Factor structure of the geriatric institutional assessment profile's professional issues scales

The Geriatric Institutional Assessment Profile (GIAP) is a self-administered survey of hospital nurses, designed to assess a hospital's readiness to implement geriatric programs. A sample of 2,211 direct care RNs in 24 hospitals was randomly split in half to analyze the Geriatric Professional Issues scales of the GIAP, using one sample for exploratory factor analysis and one for confirmatory factor analysis. An exploratory factor analysis of the six Geriatric Professional Issue scales (staff disagreement, staff/family/patient disagreement, use of geriatric services, perceived legal vulnerability, perceived upsetting behaviors, and burden of upsetting behaviors) demonstrated very good internal consistency both as a whole (Cronbach's alpha coefficient = 0.90) and as individual factors (0.94, 0.91, 0.92, 0.89, 0.85, and 0.81, respectively). The six factors were validated in a half randomly selected sample, with a root-mean-square error of approximation fit index of 0.07 and the normed and non-normed fit indices both 0.8, all indicating adequate fit of the six-factor model.

Test—Retest Reliability of the Geriatric Institutional Assessment Profile

The Geriatric Institutional Assessment Profile (GIAP) is a self-administered survey of hospital nurses designed to assess a hospital's readiness to implement geriatric programs. The GIAP measures nurses' knowledge and attitudes toward older adults as well as the organizational attributes that support or constrain geriatric best practices. Test—retest reliability estimates of the GIAP were conducted with a sample of 166 direct care nurses in three urban, university-affiliated hospitals over a 3-week time period. Intraclass correlation coefficients of GIAP scales and subscales ranged between .82 and .92, demonstrating good to very good reliability. The GIAP is a reliable measure of organizational attributes of the hospital relevant to geriatric care.

The Nursing Practice Environment and Nurse-Perceived Quality of Geriatric Care in Hospitals

The relationships between general and geriatric-specific nursing practice environments (NPEs) and nurse-perceived quality of geriatric care in hospitals were examined using the Nurses Improving Care for Healthsystems Elders benchmarking database. The overall general NPE was negatively related, but the overall geriatric-specific NPE was positively related to quality of geriatric care. Among five subdomains of the general NPE measured by the Practice Environment Scale of the Nursing Work Index, Nurse Participation in Hospital Affairs was positively related to quality of geriatric care, whereas two subdomains were not significant, and another two were negatively related to quality of geriatric care. All three subdomains of the geriatric-specific NPE measured by the Geriatric Nursing Practice Environment scale were positively related to quality of geriatric care when adjusting for general NPE. These findings suggest geriatric-specific organizational support combined with nurse involvement in hospital decision making is critical for delivering quality geriatric care.

Understanding new registered nurses' intent to stay at their jobs

Nursing turnover is costly for health care organizations. Newly licensed registered nurses work behavior is a complex process, influenced by their attitudes toward their work, personal characteristics, job opportunities, and workplace attributes. Several characteristics are significant in predicting satisfaction (ethnicity, gender) and organizational commitment (patient load, mandatory overtime, shift, and unit type) and intent to stay (income, age) over and above work attitudes. Among the most important implications are how the findings can inform management and policy. Findings from this study provide information that may be useful for those organizations that want to decrease their turnover rates.

Newly licensed RNs' characteristics, work attitudes, and intentions to work

OBJECTIVE

In an effort to better understand turnover rates in hospitals and the effect of new nurses on them, this study sought to describe the characteristics and attitudes toward work of newly licensed RNs, a population important to both the nursing profession and the health care system.

METHODS

A survey was mailed to a random sample of new RNs in 35 states and the District of Columbia. A total of 3,266 returned surveys met the inclusion criteria, for a response rate of 56%. RNs who qualified had completed the licensing examination and obtained a first license between August 1, 2004, and July 31, 2005. Data pertaining to four areas were collected: respondent characteristics, work-setting characteristics, respondents' attitudes toward work, and job opportunities. Respondents who were not working were asked to specify why.

