Chromosomal deletions and the foreign antigen

cassette in

Chromosomal deletions and the foreign antigen

cassette insertion were confirmed by PCR sequencing. The final foreign antigen cassette is shown graphically in Figure 1. Gel electrophoresis and Western blotting to nitrocellulose was performed using standard methods. A commercially available rabbit polyclonal antibody to E. coli alkaline phosphatase (Abcam, Cambridge, MA, USA) was used with a goat anti-rabbit peroxidase secondary antibody (KPL, see more Gaithersburg, MD, USA) and a chemiluminescent substrate (LumiGlo; KPL). Bacterial cultures were grown for approximately 16 hr in trypticase soy broth (TSB). J774A.1 murine macrophage monolayers (ATCC, Manassas, VA, USA) in 24-well plates were infected at a multiplicity of infection (MOI) of 20:1, and gentamicin exclusion assays for intracellular survival were performed as previously described (21). L929 murine fibroblast monolayers (ATCC) were infected with L. monocytogenes (MOI 1:50) and plaques measured five days later (22). Animal experiments were reviewed and approved by the IACUC at Massachusetts General Hospital and 8–12 week female BALB/c mice from Charles River Laboratories (Wilmington, MA, USA) were used for all

experiments. L. monocytogenes strains were grown JAK cancer overnight in TSB containing streptomycin (100 μg/mL). Cultures were pelleted, washed once with normal saline and resuspended in sterile normal saline. Serial 10-fold dilutions were made and groups of six mice were injected intraperitoneally (i.p.) in a 300 μL volume. In addition to the vaccine strains expressing the influenza antigen, three groups

of control animals received either the wild type, the BMB72, parent strain or the BMB54 parent strain. Interleukin-2 receptor Animal health was assessed several times daily and the median lethal dose (LD50) was calculated (23). For visceral persistence studies, mice were inoculated once i.p. with 0.1 LD50 of either the wild type (WT), BMB54, or BMB72. Mice were sacrificed at days 1, 3, 7, and 11, and the spleens and livers homogenized for one minute in 2 mL buffered saline, serially diluted and plated in triplicate on TSB plates. For ELISpot studies mice received approximately 0.1 LD50 of relevant strains and were sacrificed seven days later. Murine spleens were pooled by vaccine strain (three animals/group), processed with mesh strainers and red cells were lysed using ammonium chloride buffer. ELISpot experiments were performed using a pair of monoclonal antibodies (one biotinylated) directed against mouse interferon (IFN)-γ (Pierce, Rockford, IL, USA). Plates were then washed and developed with streptavidin–alkaline phosphatase conjugate and nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate (Bio-Rad, Hercules, CA, USA). The lectin control stimulus for murine ELISpot studies was concanavalin A.

This study

aimed to investigate clinical characteristics,

This study

aimed to investigate clinical characteristics, underlying predisposing factors, aetiological organisms and outcomes in patients with deep cutaneous mycoses. A retrospective medical record review of patients with deep cutaneous mycoses treated at a tertiary referral centre in Korea from 1999 to 2010. Forty-one cases of deep cutaneous mycosis were identified (median age: 49). Most patients (32/41) had impaired immunological status, and seven of the remaining Src inhibitor nine had a history of physical trauma. Neutropenia and long-term use of antibiotics were detected in 13 and 12 patients respectively. Nodular skin lesions were the most common type (17/41) and the morphology of the lesions varied. Fungal organisms were identified by culture and histopathology of skin specimens. Candida (16/41) was the most common organism, followed by Aspergillus, Alternaria, Fusarium (4/41 each). Systemic antifungal treatment was successful in 28 patients, while nine patients died from the fungal infection. Our study

may lead to improved insights into deep cutaneous mycoses as their Idasanutlin research buy incidence is increasing and they vary in different clinical settings. “
“Chronic granulomatous disease (CGD) is a rare inherited disorder characterised by inability of phagocytes to kill catalase-positive organisms including certain fungi. Aspergillus species are the most frequent fungal pathogens. This study is a systematic review of the reported cases of osteomyelitis due to Aspergillus species in CGD patients. Retrospective analysis of 46 osteomyelitis cases caused by Aspergillus species in 43 CGD patients (three females) published in the English literature (PubMed) was performed. Twenty-three cases were due to Aspergillus fumigatus (50%), 20 to Aspergillus nidulans (43.5%), one to Aspergillus flavus

