, we demonstrated this SWB political paradox: More liberal countries and more conservative individuals had higher levels of SWB. More important, we explored measurement as a moderator of the political orientation-SWB relationship to shed some light on why this paradox exists. When orientation is measured in terms of enacted values (i.e., what the government actually does), liberalism corresponds in higher SWB, but when politics is measured in terms of espoused values (i.e., what individuals believe), greater conservatism coincided in higher SWB. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

It's self defense: how perceived discrimination promotes employee withdrawal.

Integrating theory on stress, stigma, and coping, the present study sheds light on how employees react to perceived discrimination (PD) in the workplace. Using three national samples, we found that PD based on race, sex, age, family obligation, and sexual orientation related to physical withdrawal (i.e., lateness, absenteeism,and intent to quit) indirectly through psychological withdrawal (i.e., burnout and engagement) such that PD corresponded in less engagement and more burnout, which related to increased lateness, absenteeism, and intent to quit [corrected].Further, these indirect relationships were moderated by employees' coping mechanisms with those who were more apt to change the situation or to avoid the stressor exhibiting weaker relationships between PD and psychological withdrawal. Though each of these studies is cross-sectional in nature and therefore cannot provide strong evidence of causal ordering of the variables in our model, the replication and extension of results over three databases and multiple forms of discrimination, coping, psychological, and physical withdrawal demonstrates that understanding the relationships explored in these studies can aid researchers and practitioners in enhancing employee quality of life and productivity.

Investigating the racioethnic differences in the link between workplace racioethnic dissimilarity and life satisfaction.

Though researchers have examined racioethnic dissimilarity in the workplace, few have looked at how it relates to life satisfaction, and none have examined prospective racioethnic differences in this linkage. This study used data from a nationally representative interview survey of more than 500 people employed in the United States to test relationships between workplace dissimilarity, prejudice, racioethnicity, and life satisfaction. We found that the dissimilarity-satisfaction linkage is positive for Black and Hispanic Americans and negative for White Americans. Further exploring the latter finding, our results showed that the negative association between dissimilarity and life satisfaction was present only among White Americans higher in prejudice. This study extends the literature on interracioethnic interactions and further illustrates the importance of reducing prejudice in organizational settings.

Do the weary care about racioethnic similarity? The role of emotional exhaustion in relational demography.

Diversity theorists have hypothesized that similarity leads to both greater identification among individuals and reduced interpersonal conflict within organizations. Little research, however, has been conducted to identify boundary conditions for this relationship. The authors investigated the interactive effects of supervisor-subordinate racioethnic similarity and emotional exhaustion on organizational commitment in two studies. In Study 1, racioethnic supervisor-subordinate similarity related positively to commitment, but only among employees low in emotional exhaustion. In Study 2, we observed a significant indirect effect of racioethnic similarity on loyalty through supervisor support. Moreover, the support-loyalty linkage was significantly stronger for employees low in emotional exhaustion. Thus, the effects of supervisor-subordinate racioethnic similarity on employee commitment appear contingent upon employee emotional exhaustion.

It does not have to be uncomfortable: the role of behavioral scripts in Black-White interracial interactions.

Despite growing racioethnic diversity in U.S. organizations, few organizational studies have focused on Black-White interracial interactions. Two experiments examined the influence of interaction roles, and the social scripts they trigger, on White participants' anxiety during dyadic interactions with Black partners. Results from both studies reveal that White participants exhibited greater discomfort in Black-White interactions than in same-race interactions unless their interaction role offered an accessible script to guide behavior. Thus, the present findings suggest organizations may be able to attenuate anxiety among White employees by (a) providing opportunities for initial Black-White interactions in settings with clearly defined social scripts for behavior and (b) helping them to develop behavioral scripts for naturally occurring Black-White workplace interactions.

What are the odds? How demographic similarity affects the prevalence of perceived employment discrimination.

Because research is needed to identify the conditions that facilitate or impede the prevalence of perceived workplace discrimination, the authors examined the effects of demographics and demographic similarity on the prevalence of sex- and race/ethnicity-based perceived workplace discrimination. Results from a national survey of 763 full-time, United States employees show perceived sex-based discrimination at work was more prevalent among female than male employees, and perceived race-based discrimination at work was more prevalent among Black and Hispanic than White employees. Additionally, perceived racial/ethnic discrimination was less prevalent among those with same-race/ethnicity supervisors. The effect of employee-coworker sex similarity on perceived sex discrimination was significant only for women, and the effects of supervisor-subordinate racial similarity on the prevalence of perceived racial discrimination varied between Black and White respondents, depending on employee-residential-community racial similarity.