RESULTS

Of the eligible newly licensed RNs, 58.1% had an associate's degree, 37.6% had a bachelor's degree, and 4.3% had a diploma or a master's or higher degree as their first professional degree. They were generally pleased with their work groups but felt they had only moderate support from supervisors. About 13% had changed principal jobs after one year, and 37% reported that they felt ready to change jobs. More than half of the respondents (51%) worked voluntary overtime, and almost 13% worked mandatory overtime. Also, 25% reported at least one on-the-job needlestick in a year; 39%, at least one strain or sprain; 21%, a cut or laceration; and 46%, a bruise or contusion; 62% reported experiencing verbal abuse. A quarter of them found it "difficult or impossible" to do their jobs at least once per week because of inadequate supplies.

CONCLUSIONS

This study provides descriptive evidence that a majority of newly licensed RNs are reasonably satisfied and have no plans to change jobs, but the group is not homogeneous. The negative attitudes expressed in response to some survey questions suggest that newly licensed RNs may not remain in the acute care settings where they start out. Investing in better orientation and management may be the key to retaining them in hospitals. The authors will be following these RNs for two years and will develop predictive models of turnover rates.

Factor Structure of the Geriatric Care Environment Scale

BACKGROUND

Older adults comprise approximately 60% of all adult, nonobstetric hospital admissions. Nurses Improving Care for Health System Elders (NICHE) is a national program aimed at system improvement to achieve patient-centered care for older adults. The NICHE hospitals use the Geriatric Institutional Assessment Profile (GIAP) to assess their institutional readiness to provide quality care to older adults and to document improvement in geriatric care delivery.

OBJECTIVE

To explore the factorial structure of the 28-item Geriatric Care Environment Scale (GCES) of the GIAP, test its validity with a sample of staff registered nurses (RNs), and evaluate its invariance across 4 groups of RNs who worked at 4 different types of hospitals.

METHODS

Staff RNs (N = 9,400) at 71 acute hospitals, who responded to the GIAP from 1999 to 2004, were split randomly into 2 groups for cross-validation. A 3-step data analysis was completed. The a priori factor structure was developed using exploratory factor analysis. The obtained factor model was validated, and its invariance by types of hospitals was examined by confirmatory factor analyses.

RESULTS

The GCES is internally consistent (Cronbach's alpha = .93) and accounts for approximately 55% of the total variance. The 4 factors extracted from the exploratory factor analysis are Aging-Sensitive Care Delivery, Resource Availability, Institutional Values Regarding Older Adults and Staff, and Capacity for Collaboration. The 4-factor structured model is validated in a half-randomly selected sample (normed fit index [NFI] = .931, nonnormed fit index [NNFI] = .933, comparative fit index [CFI] = .939, root-mean-square error of approximation [RMSEA] = .058) and does not vary significantly across the 4 groups of RNs who worked at the 4 different types of hospitals (NFI = .969, NNFI = .975, CFI = .976, RMSEA = .027).

CONCLUSIONS

The GCES is a reliable measure of RN perception of how care provided to older adults reflects age-sensitive principles and the organizational practice environment that supports or hinders care delivery.

Portrayal of Nursing to Incoming Students: Results of a National Survey of Geriatric and Pediatric Web Images on Baccalaureate Nursing Program Web Sites

In the face of a rapidly aging America and given that older adults are the population that avail health care services the most, there is a clear mandate to stimulate nursing student interest in care of older adults. The purpose of this study was to determine if web sites of baccalaureate nursing (BSN) programs stimulate interest in care of older adults by quantifying and comparing images of older adults and children on baccalaureate nursing program web sites and examining the characteristics of these images. The reality that nurses primarily care for older adults is not reflected in images on BSN program web sites. This creates both a skewed perception of the nursing profession and a lost opportunity to stimulate interest in geriatric nursing.

Geriatric Competencies for RNs in Hospitals

Nurses in staff development are responsible for assuring nurses' competence in the delivery of care. Older patients are the predominant population in hospitals, yet there are no instruments that specifically assess the competency of nurses to deliver care to older patients. This article reports on the development and testing of an instrument, Geriatric Competencies for RNs in Hospitals, and makes recommendations as to how staff development educators can use the geriatric competency instrument with staff nurses.