and two to unspecified Aspergillus species. The median age was 8 years (range 1.5–21). Osteomyelitis due to A. nidulans was associated with pulmonary infection and involved ‘small bones’ more frequently than A. fumigatus osteomyelitis (P = 0.001). Amphotericin the B was used in 91.3% and surgical debridement in 67.4% of all cases. The overall mortality of osteomyelitis due to Aspergillus species in CGD patients was 37%; 55% for A. nidulans compared to 13% for A. fumigatus (P = 0.008). Aspergillus fumigatus causes osteomyelitis in CGD patients almost as frequently as A. nidulans and much more frequently than A. flavus. Osteomyelitis due to A. nidulans is associated with higher mortality than A. fumigatus. “
“The in vitro antifungal activity of six thioureido substituted amines (P1–P6) was evaluated against Candida species, including Candida albicans, C. glabrata, C. krusei and C. parapsilosis. These tri- and tetra-thioureido amino derivatives with different methylation levels were synthesised through easy synthetic routes to evaluate their antifungal properties against Candida species.

For example, Sialic-acid-binding Ig-like lectin (Siglec)-10 is ex

For example, Sialic-acid-binding Ig-like lectin (Siglec)-10 is expressed by monocytes 19. This inhibitory receptor can inhibit inflammatory cytokine production induced by danger-associated molecular pattern (DAMP) signaling, such as HMGB1, through binding of CD24, whereas signaling via PAMPs, Autophagy Compound Library such as LPS or poly I:C, is unaffected in vitro 20. While WT mice were unaffected, CD24-deficient mice rapidly succumbed to a sublethal dose of acetaminophen in a liver necrosis model 20. This specific regulation protects the host against a lethal response to cell death, whereas it allows a potent immune response upon infection. Besides regulating pro-inflammatory cytokine

production, inhibitory receptors may also regulate the production of anti-inflammatory cytokines. For example, Alectinib mouse upon TLR activation, Siglec-9 not only reduces the production of pro-inflammatory cytokines, but also enhances IL-10 production through ITIM signaling in the mouse macrophage cell line RAW264 21. Together, these studies demonstrate that inhibitory receptors can potently suppress

TLR-induced inflammatory cytokine production, either directly by inhibition of the TLR signaling or indirectly by increased production of anti-inflammatory cytokines. On the contrary, some inhibitory receptors may enhance inflammatory cytokine production. Finally, some inhibitory receptors Edoxaban do not seem involved in regulating pathogen-associated cell activation, but specifically modulate danger-associated molecular pattern signaling. The distinct capacities of various inhibitory receptors will therefore contribute to an orchestrated immune response during successive stages

of infection. Tissue infiltration by phagocytes requires tight regulation to limit the tissue damage by the release of inflammatory mediators. Infiltration may be reduced directly through modulation of G protein-coupled receptor (GPCR)-mediated chemotaxis, adherence, or transmigration, or indirectly by desensitization of phagocytes to these processes. Intriguingly, specific inhibitory receptors seem to have opposite effects on granulocyte migration. Mouse neutrophils deficient in paired Ig-like receptor-B (PIR-B) (the mouse ortholog of Ig-like transcript [ILT]2–5) have enhanced chemotactic responses in vitro after stimulation with macrophage inflammatory protein (MIP)-1α, MIP-2, CCL19, and CCL21 22, indicative of a suppressive function for this receptor (Fig. 1). On the contrary, Ly49Q is indispensable for neutrophil polarization and migration after N-formylated methionyl-leucyl-phenylalanine (fMLP) or cytokine-induced neutrophil chemoattractant (KC) stimulation in vitro although Ly49Q inhibits neutrophil adhesion in steady-state conditions 23. Neutrophil polarization and infiltration into inflamed air-pouches is also impaired in vivo in Ly49Q knockout mice 23.