Neglect assessment in urban emergency departments and confirmation by an expert clinical team

BACKGROUND

Elder neglect accounts for over 70% of all adult protective services reports in the nation annually, and it has been estimated that there are over 70,000 new cases each year. The purpose of this study was to conduct elder neglect research in the emergency department (ED), using a dyadic vulnerability/risk-profiling framework for elder neglect.

METHODS

Patients were recruited through four EDs in New York and Tampa from the beginning of February 2001 through the end of September 2003. Demographics, a Mini-Mental Status Examination score, and an initial elder assessment screen were collected. The diagnosis of neglect was then made by a Neglect Assessment Team (NAT) comprising a nurse, physician, and social worker, with extensive clinical experience in elder neglect.

RESULTS

Of the 3664 ED screens of adults 70 years and older, 405 (11%) met the inclusion criteria and agreed to participate. Neglect was diagnosed by the NAT in 86 of the 405 cases reviewed. Demographic differences between neglect versus no neglect cases were examined using Fisher's exact test, and differences emerged between the 2 groups.

CONCLUSION

This study documents the underreporting of cases of neglect as evidenced by differences in diagnoses by screeners versus experts. The research assistants screened positive for neglect in 5% (N=22) of the 405 cases. The NAT made the diagnosis of neglect in 22% (86/389) of the cases. This markedly different rate of neglect may mean that ED screens are important but may underestimate the true number of cases. Conversely, an NAT may make the diagnosis of neglect in an older adult more often given a higher sensitivity and a more robust knowledge base of the problem.

Dyadic Vulnerability and Risk Profiling for Elder Neglect

PURPOSE

Neglect of older adults accounts for 60% to 70% of all elder-mistreatment reports made to adult protective services. The purpose of this article is to report data from research, using a risk-and-vulnerability model, that captures the independent contributions of both the elder and the caregiver as they relate to the outcome of neglect.

METHODS

Between February 2001 and September 2003, older adults were screened and recruited through four emergency departments in New York and Tampa. The diagnosis of neglect was made by an expert neglect-assessment team. Elders and their caregivers were then scheduled for separate face-to-face interviews after discharge.

RESULTS

Constructs within the risk-and-vulnerability model were examined for scale-score significance based on the outcome diagnosis of neglect. In the risk domain, caregivers' functional status, childhood trauma, and personality were statistically significant. In the vulnerability domain, the elders' cognitive status, functional status, depression, social support, childhood trauma, and personality were significant.

IMPLICATIONS

Findings from this study underscore the value of interdisciplinary assessment teams in emergency departments for screening elder neglect, with attention given to risk factors related to the caregiver and elder vulnerability factors, including reports of childhood trauma. The risk-and-vulnerability model may provide a link between the caregiving and neglect research. Data should be collected independently from both members of the elder-caregiver dyad in order for clinicians to understand factors related to elders who receive the diagnosis of neglect from interdisciplinary teams.

Inflammatory arthritis and dermatitis in thymectomized, CD25+ cell-depleted adult mice

OBJECTIVE

To investigate the effect of CD25+ or CTLA-4(+) cell depletion on the natural history of collagen-induced and spontaneous arthritis in male DBA1/J mice.

METHODS

Male DBA/1J mice were treated with anti-CD25 depleting antibody (PC61) or isotype control (GL113), or with anti-CTLA-4 depleting antibody (4F10) at various time-points peri- and post-immunization with bovine collagen type II, emulsified in adjuvant. In order to develop a model system in which long-term depletion of CD25+ regulatory T cells can be achieved prior to immunization, adult male DBA/1J mice were thymectomized prior to administration of either PC61 or GL113. An ELISA demonstrated that PC61 and GL113 antibodies were undetectable by 21 days after administration and FACS analysis confirmed the long-term depletion of CD25+ cells in peripheral blood.

RESULTS

In the thymectomized mice treated with PC61, the CD25+ population was depleted and a spontaneous arthritis developed (P = 0.03). In the non-thymectomized mice, administration of CTLA-4-depleting antibody prior to immunization exacerbated arthritis in mice immunized with bovine collagen type II emulsified in incomplete Freund's adjuvant (P < 0.01). However, no significant difference in the natural history of arthritis was evident in mice treated with CD25-depleting antibody (PC61) compared with control antibody (GL113).