The level of AOPP was independently associated with IHD only in H

The level of AOPP was independently associated with IHD only in HD patients. “
“Adriamycin nephropathy (AN) is a rodent model of chronic kidney disease that has been studied extensively and has enabled a greater understanding of the processes underlying the progression of chronic proteinuric renal disease. AN is characterized by podocyte injury followed by glomerulosclerosis, tubulointerstitial inflammation and fibrosis. Genetic studies have demonstrated a number of loci that alter both risk and severity of renal injury induced by Adriamycin. Adriamycin-induced renal injury has been shown in numerous studies to be modulated by both non-immune and immune factors, and has facilitated further study of mechanisms

of tubulointerstitial injury. This review will outline the pharmacological behaviour of Adriamycin, and describe in DZNeP concentration detail the model of AN, including its key structural characteristics, genetic susceptibility and pathogenesis. Most types of chronic kidney disease (CKD) are characterized by the development of glomerulosclerosis, tubulointerstitial inflammation and fibrosis. Adriamycin® (Pfizer, Sydney, Australia) (doxorubicin) is a well-known inducer of renal injury in rodents, which mirrors that seen in human CKD due to primary focal segmental glomerulosclerosis.

The first published record of anthracyclines causing renal injury was in 1970 by Sternberg.1 The first description of Adriamycin inducing renal injury was in 1976 in rats,2 and 1998 in mice.3 In 1977, Burke and colleagues4 described a case of a 78-year-old man developing renal failure after the administration of doxorubicin. Since then, Adriamycin nephropathy (AN) in rodents has been extensively studied and

has enabled a greater understanding of the processes underlying the progression of renal injury. Adriamycin nephropathy has several strengths as an experimental model of kidney disease. It is a highly reproducible model of renal injury. It is also a ‘robust’ model in that the degree of tissue injury is severe while associated with acceptable mortality (<5%) and morbidity (weight loss). Because the model is characterized by the induction of renal injury within a few days of drug administration, the timing of injury is consistent and predictable. The severity and timing of renal injury means that it is a model Galeterone suitable for testing interventions that either worsen or protect against renal injury. The type of structural and functional injury is very similar to that of chronic proteinuric renal disease in humans (see below). Last but not least, this model is similar in rats and mice. Rodent models are extremely useful in the study of disease. Rodents are characterized by their short reproduction period, easy (and cheap) availability of animals and reagents, and amenability to genetic manipulation.5 There are also limitations in the use of AN as an experimental model.

, 2006; Pamp & Tolker-Nielsen, 2007) Moreover, swarming motility

, 2006; Pamp & Tolker-Nielsen, 2007). Moreover, swarming motility has been shown to be part of a complex differentiation process, which

leads to increased production of virulence factors and antibiotic resistance (Overhage et al., 2008). Swarming is dependent on functional quorum sensing (which induces the production of rhamnolipid), type IV pili and flagella (Kohler et al., 2000; Deziel et al., 2003). We have demonstrated recently that ginseng extract Y-27632 manufacturer reduces the production of signal molecules of quorum sensing (BHL and OdDHL) in supernatants of P. aeruginosa PAO1 cultures (Song et al., 2010). This finding may partly explain our results from the swarming tests in this study. However, the molecular mechanism of inhibition of swarming motility and induction of swimming and twitching motility by ginseng extract is

still unknown and needs further studies. In our animal study, pretreatment PLX4032 chemical structure with ginseng orally resulted in significantly higher phagocytosis rates and index in the BAL phagocytes from the wild-type P. aeruginosa PAO1-infected animals compared with saline-pretreated animals (Fig. 5a and b). In contrast, in the animals infected with flagella-deficient P. aeruginosa PAO1-filM, ginseng pretreatment did not improve the phagocytosis or the index. Clearly, the significantly increased phagocytosis rate and index in the PAO1-infected animals are due to the stimulation of P. aeruginosa PAO1 motility induced by ginseng in vivo. Previously, ID-8 we demonstrated in our animal models of chronic

P. aeruginosa lung infection that ginseng treatment results in faster bacterial clearance from the lungs and milder lung pathology when compared with the untreated animals (Song et al., 1997a, b, 1998). We also observed a significantly stronger neutrophil chemiluminescence in the blood, a shift of the immune response from a high anti-P. aeruginosa immunoglobulin G (IgG) response and local infiltration of mast cells in the lungs (T-helper type 2 response) to a TH1 immune response characterized by downregulation of IgG and upregulation of IgG2a levels, and improved functions of phagocytes by means of upregulated production of interferon-γ and downregulated interleukin-4 in the lung tissues and spleen (Song et al., 1997a, b, 1998, 2003, 2005). It has been well documented that a TH1 response favors host cleaning of infections by P. aeruginosa (Johansen et al., 1995, 1996., 1997; Moser et al., 1997, 2000, 2005). Our results from the present study suggest that ginseng induces increased bacterial motility in the biofilm-like alginate beads, resulting in the release of bacteria from the biofilm and loss of protective effects from the polymeric matrix, followed by an increased efficiency of the host immune system and antibiotics to clear the biofilm infection. The activation of the TH1 immune response induced by ginseng treatment and the increased motility of bacteria due to the effects of ginseng might exhibit a synergistic effect on the infection.