CONCLUSIONS

Two separate models implicate CD25+ CTLA-4(+) constitutive cells in suppression of arthritis in susceptible DBA/1 males: exacerbation of collagen-induced arthritis following CTLA-4 depletion at the start of induction and spontaneous arthritis in the thymectomy/CD25+ depletion model.

The non-thiol angiotensin-converting enzyme inhibitor quinapril suppresses inflammatory arthritis

OBJECTIVES

In addition to its vasoactive effects, angiotensin II has proinflammatory properties. Angiotensin-converting enzyme (ACE) inhibitors reduce the production of angiotensin II and could therefore act as anti-inflammatory agents. Here we investigated the capacity of the ACE inhibitor quinapril to modulate inflammatory arthritis.

METHODS

We studied the effect of quinapril on disease activity in mice with collagen-induced arthritis (CIA). Mice received oral quinapril (10 mg/kg/day) at the time of arthritis induction (prophylaxis protocol) or at the onset of mild arthritis (therapy protocol). Concentrations of immunoglobulin G (IgG) subtypes specific for bovine Type II collagen and TNF-alpha were measured by enzyme-linked immunoassay.

RESULTS

Quinapril significantly diminished the activity of CIA when given as prophylaxis or therapy (prophylaxis protocol, P<0.001; therapy protocol P=0.002). Antigen-specific IgG2a antibodies were reduced by 52% (P=0.02) in the quinapril prophylaxis protocol. Suppression of arthritis by quinapril was associated with reduced articular expression of TNF-alpha by 68% (P=0.01) in the prophylaxis protocol and 27% (P=0.06) in the therapy protocol. Quinapril therapy also inhibited expression of splenocyte TNF-alpha production following lipopolysaccharide (LPS) in vitro stimulation by 59% (P=0.02). In parallel human in vitro experiments, ACE inhibition suppressed LPS-stimulated production of TNF-alpha by monocytes. In order to confirm that the action of quinapril occurred predominantly through suppression of angiotensin II, parallel experiments with the angiotensin receptor antagonist candesartan cilexetil demonstrated that this agent also inhibited disease activity in CIA.

CONCLUSIONS

These data suggest that angiotensin II is a mediator of chronic inflammation and that ACE inhibition may have therapeutic effects in human inflammatory arthritis.

Attitudes toward working on interdisciplinary healthcare teams: a comparison by discipline

Interdisciplinary teams are important in providing care for older patients, but interdisciplinary teamwork is rarely a teaching focus, and little is known about trainees' attitudes towards it. To determine the attitudes of second-year post-graduate (PGY-2) internal medicine or family practice residents, advanced practice nursing (NP), and masters-level social work (MSW) students toward the value and efficiency of interdisciplinary teamwork and the physician's role on the team, a baseline survey was administered to 591 Geriatrics Interdisciplinary Team Training participants at eight U.S. academic medical centers from January 1997 to July 1999. Most students in each profession agreed that the interdisciplinary team approach benefits patients and is a productive use of time, but PGY-2s consistently rated their agreement lower than NP or MSW students. Interprofessional differences were greatest for beliefs about the physician's role; 73% of PGY-2s but only 44% to 47% of MSW and NP trainees agreed that a team's primary purpose was to assist physicians in achieving treatment goals for patients. Approximately 80% of PGY-2s but only 35% to 40% of MSW or NP trainees agreed that physicians have the right to alter patient care plans developed by the team. Although students from all three disciplines were positively inclined toward medical interdisciplinary teamwork, medical residents were the least so. Exposure to interdisciplinary teamwork may need to occur at an earlier point in medical training than residency. The question of who is ultimately responsible for the decisions of the team may be an "Achilles heel," interfering with shared decision-making.

An immature rat lymphocyte marker CD157: striking differences in the expression between mice and rats

We have established a novel monoclonal antibody that recognises mouse and rat CD157, and uncovered striking differences in both the level and stage of expression of this antigen in the primary lymphoid organs between these two species. Unlike mouse, the majority of rat thymocytes express CD 157. SHR and WKY rats were the exception, having unusually low levels (similar to those of the mouse) of these cells. However, in both species, a subset of CD3- CD4- CD8- thymocytes exhibited high levels of CD157. Surprisingly, these CD157high cells temporarily upregulated MHC class I molecules in both species. Furthermore, a third of CD157high rat thymocytes were CD45RC+, a marker found on immature thymocytes with regenerative capacity. Examination of the bone marrow lymphoid population shows that the expression of rat CD157 is largely observed at the CD45R+ IgM- pre-B-II cell stage, and unlike mouse, extension of expression into the IgM+ immature B cell stage was marginal. Similar to CD157high immature thymocytes, these immature B cells also expressed high levels of MHC class I. With the exception of the LEC, SHR and WKY rat strains, which have three- to four-fold less CD157+ bone marrow myeloid cells, percentages of these cells are similar between these two species. Thus, marked differences in the level and stage(s) of CD157 expression on lymphoid cells in mouse and rat indicate that CD157 may not, as previously thought, have a direct role in T or B cell differentiation.

Elder neglect assessment in the emergency department

INTRODUCTION

Emergency departments are often the first point of contact for elder neglect victims. The purpose of this article is to describe a pilot study pertaining to the screening of patients and detection of elder neglect conducted in a large metropolitan medical center emergency department. The research question to be answered was, "Is it feasible for ED nurses to conduct accurate screening protocols for elder neglect in the context of their busy practice?"

METHODS

During a 3-week period, 180 patients older than age 70 years (90% of all possible elderly patients during the screening hours) were screened to determine if they met the study criteria and could be enrolled into the protocol.

RESULTS

Thirty-six patients met the eligibility criteria to enroll in the study, and 7 patients screened positive for neglect by a home caregiver. The nurses were able to screen and detect elder neglect with more than 70% accuracy, confirming the research question. The true-positive rate was 71%, and the false-positive rate was 7%.

DISCUSSION

Elder neglect protocols are feasible in busy emergency departments, and neglect can be accurately detected in the emergency department when screening procedures are in place.

Enhancing geriatric nursing scholarship: specialization versus generalization

This article explores the relative merits of encouraging preparation of more nurses with specialization in geriatrics as compared to encouraging geriatric preparation among nurses whose major field of study is outside geriatrics. The article explores two approaches to examining capacity for geriatric nursing scholarship among nurse scholars not involved in geriatrics, and in schools of nursing with strength in research but with little geriatric research. The findings show an ongoing need to strengthen geriatric nursing as an area of specialization. Faculty prepared in geriatric nursing are underrepresented in schools of nursing, and only a small number of doctoral students specialize in geriatric nursing. Academic nursing programs with strength in geriatric nursing need ongoing support to maintain and expand current geriatric programs. Data support that encouraging individual non-geriatric nurse faculty and doctoral candidates to focus their work on areas of concern to geriatric nursing, and strengthening geriatrics in research-intensive schools of nursing that have not heavily invested in geriatric scholarship are viable options for strengthening academic geriatric nursing. Establishing mechanisms to attract nurse scholars working outside the scope of geriatric nursing to address clinical issues of concern to older adults offers promise in rapidly attracting new scholars to geriatric nursing.

Prevalence estimates of cognitive impairment in medical model adult day health care programs

Despite an increasing emphasis on adult day health care (ADHC) programs as alternatives to institutional care for persons with dementia, little research based on direct assessment of clients' cognitive status has been conducted in such settings. The goal of this analysis was to estimate the prevalence of cognitive impairment among ADHC clients using commonly used screening measures. Age-adjusted and non-age-adjusted prevalence estimates of cognitive impairment in New York State ADHC programs were developed using a probability sample of 336 clients. Estimates were made using traditional cutting scores on standard cognitive screening measures, such as the Mini-Mental State Examination (MMSE), as well as latent class analyses applied to the same item sets. Average prevalence estimates of cognitive impairment were 55% across age cohorts and 60% for persons aged 65 and over. The MMSE yielded a prevalence estimate of 58% across age cohorts and 63% for those aged 65 and over. Using a more conservative cut score, the estimate for the MMSE was 33%; latent class estimates of moderate to severe impairment indicate that approximately 30% of the ADHC clients had cognitive impairment suggestive of probable or definite dementia. Community alternatives to institutional care for the elderly are increasing in popularity. These findings suggest that 1. While institutions are serving the most severely cognitively impaired, age-adjusted prevalence ratios for the ADHC sample approach the bounds of the institutional estimates. 2. The institutional setting will continue to be an important mode of care for the more severely impaired individuals. 3. Daycare is serving a high proportion of the mildly and moderately cognitively impaired individuals. It follows, therefore, that such programs need to address the needs of these individuals by developing specialized care plans and tracks targeted for the cognitively impaired.