[11] Candida hyphae have also been shown to penetrate dentinal tu

[11] Candida hyphae have also been shown to penetrate dentinal tubules along cracks of tooth surfaces, enabling the organism to invade dental hard tissues.[12] Apart from the aforementioned biological factors, the microbial cell surface hydrophobicity (CSH), which contributes to hydrophobic interactions between cells and surfaces, is thought to be an important non-biological

factor associated in the adherence of Candida to inert surfaces.[13] Studies have also shown that hydrophobic yeast are more virulent than their hydrophilic counterparts.[14, 15] Statistically significant correlations between CSH and candidal adhesion to BEC and denture acrylic surfaces have also been reported.[16, 17] Transient exposure

to antifungals may affect the aforementioned traits of Vorinostat clinical trial candidal adhesion. For instances, it has been shown that foregoing attributes of Candida albicans were significantly reduced after limited exposure to subcidal concentrations of antifungal agents. The suppression of candidal growth that occurs following limited exposure to antifungal agents, as in the oral environment, MK-2206 in vitro has been described as the postantifungal effect (PAFE). This phenomenon has been mainly studied with C. albicans isolates. It has been documented that the knowledge of PAFE, in tandem with minimum inhibitory concentration (MIC) values of a drug, would be clinically useful in evaluating new dosage regimens of a drug.[18] Furthermore, transient exposure to antifungal agents may also affect such virulence factors of Candida pertaining to their adhesion.[19, 20] Nystatin (i.e. oral suspensions, ointments, pastilles, creams) is a widely obtainable and a frequently used SB-3CT antifungal agent available for topical treatment of various types of oral candidosis ranging from pseudomembranous, erythematous to denture-induced variants of oral candidosis. However, the diluents effect of saliva

and the cleansing effect of the oral musculature in the oral cavity tend to reduce the availability of nystatin below that of the effective therapeutic concentrations, thereby compromising its therapeutic efficacy. Hence, the pathogenic Candida may undergo a brief exposure to topically applied antifungal drugs, while thereafter, the drug concentration is likely to be subtherapeutic,[18] a scenario all too familiar in the niches of the oral cavity, which is similar to the phenomena as in PAFE. To our knowledge, there is no information on either the PAFE or its association with the adhesion-related attributes of oral C. dubliniensis isolates following brief exposure to subtherapeutic concentrations of nystatin. Hence, taken together the foregoing information, as well as the findings of a recent prevalence study where oral C.

The patients were divided into two groups

The patients were divided into two groups. RG7422 cell line In Group 1 (n = 8), the patients received an ulnar nerve fascicle transfer to the biceps motor branch. In Group 2 (n = 15), the patients received a median nerve fascicle transfer to the biceps motor branch. Two patients with follow-up less than six months were excluded. Both groups were similar regarding age (P = 0.070), interval of injury (P = 0.185), and follow-up period (P = 0.477). Elbow flexion against gravity

was achieved in 7 of 8 (87.5%) patients in Group 1, versus 14 of 15 (93.3%) patients in Group 2 (P = 1.000). The level of injury (C5-C6 or C5-C7) did not affect anti-gravity elbow flexion recovery in both the groups (P = 1.000). It was concluded that the median nerve fascicle transfer to the biceps is as good as the ulnar nerve fascicle transfer, even in C5-C7 injuries. © 2014 Wiley Periodicals, Inc. Microsurgery 34:511–515, 2014. “
“The gracilis muscle, based on the dominant pedicle, has been used extensively for free tissue transfer. Recent studies have described the constant anatomy, ease of dissection, and low donor-site morbidity of the distal segmental gracilis free muscle flap. We present three cases of free distal segmental gracilis muscle transfer. In one case, the gracilis muscle

was divided transversely into one proximally based and one distally based free flap and used for coverage of two separate wounds in a patient with bilateral buy Small molecule library open calcaneal fractures. In two cases, the preserved proximal gracilis was used as a reoperative free flap after failure of the initial distal segmental gracilis free muscle. With recent advances in microsurgery and ever-growing demands for low donor-site morbidity, it is important to ensure each free muscle flap harvested is used efficiently. Use of the free

distal segmental gracilis muscle flap maximally uses one muscle while Arachidonate 15-lipoxygenase minimizing donor site morbidity and retaining the proximal muscle for future uses. © 2011 Wiley-Liss, Inc. Microsurgery, 2011. “
“Autologous skin grafting to the donor site in patients who undergo radial forearm free flap reconstruction (RFFF) is associated with cosmetic and functional morbidity. Integra artificial dermis (Integra Lifesciences, Plainsboro, NJ) is a bovine collagen based dermal substitute that can be used as an alternative to primary autologous skin transplantation of the donor site. We describe a staged reconstruction using Integra followed by ultrathin skin grafting that results in highly aesthetic and functional outcomes for these defects. A retrospective review of 29 patients undergoing extirpative head and neck oncologic resection were examined. Integra graft placement was performed at the time of RFFF harvest followed by autologous split thickness skin grafting at 1 to 5 weeks postoperatively. Healing fully occurred within 4–6 weeks with negligible donor site complications, excellent cosmesis, and minimal scar contracture.

It was demonstrated that recently diagnosed T1D patients harboure

It was demonstrated that recently diagnosed T1D patients harboured pancreatic islets that expressed aberrantly Bortezomib cell line major

histocompatibility complex (MHC) class I and interferon (IFN)-α[30]. Both molecules are up-regulated typically in response to viral infection and could be envisioned to cause recognition and killing of beta cells by infiltrating CD8 T cells. Some reports have indeed documented enterovirus infection specifically within pancreatic islets, and there seems to be a connection with an atypical ‘fulminant’ subtype of T1D [31–33]. Nevertheless, these results are in need of further confirmation using complementary detection techniques in order to gauge the precise frequency of beta cell-specific viral infection in T1D versus controls. The concept of ‘molecular mimicry’ suggests that viruses expressing epitopes resembling certain beta cell structures have the potential to induce cross-reactive immune responses [34]. Proof of concept was offered with the

design of rat insulin promoter-lymphocytic choriomeningitis virus glycoprotein (RIP-LCMV.GP) transgenic mice, which develop diabetes after infection with LCMV [35,36]. Some potential cross-reactivity Silmitasertib solubility dmso has been documented in the past between Coxsackievirus constituents and glutamic acid decarboxylase (GAD) [37,38], a major autoantigen in T1D, but this correlation has since been challenged by others [39–41]. Thus, unlike classical examples of mimicry-induced autoimmunity such as seen in, e.g. rheumatic fever, solid support for a direct role in T1D development is currently lacking. An alternative scenario was proposed based on results in the RIP-LCMV model showing that sequential viral mimicry events can accelerate disease onset [42]. Such hypotheses are, of course, very difficult to test in a patient setting. In contrast, ‘bystander activation’ explains the recruitment and activation of autoaggressive cells to the islet milieu as a consequence Dolichyl-phosphate-mannose-protein mannosyltransferase of localized viral infection. Virus could lead to activation and maturation of antigen-presenting cells (APCs), which would then shuttle antigen

to the pancreatic draining lymph nodes resulting in priming of autoaggressive T cells [43]. The theory was strengthened by the finding that Coxsackievirus infection acts primarily by enhancing the release of islet antigens which, in turn, stimulate resting autoreactive T cells [39]. Bystander activation caused merely by cytokine release from inflammatory cells and infected cells is unlikely to be enough to break tolerance [44,45] and by itself give rise to diabetes induction, as studies show that activation of APCs in the pancreas is required for T1D initiation in RIP-LCMV mice [46,47]. The observation that enteroviruses are found predominantly around clinical diagnosis may support indirectly the idea that viral infection serves only as a non-specific, one-time trigger to allow pre-existing autoreactive T cells to reach their targets.

Endothelin-1, a potent vasoconstrictor peptide, was measured by N

Endothelin-1, a potent vasoconstrictor peptide, was measured by Nakamura et al. [57] in control individuals, along with individuals with Raynauds and also vibration-induced white finger. Opaganib in vivo The authors reported that endothelin-1 levels were elevated rapidly upon