Prevalence of behavior disorder and disturbance to family and staff in a sample of adult day health care clients

Latent class-derived prevalence estimates of behavior disorder are provided for adult day health care (ADHC) clients; informal and formal caregivers reported 11% and 14%, respectively, of these clients as engaging in severe disturbed behavior (95% confidence intervals across sources are from 7% to 18%). The prevalences, estimated for informal and formal caregivers respectively, were 12% and 16% for affective disorder, 15% and 18% for cognitive disorders, 16% and 13% for verbal-vocal agitation, and 6% and 8% for socially inappropriate behavior. These rates can be contrasted with those of the institutional population which, while higher, overlap with the distribution of behavior disorder for ADHC community residents. The degree of reported disturbance to family and staff was similar across items.

Influence of viral superantigens on V beta- and V alpha-specific positive and negative selection

In mice, V beta-specific negative selection is mediated by a number of superantigens encoded by various mouse mammary tumor viruses. We have identified Mtv-3, Mtv-27, Mtv-44, Mtv-8, Mtv-9, Mtv-11, and MMTV(D2.GD), and have confirmed Mtv-1. Although specificities of superantigens correlate well with sequences of their carboxy terminal regions, Mtv-44 appears to be an exception: the product is specific for V beta 3, V beta 6, V beta 8.1, and V beta 9. It remains to be determined whether Mtv-44 produces one or two different superantigens to exhibit this specificity. V beta 5+ T-cell deletion is induced by two groups of superantigens: V beta 3-specific superantigens encoded by Mtv-1, Mtv-3, Mtv-6, Mtv-13, Mtv-27, and Mtv-44, and V beta 11-specific superantigens encoded by Mtv-8, Mtv-9, and Mtv-11. Furthermore, these V beta 3-specific superantigens are also specific for V beta 17a(cz). In contrast, V beta-specific positive selection and V alpha-specific positive and negative selection do not seem to involve non-H-2 (super)antigens, although their involvement can not be excluded. In the near future, superantigens, powerful modulators of T-cell functions, will be exploited for clinical applications.

Characterization of experimental allergic encephalomyelitis-susceptible, Biozzi AB/H (H-2dq1) mice which express H-2Anod: analysis of T-cell receptor expression and the detection of a deletion ligand encoded by Mtv-7

Biozzi (H-2dq1) AB/H mice are marked not only by their high titre antibody responses following immunization with protein antigens but are also susceptible to experimental allergic encephalomyelitis (EAE) induction. The T-cell receptor (TcR) repertoire in this recently characterized strain was analysed. Biozzi AB/H mice were found to express the Thy-1a, Ly-1b, Ly-2b and Ly-5b alleles. Serological typing of the TcR-V beta + peripheral T cells suggested that the AB/H mice belong to the TcR-V beta b haplotype and express a deletion ligand for TcR-V beta 6+ and TcR-V beta 8.1+ T cells. This was confirmed by Southern blot analysis which revealed the presence of Mtv-17, Mtv-23, Mtv-31 (Y chromosome) and notably Mtv-7. Therefore the AB/H mice are Mls-1a. Despite the depletion/absence of the majority of TcR-V beta families in EAE-resistant (BALB/c) x EAE-susceptible (AB/H) F1 mice it was possible to induce EAE in these F1 animals. This suggests either that the deleted TcR-V beta-bearing T cells were not the principal encephalitogenic cells or that the TcR-V beta usage is sufficiently heterogeneous to accommodate such deletion events, in spinal cord-induced EAE.