finger cold immersion in both control and Raynauds individuals. In Raynauds, this rise was much higher, and it remained elevated even after immersion. However, there was no correlation between endothelin-1 levels and incidences of CIVD, suggesting that, while endothelin-1 is highly related to sympathetic hyperactivity, it does not directly contribute to the opening of peripheral blood vessels eliciting CIVD [57]. Geurts et al. [35] observed CH5424802 mouse no changes in either endothelin-1 or NO levels in response to repeated hand immersions, but the caveat of no thermal acclimation precluded any conclusions. Overall, while broad improvements in thermal responses in individuals who live or work in cold environments are possible, microcirculatory adaptations and changes in the CIVD response in the fingers and toes appear to be neither guaranteed nor predictable. Much of the evidence for adaptation has involved cross-sectional

studies, but significant gaps remain in understanding the contribution of genetic or morphological differences across different ethnic populations in cold response, along with the role of self-selection when considering comparisons across different occupations. The primary systematic improvement with prolonged acclimation is in a decreased perceptual discomfort or pain. However, with notable exceptions [1,63], longitudinal and laboratory studies have found minimal improvement in actual CIVD measures, with some finding that thermal responses actually became impaired over the acclimation period. PJ34 HCl Given the emphasis on developing strategies for protecting from cold injuries in occupational and recreational settings,

people should not rely on physiological adaptation through repeated local cold exposure. Rather, given the importance of overall body thermal status on CIVD responses, individuals should try to keep their body core warm and wear well-insulated and well-fitted gloves and boots to prevent the occurrence of local cold injuries [9]. One avenue for further research appears to be in understanding the interactions between exercise and hypoxia on local blood flow and CIVD trainability. However, such research should be performed with standardized definitions for CIVD and its measurement rather than with the historic and current wide variability in methodology. An enhanced circulation to the extremities is presumed to occur with repeated exposure to cold, serving as a protective mechanism against peripheral cold injury.

We focused on the VH7183 family because it represents a manageabl

We focused on the VH7183 family because it represents a manageable component of the active repertoire, because we and others had previously established patterns of VH7183 utilization during ontogeny and development in BALB/c mice, and because VH7183 gene segments have been shown to be components of antibodies with both self and nonself reactivities (reviewed in [8]). A total of 577 unique, in-frame, open transcript sequences were obtained including 72 from B (pro-B), 133 from C (early pre-B), 75 from D (late pre-B), 78 from this website E (immature B), and 219 from

F (mature, recirculating B). The C57BL/6 mouse genome contains only nine VH7183 family gene segments with open-reading frames (Fig. 1), or approximately half that of the BALB/c mouse genome.

Of these nine, only seven were identified in our sample of bone marrow transcripts (Fig. 2). As in the case of BALB/c mice, the usage of the C57BL/6 VH81X (IGHV05–2, IMGT) gene segment declined fourfold during early B-cell development (28% in B versus 7% in D, p = 0.0008). However, unlike BALB/c mice where there was a further fivefold late-stage reduction between fractions D or E to F (p < 0.02), in C57BL/6 mice the prevalence of VH81X usage did not change between fractions D, E, and F (Fig. 2). The most JH distal VH, IGHV05–17 (IMGT), exhibited a doubling of usage in the transition from pro-B-cell to immature B cell and beyond (BF, p < 0.05), ultimately contributing to almost one-third of the VH7183-containing transcripts from the mature XL765 cell line B-cell pool (Fig. 2). The closest BALB/c VH7183 homologue to IGHV05–17, VH7183.18, exhibited a similar increase in usage with development, but contributed to only 10% of the final repertoire. Use of the remaining five C57BL/6 VH gene segments did not vary statistically with development, also following the same pattern as their BALB/c homologues (Fig. 1). However, the VH gene segment most commonly used in BALB/c mice at all stages of development, VH7183.10, has no C57BL/6 VH7183 homologue; and thus its structure and binding

activity is missing in C57BL/6 mice. Significant differences in the complement of DH gene segments were observed between C57BL/6 and BALB/c mice. The C57BL/6 genome has only one DFL family gene segment, two DST family gene segments, and six DSP family gene segments; whereas the BALB/c genome has two DFL family gene segments, Resminostat one DST family gene segment, and nine DSP family gene segments. Both strains of mice had a single DQ52 gene segment that was conserved in sequence. In total, therefore, the C57BL/6 genome contains three fewer functional D gene segments than the BALB/c genome (Fig. 1). If DH usage were primarily a function of gene number, one might expect C57BL/6 mice to halve their use of the DFL family and double the use of DST family. However, while use of the DST family did increase, use of the single DFL gene segment in C57BL/6 mice increased to match the combined usage of the two DFL gene segments in BALB/c mice.