Tcrb-V3+ T-cell deletion and a mouse mammary tumor provirus, Mtv-27

Genes encoding superantigens which delete Tcrb-V3+ T cells co-segregate with mouse mammary tumor proviruses (Mtv), Mtv-1, Mtv-3, Mtv-6, Mtv-13, and Mtv-44. We have examined percentages of Tcrb-V3+ T cells and Mtv integrations in [(B10 x NZB)F1 x B10.BR] mice, and show that Mtv-27 as well as Mtv-3 from NZB mice co-segregate with genes encoding deletion ligands for Tcrb-V3+ T cells without recombination.

Positive and negative selection of Tcrb-V6+ T cells

Tcrb-V6+ T cells are deleted by an endogenous superantigen probably encoded by a mouse mammary tumor provirus (Mtv), Mtv-7, in association with major histocompatibility complex (MHC) class II molecules. In contrast, Tcrb-V6+CD4+ T cells are positively selected by MHC class II E molecules in Mtv-7- mice. We have examined the levels of Tcrb-V6+CD4+ and Tcrb-V6+CD8+ T cells from six combinations of backcross mice. In this paper we show that: 1) Tcrb-V6+CD8+ T cells can be positively selected by MHC class I molecules; 2) MHC class II A molecules can also influence the levels of Tcrb-V6+CD4+ T cells; 3) Mtv-7- NZW mice have a new Mtv, Mtv-44, which cosegregates with a gene encoding the partial deletion ligand for Tcrb-V6+ T cells; 4) the remaining Tcrb-V6+ T cells from mice with partial deletion of these T cells appear not to be anergized in the periphery.

Tcrb-V3+ T-cell deletion and a new mouse mammary tumor provirus, Mtv-44

Genes encoding endogenous superantigens causing Tcrb-V3+ T-cell deletion co-segregate with mouse mammary tumor proviruses (Mtv), Mtv-3, Mtv-6, and Mtv-13. In addition Mtv-1 has been implicated in deletion of these T cells. We have examined levels of Tcrb-V3+ T cells and Mtv integrations in the following offspring and their parental strains, [(CBA-T6 x NZW)F1 x CBA], [(CBA x C3H/He)F1 x CBA], and [(B10.S (9R) x NOD]F1 mice. We show that a new Mtv (Mtv-44) from NZW mice and Mtv-1 from C3H/He mice cosegregate with genes encoding ligands for partial deletion of Tcrb-V3+ T cells and that some NOD mice have an additional Mtv (Mtv-45) which is closely linked to Mtv-3.

Endogenous ligands selecting T cells expressing particular V beta elements

It has recently become clear that the minor lymphocyte stimulatory antigens (Mls) and other endogenous ligands which lead to the partial or total deletion of T cells bearing particular V beta segments are encoded by mouse mammary tumor virus (MMTV). We review here the genetic analyses of multiple V beta 11 and V beta 3 deletion ligands and demonstrate the involvement of MMTV in all examples. Several features of Mls and the V beta 11/V beta 3 deleting ligands identify them as members of the superantigen family. Bacterial superantigens are known to bind both MHC class II and the TCR in regions distinct from conventional peptide antigens. Within the MMTV genome, the 3' LTR has been identified as encoding superantigen function. We present data demonstrating that in vitro translation identifies the major product of the open reading frame (ORF) within the 3' LTR as a type II integral membrane glycoprotein. It is proposed that the type II membrane glycoprotein interacts with MHC and TCR in a manner analogous to the bacterial superantigens and distinct from conventional peptide antigen. Several unanswered questions regarding superantigen action remain; what determines total or partial deletion? How is Mls transferred between cells? These questions are addressed in the discussion.

Co-segregation of a gene encoding a deletion ligand for Tcrb-V3+ T cells with Mtv-3

A gene encoding the endogenous superantigen Mlsc, which deletes Tcrb-V3+ T cells in the NOD inbred mouse strain, was found to co-segregate with Mtv-3 on chromosome 11. This identifies a fourth gene encoding a deletion ligand for Tcrb-V3+ T cells and extends recently published observations in support of the hypothesis that a number of endogenous superantigens are the products of Mtv proviruses.

The genetic basis of negative selection of Tcrb-V11+ T cells

Non-H-2 genes responsible for negative selection of Tcrb-V11+ T cells were examined using backcross mice of various strains with C58, which does not delete Tcrb-V11+ T cells. Two independently segregating genes were found: one leading to partial deletion was closely linked to Ly-2/Ly-3 on chromosome 6, and the second giving virtually complete deletion has not yet been mapped. The A strain had only the former, whereas BALB/c, BALB.K, B10.BR, CBA-T6, C3H/He, and DBA/2 expressed both of these genes. Although a gene(s) of the NIH strain led only to partial deletion, the chromosomal localization of the gene(s) has not yet been determined: no informative polymorphic molecules are expressed from genes on chromosome 6 of this strain.

Genes encoding ligands for deletion of V beta 11 T cells cosegregate with mammary tumour virus genomes

The T-cell receptor (TCR) repertoire is selected in the thymus after rearrangement of genes encoding TCR alpha and beta chains. Selection is based on the recognition by newly emergent T cells of self-ligands associated with molecules of the major histocompatibility complex: some combinations result in positive selection, others in negative selection. Negative selection, or clonal deletion, is an important mechanism for eliminating autoreactive T cells. A group of self-ligands involved in clonal deletion was identified because they, like exogenous superantigens, were recognized by almost all T cells expressing particular TCR V beta genes. V beta 17a T cells are deleted by a tissue-specific ligand; V beta 6, V beta 7, V beta 8.1 and V beta 9 T cells are deleted by the minor lymphocyte-stimulating (Mls) determinant Mls-1a; V beta 3 T cells by Mls-2a and Mls-3a; V beta 11 T cells by ligands encoded by independently segregating genes; and V beta 5 T cells by ligands encoded by two genes. Chromosome mapping using recombinant inbred strains of mice and classic backcrosses show that Mls-1a in DBA/2 mice is encoded on chromosome 1, that one of the two ligand genes for deletion of V beta 5 T cells maps to chromosome 12 and that a ligand gene for V beta 11 deletion is linked to the CD8 locus on chromosome 6. Here we present evidence from three sets of backcross mice for concordance between V beta 11 deletion ligand genes on chromosomes 6, 12 and 14 and endogenous mouse mammary tumour virus integrant (Mtv) genomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Two monoclonal antibodies specific for the T cell receptor V alpha 8

Two monoclonal antibodies, KT50 and KT65, specific for V alpha 8 have been established. This was determined as follows: (a) 4 T cell clones, C6, R1, G22 and I9, out of 43 T cell clones with various antigen specificities, major histocompatibility complex restrictions and V beta usages not only bound KT50 and KT65 but also expressed V alpha 8 mRNA, (b) KT50 and KT65 precipitated molecules from the clone C6 similar to the T cell receptor molecules precipitated in C6 cells by KT11 (anti-V beta 11) or KTL2 (anti-Ti) and (c) KT50 and KT65 were mitogenic and induced cytotoxicity. All strains of mice so far examined have populations of KT50+ and KT65+ T cells of 1.4%-3.6% and 0.9%-2.6%, respectively. Different H-2 haplotypes were not observed to affect the number of cells expressing KT50 or KT65. In addition KT15 (anti-CD8), without cross-linking to KT50 or KT65, augmented proliferation triggered by KT50 or KT65.

H-Y responses of non-obese diabetic (NOD) mice

Female non-obese diabetic (NOD) mice were tested for their ability to make responses to the male-specific (H-Y) transplantation antigen. In vivo assessment of this ability was made using skin graft rejection. A proportion (60%) spontaneously rejected NOD male tail skin by 80 days post-transplantation. The detection of the generation of H-Y-specific cytotoxic T cells, following in vivo priming and secondary in vitro restimulation, was carried out using a conventional 51Cr release assay. Female NOD mice primed either by skin grafting, intraperitoneal (i.p.) or footpad (f.p.) injection of male NOD spleen cells could be induced to make anti-H-Y cytotoxic responses, but not every immunized mouse responded. The nature of the H-Y-reactive T cells was investigated further by the in vitro isolation of T-cell clones of which some were H-Y specific.